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2001 Prehistoric diet and human adaptation in west central Chihuahua, Mexico

Webster, Monica

Webster, M. (2001). Prehistoric diet and human adaptation in west central Chihuahua, Mexico (Unpublished master's thesis). University of Calgary, Calgary, AB. doi:10.11575/PRISM/12721 http://hdl.handle.net/1880/41004 master thesis

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Prehistoric Diet and Human Adaptation in West Central Chihuahua, Mexico.

by Monica Webster

A THESIS SbBMITIED TO THE FACULTY OF GRADUATE STUDIES IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTERS OF ARTS DEPARWOF ARCHAEOLOGY CALGARY, ALBERTA JULY,2001

O Monica Webster National Library Biblioth&que nationale du Canada Acquisitions and Acquisitions et Bibliographic Services services bibliographiques 395 Welington Street 395, rue^ Wellington Ottawa ON KIA ON4 OlMwaON KlAON4 Canada Canada YOurmn VoM - Our YI IWm duma

The author has granted a non- L'auteur a accorde meIicence non exclusive licence allowing the exclusive permettant a la National Library of Canada to Bibliotheque nationale du Canada de reproduce, loan, distniute or sell reproduke, preter, distribuer ou copies of this thesis in microform, vendre des copies de cette these sous paper or electronic formats. la fonne de microfiche/film, de reproduction SUY papier ou sur format electronique.

The author retains ownership of the L'auteur conserve la propriete du copyright in this thesis. Neither the droit d'auteur qui protege cette thi?se. thesis nor substantial extracts &om it Ni la these ni des extraits substantiels may be printed or otherwise de celle-ci ne doivent i5e imprimes reproduced without the author's ou autrement reproduits sans son permission. autorisation. Abstract

Understanding the subsistence strategy of a prehistoric population can lead to knowledge of past adaptations to the local environment. Subsistence can also be used to elucidate differences and similarities betureen populations in a region. The main research goal of this thesis is to use an ecological framework and chemical techniques to &cover the main conmbutors to the prehistoric diet of populations inhabiting the study regions in west central Chihuahua Fifty nine local plant samples and twenty one local animal samples were tested for stable carbon and nitrogen isotopes. These were compared to five human samples fiom two archaeological sites in order to determine the prehistoric diet. It was determined that the prehistoric populations in the study region were primarily agricultural, and subsisted on beans and corn. This base was fortified with animal meat kom deer and other animals such as rabbits and scavengers that frequented fields and settlements. Acknowledgements

A number of institutions and people have helped in the research and writing of this thesis. Firsf my supemisor, Dr. M. Anne Katzenberg made insightful comments and hays supported my ideas and decisions. Dr. Jane H. Kelley hired me for her project and thereby presented this topic. She was always available for information, support, kind words and understanding. The advice of my other committee member, Dr. Mary Pavelka, was much appreciated. Thanks goes out to other members of the Proyecto Arqueologico Chihuahua, Dr. Joe Stewart, Dr. Art MacW~lliarns,Karin Burd. A special thanks to Mitch Hendrickson who aided in the collection of the samples, and was always around to listen to my ideas and concerns. Tamara Varney and Sandra Gamie-Lok Wedme in the lab and helped out whenever I needed, and Steve Taylor of the University of Calgary stable isotope laboratory was the one who fed my samples into the machine and gave me the results. None of this would have taken place without the kind support and generosity of Darcy Sirnonelli, Norman Webster and Margo Madeod, to whom I am greatly indebted. TABLE OF CONTENTS

ABSTRACT ...... 111

ACKNOWLEDGEMENTS ...... IV

LIST OF TABLES...... tX

LIST OF FIGURES...... X

CHAPTER 1 .1fUTRODUCTION ...... 1

CHAPTER 2 .ENVIRONMENTAL CONTEXT AND PHYSIOGRAPHY.o.m.m.~~s-m~~-9

stain++...... -.... Phylic-rr stain++...... -.... 9 b@maBuStiuos ...... * ...... 9 Santa Maria River Valley ...... 10 . * m~...-....L.m.o.e....~.-.--...e.~.....M...M...... m....-..o.....o....u Biotic COPDIII- .-0- .. m~...-....L.m.o.e....~.-.--...e.~.....M...M...... m....-..o.....o....u . 10 Plains Grassland...... 11 Madrean Evergreen Woodland ...... 12 MadreauMoataueCanifir Forest ...... 12 Semi-Desert cbsslad...... 12

Summary o..-w....nu.oo~*.co~~.mw ...no*.*..m.rrr..wo.~ooowomo o...~ooooo14

CHAPTER 3 - STABLE ISOTOPE ECOLOGY ...... 15

Envimmmcntrrl Recoastmctioa and Ecolopjcd Stability ~O~~aw~~~~o~~~~~~W~mmO~~~WoWoW~o~~~oeH~O~o~~~~O~~O16

Natritnt and Ekmcnt Cyding .ad Stable Isotopes ..- ..--...... l.....ww--...... 17 Carbon ...... 17 Nitrogen ...... 18 Carboa in PtmtS.. ..w...w..Uu...... o.*.-...... t....we....*...... t.uu-.w.....*...... w.-. 20 The Calvin Cycle ...... 22 C4 Plants ...... 24 CAM Plants ...... 25

Carbon in bimd~.~.-~-.....-.-....- ~.H....HH...... U.-.u...... -...... ".-....-...+r...... -.....--.. 28

Stabk lsatope Ecdogy .-...... - ..-...... ,,.,...... -.. 37

CHAPTER 4 .PREHISTORY ~moomoowooooomoomowoooooooooowooooo~oooooomoooooowooowowwomwowooo~ooowowwoooo39

The myact~-0 de Cbihu8hw n...w...... 0-0 4'3 Laguna BustiUos ...... 44 Saata Maria River Valley ...... 45

CHAPTER 5 PREHISTORIC DIET IN CHIHUAHUAwooomooooooooommoooommomoooomoooooooowoo49

Tbt Mcb- Evi~for~ricDi .-.. 49 Methodology and Biasing Factors ...... 50 -logical Evidence for Rehistoric Diet in Chihuahua ...... 52

CHAPTER 6 MATERIALS.ooooooo.owo.oo~~ooo~ow~~~oowowsooowomoooowomww~oowomoowmomowso.mmwoowwoomwowooo66

Pj~b...... I.-.....-.-...N ...... -.- ...- ow ...... mWOHI...... 66 Collection and I&mification ...... 72 Human Remaim -..-o.-C.~.~-.-.WUIe.eU~~ee.e--e-UWw..-...-.w-..~~III 77 Ch-202 (La Cruz site)...... 77 Ch-254 (A Chihuahuan CuIture site)...... 79

CHAPTER 7 - METHODS ... -...... m~mmemom...m.~...mm...m.~.m~~.~...... ~.mm...o-~~m...m..o~~...86

Bone Collagen .....,.,,..,. "...... ~..e.ee...o...e.....o.e.e..ee~...... r..-...... -...... e...... H..e.e...e 87

~rvatimof Bone Collagen Samples ...... - .-....~...... 05L.05L05L...... 05L05L...05L.05L.05L.05L05L05L...05L.05L05L.05L05L05L.05L05L.05L05L05L...05L...05L05L..05L..05L...05L....8%

CHAPTER 8 RESULTSmsosoo.m-msmmooommomsooomomooooo~m.-soosmso-smoosmssoommesm~~omoosmmm.~mms~ssmomomooSl

RcdbOC Stabk htq~~~dy~i~~~~~~~..~~~~~~~.~..~~~~~~~~~~~~.~.~~~~~~~~.~. 91 Plants...... -...... 91 Preservation of CoIlagen Samples ...... es.es....es...... es...... es...... 94 Fauna.....-...... *....-....- *..-* .-.---...~.~..*.*-....-..~-~-~.-.-*~...... 95 Human Remains ...... %

CHAPTER 9 - DISCUSSION msosmmmm.e.mmmmommmommommmoo.mommommmmmmmmmmmmmmmmmmmemommmoommmomemsmomsosm 100

Discusdon --~-Im~----.w-~.w~-m.e"~~o.o~u1Iee.+on~o~-~o-euw~~~.u~-o+tormrn~oo~oow~~mo-o~o 10.1 Botanical Remains ...... 101 Faunal Relrcrins ...... 102

I~t~rpttSatIoad Human mope Andy&. .ss~.m~~.~~.~~~eoH~~~~~~u.o~~~e~e~~mo~ne~~~~~~~~~~o~m~~~w~~ee~~~ee~105

AltCI'QttC E~n-..eoeoHoee~mom~~e+w---.-.eeomouem 109 Dietary Stable lsotopc Values ...... 109

APPENDIX A - PLANT SPECIES OF WEST CENTRAL CHIHUAHUA ..mmmmsm.m 123 1. lldm G~d-~----. .- ... .I...... --...... -. .- .--- ... ..mn.-.mr.mr.M..r)123 2. Madman Eve- Woodland .-I..-.-...--.tHnH~.u..n...... -.-m-.t.-~.. .. 1U 3. Madm Montane Conifer Foe...~~,...~wH...HU-.~nn.H.u..~.~.~..~.~.~..~.~.n~UI .-. 128

APPENDIX 8 .ANIMAL SPECIES OF WEST CENTRAL CHIHUAHUA ...... 131 1. Plains Grassfad .. ...--.....MII...H....H....g...Hlt...... ~...... Ut....--...... WH...... C....o...... -.13 1 2. Madrcra Eveqgnxn Woodland ...... --.-...... --H--.n.-UIIm~.CI-....UIUU.n...WWII .133

3. Madman Moataoe Coaifer Few.,....-...... orrm~...... ~...HU....H...UI....U.n...... nW.... *- 135

REFERENCES ...... 138 List of Tables Page 3-1 : Possible Dietary Elements Based on Carbonate and Collagen Spacing .....31 4-1 : List of Important Sites ...... -47 5-1 : Summary of Sites and Plant Remains Discussed ...... 55 6-1 : Collected Plants ...... -68 6-2: Faunal Samples ...... -73 8-1 : Botanical Material - 6 13C and 6"~Results ...... -91 8-2: Faunal Sarnples- Preservation Indicators...... -94 8-3:Human Samples - Preservation Indicators...... 95 84: Faunal Material - 613c and G'~NResults...... 95 8-5: Human Material - 6 13C and 615 N Results...... 97 9-1 : Whole Diet Stable Carbon Isotope Values Based on Carbonate Results.. 110 9-2: Hypothetical Diets and Their Resulting Stable Carbon Isotopes Values .. -11 1 9-3:Species that Grow in Disturbed Habitats...... 115 List of Figures Page 1-1 : Map of Chihuahua and West Central Chihuahua ...... 2 3-1: Stomata ...... 21 3-21C3 Photosynthetic Pathway ...... 23 33: C4 Photosynthetic Pathway ...... 25 34: CAM Photosynthetic Pathway ...... 26 3-5: Carbonate - Collagen Correlation ...... 32 3-6:Nitrogen Cycle ...... 35 6-1 : Ch 202 . Burials 1 and 2 ...... 78 6-2:Ch 254 . Burial 1 ...... 80 6-3:Ch 254 . Burial 3 ...... 83 7-1 : Schematic Diagram of Mass Spectrometer ...... 90 8-1 : Human Samples Plotted for Collagen and Carbonate...... 98 9-1 : Faunal and Human Samples...... 103 9-2: Percentages of C3 . C4, and CAM Plants fmm Different Contexts ...... 106 Chapter 1 - Introduction

Introductzctzon Chihuahua is an important region to the study of North American prehistory. This is primarily due to its intermediate location bemeen the cultural areas of the American Southwest and Mesoamerica Similarities between these two large culture areas have been the focus of studies over the past century. Examples of these similar characteristics indude krge public architecture, exotic trade goods, and T-shaped doomays (Di Peso 1968). Research on the similarities between Mesoamerica and the Greater Southwest has been directed towards uncovering the reasons for these similarities, such as trade and contact. In order to evaluate these theories, it is necessary to study the characteristics of the intermediate locations.

Northern Chihuahua is located within the Greater Southwest, however it is on the southern fringe of the culture area. The majoricg of archaeological research has taken place within one valley in central Chihuahua and at one particularly large and complex site. There has been extensive research at the site of PaquimC (also referred to as Casas Grandes) in the Casas Grandes River valley @i Peso et al. 1974). Excavations in the Casas Grandes valley and at PaquimC have lead to an understanding of the prehistoy and human adaptation in the area Research also has focused on gaining knowledge perraining to the relationships between Mesoamerica, Northwest Chihuahua, and the American Southwest. There have been a number of recent advances in this area (reviewed by Schaafsma and Riley 1999), however important questions still remain.

A current subject of research is the interregional variation within Chihuahua. The Casas Grandes area does not exhibit the same cultural characteristics as do regions to the south. The Proyecto Archaeologico Chihuahua focuses on the region to the south of Pa+&, including the Babicora Basin, the Santa Maria River Valley, and the Laguna Bustillos Basin (Figure 1-1). This project is directed by Dr. Jane H. Kelley and Dr. Joe D. Stewart and uses archaeological survey and excavation in west central Chihuahua to gain a more complete understanding of the regional prehistory. While general statements can now be made regarding subsistence, setdemenb and architecture in west central Chihuahua, other subjects such as regional relationships are just beginning to be explored.

Figulr 1-1. Map of Chiburbua adWest Ceacml Chihuahua (iiii). Stemct d. 2001 Re~emrhPmhhm The exact relationships bemieen these regions in west central Chihuahua and the area around Paquime to the north are important to the larger question of interaction between Mesoamerica and the Greater Southwest Charles Di Peso (I 968) believed that the areas of Northern Mexico and the American Southwest were liked to Mesoamerica by trade relationships. His ideas were based on the presence of unique 'Mesoarnericzn adits' such as T-shaped doorways, ballcourts, and the large-scale construction of pueblos. The Casas Grandes valley, located between the American Southwest and Mesoameril-x, would have fimctioned as a trade centre for goods and people travelling south to Mesoamerica and those travelling north to the American Southwest @i Peso 1968). These ideas led to increased interest in the regions that were geographically intermediate between the American Southwest and Mesoamerica, specifically by Dr. Jane KeUey and Dr. Joe Stewart. However, hrther research into areas to the south of Casas Grandes revealed little evidence that any Mesoamerican or Greater Southwest cultures had ever had any significant presence. Other possible mde routes eds~for example along the western edge of the Sierra Madre in Sonora &at could account for the transfer of artihcts and ideology across the continent. The current belief is that the regions around Laguna Bustillos, the Santa Ma& River and the Babicora basin were not directly involved in the Casas Grandes sphere, or in any large scale trade between Mesoamerica, Casas Grandes, and the American Southwest.

Before the indirect relationships between west central Chihuahua and the Casas Grandes deycan be explored huther, knowledge of the prehistoric people who lived in west central Chihuahua must be increased. Large-scale excavation and survey in the Casas Grandes valley and at Paquixnti have been raking place since the nineteen-ti fie, and herefore much is known on the topics of public and domestic architecture, subsistence, water control, and material culture. The main goal of the Proyecto Arqueologico Chihuahua (PAC) is to increase the amount of knowledge that is held on the prehistory of people living in the regions south of Casas Grandes during the ceramic period, in the range of 800 - 1450 AD. This includes gathering information on architecture, material culture, settlement patterns, and subsistence by survey and archaeological excavation. One important aspect of both large and small archaeological research projects is dietary analysis. Most projects include methods of dietary analysis such as faunal or archaeobotanical analysis. Dietary reconstmdon and nutritional analysis provide information on the subsistence strategies of the group under study. Knowledge of the subsistence strategy provides indispensable information on the adaptation of a past culture to its surrounding environment. An understanding ofa group's adaptation can lead to in formation regarding their lifearays and eventual persistence, demise or relocation.

The term subsistence refers to the strategy that a group uses to acquire nourishment. Examples include agriculture and fishing-gathering. Diet refen to the suite of plants and animals that groups consume as food in order to survive. Nutrition refers to the vitamins, minerals, protein, fats, and carbohydrates contained in the dietary foods that are required for healthy living. All of these terms are considered in this paper, as well as their application to prehistoric populations.

Subsistence is oknlinked to other aspects of culture such as the degree of sedentism, population density, disease occurrence, and specialisation. It is also ofien associated with large scale political, economic, and ideological attributes such as religion, icons, trade, and homeland boundaries. Changes to a culture over time are often attributed to changes in the subsistence strategy of a culture. Important changes that are addressed with subsistence include abandonment, movement or relocation, growth, and acculturation of other groups or into other groups.

An important distinction is made between pups that primarily hunt and gather their food, and those that grow or domesticate wild resources in order to survive. In the past, subsistence strategies were seen as dichotomous; the populous either depended on agriculture or on hunting and gathering (i.e. Mangiesdorf 1958, Sauer 1952). However, more recently subsistence has been viewed as a continuum between pure hunting and gathering to pure agriculture (Harris 1989). There ace an inbite number of possibilities between these wo extremes. Orher cultural charactetistics are associated with these different ways of life. Hunters and gatherers are seen as mobile, while agricultumlists have commitments to the land they cultivate and are therefore more l~kelyto settle in a permanent or semi-permanent situation near their fields. Groups practising different subsistence strategies will differ markedly in population density due to the number of people that can be supported by the food collected or produced. In the case of higher population densities, this may lead to specialization and the development of more complex characteristics in the arm of infrastructure, religion, political organisation, and economic development The relative contributions of wild and domesticated products in the diet of a prehistoric population can form the basis of debates on a wide range of subjects, including the topics mentioned. Prehistoric diet must be analysed carefully and all possible contributors to the diet must be understood before these debates can occur.

There are a number of research questions addressed by the Pcoyecto Arqueologico Chihuahua (PAC), however it is the question of subsistence that is under investigation here. Research done by Dr. Karen Adams, the paleobotanist on the project, has indicated that the groups who inhabited these sites exploited a range of wild resources as well as cultivated corn and beans (Adams 1992,1998). Large amounts of burned corn have been found in some sites within the PAC study area, however, wild plants also turn up in the archaeological remains. Many edible species grow in the areas surrounding sites. It is presumed that both domesticated and ddspecies were important to people living in this region during prehistory.

The main research goal of this thesis is to use an ecological framework and chemical techniques to discover the main contributors to the prehistoric diet of populations inhabiting the study regions in west central Chihuahua. This project includes the stable nitrogen and carbon isotope analysis of plan< animal and human samples from Chihuahua. The results of the chemical analysis on human bone will be compared to the results of the chemical analysis on modem plant specimens and archaeological faunal bone specimens. Together, these will be analysed in order to determine the relative amounts of wild and cultivated plant species, and the relative amounts of vegetable to meat foods, utilised by prehistoric populations. It is hypothesised that the chemical analysis will lead to the conclusion that these populations were subsisting on a mixed diet of wild plants, hunted animals, and domesticated corn and beans. Although the archaeological remains are dominated by domesticated cultigens and some hunal remains, it is believed that wild plants did contribute to the prehistoric diet. The local landscape provides many edible species to groups that would have inhabited the region and there is a plethora of ethnographic evidence pointing to the exploitation of wild resources.

In Chihuahua, application of stable isotope techniques on human bone has been limited (see Hodgetts 19%). The main reasons for the lack of chemical bone evidence are the poor preservation of bone in west central Chihuahua and mechanical damage by ploughs, as well as the overall tendency of research interests to concentrate on other areas of prehistoric Iife, such as architecture and settlement patterns.

Another goal of this research is to provide a stable isotope ecology base for hture chemical analyses of human skeletal material in west central Chihuahua. Direct dietary evidence is not readily available in west central Chihuahua due to the lack of skeletal collections. However, if the collection of skeletal material becomes large enough to provide an adequate sample for dietary study, chemical analyses will be quite usefbl in this region. The ecologg of west central Chihuahua is complex and requires documentation before stable isotopes can be applied to a collection of human skeletal remains. This thesis will record the chemical signatures of many species of plants and animals in order to determine the likely dietary conmbutors and potential wild plant food species. These data will be useful for future researchers who study prehistoric diet in west central Chihuahua.

This research dlexpand the amount of knowledge held regarding prehistoric groups in west central Chihuahua. It is hoped that a clear understanding of subsistence strategies and diet will allow for better analysis of prehistoric adaptation in the area. The results and conclusions presented here will hopefully lead to further research on prehistoric subsistence and adaptation in west central Chihuahua, change over time and space, and the eventual movement of groups out of the region. This research was done in conjunction with the project of Dr. Jane H. Kelley of the University of Calgary and Dr. Joe D. Stewart of Lakehead University. Drs. Kelley and Stewart began the Pro yecto Arqueol6gico Chihuahua (Chihuahua r\rchaeological Project) in 1990 with archaeological survey in the Santa Maria River Valley, and later included the Laguna Busallos Basin, the Babicora Basin, the San Rafiel Basin and the San ta Clara River Valley. I took part in field work including excavations as well as completing the collections for the present study in the summers of 1998, 19W, and 2000. To date, more than 200 sites have been surveyed and recorded, and 28 of those have been tested or more extensively excavated. Faunal and human remains fiom six of these sites have been incorporated into the present study.

Then's OqDnirariolion This thesis will include chapters cove~gaspects of stable isotope ecology and prehistoric human adaptation in west central Chihuahua, Mexico. Chapter two will provide the environmental context of the region. It will also include a discussion of the plant and animal species present in the three envLonmeneil zones identified as relevant to the study arra These eneonmend zones are the Plains Grassland zone, Madrean Evergreen Woodland zone, and Madrean Montane Conifer Forest zone (Brown 1982). Each zone has a set of environmental and climatic characteristics that are suitable to a different suite of plant and animal species.

Chapter three considers ecology and its place in smble isotope analysis and dietary reconstruction. The various metabolic pathways utilised by plants and the way in which diets based on certain groups of plants can be detected in bone will be presented, as well as the consequences of these differences to human groups. The prehistory of the region fiom Laguna Bustillos to the Babicora Basin is sufnmarised and discussed in chapter four. The history of archaeological research is presented, with a discussion of thc current major archaeological project in the region. Chapter five presents an overview of knowledge regarding prehistoric diet in central Chihuahua and related areas. The lines of evidence used to reconstruct the prehistoric diet stem from ethnographic, archaeobotanical, and osteological sources.

The plant and animal samples as well as the human bone used in this research project are described in chapter six. The collection and identification of these samples and complete lists of their provenience are provided. The methods used to process and analyse the samples are reported on in chapter seven. These include the methods used in the archaeology laboratory and in the stable isotope laboratory. The results of the stable isotope analysis of the faunal bone, human bone and plants are presented in chapter eight. Chapter nine presents a discussion of the results and how they differ fiom the initial hypothesis. Alternate hypotheses are suggested and evaluated. The conclusions of this thesis and Future research areas and considerations for hture projects are presented in chapter ten. Chapter 2 - Environmental Context and Physiography

Chihuahua is the largest state in Mexico, encompassing 244,938 square lulometres. It borders on the Mexican states of Coahuila, Sonom, and Durango, and on the American states of Texas and New ,Mexico.

The landscape of Chihuahua is desert plain in eastern portions, and basin and range in western areas. The far west is characterised by the high mounrains and deep canyons of the Sierra Madre Occidental. The specific area under study in this report is located in the west central region of the state, and is identified by Southern Basin and Range country. Some areas are internally drained basins, while others are dominated by large linear valleys with north-flowing seasonal streams.

The specific focus of this research is on ouo areas within the larger study area These are the Laguna Bustillos basin, and the middle Sanm Mark River valley.

wnaBustillos Laguna Busaillos is a dosed basin approximately 3500 km2in size. It is chmctetised by the Plains Grassland vegetation zone at the lower elevations, and Petran Montane Conifer Forest and Madrean Evergreen Woodland in the surrounding mountainous regions (Brown 1982). These vegetation zones are discussed at length in later sections. The town of Anahuac on the south-eastern border of Laguna Bustillos lies at 28O 30' N and 106O 45' W- Elevations range from 1985 metres above sea level (m.a.s.1.) at lake level up to 2400 m.a.s.1. in the mountains that surround the basin.

Mean annual daytime temperatures around Laguna BustiLlos average 14OC to 16OC- These data incorporate temperatures fiom the last 30 years (Estados Unidos Mexicanos, Secretaria de Prograrniacibn y Presupuesto 1981 b) . Precipitation is low-, characteristically between 400 and 500 millimetres per year (Estados Unidos Meuicanos, Secrearia de Prograrniacibn y Presupuesto 1981a), most of this filling in the summer rainy season, kom mid-June to August (Brown 1982).

Santa Maria River Vallev

The Sanm Maria Valley is a Linear, north-south oriented valley containing a small seasond river and fed by a number oE tributaries. The valley floor is characterised by Plains Grassland biotic community @own 1982). The middle elevations are composed of Madrean Evergreen Woodland, and the highest elevations are described as Madrean Montane Conifer Forest (Brown 1982). Therefore, there are three distinct ecological zones available to any groups inhabiting this valley. These zones will be discussed and described in more derail in later sections. The map co-ordinates for the area of the deyare from 29O 15' to B0 00' N, and from 107O 20' to 107O 35 W. The elevation beside the river is 1880 m.as.l., with the mountain ranges reaching up to 2700 m.as.1.

Temperatures in the Santa Maria Valley generally range fiom 12 to lti°C, with more northerly iocations such as El Terrero and Narniquipa averaging 14.1°C, and more southerly locations such as Oscar Soto Maynez and Bachiniva recording temperatures ranging from 12 to 14OC (Estados Unidos Mexicanos, Secretaria de Programiacibn y Presupuesto 1981b). Precipitation is low, and similar to Laguna Bustillos fds in the range of 400 to 500 millimetres per year (Estados Unidos Mexicanos, Secretaria de Programiacibn y Presupuesto 198la).

Biotic Cornmumties Brown's (1982) volume on the biotic communities of Northwest Mexico and the Southwestern United States contains useful information on the study area, particularly the plant and animal communities. Brown lists all biotic communities, the physical characteristics, and the common floral and faunal components of those communities. It was used to identify potential animals and plants that mav have been included in the prehistoric diet.

Chihuahua is comprised of many ecological zones. Of importance to this study are the Plains Grassland, Madrean Evergreen Woodland, and Madrean Montane Conifer Forest (Brown 1982). The areas around the sites that were excavated in Laguna Bustillos and Santa Maria Valley are characterised by Plains Grassland. However, prehistoric groups travelled in order to exploit more than one biotic zone (Adarns, 1992, 1998, 1999,2000). Therefore, the other zones (Madrean Evergreen Woodland and Madrean Montane Conifer Forest) are analysed in this research. These zones are found on the slopes of surrounding mountains and in higher valleys and canyons. Brown describes the modem environmental zones that can be found in Chihuahua Evidence for the prehistoric environment is discussed in chapter three.

For comparison, Semi-Desert Grassland was also investigated. This zone characterizes the Casas Grandes River Valley. Dierary aspects of the study area and the Casas Grandes river valley are not well understood. Given that the ecological zone characterizing each area is slightly different and that resources vary kom one location to the other, one would expect that the diets would differ- An understanding of the ecology and how it varies betareen cultural zones may aid in the reconstruction of larger regional relationships and events in the past Therefore, the Semi-Desert Grassland biotic zone is summarised in this section, and any important differences or similarities will be discussed.

Plains Grassland

Brown (1982) outlines Plains Grassland as having the following characteristics. Elevations are usually higher than 1700 m.as.1. and less than 2200 or 2300 m.as.1. Precipitation averages from 300-450 mm per year, however exaemes can reach as low as 250 mm and as high as 530 mm. These criteria are met by both the Laguna Bustillos Basin and Santa Maria River valley bottom. Many grasses, forbs and low shrubs as well as some cacti can be found in Plains Grasslands. Aninlals such as deer, rabbits, and a plethora of bird species thrive in this community (Brown 1982). .Appendices A and B list all of the plants and animals normally found in areas charactetised by Plains Grassland.

Plains Grassland areas are excellent areas for agriculture due to the level ground, organic content of the soil, and the relatively high avdability of water. Therefore these areas were, and are now, used intensely for cultivation. The disturbance that modem agriculture creates for the archaeologists is discussed Merin chapter three.

Madrean Everereen Woodland

This zone is characterised by open woodland of the middle elevations in the Mexican Sierra. Precipitation ranges from 400 to 600 mrn per year, most of this falling in July and August (Brown 1982). Elevations depend upon the region and precipitation, however this biotic community is usudy found dtitudinally above grassland, and include resources such as acorns, juniper berries, piiion nuts, grasses, cacti and succulents. Deer, grizzly bears, and a number of birds, rodents, and reptiles live, or once Lived, in the woodlands (Brown 1982).

Madrean Montane Conifer Forest

This forest is usdyfound above the Madrean Evergreen Woodland, typically above 2300 m.as.1. and up to 3050 m.as.1. (Pase and Brown 1982). Average yearly precipitation ranges from 460 to 760 r-rt.cn. Typical species found in this zone include Doughs-fir, white fir, and aspen. Mountain shrubs such as rose, currant, and gooseberry are also present. Grasses that prefer cooler temperatures can also be found in this community. Animal species include deer, ells wolves, and a large number of rodent and bird species (Brown 1982).

Semi-Desert Grassland

Areas that are characterised by Semi-desert Grassland typically reach elevations between 1500 and 1900 m.a.s.1. Annual precipitation is on average between 250 and 450 mm of precipitation, with 50 percent of that falling &om April to September (Brown 1982). The types of plant and animal species found in this zone are similar to those growing in Plains Grassland, such as many grasses, cacti and shrubs, as well as rodents, birds, rabbits and deer. However the species themselves are slightly different.

West central Chihuahua presents a large number of resources available to prehistoric groups who may have occupied the area in the past. The resources themselves are arranged in such a manner that over a small horizontal distance, a number of different zones may be encountered as altitude changes. This provides groups living in these regions with a variety of edible resources that may be available at different times during the growing season, thereby presenting them with choices and opportunities to exploit a wide range of nutritious food resources.

As is made apparent by the statistics on temperature and precipitation of the ~o study areas, this region is marked by a hot and dry climate. This can lead to drought situations which are not conducive to the exploitation of wild or domesticated crops. In this instance, not all of the resources listed in the appendices may be available for consumption. The animal populations would also suffer in a drought. Therefore, the types and amounts of resources that are actually present and available for human acploitation could vary from year to year and from decade to decade. Whether this was an impetus for the development of dependence on cultivars is not now and may never be agreed upon. However, the fact remains that the resources in this arid environment would not always be available due to the possibility of low precipitation and high temperatures.

The presence of a number of environmental zones in a relatively small area may help buffer the scarciy of resources. It is apparent fkom the appendices that a number of species grow in more than one biotic community. The large variety of resources and range of growing conditions allows some resources to survive in varying weather situations. If a particular resource on the plains, for example, was reduced due to hot and dry conditions, the same resource in the higher altitudes may have either better conditions (i.e. more rain) or may be able to tolerate the conditions present more effectively than those in the plains. In this instance, the hwnan populations would be able to exploit the region in which the resources were surviving and abandon the regions that were esposed to the drought. Therefore, resources that do not survive conditions in one area may still be available for exploitation at a slightly different altitude or aspect.

Laguna Bustillos Basin and the Santa Maria River Valley are located in west central Chihuahua The ecological zones found in these locations that are important to this study are Plains Grasslands, Madrean Evergreen Woodlands, and Madrean Conifer Forest. A wide variety of plant and animal species can be found. The physiography of Chihuahua is organised in such a way that many different ecological zones are available for esploitation by a group living in any region. The differences between these regions are beneficial in that at any given time there will be a multitude of resources that can be gathered in one or more zones. This is true even if one region is experiencing adverse conditions. The differences between the ecological zones ensures an adequate supply of plants and animals to human groups living in the region. Chapter 3 - Stable Isotope Ecology

"Ecology is the body of knowledge concerning the economy of nature - the investigation of the total relations of the animal both to its organic and to its inorganic environment; including above all, its friendly and inimical relation with those animals and plants with which it comes directly or indirectly into contact - in a word, ecology is the study of all the complex interrelationships referred to by Darwin as the conditions ofthe struggle for existence." (Haeckel 1870, in Rickiefs 1993).

Ecology and the Pwhistorir Diet To understand the prehistoric die&it is necessary to study the ecology of the regon. This includes the plant and animal community structure, food web relationships, and element and nument cycling. All segments of the food chain that were udlised by human populations should be considered. Communities are composed of many relationships, each species linked to all others by trophic reladonships.

Humans are involved in the local food web to greater or lesser extents depending on the economic strategy practised. Groups who hunt and gather in order to survive are involved in more than one level of the food web. They gather primary producers and hunt secondary and tertiary consumers. In this way, they are affected by the status of all plants and anunals in their environment Agriculture focuses prLnarily on the lower levels of the food web. Although agriculavalists may hunt the consumers (i.e. the animals) in the region to a degree, they concentrate on crops, the primary producers. In both situations and in dl possible states in between, the ecological organisation is an important s&g point for any study concentrating on subsistence and diet.

Human communities have complex relationships with plant and animal communities. Humans may be indirectly affected by certain resources even though these resources are not directly consumed. For instance, not all grasses in the region of study are eaten by humans. However, antelope are grazers that are in turn exploited by human populations. The status of the grasses and other foods needed to sustain the antelope and deer populations may eventually affect human groups. A drought that primarily affects grasses not eaten by humans could have an impact on the diets of the human population through stress put on the deer and antelope populations. Hunters may turn to other prey once the scarcity of deer and antelope is realised. The pressure on other prey populations will affecttheir status and population structure. This means that all exploited plants, insects, and animals as well as the diets of all the exploited animals must be understood. In order to achieve this rather heavy demand trophic relationships must be researched.

All of the possible connections between plants and animals d never be completely understood. However, recognition of the preferred foods exploited by a certain group of species, herbivores For example, will be very useful in terms of reconstructing the ancient diet If we can understand broad-scale relationships between certain groups of species and their major foods, then specific relationships between each taxa and its food species mag be simplified and understood.

The current climatic and biotic regime was relatively well established 4 000 years ago (Van Devender 1990). The populations under study in this project do not predate 2000 years. Therefore, we can assume with relative certainty that the species of the past time period under study were similar to, if not the same as, what we see today. There are problems, however, when considering community composition in the past. When climatic or physiographic change occurs, all species are not affected in the same manner. For example, as climate cools, the distribution of some species may shift to lower altitudes while the distribution oFothers remains the same. Therefore in certain locations the plant associations may have changed over time such that the distribution of some species is sirmlar to that seen before the climatic change, while some species may have moved into the zone From other areas, and some species may no longer be found in the region. Studies done in the Chihuahuan Desert show certain mammals and reptiles living in plant communities that they are not found in presently (Van Devender and Bradley 1990). The composition of an ecosystem can change over time. These changes may be caused by small climatic or environmental fluctuations that may not be detected by paleoenvironmenml reconstructions. Therefore, it is not acceptable to assume that all species seen in modem plant and animal communities were present in obsenred amounts in the past. In some cases there is sufficient evidence fiom packrat middens to reconstruct the plant and animal associations in the past. However, in other situations, there are no data available to indicate these past associations. In these circumstances, researchers can only proceed with the knowledge that the modem landscape likely looked similar to that of the past, however with the recognition that there could be differences in plant and animal associations. These differences could be either significant or small and therefore would not alter inferences made with regards to ancient diet-

Nutnent and Element Cjcdng and Stabk Isotopes

Another aspect of the ecology that must be understood is the chemical environmenq or in this particular case, the cycling of carbon and nitrogen in the local environment. Stable isotopes of carbon and nitrogen arill be used as the primary method of diet analysis in this study. Therefore the manner in which these isotopes kctionate in certain conditions are important to the question of how they are represented in human foods, human systems and human remains. The meaning of stable isotope signatures is important when interpreting human diet and the manner in which human populations interacted with the environment-

Carbon The carbon cycle is played out in the realm of the atmosphere, biosphere, lithosphere, and hydrosphere- Compounds involved include carbon dioxide, carbonates both as precipitate and in solution, and various biological carbon compounds such as glucose. One of the largest storehouses for carbon is the biosphere. All living matter is composed of large amounts of carbon. This is rdygained and lost through respiration, metabolism, and waste production by every living oqpism. The land-based carbon cycle is centred around living organisms. Plants are able to acquire carbon directIy horn the air through respiration of CO, Anrma)s maintain their carbon content by the consumption of plant material or other animals. The death and decomposition of living matter replenishes the soil and the air with carbon compounds and redistributes carbon throughout the watershed.

Organisms living in the oceans are continually exposed to dissolved carbon in the form of CO, from the atmosphere as well as carbonic acid and dissolved bicarbonate. Animals can acquire their needed carbon molecules from the plants or other animals they eat, or alternatively, some species can absorb the carbon nutrients directly from the surrounding water.

All carbon atoms are not equal in molecular weight. Three isotopes exist that have the same number of protons and electrons but have differing numbers of neutrons. These are "C, "C, and 12C. "C is a radioactive isotope. It has a half life of 5730 years (Goh 1971) and is the basis of radiocarbon dating. Although "C is critical for archaeological research, this study is concerned only with the stable carbon isotopes, '% and "C. '% is the most abundant of the carbon isotopes, accounting for 98.9Y0 of all carbon atoms, with 13C being the next most abundant, with 1.1% of carbon atoms.

Nitrocwn Nitrogen is essential to all plants and animals. It is abundant in the atmosphere, however it is in a form that is of limited use to plants (NJ. Plants are not able to remove nitrogen kom the air as they can with carbon. N, is a stable compound that must be broken down and combined with other elements in order to be incorporated into plant tissues. Organic nitrogen sources in the soil are also not usehl to plants. Plants require inorganic compounds such as ammonia, nitrate, or nitrite pray 1983). Plants can get adequate amounts of nitrogen through organisms living in the soil that transform atmospheric nitrogen or organic nitrogen into forms that are usable to the plant roots and plant tissues. Nitrogen pools are more isolated and varied than carbon pools. Whereas carbon is very abundant and accessible in the atmosphere, usable nitrogen is located in the soil. When a plant or animal dies and decays, the nitrogen becomes readily avadable to micro-orpisms, plants arid then to animals. Nitrogen is not ofien transported over large distances. This leads to variability in quantity, quality, and isotopic composition among local ninogen pools. The carbon cycle involves the movement of air and contained carbon dioxide by winds. The result is a homogeneity in carbon molecules throughout large regions. The small scale of the nitrogen cycle leads to the possibility of one region having a different amount or quality of nitrogen than another region that may be relatively close. Niwgen molecules could be transferred to other locations by the movement of animals and their subsequent death and decay, or by plant matter falling into rivers and streams. However, this transfer involves much smaller quantities of nitrogen than does the msfer of carbon as carbon dioxide over large distances.

Like carbon, nitrogen exists in different forms. This study is concerned with the stable isotopes of 15~and 14N. 14N is much more abundant than "N, wirh 14N accounting for 99.G0/o and "N for 0.4O/0 of nitrogen atoms. Both of these forms are stable and therefore are usehl for dietary analysis.

Isotc'pe Notatzon

Stable isotopes are studied in ratios. The ratio is calculated with the following formulae: Numbers are cited as 'delta' values (6) and are measured in the units 'per mil', or per thousand (!&). The standard used for carbon isotopes is derived from the ratio of I3C to "C in a sample of Peedee Belemnite Carbonate (PDB), a marine carbonate. That of nitrogen is based on the ratio of the two isotopes in the atmosphere. Both standards are recognised internationally. The PDB sample contains more 13C than most samples in the terrestrid environment, and therefore most items tested have delta values that are negative when compared to the sample. Atmospheric nitrogen, however, contains less "N than most items tested, and therefore the tested specimens ofien have positive delta values.

All species in the andkingdom synthesise carbon-based molecules in the same manner. Plants on the other hand, are divided into three groups, each of which assimilate carbon horn atmospheric CO, in a different manner. The most primitive of these metabolic pathways is the Calvin cycle, or C3 pathway. This is so named because the first carbon compound formed is a molecule composed of three carbon atoms. A derived metabolic pathway found in arid and tropical regions ends the ktstep of carbon assimilation with a four carbon chain, and is therefore termed C4, or the Hatch-Slack method of photosynthesis. This type of photosynthesis likely evolved out of the C3 pathway during a period of lower atmospheric CO, levels (Ehrlinger et. al. 1991). Some species display a metabolic pathway that has characteristics of both the C3 and C4 pathways, and is called the Crassulacean Acid Metabolism (CAM) method.

The physical mechanisms of respiration, the stomata, are integal to the incorporation of carbon molecules into the plant and plant respiration processes (see Figure 3-1). It is by these openings that carbon dioxide molecules containing C1*or C1', are brought into the plant tissues. As the main ports for respiration, they must remain open for periods of time, which leads to loss of water vapour from plant cells. The water potential of the leaf is much higher than that of the atmosphere and therefore the natural gradient is towards the atmosphere, leading to a potentially high water loss fkom the plant. The stornatal complex of cells is responsible for regdating the size of the opening and therefore the amount of carbon dioxide brought into the plant tissues and the amount of water papour that escapes (Hinckley and Braatne 1994)-

Figuh 3-1. Stomata. Adapted from Hincldey and Bmmc

The opening and closing of the stomata are controlled by ion pumps that influence the turgor pressure within the BJard cells on either side of the stomatal openings. The swelling or deflating of the guard cells decreases or increases the size of the opening, thereby allowing more or less carbon dioxide into the plant tissues. Carbon dioxide concentration within the plant tissues does affect the sue of the stornatal opening. If the concentration of carbon dioxide within the plant cek is low, the stomata will be triggered to open. If the concentration is high, the stomata will dose. An optimum concentration is maintained within the plant cells in order to provide the best environment for carbon fixation and glucose production. However, not all fictors affkting the relationship between carbon dioxide and stomatal activity are well understood. For emmple, influences may include the age of the plant, stress, and hormone levels. 0th- kctors decting the opening and dosing of the stomatat aperture include relative humidity, light, leaf and soil water status, and plant growth substances (Hinckley and Braatne 1994).

All plants, independent of the metabolic pathway, contain less 13C than the surrounding atmosphere. Molecules which contain '% are heavier and form stronger chemical bonds than '%. These properties cause reactions involving I3C to be slower than those involving 12c.Therefore 13C is less likely to break out of its formation in atmospheric CO, and enter the plant stomata (O'Leary 1988). The propemes of the different carbon isotopes, the enzymes involved in the conversion oCCO, as well as other physiological differences between plant groups lead to the differences seen beween plants in their carbon isotope values.

The Calvin Cvcle The C3 pathway is the most prevalent metabolic pathway world-wide, being found in all trees, most large shrubs, many grasses, and forbs. Figure 3-2 diagrams the way in which CO, is incorporated into plants through the stomata. The primary component produced is phosphoglycerate (PGA), a compound composed of three carbons, and hence the label of C3 pathway. Each RuBP molecule produces one molecule of carbon for the synthesis of glucose (C6H,206)-Conside~g that one turn of the Calvin cycle results in one molecule of RuBP, six turns of the Calvin cycle are necessary to create one molecule of glucose for the metabolic requirements of the plant (Fbcklefs 1993).

Although this method of cellular respiration is the most common, it is not the most effective or efficient. The enzyme responsible for assimilating carbon, RuBP carboxylase, in part works against the assimiktion of carbon (O'Leary 1988)- The enzyme has a low afhity for CO, and therefore its presence discourages the presence of CO,. In order to complete the carbon assimilation and begin the synthesis of glucose, CO, concentration within the plant cells must be high. In order to maintain high levels of CO, inside the plant tissues, the plant must maintain low stornatal resistance (O'Leaty 1988). This leads to a loss of CO, and water vapour. Most plants using the C3 pathway live in temperate environments, and therefore can tolerate moderately high levels of water loss. Problems arise, however, in situations of water stress and high temperatures, therefore C3 plants are not well adapted to tropical or drough t-stricken regtons.

Glucose

RuBP

PGA - phosphoglycerate (3 carbon compound) RuBP - ribulose biphosphate (5 carbon compound)

I Figure 3-2. C3 Photosynthetic Pathway. Adppted from Ricklcfs 1993.

the plant cells, dissolved CO, that contains "C is preferentially converted to phosphoglycerate over that which contains 13cdue to the nature of the RuBP carboxylase (Deines 1980). Therefore, the ratio of 13C to '% is lower in the plant cells than that in the atmosphere. In other words, there is less "C in the plant than is usually found in the outside air. This is exhibited in the delta values of the plant tissues. C3 plants will usually have delta values near -27% (Boutton 1991). The amount of 13C in the plant tissues is not in itself maladaptive or disadvantageous. However, 13C is heavier and chemical reactions involving

these molecules will occur at a slower rate than lighter 12cmolecules.

In warmer regions, adaptive stresses from increased transpiration and water loss lead to an evolutionary trend in which the stomata were either opened for a shorter period of time (C4 plants), or were only opened during the night (CAM plants). Other adaptations for these functions are evident in the chemical pattiways taken during photosynthesis and in the physioIogical attributes of the plant tissues. CS Plants

Plants exhibiting the Hatch-Slack metabolic pathway have a higher ratio of "C to I2c and therefore are characterised by 6 values near -1 3% (Deines 1980). They are said to be heavier, or more enriched, meaning enriched in "C. Physical and chemical differences are evident within C4 plant tissues. Figure 3-3 displays the organisation of plant tissues and the chemical pathways taken in C4 metabolism. The physiologrcal difference bemeen C3 plans and CQ plants lies in the organisation of the cells themselves. As is evident from a comparison of figures 3-2 and 3-3 ,C4 plans have bundle sheath cells, which are differentiated from the regular mesophyll cells. The initial carbon assimilation takes place within the mesophyll cells. -Actual glucose Formation still occurs by way of the Calvin cycle, however this occurs in the bundle sheath cells.

Efficiency is improved by the production of phosphoenol pyruvate (PEP). The reactions that involve this molecule are controlled by PEP carbosylase which has a higher affinity for CO, than RuBP carboxylase. RuBP is removed to the bundle sheath, and therefore the stornatal resistance can be higher and CO, is more easily accumulated in the plant tissues than is the case in C3 plant metabolism (O'Leary 1988). -As is evident from Figure 3-3 ,almost all of the carbon molecules lefi over fiom the Calvin cycle are reused in the Hatch-Slack cycle. This could also contribute to the higher percentage of "C molecules becoming incorporated in to the plant tissues. OAA - oxaloacetic acid (4 carbon compound) PEP - phosphoenol pyruvate (3 carbon compound) PGA - phosphoglycemte (3 carbon compound) RuBP - cibulose biphosphate (5 carbon compound) Figun 3-3. C4 Photosynthetic Pathway. Adapted from Rickleffs 1993 and Hhme1988. I

CAM Plants

The final pathway employed to assimilate carbon dioxide and produce glucose in plants is termed the Crassulacean Acid Metabolism, or CAM, named after the Crassulaceae family of plants. This type of metabolism occurs in cacti and in succulents such as agave. As can be seen from figure 3-4, CAM plants have the ability to separate respiration and the production of glucose temporally. Respiration can occur during the night when temperatures are lower and transpiration through the stomata is consequently decreased. Malate and OAA can be produced during the night and slowly released during the day to provide a source of carbon dioxide for the production of glucose in the Calvin cycle. The timing of respiration during the cool hours consequently reduces evapotranspiration by allowing the stomata to remain closed during the hotter hours of the day (Boutton 1991, Harborne 1988).

I DAY I

OM- oxaloacetic acid (4 carbon compound) PGA - phosphogiycerate (3 carbon compound) PEP - phosphoenol pynrvate (3 carbon compound) RuBP - ribulose biphosphate (5 carbon compound)

Figure 3-4. CAM Photosynthetic Pathway. Adapted fiom Rickkffs 1993. Depending on local conditions, these plants can exhibit carbon isotope signatures indicative of C4 plants or C3 plants. If the cycles of respiration and glucose production are temporally separated and stomata remain closed during the daylight hours, a C4 signature will develop. However, if conditions encourage the stomata to remain open during the day, the cycle is similar to the Calvin cycle and a C3 isotopic signature will result. Because of the flexibility of CA!! plants to adapt to specific circumstances, it is not possible to predict the carbon isotope signatures of important CAM plant resources such as prickly pear cactus and agave. The signatures of CAM plants may vary over geographic distances and environmental variability.

As can be deduced horn the previous discussion, C4 and CAM plants are particularly important in hot and dry environments. The benefit that is brought to plants utilising the C4 and CAM methods of photosynthesis is an increased resistance agdlnst water loss and also an increased efficiency in glucose production. In desert ecosystems and low latitude grasslands C4 and CAM plants contribute large amounts to the overall biomass. The production of edible plant matter in these environments is important to both animal and human communities.

In the region of this study, over 40% of the total number of species growing in the region are either C4 or CAM plants (Brown 1982, Appendix A). Without these particular species and without C4 and CAM plants in general, this ecosystem could be less diverse and lower in productivity. Moreover, human populations might find it harder to exist under these conditions. These adapted forms of plant life are important resources in desert and tropical grassland communities, and must be included in any study of diet and ecology in central Chihuahua.

As can be seen fiom the previous discussion on carbon assimilation in plants, there are many explanations for the obsemed differences in the ratio of '% to 12C in plant tissues. and hence the lower 6°C in C3 plants as compared to C4 and CAM plants. C3 plants require more C02due to the low stomatal resistance and the low affinity of the plant tissues for CO, and therefore stomata must remain open for longer periods of time than is seen with C4. In conjunction with the longer opening time, the plant may actively select "CO~ over 13c0,due to the fact that I3c is slower to react in chemical reactions than is '%. Importing "C02will lead to a decrease in chemical reactions that take place within the plant tissues. It would seem that '*Cwould be more beneficial to efficient carbon assimilation and glucose production. C4 plants grow in circumstances that do not allow for long periods of open stomata, and therefore the opportunity to select "C0,over 13C0, is not avdable.

Another factor involved in the higher amounts of "C in C4 plants involves the pathway of CO, within the mesophyll and bundle sheath and mesophyll cells of the plant. Figure 3-3 illusbates that after the CO, is released from the Hatch-Slack cycle, it is reintroduced into the Calvin cycle. Whereas in C3 plants, this CO, is released back into the atmosphere and new CO, is incorporated via the stomata. The C3 plant assimilates more 12CO, molecules than 13C0, molecules, again for reasons of reaction time. C4 plants use a higher percentage of the CO, that is introduced which leads to a higher 6°C value in C4 plants.

Animals replenish their stores of carbon by eating plants or other animals. Carbon molecules are used in the construction of body tissues, including muscle, fat, skin, hair, and bone. The ratio of "C to I2C in plants will be passed on the primary consumer, and subsequently to the secondary and tertiary consumers. Therefore, stable isotope analysis of animal tissues can indicate the type of plants that dominate its diet or the diet of the animals it ate.

The stable carbon isotope signature of the foods eaten by animals, including humans, is reflected in the protein (collagen) and mineral (carbonate) portion of bone. However, the ratio of 13cto 12C in the diet is not equal to that in the body tissues. This difference is due to kactionation, the differential uptake of various stable isotopes, and the absolute value of the spacing between diet and tissue varies between collagen and carbonate. An important study was conducted on laboratory raised rats, fed consistent diets kom birth (Arnbrose and Norr 1993). The researchers fed the rats diets that varied in protein amounts, and the sources of the protein (C3 vs C4). It was discovered that the spacing between collagen and diet carbon stable isotope results also depended on the percentage of protein coming from C3 and C4 sources (Ambrose and Norr 1993). The information fiom this controlled feeding experiment is likely applicable to humans, however there is the possibility that these results do not describe exactly what happens within human bone. This study is currently thought to be applicable to human bone and human die&and is the best that is avadable at this time.

Bone Collagen Spacing between the diet and bone collagen is not constan%but amounts to approximately +5% from the diet to bone collagen (van der Merwe and Vogel 1978). The actual value of this spacing can range from -22 to +9.6%0 depending on the amount of protein in the diet and where it is coming from (Ambrose and Norr 1993). The collagen in bone is composed of carbon atoms from the protein portion of the &et. Many plants, and corn in parti&, do not contain iarge amounts of protein. What protein is present in corn will be reflected in the collagen portion of bone, however other protein-rich portions of the diet such as meat are reflected to a hgher extent in the collagen carbon isotope results.

In general, a 6'% collagen ranging around -22400will indicate a diet composed of C3 resources, while a 613C collagen duefrom human bone ranging around -8% will indicate a diet composed mainly of C4 resources. There are other possibilities, such as mixed diets, and those including marine resources, however the range indicated by W and C4 resources comprise the outer Limits of 6% collagen results.

Bone Carbonate Bone carbonate stable carbon isotope values also indicate diet. However, as with collagen, bone carbonate GL3Cvalues do not directly reflect dietary 6°C values. Unlike collagen, the difference between diet and carbonate does not widely fluctuate in response to the composition of the diet. An intensive feeding study was performed on rats by Ambrose and Norr in order to examine the contributions of the diet to carbonate and collagen and to illustrate the spacing between the diet and the two portions of bone. The dietary 6°C values will differ from bone carbonate S1'C values between +9.1 to +10.3, a range of only 1.8% (Ambrose and Norr 1993). Therefore, bone carbonate 6"~values are a more consistent reflection of the actual dietary 6I3C values. Carbonate 6'% values of human bone range fiom around -17% (indicating a diet high in C3 resources) to around -3% (indicating a diet high in C4 resources).

The carbonate or apatite portion of bone receives carbon atoms from blood bicarbonate. These carbon atoms come from celIuiar metabolism, which receives energy kom carbohydrates, lipids, and protein in the diet (Ambrose and Norr 1993). Therefore, stable carbon isotope values fiom bone carbonate lead to a more complete reflection of the whole diet.

Carbonate - Collagen Spacing Although 6% values fiom the collagen and the carbonate portion of bone can be interpreted on their own, additional information becomes available when the spacing between carbonate and collagen 613C values is included. The information is based on the fact that carbonate and collagen ti1% values come fiom different components of the diet. The way in which cubonate and collagen 6'% values relate to each other can illustrate which part of the diet the protein or whole diet, is more enriched with respect to "C.

The following are explanations of difFezent spacings between carbonate and collagen 6°C values. They are diagrammed in Table 3-1. If carbonate and collagen 613cvalues are correlated, then the 6'% values of dietary protein is similar to that of the whole diet. This would be apparent if the carbonate and collagen 613C values for all members of a population consistently differed a given amount. There are two instances in which this would ocm, first, if the diet was vegetarian and the plants used the same metabolic pathway (i.e. all C3 plants, or all C4 plants; A-1,2 in Table 3-1); second, if both plants and animals were exploited and the plants eaten by the animals were of the same group as those eaten by the human population (i.e. C3 plants and C3 plant-eating animals, or C4 plants and C4 plant- eating animals; A-3,4 in Table 3-1). In these circumstances, the protein portion of the diet would contain the same ratio of "c/'%atoms as the whole diet, and therefore the 8°C vaIues of carbonate and collagen would be highly correlated.

On the other hand, if the 6% values of carbonate and collagen are not correlated, then dietary protein 613C dues are not the same as whole diet 613C values. In other words, the population is gemng its protein from a different source than its whole diet. These two sources would dffer in their stable isotope composition. There are taro possibilities within this situation, either the 613C value of the bone collagen is much more enriched than that of the bone carbonate, or only slightly more enriched. In the first instance, the dietary protein is much more enriched in "C than is the whole diet. There are two situations that may lead to this; a mixed plant-animal diet containing CCeating animals and C3 plants (B-1 in Table 3-I), or a mixed diet containing C4-eating animals, C3 plants and C4 plants (8-2 in Table 3- 1). Depending on the relative amounts of C3 plants and C3-eating animals, this third dietary possibility could also include CCeating animals. If the results showed carbonate 613C values only slightly greater than collagen 6% values, then the whole diet would be less enriched than the protein portion of the diet There are two possible diets that would result in this; a diet composed of C4-eating animals and C3 plants (C-1 in Table 3-1); or a diet of marine protein resources and C3 plants (C-2in Table 3-1).

Table 3-1. Possibk Dietary Elements Based Upon Cdmmue and Collagen Spacing. Carb-CoU Spacing (6°C) Dietary Protein UCSource Whole Diet "C Source A. Carb and Coll Veg 1. C3 piants C3 plants are correlated 2. C4 plants C4 plants Mixed 3. C3-eating animals C3 plants 4. C4-eating animals C4 plants B. Carb is much Mixed 1. C4-eating animals C3 plants more enriched than 2 C4-eating animals C3 plants and Coll C4 plants C. Carb is Mixed 1. C4-eating animals C3 plants slightly more 2. marine resources C3 plants enriched than Coll L This interpretation of the carbonate - collagen spacing has been documented and reported on by Ambrose and colleagues (1997). Specifically, if the carbonate - collagen spacing is greater than 4-4%0, the diet includes a protein source that is more negative (or lower) than the whole diet Alternately, a spacing that is less than 4.4% indicates that it is the whole diet that is more negative than the dietary protein (Arnbrose et al. 1997). Therefore, correlation of 6°C values occurs when the spacing between collagen and carbonate equals 4.4%0. This relationship is expressed by the regression line in figure 3-5. A sample that has a carbonate-collagen spacing greater than 4.4% would fall above the line, while a sample that has a carbonate-collagen spacing less than 4.4% would be found below the line.

Figure 3-5. CarbomhgenConehion. Based on Ambnwe et al. 1997.

The carbon isotope signatures of C3 plants ranges from -20%0 to -32/-, the average being -27%o (Boutton 1991). An animal subsisting wholly on C3 plants will exhibit an average collagcn carbon isotope signature of appro~rimately-2203~0. There is a range of collagen 6% values resulting from a diet of C3 plants due to the variation in plant metabolism and carbon isotopic signatures, however most bone collagen will exhibit &'% values between -18%0 and -2% for a C3 diet. Most bone carbonate will exhibit 8''~ values around -17%0. Plants utilising the C4 metabolic pathway will exhibit 6'% values between -90~and -17%0, with an average of -13% (Boutton 1991). W~thfractionation, the bone collagen of an animal eating only C4 plants would exhibit 6% values averaging 4%.The bone carbonate hction would exhibit 6°C values around -3%. CAM plants are so varied in their metabolic responses to climate and environmental fluxes that the 61JC values of CAM plant tissues can exhibit wide ranges, but are most commonly between -20% and - 10%. As a result, it is difficult to predict the 613C value of bone in an animal subsisting on that plant matter without also testing each CAM plant in the diet. The carbonate and collagen 6°C values, however, would fill intermediate to those seen in C3 diets and C4 diets. This situation would also occur if one was eating a diet mixed between C3 and C4 plants.

A diet based on marine foods is distinguishable from a diet based on terrestrial food using stable carbon isotopes. This is not applicable in the present study due to the landlocked nature of the study area and the low probability that prehistoric occupants were eating marine foods. For funher information regarding marine plants and animals in the die%see Schoeninger and Moore (1W2).

The 61SNvalue of a plant or its tissues is a hction of the SISN value of the nitrogen source (Handley and Raven 1992). Therefore, plants growing in locations that have different sources of nitrogen will have different 615~values. The nitro- source of most terrestrial plants is the soil. The 6''~values of plants may even differ within sites that contain the same soil we, and are cppified by the same land use, climate and origin (Hopkins et. al. 1998). The causes of diEe~g6% values in soil are complicated and variable. Some of the factors include climate, fertilisation, tillage, vegetation cover, land use, burning grazing, and moisture content (Handley and Raven 1992).

Nitrogen is made available to plants by the process of fixation. This can happen in a number of different ways. Biological fixation is done by micro-organisms in the soil, and accounts for 70 to 7S-10 of all fixation (modem measurements). Non-biological fixation accounts for approximately 10% of nitrogen lixation and is accomplished by lightning, L'V radiation, and other human induced electrical sparking incidents. The other 15% of &ation is provided by chemical ferdlisers (Bray 1983).

Biologcal Fiation will be discussed at length because it is responsible for the large majority of nitrogen availability to plants and mias more so prehistorically. There are two different situations that result in fixed nitrogen. In he hrst situation, free-living micro- organisms in the soil produce arnmonia from the organic nitrogen compounds in the soil from decomposed organic matter. These bacteria use the ammonia for their own metabolic processes and the nitrogen only becomes available to the plant her the bacteria have died and decomposed. The second, more efficient manner of gaining nitrogen, is through symbiotic associations between the plant roots and nitrogen fixing bacteria. In these cases, the bacteria live close to the roots of the plant Ammonia is produced in large quantities from atmospheric nitrogen and the large majority is exported to the plant roots, as only a small amount is required for the micro-organism itself. This symbiotic relationship occurs only bemeen leguminous plants and Rhizobiurn bacteria (Bray 1983). After fixation, the plant can absorb the ammonia, or absorb nitrates that are olridised by other bacteria in the soil (see figure 3-6).

Nitrogen isotopes are useful to research problems that focus on vegetarian diets as well as mixed diets. Leguminous phts tend to have lower 6'- dues, dw to the hct that they have access to fixed atmospheric nitrogen through the nitrogen-king bacteria (Handley and Raven 1992). Non-leguminous plants metabolise soil nitrates in order to have access to nitrite for building nitrogen compounds such as amino acids. With the reduction of nitrate to nitrite there is a nitrogen isotope hctionation, which results in a higher 6"~values than those seen in plants that are able to fix atmospheric nitrogen (Yoneyama et al. 1998). (7-Ezl ANIMALS 1 Vl. derrlb,

Figuh 3-6. The Mtm- Cyck. Fmm Bray 1983.

Nitrogen in Am-moLr

As with stable carbon isotopes, stable nitrogen isotopes of food items are incorporated into the tissues of animals. Although nitrogen isotopes are not useful in distinguishing bemeen a C3 and C4-based die& they are very applicable when trying to determine the trophic level of the animaL Within a terrestrial or marine system, there is a shift in 6''~values of approximately 3% (Katzenberg 1992). As one moves to higher trophic levels, there is an enrichment in the 6'*~values of the body tissues. This presents an opportunity for researchers to identify whether the individual being analysed lvas subsisting on a diet composed mainly ofplants, animals, or as is usually the case, a combination OF both. In some cases, the particular animal species being targeted as prey can be identified.

,4s previously mentioned, conhsion arises when trying to interpret carbon isotope values from mixed C3 and C4 environments, where the population was also consuming animal meat. An isotopic signature that is similar to that seen with C4 plants could also indicate the consumption of animals who fed on C4 plants, and not necessarily the direct consumption ofC4 plants. With the added interpretative ability of stable nitrogen isotopes, it becomes more clear where the C4 signature is corning from. A C4 isotopic signature and a low 6'" value would result from the consumption of C4 plants. However, a C4 isotopic signature and a higher 6''~value would point to anirnal consumption. The C4 signature could potentially be a result of direct consumption of C4 plants, or of the animal consuming C4 plants. Further analysis of the plants and animals in the region and other archaeological evidence for the consumption of plants and animals will aid in interpretation.

There are other factors that seem to complicate stable nitrogen isotopes in animals. The first indication of other elements at work was the discovery by Schoeninger and DeNiro (1984) of higher than expected 6"~values in animals inhabiting arid environments. Other studies have shown this correlation of higher 6"~values in areas of low precipimtion (see Schwarcz and Schoeninger 1991 for a review). However this trend does not hold true in all areas of the world and other Factors in addition to, or instead ot; low rainfdl have been investigated. Urea is depleted in 6"~,and therefore any characteristics of the environment or the animal itself that cause more urea to be produced will lead to elevated 6"~values in body tissues. Animals living in environments of low water availability excrete more urea, which is why they ofien exhibit high 6''~values. Protein intake levels may also be linked to urea production, as the amount of dietary nitrogen excreted by the body does not change under protein stress. Other possibilities include re cycling of nitrogen by bacteria in Nminant stomachs. The factors involved in the elevation of 6% values in certain animals in various parts of the world is not completely understood at this time. More research is required on the paths that nitrogen takes through the digestive tract in different types of animals, as well as the roles of water stress, protein stress, and ruminant bacteria (Schwarcz and Schoeninger 1991).

Stable isotope analysis can not dstingulh between wild and domesticated C4 species. It is therefore important to survey for other wild dietary components that use the C4 pathway. A bone stable isotope signature that reveals a diet based on C4 plants can only be considered indicative of a diet based on maize in temperate zones. In regions of the world that are characterised by wild C4 species, the local haand flora must be understood. All eQble wild plants that utilise the C4 metabolic pathway must be considered possible conmbutors to the C4signature in bone. Cacti and succulents utilise the CAM pathway for photosynthesis, and can have isotope signatures that are in the C3 or C4 range depending on the local climate. Northern Mexico contains many wiId C4 species as welI as CAM plants and as such is a complex dietary region that needs to be studied before generalisations can be made.

The fauna in Northern M&co potentially will consume other wild resources that may be C4 plants, which are not consumed by humans. In this case it is important to be familiar with all of the plants in a region as wen as have an understanding of the dietary habits of the local haIn this way, all possibilities may be investigated if a bone isotope signature indicates a C4 diet The possibility of the diet including wild C4 plants or animals that consume C4 plants can be evaluated and appropriate hypotheses or Wertesting may be carried out.

One particular area of investigation that is essential is a stable isotope ecology reconstruction of the study area. The relative proportions of wild C3, C4, and CAM plants in the region gives researchers a better understanding of the isotopic signature ranges that may be expected from human bone analyses. Some recent investigations into prehistoric diet use ecological dier or extol the virtues of this type of analysis (Hard ct. al. 1996, Huebner 1991, Katzen berg and Kelley 1991).

There are two occurrences that tend to interfere with the reconstruction of the stable isotope ecology of cenaal Chihuahua; the introduction of non-native species and the decrease of indigenous species and associated habitat due to large scale agriculture and grazing activities. A number of the species found today in west central Chihuahua were introduced with European contact and during modem times, for example sorghum and some species of mustard. Introduced species will not play a role in this study because they were not available for exploitation by past populations. In most of the regions in west central Chihuahua there are large areas under modem cultivation. Although there has been little climatic change within the last few thousand years (Van Devender 1990), there has been a vast change in vegetation cover within the last 50 to 75 years. An increase in large-scale agriculture and the introduction of grazing herds has led to desertification, arroyo down- cumng, a decrease in forest cover, and a decline in indigenous plant species in favour of introduced crops such as potatoes and hybrid corn species. Not only is the ecologg of the region inherently complac, but additional complications such as introduced species and alteration of the landscape and natural biotic communities causes further difficulty in understanding the prehistoric relationships betareen plants, animals, and human populations.

ConcCHsians

This chapter has presented an overview of carbon and nitrogen, the workings of C3, C4, and CAM plants, as well as a discussion of stable isotopes and how they can be used to indicate diet. It is made apparent in rhis chapter that the ecology of a study region must be considered and researched before any inferences regarding diet can be made. An understanding of the plant and anLnal communities d aid in the interpretation of diet from the stable isotopic signatures of human bone. Chapter 4 - Prehistory

While the history of archaeological fieldwork in the southwestern United States is long and involves many large projects, archaeological fieldwork in neighbouring northwestern Mexico has been sparse. However, important surveys have been carried out in Northern Mexico, and many important sites have been recorded. The reasons behind research into this area have been varied. Some early archaeological surveyors were interested in exploring similarities bemeen New Mexican pottery and that found in Northern Chihuahua (Sayles 1933, 1936), while others were interested in visiting and recording sites (Amsden 1928, Brand 1943, Carey 1931, Lumholtz 1902). Amsden had no specific research design in place and travelled into Mexico in order to iearn more about the sites and cultures that existed. Carey was interested in the relationships within Chihuahua between the mound cultures of the plains and valley bottoms and the cliff dwelling cultures of the Sierra Madre. In a broader scope, Carey investigated the relationship between northwestern Chihuahua and adjacent areas, as well as that between northwestern Chihuahua and the American Southwest. Brand identified the central position northwestern Chihuahua held between the American Southwest and central Mexico. Its prehistory was thought to be important in the overall relationships in westem North America (Brand 1943).

In west central Chihuahua, the region where this study took place, smeys done by Brand and Sayles (Bmd 1933, Sayles 1933, 1936) are particdady useful. Archaeological sites were located that have become important to the interpretation of the regional prehistory. Sayles recorded sites along the Santa Maria River and in the Bustillos Basin (Sayles 1936), while Brand travelled through both areas, but recorded sites only in the Santa Maria River valley. The last 10 years have been particularly importan&with the development of a number of larger projects focussing on the archaeology of central Chihuahua itself, without drawing associations to the cultures and archaeology of the southwestern United States. Although there are important similarities between these two regions, the northern Mexican cultures portray enough differences to be considered as cultural entities on their own, deserving the intense study that they are just now beginning to receive. The early survey records are very important to recent projects. The survey records can be ref'erred to, the sites relocated, excavated, and the information analysed and interpreted. Without these early records survey efforts would have to be greatly increased. In many cases, the sites cannot be located today due to erosion or human induced landscape changes since the early surveys. These sites would not be included in broader range interpretations if it weren't for the early records.

This report is concerned with the prehistory of west central Chihuahua This includes the Babicora Basin, the Santa Maria River valley, and the Bustrllos Basin, and tend to concentrate on sites within the time period ca. 800 - 1450 AD. The study region is divided into two sections, northern and southern. The northern area consists of the Babicora Basin, Middle Rio Santa Clara and Middle Rio Sanm Maria valleys, and the southern area is concentrated around Laguna Bustillos. These two areas differ in terms of mated culture, architecture and settlement pattern. It has been a major goal of the Pmyecto Arqueologico Chihuahua to discern the reasons behind these differences.

Most of the archaeological work done in the past has occurred at the large site of Casas Grandes (also known as Paqui.6) and its surrounding and associated regions located north of the study area. The aforementioned regions to the south of Casas Gcandes have received litde archaeological attention. The surveys done by Brand and Sayles did include regions in west central Chihuahua, and others have done limited survey. Early researchers such as Arnsden, Carey, Sayles, Kidder, and Brand also eycavated more than 12 sites, mostly in the Babicora Basin (Kelley et al. 1999b). After the early 1930s, limited archaeological research was done in west central Chihuahua until 1989 and the inception of the Proyecto Arqueol6gico Chihuahua.

P&u-Indian and Ambaic Peroak

There have been no excavations of Paleo-Indian sites in Chihuahua However, the presence of humans in this region during this period is evidenced by isolated finds of Paleo- Indian projectile points (MacWilliams et al. 1998). One fluted point base was located in the study area just north of Laguna Bustillos (Kelley and Stewart 1991, cited in h~ac\~lliamset al. 1998), and later Paleo-Indian points exist in private collections. Likely, the situation around 11,000 years ago BP was similar to that in the western United States, with small bands of hunters-gatherers ranging over large areas (Phillips 1989). In Chihuahua, the locations of these isolated finds tend to point to the adaptation of Paleo-Indian populations to pluvial lake margins.

The Archaic period is defined as the time after the Paleo-Indian period and before ceramic technology. Extensive survey was done within the scope of the PAC, however no buried Archaic sites were located. An important recent project that attempts to increase the amount of information available for the Archaic period is the work that has been done on Cerro Juanaqueiia in northwestern Chihuahua (Hard Ad Roney 1998). This massive terraced hill provides evidence of early corn and squash domestication in Chihuahua There are 8 kilometers of terraces on the hill, with the average length of the terraces being 17.8 rn. They appear to have been used for residential purposes. Excavators recovered plant remains, stone tools, metates, stone pipes, and stone bowls of Archaic design (Hard and Roney 1998). Corn and squash radiocarbon dates fall in the neighbowhood of 3000 B.P., indicating that these domesticated crops were present in Chihuahua during the Late Archaic period. The Proyecto Arqueol6gico Chihuahua has sweyed pre-ceramic sites around Laguna Bustillos that contain projectile points described as Archaic in Western Texas (MacW- et d. 1998). However, the provenience of these sites in active sand dunes leads to difficulties in location, excavation, and interpretation.

Archaeological research in west central Chihuahua for the ceramic time period has been more widespread than for earlier time periods. It is during this period that a major differentiation between central Chihuahua and the area around Casas Grandes takes place. After the Archaic period, the Casas Grandes River valley increases in complexity and exhibits many characteristics that are interesting to researchers. The suite of characteristics that is seen in and around the Casas Grandes River valley is referred to as the Chihuahuan Culture core area This core area is characterised by large room blocks, often multiple storeys, large scale public architecture, water control, trade in copper and shell artifacts, social stratification, and polychrome pottery. Some of these characteristics of the Chihuahuan Culture can be found in the northern regions of the west central Chihuahua project area, such as site layout, pottery and other arifacts, and architecture. However, characteristics of the Chihuahuan culture are not seen to the same extent in areas south of the Santa Maria and Santa Clam drainages. This forms a distinct boundary that the characteristics of the core area to not cross. In the Bustillos Basin, the archaeological record suggests that scattered small agridtural hamlets of shallow pit houses and small adobe houses existed during the period fiom 800 to 1200 AD, and have been termed La Cruz sites. This time period is contemporaneous with the Viejo Period @re-1200 AD) in the Chihuahuan Culture zone (Stewart et al. 2001). Why characteristics such as Casas Grandes polychrome pottery, public architecture, macaw and turkey breeding, large multi-storey adobe complm, and exotic trade items such as copper and ocean she& are not seen in areas to the south during the Viejo Period is an enticing area of study. At this point in time it appears that the Babicora Basin, the SamClara River valley and the Santa Maria River valley were not under the direct control of Casas Grandes and its outtying communities, however did share a widespread cultural pattern. This is shown by the presence of Medio period style architecture, possible macaw raising, and polychrome pottery closely related to pottery of the Casas Grandes drainage (Kelley and Vipando 1996, Meyet al. 1999b, Hendrickson 2001). During this later Medio Period (AD 1130/ 1200 to the early-to-late 1400s, Stewart et al. 2001), of the Chihuahuan Culture area, the Bustillos Basin seems to be depopulated. All radiocarbon dates from the Bus tillos Basin fall in the time range after about 1200 AD, except for three dates, two of which occur at a terraced hill site, and one in which context is not well understood.

The timing of the adoption of agricultural cultigens in central Chihuahua is still under investigation. It is generally accepted that the domesticated species and the associated technology difhsed fiom areas to the south, through central Mexico, and then to areas fhher north (Manglesdorf and Lister 1956, MacWilliarns et al. 1W8). From the dates acquired at Cerro Juanaquefia, it is apparent that corn and beans were both domesticated and being cultivated in areas to the north of Laguna Bustillos and the San ta Maria valley by 3000 BP (Hard and Roney 1998). Excavations at Swallow Cave turned up corn cobs in cultural layers that contained no pottery (Manglesdorfand Lister 1956). This suggests that corn was present here by the end of the Archaic as seen at Cerro Juanaqueiia. This would seem to indicate that domesticated corn reached west central Chihuahua at or near the late Archaic, around 2000 - 3000 BP. By the time the populations under study were inhabiting the Bustillos basin and the Sanm Maria valley, corn and beans were well established as agricultural products.

The Proyedo Arq~eologico& Chihuahua Dr. Jane H. Kelley and Dr. Joe D. Stewart conducted fieldwork under the Proyeao Archaeolbgico Chihuahua (PAC), 1990 - 2000. The main goals of this ongoing research project are to increase the understanding of the prehistoric cultures that existed in west central Chihuahua during the ceramic period, ca. 800 - 1450 AD. This includes outlining the chronology and the cultural sequences of the region, as welI as increasing the understanding of settlement diskbution, interaction patterns, and subsistence (Kelley et al. 1999a). Cultural evidence from west central Chihuahua is compared to and contmsted with cultures in neighbouring regions in order to understand the relationships among them. The main objective of the project is to understand west central Chihuahua as a distinctive area.

This project began in 1990 with a swey of the Bustillos region and the Sma Maria River valley, and later expanded to include the Babicora Basin, Santa Clara River Valley, Laguna Las Mexicanas Basin, and Laguna San MelBasin. Ten years later, over 200 sites have been sumeyed and recorded, and 25 of those have been tested or ewcavated (Kelley, personal communication).

Modem disturbance obscures sites and has led to destruction of sites. Modem agriculture is the main culprit. Ploughs tend to invade the earth 20 cm or deeper, which ia destroys the context of everything in the upper levels of these sites. Furthermore, agricultural activity tends to concd the actual location of the sites that have been located and identified by previous researchers. Pothunting of Medio period sites for grave goods and whole pots has been extremely destructive.

Lamma Bustillos Many ceramic period sites have been located on or near the shores of the lake, most representing communities practising some amount of agriculture, collecting a rang of wild plants and hunting local huna The ceramics from these sites are for the majority of plain design, with no decoration or with red paint on brownware. These sites are defmed as La Cruz sites.

Burials around Laguna Bustillos were not often encountered in excavation, due in part to excavation strategies and extent of excavation, as well as poor preservation and destruction. Sampling strategies of the project focus on structures and areas of occupation. If burials were located outside the habitation area or structure, they would not be encountered. Modem agricultural practices have disturbed or eliminated shallow burials, and the sandy soil and alternating wetting-drymg periods have probably contributed to the poor condition of shallowly buried remains. A 1998 excavation on the north side of the lake (Ch- 202) exposed a double burial removed fkom any sign of structures. Samples of this material were used in the stable isotope analysis for the determination of prehistoric diet. Two radiocarbon dates were obtained fkom (3-2022 sigma calibration range 860 - 1030 BP (lab code TO-7468,Stewart et al. 2001) and 990 - 1200 BP @b code TO-7603,Stewart et al. 2001.

During the Medio period, a time of heightened activity in northern Chihuahua regions, there is little evidence for any populations inhabiting the Bustillos Basin (Kelley et al. 1999b. Stewart et al. 2001). An exception is the cerro de tcincheras (Ch- 005) diswsed above which dated to a nvo sigrna calibrated range of 1400-1530 AD (lab code TO-7602 Stewart et al. 2001). These sites are terraced for agriculture, habitation, defence, or some other purpose. The specific purpose of this particular site was unclear from excavation and survey data. There are a number of explanations for this general lack of sites for this time period. Sites may exist and have not yet been located, however this possibility is doubtful. Perhaps the lake levels were different in the past and sites exist below the water line, however the lake is very shallow. Alternatively, populations in the Bustillos Basin may have reverted to a primarily hunter-gatherer lifestyle, therehre leaving no temporally diagnostic evidence of their occupation on the landscape. More likely, the area around Laguna Bustillos was abandoned bemeen ca. 1200 and ca. 1300 or later for reasons as yet unknown.

Santa Maria River Vallev

This valley lies to the no& of the Busollos Basin, and on the southern edge of the area recognised as belonging to the Chihuahuan Culture. Over 100 sites have been recorded, with nine excavated by PAC Viejo period sites are different kom the La Cruz culture sites in the Bustillos Basin. During the Medio Period, a number of sites in this region exhibit Medio period characteristics such as large room blocks, raised floor features, and T-shaped doorways. The largest of the Medio Period sites in the Santa Maria River valley is the Raspadura site (Ch-011). Some of the pueblo room blocks are more than one story, and Medio period characteristics include architecture and ceramics. There is, however, no known large-scale public architecture except for the presence of plazas. Other traits apparent at PaquirnC (Casas Grandes) that are not evident in the Santa Maria River valley Medio Period sites are the presence of exotic trade items, imported raw materials, ball courts and pla~ormmounds. The archaeological and archaeobotanicai evidence suggests that populations living in the Santa Maria River valley subsisted on a mixture of domesticated agricultural products, wild plants and hunted animals. The ceramic assemblage includes polychrome, bichrome, plain, and textured wares, sometimes with painting and texturing together on a single vessel.

Burials were recovered horn a site excavated in 1999 (Ch-254). Twelve radiocarbon dates were obtained fiom Ch-254 and ranged &om 1300 - 750 BP (taro sigma calibrated ranges, Stewart et al. 2001). The dates as well as the architecture and pottery suggest that this site lies transitional between the Viejo and Medio Periods (Stewart et al. 200 1). Three separate interments were exposed and analysed from this site. In two of these interments, the individuals were relatively well preserved and intact. The other burial was highly disturbed and contained scattered remains of three individuals. The long bones were &om a single individual, however the dental remains were from three individuals of differing (adulc juvenile, and infmt). The long bones of all three interments were sampled for isotopic analysis.

There are no discernible differences between the plant remains recovered kom sites in the Sanm Maria River valley and the Bustillos Basin (Adams 1992). In both areas, there is evidence for exploitation of riparian habitats as well as uplands and mid-slope communities. The presence of piiion, juniper, oak, and other high-elevation plants leads researchers to believe that resources from all ecological zones were exploited. If the subsistence strategy included the gathering of wild plant resources, the population of some communities would have travelled moderate distances in order to procure nuts and berries fiom the higher forests. Other sites are closer to hills and mountains, and would not have required long trips for procurement of wild resources. Agricultural products are present in all sites.

Although it is possible that some communities were trading for corn or beans, it is more likely &at most populations were engaged in agricultwai activities. Agriculture was either the major contributor of food or was used to supplement, to a larger or smaller degree, wild phtfoods. One diffefence that is quite apparent is the large amount of khtershell present in one site in the Santa Maria valley (Ch-254). Shovel tests that were done in off-site areas did not reveal any shell. The shell only occurs in habitation areas, and therefore leads researchers to believe that khwater shellfish were significant in the local diet. The following table lists sites that will be discussed in the following chapters. These sites are the sources for the samples used in the stable isotope analysis of faunal and human bone. Table dl: Sites impomant to research Time Period p Source of faunal bone and human bone samples Ch-112 Bustillos Basin La Cruz 770-1220 BP Source of faunal bone samples Ch-006 BustillosBasin LaCruz770-1220BP Source of faunal bone samples Ch-218 SantaMaria Viejo Period 990-1260 BP Source of faunal bone samples Ch-254 Sanm Maria Viejo Period 750-1300 BP Source of faunal and human bone Valley samples

Overall, the region under study exhibits some Archaic period population, however the density is not known due to the lack of identification of buried sites. Around Laguna Busdos and in the Santa Maria River valley, ceramic period settlements were small, composed of pithouses and small surface jacal structures, and located close to small streams or the lake itself (MacWhs et al. 1998). It is currently believed that these populations subsisted on wild plants, wild animals, and agricultural products such as corn and beans. The extent to which populations depended on agridhlral products or wild foods is the focus of this thesis, although is it apparent from previous work (Adams 1992) that the occupants udlised wild plant foods to some extent.

The extent of contact that occurred between Bustillos on the one hand, and the Santa Maria valley, the Santa Clara valley and the Casas Grandes valley on the other, is minimal. Data from obsidian geochemistry suggests that communities in each of the study areas in west central Chihuahua were not tradmg for this raw mated, but using locally available stone (Fralick et al. 1998). The differences between the Bustillos Basin and the Santa Macia River valley are quite interesting and extend back in time to the Viejo period at least (Kelley et al. 19Wb). These two locations offer the same opportunities in resources and environment to populations. The diets seem to be the same, although the extent to which either practised agriculture is unknown.

The sites situated in the Babkora Basin, the Upper Santa Maria River valley and the Santa Clara valley are thought to belong to the same cultural tradition as those located close to Casas Grandes, exhibiting features such as macaws, turkey burials, adobe room blocks and elaborately decorated pottery. This is identified as the Chihuahuan Culture. The sites in the Busallos Basin do not exhibit these features, however they share a similar subsistence strategy and plainware ceramics with the more northern sites. The environments biotic zones of the two regions are quite similar, however the moderate differences in drainage patterns, elevation, precipitation and temperature may be significant. There is no evidence for any of the areas having been under political control from Casas Grandes at any time. "The regionaiization of Chihuahua pottery assemblages, including the southern Chihuahua culture area, does not suggest strong economic centralization" (KeUey et al. 1999b:75). Chapter 5 - Prehistoric Diet in Chihuahua

In order for the ancient diet of groups living in Chihuahua to be understood, it is necessary to exploit many different forms of information. 'The most accurate and reliable information would come kom direct descendants of the groups who inhabited the area in the past. In west central Chihuahua, however, direct ethnographic analogy is not possible, as little is known of the few groups who lived in the basin and range environment at the time of European contact. Analogy can be made with groups in the nearby mountains to a iimited extent although technology and adaptational strategies of these mountain groups is different than those of any communities that would have lived in the valleys. The types of information that are accessible and informative to archaeologists come from a number of sources. These include macro bo tanical and microbo tanical remains, faunal remains, ethnohistorical Spanish sources, ethnographic accounts written earlier this century and in the late 19th century, and skeletal evidence such as paleopathology and stable isotope analysis. These sources are used to study the diet in Chihuahua over the last few thousand years. They will also be examined in an attempt to indicate how foodways may have affected, or been szffected by, other aspects of culture and adaptation.

Thc AmhaeoIbgrgrdEiahce for Pnktm'c DieXF

By 1958, it was known that the groups living in the Sierra Madre Occidentai of Chihuahua during the Archaic Period were cultivating corn (Lister 1960). However, many groups in Chihuahua and in other parts of northern Mexico never mydevoted their economy to the production of agricultural crops (Phillips 1989).

One of the most critical issues facing archaeobotanists and other researchers who attempt to interpret plant and animal remains is the representativeness of the assemblages. Patterns apparent in the archaeobotanical record can be due to real changes in the use of resources over time, or they can be constructs of natural and cultural processes that occur before burial, during burial, or during excavation and analysis (Schiffer 1987). Methodolom and Biasins Factors Possible natural and cultural processes that may influence the information recovered include prehistoric manipulation, preservation, deposition in to the archaeological record, sampling, recove y, and analysis (Johannessen 1988, Begler and Keatinge 1979, Schiffer 2987, Sutton 1994). These individual processes will be discussed so that possible biases can be recognised, should they occur.

It is a well-known fact that certain plants and plant parts are preserved more often and more completely than others. This has to do with the morphology and composition of the remains (Gustafsson 2000), but also how they entered the archaeological record when prepared and discarded by the consumers. Behavioural characteristics of the groups involved can have important effects on what is recovered in archaeological contexts. Those resources that were habitually charred during preparation have an increased probability of being preserved in middens or other archaeological deposits. Those resources that were pre- processed in the fields or in the areas where they grew wild may lose some of the easily preserved portions in regions fiu horn the settlement This would apply to Faunal as well as bo tanicd resources.

Observed changes through time could possibly be due to changes in behaviour and processing, and may not necessarily indicate a new resource. For example, an inaease in a particular resource represented in a site may be due to a change from eating the resource raw to charring or otherwise preparing the resource (Johannessen 1988). nischange would introduce more of the plant into the archaeological record even though the amount of maize eaten before and after this shift in behaviout was unchanged. Interpretation of this situation could lead to implications in other aspects of the culture such as land use and mobility. However, if a change in overall strategy occurred, there would be other lines of evidence exemplifying intensive agriculture such as artifact composition, the presence of storage bins, grinding stones and sedentism. Each of these on their own do not present conclusive evidence for agriculture, however taken with paieobotanical remains and other lines of evidence they will indicate either a change in subsistence strategy or a shift in processing behaviour.

Differential preservation is most ofien due to processes that occur afier deposition. The small bones of animals and the tkqqle portions of p~antswill decompose more readily than other parts. This is considered one of the major obstacles in the accurate interpretation of plant and animal remains (Popper and Hastorf 1988). These types of concerns relate mainly to stuhes in which the relative proportions of certain resources in the prehistoric diet are under scrutiny, but also will dfect those using presence/absence techniques. The problem of differential preservation is counter-acted by at least some of the material, be it macro- or microbotanical remains, being preserved in an area of the archaeological site. This d indicate that the animal or plant species was in fact present to some extent- The archaeologists must also keep in mind potential differences in preservation within the region, site, and feature. If one area under study is drier than another is, more plant remains may be preserved. This may lead to a biased interpretation of an increased variety of resources exploited when compared with moister sites where the preservation is poor (johannessen 1988).

Differential preservation may in fact be due to the mode of abandonment by the prehistoric group. A study by Hally (1981) considered non-cultural faaors that may have formed the patterns obseroed in the archaeobotanical record. These patterns could have been the result of changes in subsistence over he. However, the researchers ded other possibilities such as the excavation procedures, the duration of occupancy of the structure, the hction ofthe structure, the nature of abandonmen~and the season of abandonment- Three structures were excavated, two ofwhich were burned and one that was simply abandoned. Significant differences existed between the remains in the unburned structure and the remains in the burned structures. The remains in the burned structures were more varied and complete. The unburned structure contained only those resources that were prepared in a way that enhanced presemtion (i.e. chamins). Differences between these three structures were due to differences in the mode of abandonment and not temporal or cultural differences. This led the researcher to conclude that it is important to identifj the method of abandonment, the season of abandonment, and the method of preparation of the major food resources. Questions such as which foods were charred and which were eaten without significant preparation become important in most archaeobotanical studies (Hally 1991;.

It must also be kept under consideration that not everything recovered was eaten as food, and not everything included in the prehistoric diet will be recovered Q3egler and Keatinge 1979). Artifacts such as grinding stones and other indications can aid in the interpretation. For example, agave consumption could be indicated by agave roasting pits even if no remains of agave are recovered.

During sampling, recovery, and analysis the researcher has the potenbal to contribute to the skewing of results. Sampling and recovery of paleobotanical samples should be consistent and in proportion to the material excavated, with attention being paid of course to the time and money required for analysis. For example, if samples are only removed from storage areas, potential food sources such as some wild plants that may not have been stored would be neglected. The picwe of prehistoric diet, therefore, would not be complete. In this case, it would be wise to sample areas thought to be storage as well as those thought to represent preparing and cooking, and refuse dumps.

Archaeolo@calEvidence for Prehistoric Diet in Chihuahua Botanical The general picture from the archaeological evidence is of a diet consisting of a mixture of some gathered wild plants and animals as well as cultivated resources. There have been fear studies exclusively on the ancient diet of prehistoric groups in Chihuahua. However, recent studies have tended to include paleobotanical analysis and conclusions re-ding diet. It is also possible to extrapolate fiom results acquired in other parts of Chihuahua and, to a lesser extent, Sonora and American border states. Studies of paleobotanical remains from the United States are less applicable in this situation but are usefd in that they represent fbrther evidence of varied and mixed diets. Such studies have been conducted by Adams (1980), Bohrer (1791), Gasser and Kwiatkowski (199l), mats son and Chisholm (1991), and Minnis (1982).

Agriculture was introduced into Chihuahua hmmore southerly areas O t Mexico during the Archaic. The timing and exact route of this procas is sdbeing inves tigated (MacWrrlliams et. al. 1998). More research is needed on sites that represent the transition to agriculture. Knowledge of the proportion of meat to vegetables and the wild resources that were exploited before agriculture as compared to those exploited alongçide cdtivation would contribute greatly to the understanding of the aspects of diet and culture that underwent change and those that remained constant.

An early site recently excavated in Chihuahua is Cerro Juanaquefia, which has been dated to 3000 BP (Hard and Roney 1W8). Cultivated maize was recovered as welI as a variety of wild species including gourds, chia, Chmopodum-Amanntth, plains lovegraçs, other grasses, milk vetch, bulush, and globe mallow (see Table 5-1 for a summary of ail sites discussed) . The Amaranth shows signs of being a domesticated variety. There is no evidence that shows unequivocally that these wiid species were consumed, however the authors suggest that the gound Stone artifact assemblage indicates that it is highly likely that wild seeds were processed. The îisted species are potentiai contributors to the diet.

Once agriculture became established, somehme before 3000 B.P., groups cultivated rnaize, bans, and squash. This is evident fiom rnany sites in Chihuahua and surrounding areas, and has been well docurnented in the Arnerican Southwest. The remains €rom Paquimé are more direcdy applicable to this discussion than those kom sites in Arizona and New Mexico because the site is located in the region of interest. Corn was the only species recovered fiorn Viejo contexts at Paqu.uk. Corn remains were also the most abundant plant remains, in the Medio Petiod (72% of al1 plant remains found) (Di Peso et al. 1974). Other cultivated material included squash (23O/0) and Cotton. Non-cultivated remains were not abundant, and made up only 4.8% of the remains. The species that were recovered include psseed, agave, hackberry, piiion, purslane, mesquite, walnut, saltbush, and Chenopock'um (Di Peso et al. 1974) (see Table 5-1). The populations living at Paquimé were subsistence farmers, and likely spent little time collecting wild plants. Wlth the esception of walnut and piiion, the uncultivated species found in the -Media deposits at Paquimi represent species that can be found in disturbed contexts around fields and settlement areas. The large populations living in this settlement would have required intensive agriculture to sumive. The intensity of the agriculture is also apparent fiom the large network of irrigation canals seen around Paquimi and in the nearby mountains (Di Peso et al. 1974).

The mountains in the western region of Chihuahua contain numerous caves, some of which have preserved remains including mats, blankets, and cultivated and gathered plants &om burial contexts- Waterfall Cave (Ascher and Clune 1960, Cutler 1960) is one such cave, located in the Sierra Madre Occidental in Western Chihuahua From the excavations it is apparent that at around AD 1000, people in this region were cultivating corn, beans, and squash, as we1 as eating gathered plants such as yucca, cactus, and certain small seeds (see Table 5-1). Animal bones also were found, and identified to tortoise and small mammal. Presumably these animals contributed to the diet.

Another cave in the Rio Zape region, Durango, dating to AD 660 contained similar rernains (Brooks et al. 1%2). However this cave yielded a broader range of remains including acorns, piiion nuts, juniper bemes, black walnuts, cactus fruits and pads, yucca, and wild seeds (see Table 5-1). The authors state that the diet was based primady on the cultivated resources based on the btge numbers of corn, beans, and squash compared to the amount of wild species. The data presented by the authors does indeed suggest that the majority of the plant remains were from cultivated species, however they do not discuss possible biasing factors such as preparation methods that may cause increased preservation in some species. It is likely that corn, beans, and squash did represent the majority of the resources consumed, however it is also likely that the other components of the diet are not adequately represented in their sample.

Epez (1992) examined a number of caves in the region of Cuarenta Casas and Valle de las Cuevas for archaeobotanical evidence. In addition to the wild and cultivated plants listed above, L6pez includes amaranth, manzanilla, hickory nuts and purslane as contributors to the diet of the mountain population (see Table 5-1).

The excavations by PAC involved paleobotanical analysis by Dr. Karen A. Adams. She identified edible Fragments of the following species; maize, beans, squash, chenopodum, amaranthus, juniper bemes, grass, walnut, groundcherry, and purslane (see Table 5-1). These remains came from a number of sites in the Babicora Basin, the Santa Maria River valley, and the BustiUos Basin. The presence of corn cobs used as fuel indicates that the fields were Likely close by the settlement (Adams 1992).

Tabk 5-1. Summary of the Sites and Plant Remains Discussed.

E 4) 9 'P P *= 3 u 5 o a C ItaspegE Site Coma e~=g~$g-~=e~~~gg eamao,w3 cst~~ee, la& Cerro terraced c w cw Juanaquena site w 3000 BP' Paquimg bd c c c WWW w w www Medio period2 habitation midden Waterfill Cave burial ccc w W W AD 1000' Rio Zape Cave, burial, ccc www w w Dutango AD midden 660' Valle de las cavesites c c c w wwwww w Cuevas5 SW Texas coprolites w f f I f f w 800 BC - w w AD5006 PAC sites7 habitation c c c w w www w c=cuItivated, w=wild, f=flowers @ofla) 1: Hard and Roaey 1998; 2: Di Peso et al. 1974; 3: Ascher and Clune 1960, Cutler 1960; 4: Brooks et al. 2962; 5: Ln*z 1992; 6: Bryant 1974, Minnis 1989; 7: Adams 1992

A more direct source of information regarding diet is coprolite analysis. The taphonornic problems associated with the study of paleobotanical remains still exist in coprolite study, however the nature of the specimen causes some of the factors to be less of a concern in this type of research. The locations where coprolites are found are typically dry. The preservation of the coprolites is a good indication that preservation of varying plant parts will be relatively good in these cases, and therefore the proportion of actual plants eaten that are presemed will be high. In addition, researchers know without a doubt that the paleobotanical remains found in coprolites were eaten. However, it is not definite that the resources were important in daily consumption. Other possibilities include medicinal and ritual use. If certain species have a high ubiquity among many samples, it can be stated with relative confidence that they were consumed as food on a kequent basis, and therefore contribute to the diet. However, biasing factors related to coprolite anaiysis do exist. Most coprolite remains come from cave or rockshelter settings, which have not been proven to represent year-round settlement. It is possible that only a portion of the yearly diet is represented by the paleobotanical assemblage (Minnis 1989). Another problem related to other paleobotanical studies is the differential surpival of less hardy plant parts. Although kagde remains would survive in cave coprolite contexts more readily than other archaeological contexts, there will still be a higher percentage of the hard remains such as seeds than sofker vegetable matter preserved (bhnis 1989).

Many studies have been done in the United States that extract botanical remains fkom coprolites in an effort to determine paleodiet (e.g. Bryant 1974, Minnis 1989). Pollen analysis of coprolites can give results that other macrobotanical analysis can not give. Byant completed a study in Southwestern Terns. Pollen analysis of the coprolites led Bryant to the conclusion that many flower species contributed to the prehistoric diet of the area including flowers from yucca, agave, mesquite, and sot01 (Bryant 1974). These species produce pollen that is transported by animals (zoophilic), and therefore it is likely not ingested in large quantities by chance alone. This is a very important study due to the low probability of flower parts being preserved in any archaeological contact. Pollen analysis of coprolites is likely the only method that is able to detect this portion of the diet. southwestern Indians considered flowers of agave and cactus both a delicacy and an important component of the diet (Bryant 1974). Macrobotanical remains indicate that the flesh and hits of cactus, agave, onion, and Chenopork'um q.were also consumed (see Table 5-1). .%n interesting characteristic of the data set is the lack of cultivated plant remains. Fauna Archaeobotanical remains are the centre point of most paleodietary studies due to the interest in cultivated resources and the changes that accompany a shifi to an agricultural subsistence strategy. However, the portion of the diet that results fiom the evploitation of animals is an important aspect. El Zurdo (Ch 159), =cavated by the PAC, is one ofthe few archaeological sites in Chihuahua that has had extensive repomng on the faunal analysis (Hodgem 1996). It is located in the northwestern region of the Babicora Basin. Dates from the site suggest that the settlement was occupied sometime between AD 600 - 1400. The identified tam horn this site contain a large percentage of turkey including five burials (13.6 % OF the total identified remains or 6.8% when the burials are excluded). The presence of turkey burials suggests that this species was likely domesticated. The next most common taxa represented at El Zurdo is jackrabbit (10.8Oh). Large birds make up a significant portion of the assemblage, accounting for 9.4S0/o of the identified bones. Also present are fish, frogs, reptiles, a large variety of birds, rabbits, a varietg of small mammals and rodents, canids, bear, weasels, mountain lion, and deer. Hodgetts concludes that the majority of hunting probably took place around the fields and therefore the assemblage includes many species attracted to cultivated fields and gardens (Hodgetts 1996).

Pa+& produced many faunal remains, which were particularly assorted, fiom birds and hhto mammals, and reptiles for a total of close to 1000 'minimum faunal count' (Di Peso et al. 1974:8:242), which is equivalent to NISP (or number of identified specimens). No report was made on the suspected ratio of faunal to floral resources exploited, but it is believed that during the Medio Period the emphasis was on cultivated plant remains and not resources that were hunted or gathered.

The sites discussed here include a wide variety of remains, from pollen to fauna, and range from the Archaic to Di Peso's Medio Period (Di Peso et al. 1974). In all studies surveyed there is evidence for the exploitation of a wide range of wild plants and animals as well as agricultural products. From this brief summary of archaeological evidence, it is apparent that gathered resources never lost their importance to the overall diet in prehistoric Chihuahua

Ethnogaphic evidence is very useful to studies of prehistoric diet if a direct link can be established between the group under study and the modem populations living in the area. At the time of contact, there were few native groups inhabiting the lowland valleys and basins around Laguna Bustillos or the Santa Maria valley. There are no accounts of the dietary habits of any direct descendano; from the study time period in this gwgraphical region. In early historic times as well as today, traditional soups live in the Sierra to the west of the basin and range regions. Although the direct ancestry of these populations is unknown, ethnographic studies of these groups can contribute to the understanding of prehistoric diet in central Chihuahua by allowing researchers to understand which resources were used and in what context. Knowledge of food preparation techniques is also usefd to archaeologists. This allows researchers to consider the possible consequences that the method of preparation 62. charrinpj may have on the preservation, deposition, and recovery of certain species in certain locations (Johannessen 1988).

As in all subdisciplines used to aid in archaeological interpretation, problems may arise if ethnographic information is applied directly to archaeological pro blerns. Srgnrficant changes can occur between the deposition of archaeological material and ethnographers observations, even if the groups are directly related. -r differences can exist if there have been changes within the culture itself. Environmend change is one of many factors that can have large ramifications to ethnogaphic analogy in archaeological contexts. If shifts have occurred in the plant community composition then it can not be assumed that the same resources were available for exploitation in the past as in the present. Other changes can cause variability in resource availability or existence such as the introduction of other crops, urbanisation, and over-grazing (Bohrer 1975). MacWrlliams and colleagues (1998) noted that for particular periods in time, there has been a continuity between the mountain and the basin populations based on "(m)aterial culture, architecture, burials, subsistence, and contempomeity" (Ma~\~lliamset al. 1998: 10). Since these groups were seemingly related during certain periods in the pas& the information gathered on the diet of the extant mountain groups should be applicable to the diet of prehistoric basin and range communities. This of course must be done with caution and does not allow generahations regarding particular groups, however certain observations regarding the species exploited and common preparation techniques from ethnographic research are usefid.

The Mountain Pirna and Tarahumara are groups that practice a combination of agriculture and gathering of wild plants. These two groups would be most closely related to any populations that may have lived in the Chihuahuan grasslands or mountain ranges in prehistoric times. Many studes have been done on the ethnography of these groups (Bennett and Zingg 1976, Laferriere and Van Asdall 1992, Pennington 1963).

Laferriere, Weber, and Kohlhepp (1991) described the use of wild plants by the Mountain PkSix species of prickly pear cactus, cholla, agave, rnanzanilla, madroiio, yucca, amaranth, chenopods, roots, and onion are among those most commonly consumed by the Mountain Pima and can also be found to some extent in the basin areas. For other populations, the proportion of ddplants to cultivated plants exploited would depend on the resources available in the local area, as well as individual group preferences and haditions- In prehistoric populations, the proportion of wild to cultivated resources likely varied greatly depending on the goup, region, and point in time (Lafemere et. al. 1991).

Important research is also done on the way certain groups use specific resources. An understanding of specific plants or plant groups can contribute a great deal to the overall picture of a population's adaptive strategy. For example, wild grasses are seldom thought to be a major contributor to the diet, especially for agricultural groups. However, their ubiquity and relative dependability over drier or moister growing seasons made grass seed an important addition to the die\ or a substitute in years of crop fdure. Ethnographic surveys of the American Southwest indicate many important grass species that were widely used by many groups (Doebley 1984).

Another informative study was done on a sub-set of grasses called cool-season grasses. These species mature early in the summer before crops or other wild stands mature, which makes them a particularly important resource for hunter-gatherer groups as well as agricultural populations. Information regarding the use of cool-season grasses was obtained in a study of extant populations in the American Southwest (Bohrer 1975). Included in this analysis of cool-season grasses is a survey of archaeological sites containing evidence for the exploitation of grasses maturing before the regular harvest. Domesticated animals have also benefited ftom these resources, which has led to a serious decrease in the modem extent of the native cool-season grasses. Recent attempts at limiting cattle and sheep access into grasslands during seeding periods has Ied to a recent increase, however the modem extent of these grasses should not be used for determining their possible use in the past (E3ohrer 1975). Cool-season grasses such as Indian rice grass (Oywxh hymnroi&~)grow in west central Chihuahua and were undoubtedly exploited where possible.

Another important component of the diet world-wide is insects (Defoliart 1995, Ruddle 1973). Ethnographical evidence from Mexico as well as other regions of the world becomes pertinent in this case. It provides background for the type of insects eaten as well as the carbon and nitrogen stable isotope values of certain species. Research kom western Chihuahua among the Tarahumara suggest that insects such as lowts, grasshoppers, water beetles, and larvae (Hr&cka 1908) were consumed. However, insects were not thought to be important to the diet of American Southwestern or Northern Mexican goups (Bodenheimer 1951).

Insects are nutritious. Fat and protein contents are high, and most species are easily acquired. De Conconi and colleagues (1984) documented 101 species of edible insects and tested the protein content of 77 species across Mexico, induding dragonflies, grasshoppers, lice, water bug, cicadas, beedes, butterflies and moths, flies, ants, bees, and wasps. The percentage of protein varied from 10°/' to a high of over 81% for a species of wasp. As supplements to the diet or as staples, insects provide essential amino acids and large amounts of calories to populations who collect and consume them (Rarnos-Elorduy et al. 1997).

Ethnographic analysis of the diet of extant groups provides an immeasurable resource in inferring the diet of prehistoric communities. Care must be taken, however, as analogies can have serious complications such as differences in culture, environment, and a multitude of other changes that occurred throughout history and prehistory.

Very few skeletal analyses relating to diet have been carried out in Chihuahua The collection from Paquimi represents the largest sample, with over 500 excavated burials (Di Peso 1974). Potentially, studies of this collection can reveal much on prehistoric diet in Chihuahua- However, no studies employing stable isotope analysis have been attempted with the Paw6skeletal remains. Any hture information that could be extracted from this population would greatly enhance our knowledge of ancient diet and life in Northwestern Mexico.

Katzenberg and Kelley (1991) analysed human bone from seven sites in south- eastern New Mexico. The stable isotope ecology of the region was also established by analysing the carbon and nitrogen isotope values for archaeological fauna, charred archaeobotanical remains, and modem botanical samples. A number of C3 and C4 plants were analysed as well as animals that consume C3 and C4 plants. Comparisons between the human bone stable isotope signatures and the plant and animal data indicate that the prehistoric diet was likely composed of C4 plants and C4 plant consumers. This was evidenced by 6"~values of collagen ranging from -6.7 to -8.4% and 615Nvalues ranging from 9.7 to 12Ym (Katzenberg and Kelley 1991). The value of studying the stable isotope ratios of plants and animals in the region of the archaeological site is immense. The recognition of the need of the base ecological data before making conclusions regarding diet and agricultural dependence is becoming more widespread. Burials were found at the El Zurdo site in Chihuahua. Hodgetts (1996), as well as performing the faunal analysis, completed a stable isotope analysis of the human skeletal remains found at W Zurdo. One burial including an adult male and an adult female was excavated and analysed for bone carbon stable isotopes. Hodgem reports a 6% value of - 7.2 % for the male and -7.1 960 for the female skeleton. These numbers indicate a diet reliant on C4 plants for protein, or alternatively on animals feeding on C4 plants, such as grazers and jackrabbits. In the relatively cool upland region of El Zurdo in the Babicora Basin there were not a large nmber ofwild C4 plants, and the low number of faunal remains in proportion to the area excavated indicates that the animal portion of the diet was Likely small (Hodgetts 1996). The excavation turned up large quantities of maize, and this as well as the other considerations lead researchers to believe that the C4 signature of the bones likely came fiom maize consumption and not from wild C4 species or fiom animals consuming maize or wild C4 species.

Other studies of stable isotope signatures of prehistoric human bone have been carried out in the American Southwesf however they are of little relevance to this study. W~thstable isotope analysis, the opportunity for precision is greater than with other methods of interpreting diet Comparing regions that are chamcterised by differences in environmental aspects and types of plant and animal resources d not give useful results.

In order to attempt to interpret human adaptation and cultural aspects, other areas of archaeology and lines of evidence must be incorporated into the diet analysis. One such study by Hard and cotleagues (1996) integrates artifaq skeletal and archawbotanical analysis for a complete picture of diet. From such a comprehensive study, one can begin to attempt to understand the overall method of adaptation by prehistoric groups. In six regions of the American Southwest ranging fiom Black Mesa to Southwestern Texas, Hard and colleagues provide convincing evidence for the use of rnano size, carbon isotope analysis, and paleobotanica! remains in order to study agricultural intensity. A usehl expression of paleobotanical remains is used: the ratio ofC4 to C3 wild plant species recovered by flotation. This is useful when interpreting the stable isotope data- The groups with a higher reliance on agricultural products can be interpreted as exhibiting different social and political organisation than those with a mixed reliance on agriculture and gathering.

One area Hard and his colleagues studied was the Southern Jomada area in Southwest Te~as.This area is chatacterised by Chihuahuan desert and is applicable to this research paper due to the dry and hot conditions. The Archaic period is composed of the pre-maize era and the era after maize adoption. The pre-maize phase exhibits a human bone carbon isotope value reflecting some C4 plant consumption, however the high percentage of wild C4 plants in the flotation sample could indicate that the population was consuming wild gathered plants and not a significant portion of maize. Significant increases in carbon isotope values, maize remains, and mano area around 1100 AD (Doiia Ana Phase) make this a region that began to rely heavily (but not solely) on maize rather late in prehistory (Hard et al. 1996). Maize cultivation never reaches the large proportions in this region as it does in the other areas studied, and therefore it can be stated that other gathered resources were always of importance for prehistoric populations in Southern Jomada. If this kind of information is applicable to the Chihuahuan populations, then it can be inferred that large changes to social organisation did not occur until relatively late compared with other groups in the American Southwest. It should be no surprise to find that both the ethnographic data and the archaeological remains suggest a varied diet of gathered and cultmated resources throughout history and prehisto y.

The excavations at Cerro Juanaqueiia (Hard and Roney 1998) are another example of a study that integrates many lines of evidence. The inferences that are made regarding adaptation are important in that they call into question the traditional view of Archaic Chihuahuan populations of hunter-gatherers and ernphasise the real possibility of extensive communities subsisting on cultivated and gathered plant resources. The extent of the terracing and the assemblage of artihcts suggest a complex organisation responsible for large public infrastructure and a relatively large population (Hard and Roney 1998). The potential biasing factors related to excavation, analysis, and interpretation of paleobotanicd and faunal remains are of crucial importance. Defining the cultural contexts of the excavated remains will diminish some of the force of these factors, as will special attention to the problems with quantification (Hard et. al. 1996, Johannessen 1988, Popper and Hastorf 1988). Future research into biasing factors and explicit mention of special techniques or methods used to avoid these problems is critical.

Stable isotope analysis can contribute much to the knowledge of the relative proportions of maize and meat in the prehistoric diet. In the hture, research in prehistoric Chihuahua would benefit kom additional studies directed towards a more involved understanding of the dietary components; gathered, hunted, and grown. Simple stable isotope analysis, however, is not sufficient. Research must be done on the plants that are found naturally in the area, as well as the evidence for exploited resources in archaeological context. Ecological reconstructions that include a stable isotope analysis are insightful and are necessary when hterpreting the results of stable isotope signatures of human bone. If the mode of photosynthesis of the surrounding plants, the paleobotanical remains, and the ethnographically documented foods is determined, possible resulting stable isotope signatures of individuals eating particular combinations of foods may be determined.

Studies that integrate many different types of analysis are the most appropriate for infuring prehistoric human adaptation. Of these analyses, dietary reconstruction is a critical aspect that must be included. For accurate dietary research, it is necessary to consult archaeological, ethnographic, and skeletal sources of information.

In Chihuahua it is apparent from these lines of evidence that prehistoric groups practised agriculture and collected a wide variety of wild resources (see Table 5-1). The actual timing of adoption of agriculture tends to vary from region to region. As seen in the evidence from Cerro Juanaqueiia, northern Chihuahua likely had maize cultivation technology before or near 3000 B.P. Chihuahua, composed of valley grasslands and mountain ranges, was not a hospitable environment for dependence on wide-scale agri~~ltureor on wdd resources alone. In order to exist in Chihuahua, prehistoric groups adapted to the situation and exploited many resources for subsistence. Apcultural crops such as maize, beans, and squash likely provided the volume of food necessary to maintain relatively large populations. Certain wild resources supplemented the diet in quantity and in nutritional quality and also provided food during periods when the cultivated crops were not yet available (Bohrer 1975). By seeking evidence of prehistoric die&researchers can understand the adaptive strategies and coping mechanisms of past populations. Chapter 6 - Materials The materials used for this research include samples of plants, animal bone, and human bone that were collected for stable isotope analysis during the 1998 and 1999 field seasons in Chihuahua, Mexico. The plant samples were collected by myself from the modem landscape (Fosberg 1960). The animal and human bone samples were collected kom archaeological deposits alone. Archaeological animal bone was collected and sampled in place of modem animal remains due to the possibility of modem contaminants to nitrogen and carbon isotope values in modem bone. These contaminants include pulp and paper mill effluent, agricultural fkrtilisers, and modem corn hybrids. Faunal bone was relatively abundant in the sites, and its presence usually indicates the species' inclusion in the prehistoric diet. While there is a risk of modern contaminants in the plant samples, it was considered preferable to using archaeobotanical remains. The sample of archaeobotanical plant mains is small and does not cover the numerous edible wild plants available in the region. Therefore, modern plants were collected and sampIed.

Plant samples were collected on the basis ofa number of factors. Brown's (1982) list of plant species growing in the appropriate ecological zones (Plains Grassland, Madrean Evergreen Woodknd, and Montane Conifa Forest) was thought to represent the majority of plant species that may have been available to prehistoric populations. Considering that the composition of communities may have been diffetent in the past (Van Devender and Bradley 1990), it is impossible to know the exact species that were present and available to prehistoric peoples living in the region. However, as was noted in Chapter 3, there is evidence to suggest that modem plant communities were established thousands of years ago and the species present on today's landscape likely were present during the time period under study (Van Devender 1990).

Not all of the plants included in Brown's (1982) lists are edible. Those plants that are toxic or are othenwise inedible do not represent conmbutors to the prehistoric diet. A number of sources were consulted to document the species present in the ecological zones that are edible (Altschui 1973, Ebeling 1986, Facciola 2990, Kirk 1970, Usher 1974, WmHer 1982). Edible plants were sought out during field collection trips. Ail edible species were not encountered on these collection trips, likely due to seasonality and/or environmental attributes that were not optirnal to certain plants in the microenvironment. Those plants that were the main staples of the prehistoric diet will be the ones that have the greatest effect on the bone stable isotope signature, and therefore plants of minor importance and minor usage will not be included in this study. The wild plants that are used as medicines, teas, condiments and spices are not considered, and the emphasis lay on those plants that more likely contributed to the diet.

The best evidence for the utilisation of certain species by prehistoric populations is their presence in archaeological contexts in PAC sites. These species were known to have been used by prehistoric populations, however there is little evidence to confirm whether these species were consumed or were used for other purposes such as he1 or construction. Other evidence is used to decide whether the plant part was eaten, such as the edibility of certain plant puts, and the context in which the plants were discovered. Species represented by charcoal or posts are not considered as dietary items. Bemes and seeds that are associated with these species are more difficult to analyse For example, there is a possibiliq that juniper berries were eaten, howwer the large amount of juniper charcoal present suggests the likelihood that the bemes became established in the archaeological record along with the wood and do not represent a dietary item. Other species are more straight forward. The presence of maize kernels, beans, seeds of Chenopodiurn and Amaranth are more likely to have been present in site deposits due to consumption. These species and others represent dear evidence of dietary items. Species that were clearly eaten and those that may or may not have been eaten were both collected for analysis.

The part of the plant that is considered edible or was located in archaeological contexts was the primary goal for collection. Seeds, nuts, green leaves, roots, and flowers were collected fiom various plants. In some cases, more than one part of the plant is edible, in which case all useful parts were collected. In other cases, the most useful part was not available at the time of the project due to such factors as seasonality. In these instances, other pam of the plant were collected, such as substituting leaves for seeds, or unripe fruit for ripe hut. In analysing these samples, it is with the undeistanding that the isotopic values may not be entirely representative of the consumed part of the plant. There is risk involved in substituting plant parts for others due to the possibility of differences within the plant itself due to panslocation of elements (Yoneyarna et al. 1998) and variations in plant biochemicals throughout the plant pieszen 1991). These differences have been reported as 0.7%0in regards to leaves differing from other plant parts (Hubick et al. 1986), however can be much higher or lower in the case of plant biochemicals viesten 1991).

Table 6-1 lists the species that were collected during the summers of 1998 and 1999. Some of these species are not in-ous to the aceq however these were included in the study with the native species. The non-indigenous species are marked with an asterisk.

Tabk 6-1. CoIkctcd Pbm Smpl# Tuu Podion(s) Place Collected -n Date (-1 MCB 01 Cb~cufaiw'8pihfk?h 0kit tot^ plant, see& MOW Merr)rs OSCW 1880 31105/1999 s&p. Glaka (Woot & Stand.) Delting

MC6 02 bSaIdN'8 (w- Britton NwdOstarSdo 1910 07E0611999 arh#l. Glah(Woot 8 Stand.) Delting Maynee wB03 Skynbn'um lrid Plant ~SofoMaynee1880 31m1999 MCB 04 Mdka ne- Wdroth plant,?pnnrk OSCBfSdO~1880 3110511999 MCB 05 Altemanthere camasma Kunth @ant NWof OscarSoto 1910 0710611999 Maynez MCB 06 Lotus pMus (Bmdeoee) Bameby plant, beans NW of Oscar Soto 1890 07106/1999 Maynez MCB 07 Theleqmma nqppobrnkurn Plant NWofOscarSoto 1890 0710611999 (Spreng.) 0.Klmlze Mgcner MCB 08 Desmmth OOdeyi (Eaton) Tdease plant, beans W d Oscar Soto 1890 1 OW1999 Maynez, road to cm Table 6-1 (cont'd) SmplW Taxa Portion(s) Place Cdleded Elevrtion Date (=I) MCB 09 Amaranthus pslmeri S-Watson piant, seeds NW of Oscar Soto 1910 07199 Maynez MCB 10 ChamaedaSOrdida (Dun.) A Gray plant, hit NW of Oscar Soto 1910 0710611999 Maw MCB 1 1 Sdanum eleagnilblium Cav. ' plant, fruit EofOsmrSoto 1880 10106/1999 Maw MCB 12 Gapstis cunuIa (Schrad.) Nees. var. plant, seeds NW of Oscar Sob 1910 07W1999 cuWa MaYner MCB 13 Muhlenb8@8 rigitfa (H.B. K.) Trinius pht EofOscarSoto 1880 07/06/1999 Mm MCB 14 Sorghum ha/- (L)h.' plant, seeds Motel Meny's Oscar 1880 13Kl711999 Soto Maynez MCB 15 S~us~8s planfd EofOScarSdo 1880 06CO711999 Maw MCB 16 [email protected].? Wheelen' S-Watxnex flauver, stalk, La Rsspadura 2080 07113611999 RouUUck leaves MCB 17 Agam Engelm. leaf, stalk La Raspadrra 2040 07Ml1999 MCB 18 Agampmyi Engelm. stalkikmm lndeperrdencia 2080 06(0711999 MC8 19 Yucca elate Engelm. ~,~ cUtMlmc 1980 04RW1989 11990 107'06n999 I I I I I MCB 21 lM8mmiW gu- Engelrn. 1-m pdapmw& ~2080 ~06EO711999 MCB 22 Cucu~~~issime fruit E d Oscar Soto 1880 07106/1999 MaVnez MCB 23 Apodanhm undulete AGray plant, fruit LaRaspadwasite 1940 06n)711999 (a11) Table 6-1 (cont'd) Smplt Taxa Portion(s) Place Collected

Mc8 28 CUCUM~-ma seeds CUitlahua~

I I i MCB 31 1Arm lnuts fO!w Soto Maynez I I 1 MC8 32 1Rhus mmdica Aiton var. ? anisqhylIalpfant, bem's 1I- (Greenel MCB 33 ha- mlis (H-B.K-) Lag. ex plant, seeds NW of Oscar Soto

I I I MCB 34 1Cucurbita fbefedissima [seeds IOaer Faias L MCB 35 CalIiandm humilk Bath. var. humilis plant, beans NW of Oscar Soto I MaVnez MCB 36 Oemfkahsvardii S.Watscm plant, lesves Ch 254 I I MCB 37 IAminnlhus sp. Iplant, seeds Ch 253 SE of Oscar

I I MCB 40 1chempdiun kfbdieti Moq I-, seeds ICh 253 SE ~f

MCB 41 ChqWurn6edmIM Moq. mm Ch253SEQIOsCBC ---- WMaynez MCB 42 &utebuahimtalag. plant, pannides SE d Oscar Soto Maw

I 1 1 I~c844AlCWmse- om. laculls (vista Hemo6a,Bust I 1 I MCWBlOuelicus enwyi Tom. lacom- lvista Hm, lyghlised Bust MCB 45 Porb(scs~L Pmseeds wsOscar Sdo Maynez Table 6-1 (cont'd) Smpl# Taxa Portion(s) Place Cdlected Elevation Date (MI) MCB 46 Opuntia englemani Salm-Dyck ex. pad, tuna Independencia 2080 1510711999 Engdm. var.? MCB 47 Chenopodium bedandied Moq. plant Oscar Soto Map1900 15107f 1999

I 1 I I Crotwr ~8IiliomicaMuell and Arg. pant l~sta~enosa,~u~r~2OOO 1 20iO711999 I 1 Amamnthus sp. lplant IVista ~emasa.Bust 1 1970 I 1 I Zea maize Ik~mels loscarSotoMsynez11880" 121/07/1999 izm Vi8nimica Engelm. fndt El Fresno 2200 1991 I MCB 60 Agave pmyi €n@mm heart CerrodelApactre 2020 20m1905 I I 1 I l MCB 61 Agave CnwIm. p~eart ~CenodelApache 12020 11 998 I 1 I I I MCB 62 IVine ]mot IS ofcuitlahuac (2000 lM7f1998 MCB63A Qwnba sp. pad S of Cuitlahuac 2000 0110711998 Mc6636 mnb'8 Sp. fruit Sofcuitlahuac 2oo0 0110711998 MC8 64 Afcb&@ybspungens benies lagma Bustillos 2280 18106/1998

I I I I I MCB 68 $p. lw pWP= 11940 101/W1998 I wnba sp. Pad SE ofCuitlahu#: 2000 0810711998 MCB 68 Mum sp. krlb S dcuitlahuac 2000 08E0711998 MCB 69 mW. W~S SoSCuitlahuac 2000 08EO711998 Jun'ylerus W- berries CMW)3,Bustillos 2280 1998 Basin MCB 71 Junipetus sp. berries Anahuac 1800 05r0711998 MCB 72 Junipenrs sg. berries S ofcuitlahuac 2000 08EO7f 1998 MCB 73 Juniperus sp. berries La Avispe 2100 1998 *-introduced species **-collected near this location

As mentioned in Chapter 3, some indigenous species of these regions around Lapa Bustillos and in the Santa Maria River Valley have decreased over the past few decades due to intense agriculture and livestock grazing. In order to locate native plants, the margins of agticulnval fields, the margins of basins, and the mountainous areas were visited. In some instances, the plants under investigation were attracted to disturbed habitats and hence were readily obsenrable in agricultural ditches, along roadsides, and in urban areas. in other instances, plants could not be located or collected. This could have been due to modern disturbances or slight climatic changes.

Collection and Identification Collection of plant samples took place during the summers of 1W8 and 1999 in the Bustilios Basin, the Santa Maria River valley, and the Babicora Basin. Plants were sampled based on their known edibility or their presence in the archaeobotanical record. Dr. Karen Adams, a palaeobotanist associated with Lakehead University and the Crow Canyon Research Center, assisted with the field collection.

A broad taxon was assigned to each sample upon collection, which was confirmed or corrected back at the lab. This was done with reference to a number of identification kegs. Samples that were deemed important to the research were sent to the Universitg of Arizona, Tucson, for more specific species designation by Kathryn Mauz at the University of Arizona

Animals

Archaeological hmal remains were bountiful in the Santa Macia Valley site (Ch-254) and present, though not frequent, in the Laguna Bustillos site of Ch-202 (see figure 1-1). A sample of the various harepresented in the archaeological remains was removed fiom the general collection for stable isotope analysis (see Table 6-2).

Archaeologically, these remains represent dietary items. Finding them in the context of an archaeological site provides evidence that these bones represent species that were contributing to the diet of the population at the time of site occupation. However, certain burrowing species may be intrusive. Frogs, snakes and rodents are among the taxa that possibly represent species that are not present in the archaeological site due to human behaviout. Considering that these animals are edible, they are still potential dietary items due to their presence in the local environment.

Tabk 6-2. Faunal Sunpks Sample Site Ta%a Commorr Name ' Portion Date and Excavators MCF 01 CM)06 Odocoileus virainiarms White-tailed Deer (Juv.) P3 1!3V98 MW KT0 MCF02 Ch112 Svhribaus Cottontail L Rox Tibia 3/7/98 MH AM MCF 03 -112 Anti- ameticana Ant- LMandble 3016198 MW AM MCF 04 Ch-218 !4ZS Jadvabbit Prox Femur 09/0611998 MCFOS Ch-261 OQcoileus hemoim Mule Deer Pelvis 6/7/98KT0 AM MCFM Ch-254 Mele#n'stlakmw Turkey Cenr Vert 9- MW JPB EJG MCF07 Ch254 f%saifumes Perching bird Humerus 10/6/99 MV PO MH .. . . MCF08 Cb2S WOMIsmeDhlfis Skunk R Mandible 1WB9 KTB DRH MCFOS Ch-254 Odocaileus hernoinus Mule Oeer Occipital Cond 14(6/99 MH MHRV MCF 10 Ch-254 b Jacktabbit Cdcaneum 1!YW99MHRVMWEJG L MCF 11 Ch-254 Microhrs sp. Vde Skull 8 Mand 2- KTB DRH MCF 12 Ch-254 Ussamphibia Ffog Pel, hum, ~uI24/6199 KT6 DRH MCF 13 Ch-254 ~latmns Ctwe Pl,P2,mtqmW 25M9MWDRH MCF 14 Ch-254 Anti- americana Antem Mandble lnB9 BMO MW MCF 15 a254 Anas PlatHmchos Mallard LCoracoid 217199 KT8 DRH MCF 16 Ch-254 Teshrdnes Turtle Nuchal Bum 2/7/99KTB DRH MCF 17 Ch-254 Svhrilaaus Cottorrtail h,lib, MH EJG

The collection of faunal remains represents a large range of species, however, it may or may not represent all species included in the diet of the group living in these regions. The samples that were collected represent what was present and identifiable in the archaeological record. It is possible that some small unidentifiable hgmena of bone left in the archaeological record belonged to an animal species that was eaten, or some animals that were eaten were not present in the archaeological record (see chapter three for a discussion on biasing in the archaeological record). The sample that was collected represents the only evidence of rhe animal portion of the prehistoric diet and it is not possible to evaluate the completeness of the sample. More likely than not, this sample is an adequate representation of the prehistoric diet. This sample of species can also be used to demonstrate the scope of the food web. This may be illustrated by an analysis of the diets of the andsrepresented by this faunal assemblage. The diet of each species, or group of species, will be discussed. It is hoped that the statements made in chapter three regarding the complexity of the food web and its potential impact on human populations will become clear.

Thirteen species are represented by this list of faunal samples in the assemblage. Eight of these are mammals, two belong to the reptile and amphibian group, and three are birds. Although mule deer, white-tailed deer, and antelope all inhabit similar geographic locations, small differences in the ecosystems in which they live and feed lead to large differences in their preferred foods. Studies conducted in the southwestern United States indicate that the mule deer prefer to browse on shrubs (Severson 1981). Other potential food item are tree shoots such as pine and oak, and grasses, especially in the spring and early summer, as they are the first vegetation to grow after the dry season. The majority of the main food items of the mule deer are likely to be C3 plants - trees and shrubs (Severson 1981). The white-tailed deer, similarly concentrate on shrubs, trees, and €orbs in that order of preference. Again, the diet is mainly represented by C3 species (Gallina et al. 1981). Antelope are more likely to graze than to browse, therefore eating more grasses and forbs than shrubs and trees Puechner 1950). The potential for antelope to ingest C4 plants is higher than that of mule deer and white-tailed deer beause antelope eat more grasses and forbs than do the other two deer species.

One rabbit species and one hare species were consumed by prehistoric people in this region: cottontail (SpIvdq&, and jackrabbit @pus). These two species inhabit slightly different habitats. CottontaiIs inhabit various disturbed or successional habitats where there are abundant hiding places such as dense or thorny lowlying woody shrubs (Chapman et al. 1982). Jackrabbits tend to prefer arid regions and desert scrub, which is more open than that inhabited by cottontails (Dunn et d. 1982). Their preferred method of escape is speed, and therefore tend to avoid dense shrub ecosystems. Therefore it is expected that the stable carbon isotope values of the cottontail and jackrabbit samples would differ (Katzenberg and KelIey 1991). However, both cottontails and jackrabbits eat grasses (Chapman et al. 1982, Dunn et al. 1982). &Mostof the grasses common to the ecosystems around the study areas (Brown 1982), both scrubby and open, are C4 grasses (see append^^ A). Therefore, the stable isotope values of jackrabbit and cottontail body tissues may exhibit a C4 signature. This would in turn be passed on to those individuals and animals who consume cottontails and jackrabbits.

Other mammals that were sampled include coyote, skunk, and shrew. Coyotes are known to subsist on vegetation and vertebrates (Anderson and Knox Jones 1984) in the region, which would likely lead to an intermediate stable isotope value. This is due to the likelihood that the coyotes would eat whatever they can find. The mixed environment of the study area can readily be seen kom appendix A- Sirniiar\y, skunks are omnivorous and will eat various plants, small animals and insects in the local environment (Walker 1975). One skull that was identified as vole (Microtus sp.) was part of the faunal assemblage. This specimen may be intrusive and modem, however it is possible that these animals existed in the region in prehistoric times and therefore this sample d be considered as a potential dietary item. Voles are herbivorous and tend to concentrate on grasses, forbs, leaves and roots. In this study area, this diet could either lead to a C3, C4, or a mhed stable isotope

It was not possible to identlfg the samples of turde and frog to genus or species. Therefore it d not be possible to predict their stable isotope signature. The diets of these groups of animals are varied and could range fiom insects to vegetation. The diet of the frog sample is likely to have been insects (Stebbins 1962), and that of the Nnle probably included a diverse range of foods such as insects, berries, snails, and other vegetation (Barker 1964).

The sample of bird bone that was identified probably represents a small amount of what was actually available and exploited, In this assemblage there are samples of turkey, duck (Anas sp.), and a perching bud (Passeriforrnes). Rugers and Norris (1970) state the diet of Gould's turkey (Melepllopavo mexican& to include berries, fruit, tuben, seeds, grains, worms, snails, insects, and small vertebrates. The resulting stable isotope signature of this diet could vary depending on what was available in the microenvironment in which the turkey population lived and would represent a highly varied diet. Although the group Passeriformes includes many genera and species of perching birds, their diet seems to consist mainly of insects, seeds and berries (Rutgers and Norris 1970) and therefore may lead to body tissues that give varied stable isotope signatures, depending on what types of tlora are in the local ecosystem. The duck bone seems to be identifiable to Anas platyrplchos. However two subspecies exist, that of mallard (A. p. ~lat)~~-pncho$and the Mexican duck (A. p. diazi). Both have a very diverse diet consisting ofgrasses, seeds, nuts and vegetation, and may include estuarine environments and brackish water marshes during migration @ellrose 1976). Because the sub-species is not known, we are unable to comment on the season of occupation. The Mexican duck is seldom encountered in Chihuahua during the winter, however the mallard has a more wide distribution and may be encountered in this region during the winter (Bellrose 1976).

She'4pi.h

Shell was found in the Santa Maria Valley site (Ch 254) in great quantities. It is accepted among the site archaeologists as part of the midden sediments and not intrusive or nadyoccurring in the soil. Local bivalves were not present in off site locations, and the shells were not modified. Therefore, the local shell species are believed to have been dietary items. Some non-native species of shell were transported from the Gulf of California. The exotic species are not thought to represent dietary items, but decorative, religious or trade items.

The local shell has been identified as Anodonta caiiforniensis (sometimes known as A. dejects. A. Vokes pers. comrn. 1999). This mollusc would have lived in keshwater rivers and streams, and burrows into the mud, therefore is easily extractable by humans. It is edible, can grow to a large size, and could have been harvested year round (A. Vokes pen. cornrn. 19W). No modem examples of these animals could be located, and therefore shell was not included in the stable isotope analysis. The reason that molluscs are not present in the modem environment could be the recent human-induced changes in hydrology, especially the decrease in surface water (A. Vokes pers. comm. 1999).

1n.red.r Insects must not be excluded from dietary analyses even though evidence for the consumption of insects was not found in an archaeological site. The presence of insect remains in a site is Likely a representation OFintroduced remains. Positive evidence of insects in the diet would be charred remains around a hearth area This was not evident at the sites excavated in west central Chhuahua, however this will not be taken as evidence for the exclusion of insects fkom the diet.

A sdnumber of insects were collected kom the study area during the 1W9 season. This was done in order to test the stable isotope signature of a sample of this important dietary resource. The insects were then broadly identified at the University of Calgary by Dr. Rob Longair of the Biological Sciences department. One beetle was identified to the Dynastinae sub-y (rhinoceros beedes, herdes beedes) and a caterpillar was identified to the Sphingidae fhdy (sphinx moths, hawk moths). Another catexpillar that was very dehydrated was unidentifiable past the order Lepidoptera, but could be identitied as moth lama

Human burials have been located in a fear sites within the context of the Proyecto Arqueologico de Chihuahua. This report will deal with the analysis of two sites and five burials. The sites involved are Ch-202 in the Bustillos Basin and Ch-254 in the Santa Maria River valley.

Ch-202 (La Cruz site) Ch-202 is located on the northern shore of Laguna Bustillos in an agricultural field, and was excavated in 1998. The top 10 centimetres have been severely disturbed by ploughing, and there were many surface artihcts that indicated a site in this location. Human bone ti-agments and teeth were aiso scattered on the surface and an excavation unit was started in order to locate the source of the human bone. A nearby excavation block uncovered floor, however it is unlikely to have been associated with the burial.

Description A double burial was located approximately 10 to 15 centirnetres below the surface, disturbed by agricultural activity. Two sub-adults were placed on their left sides, curled together (see figure 6-1). No burial artihcts were located. The ploughing activity had removed the upper (right) bones leaving only the lower (lefi) sides. The left femora of each individual was sampled for stable isotope analysis. There were not enough complete bone or teeth remains to estimate the ages of the pair. However, it is safe to say that subadult 1 (burial 1) was older than subadult 2 (burial 2) due to its larger size and seemingly hrther development of long bones and epiphyseal fusion.

Ch-254 (A Chihuahuan Culture site]

Ch-254 is situated about 3 kilometres south-west of Oscar Soto Maynez. .e site was tested in 1998, and excavated in 1999. Four structures and three burials were located. Burial 1 was located in structure 2, burial 2 was found while exavadng a trench between structures 1 and 2, and burial 3 was located in structure 3. Preservation was moderate in burials 1 and 3, however was very poor in burial 2 No artihcts were found in association with any of the burials.

Burial 1 Description Bud1 contained the remains of an adult male that was buried in an ill-dehed pit that originated in the fill of abandoned Structure 2 and continued through the floor (see figure 6-2). The human remains were located at a depth of 51 to 70 cm below the sucface. The sbull, which was encountered firsf was higher than the pedal phalanges which were in the deepest part of heburial. The body was placed in a flexed position with the head to the north hcing east. The left hand was curled under the chin and the right hand was near the orbits. All bones were present except for some of the phalanges of the hands and fee&as well as one carpal and some tarsals. Most of the long bones were in good condition, however the vertebrae, sternum, sacrum and pelvis were not well-preserved. The sex estimation was based on skull Fatures alone.

Stature, Age and Pathology The estimated stature of this individual is kom 149 to 157 cm using regreesion equations of the tibia and femur potter and Gleser 1958 cited in Bass 1987). The upper limit was calculated from the tibia and represents a more accurate estimate than the lower estimate. The measurements for the lower limit were taken from the femur, which was not complete, and had to be estimated. Therefore, it is likely that the actual stature of this individual is nearer to the upper limit of 157 cm (k 3.73 cm). The muscle attachments of this individual, specifically of the tibia, femur, radius, ulnq humerus, and metacarpals are large. This can be a good indicator of strength and a high level of activity during life.

Unit 54

Unit 55

Mild pathological lesions present on several of the bones indicate osteoarthritis. The bones most affected are those of the feet and the proximal ulna In addition, the atlas is asymmetrical and has severe lipping on the left articular facet. This could be the result of trauma or osteoarthritis. Caries occurred on the following teeth; mandibular molars 1 and 2 on the lefi side, with M2 being much worse than MI. No other teeth displayed caries or any other dental pathology. Tooth weac is very li&t Incisors, canines, and premolars exhibited wear stags of 1 or 2 (out of 8, Buiksaa and Ubekker 199452). The molars showed wear ranging from 4 to 8 (out of possible 40, Buikstra and Ubelaker l!N4:53). Burial 2 Description Bund 2 was discovered in a trench excavated between structures 1 and 2. Preservation was poor, the contexf seems to have been disturbed. This disturbance could have been due to rodent, snake or frog burrowing aaivity. Bones were disarticulated, and not all elements were present The skeletal remains that were removed from this area were fragmented and in wecondition.

Number of Individuals ~n examination of &e tee& lad to the conclusion that there were more than one individual buried at this location. Although the long bones suggest a single burial, there were three dis~ctset- of teeth. One set of teeth included a number OF incisors, premolars, canines and molars representing an adult individual. These teeth were moderately worn, with the incisors, canines adpremola~~ exhibiting stages 4 to 6 (out of a possible 8 Buikstra and Ubelaker 199452). The molam exhibited stages 18 and 21 (out of a possible 40 Buikstra and Ubelaker 1994:53). The second gtoup of teeth included one incisor, and two premolars. These tee& were not worn and were small. A third individual was represented by a crown of a deciduous molar in the process of development. The aown kelp represents an individual around heage of biah to 9 months. These two last sets of teeth were not well- worn. How &=second set of teeth and the developing crown came to be located in this i unbo-. mefaa that the long bones only represent one individual suggests that perhaps the other teeth were present due to transport by a burrowing animal, or some other disturbance.

Stature, Age and Pathology The remains were too -enred to attempt an estimation of stature. Age estimation was only possible on the incomplete dental remains, as mentioned in the previous section. The fragmented long bones arere not sufficient to provide an age estimation beyond adult. Genedyit be said that the bones seemed to be similar to the other burials; slightly robust and seemingly healthy. One femur did seem to exhibit a lesion of some sort, likely a healed fracture or infedon. The surface of the bone was roughened, but the poor preservation of the bone did not lend itself to specific identification of the lesion. The healed nature of the lesion leads to the conclusion that the infection or f+acture occurred prior to the death of the individual. The nodfemur was sampled for stable isotope analysis.

Burial 3 Description Burial three was flexed, lying on its left side, with the head upright and oriented towards the north-west. The individual was placed in a relatively small pit The dimensions of the burial pit were 85 crn long (axis running northwest-southeast), and 55 cm at the widest (see figure 6-3). The condition of the bone indicates that those in charge of the burial had difficulty placing the individual into this pit. The right femur was dislocated from the acetabulurn likely because of the force needed to bury the individual in the small pit. The toes and metatarsals extended up the sides of the pi5 another result of a small burial pit. The left femur was sampled for stable isotope analysis.

Stature, Age, Sex, and Pathology Burial 3 included the remains of an adult that was located in a shalIow pit dug into the floor of structure 3 (see figure 6-3). The individual is Likely in the 35-49 year age range based on cranial suture hsion and tooth wear. This estimate is broad due to the variable timing of suture fusion and the possible pathological condition of the skull. The burial pit was excavated 31 centhetres into the floor, however the floor was not re-plastered, and the skull extended above the level of the floor. This suggests that the interment of this individual took place after the structure had been abandoned. Legend - ceramic

Unit 49 Unit 50

Figwe 6-3. Qt-254, Burial 3.

At htglance, the skull of this individual seemed to have denceof fionto- occipital deformation. This could not be confirmed, however, due to the position of the skull in the burial pit and the wenature of the skull upon removal. Charaaeristics of the skd bone that lend credence to this theo cy are an inconsistent thickness of the skull bones and a protrusion of the parietal sections of the cranium. All other characteristics of this skeleton match those of the remains fiom Burjall. These include robusticity and the presence of osteoarthritic lipping on the bones of the feet, right os coxa, distal humerus, and the bones of the hand. There was also one @ lesion on the left ulna It is characteristic of an osteoma, a benign bone turnout. These are usually found on the cranial bones or at the ends of long bones (Ortner and Puschar 1985). This example is interesting, however, because the lesion is located on the proximal sh& of the long bone. Considering the hct that osteomas are benign, this lesion is not likely a cause in the death of this individual. Dental lesions such as caries and abscesses were absent. Tooth wear, however, was more advanced in bud 3 than in burial 1. Indsors, canines, and premolar wear ranged from 4 to 7 (out of 8, Buikstra and Ubelaker 199452). The wear on the molars ranged from 22 to 32 (out of a possible 40, Buikstra and Ubelaker 199453).

The similarities between these three individuals kom Ch-254 are interesting and may lead to a further understanding of the population that once inhabited this area. The sample size of this study is very small, evidence of five individuals, however only three complete individuals, one of those kom a disturbed context. Therefore, any information or generalisations drawn kom these skeletal remains are not conctusive or applicable to the entire population or region. Considering this disclaimer, it is still interesting to use these three individuals to draw some similarities between them and speculate on the possible reasons for these characteristics.

The lack of signs of infection and abscesses suggests that the overall health of the three individuals is good. The three skeletons consistently show signs of arthritis. The evidence shows up in the bones of the hands, fee&elbows, and hips. The muscle attachments of all skeletal remains show a robusmess that indicates a moderate to high level of physical activity during life. Lesions suggest that infection and other diseases were present as in every population. The severity of these lesions is low, and likely did not direcdy cause the death of these individuals.

Based on the robusticity and ovet-all heal& of the three individuals that were excavated, we can assume the diet of the individuals was sufficient and nutritious, and that the activity levels were high. The population was likely of shorter stature and good health.

The preceding discussion has provided information regarding the collection and identification of the samples used in this study. These samples include flora, faunal bone, human bone, insects, and shell. AU of which, excluding shell, were sampled in order to identify the carbon and nitrogen stable isotope signatures. All of the plant and animal samples tested are believed to represent potential dietary items that were available to the prehistoric groups living in the study region. Some are possibly intrusive at the site, however the species are believed to have been present in the area prehistorically, and therefore are potential dietary items. The flora were mainly from modem contexts. The fauna were all archaeological except for the insect species and a snake skin. Human skeletd samples were taken from an archaeological context. Shell was an important dietary contributor, however was not sampled because no examples of bivalves are now found in the region.

These samples were tested for their stable isotope signatures, and were used in this examination of prehistoric diet and human adaptation in west central Chihuahua. The samples of plant and animal material will provide examples of potential dietary items, while the human bone will show the results from a small number of individual diets. Chapter 7 - Methods This chapter will provide an overview of the laboratory methods used while working with the samples of plants, animal bone, and human bone. It will also oudine the mechanisms and workings of the mass spectrometer, the instruments used to analyse stable isotope signatures of the samples.

Ph~ts The plant samples that were separated into different plant parts (i-e. leaves, flowers, seeds) in the field were kept separate in the analysis. Plant samples were first brushed of soil and other contaminants and placed in the freezer. They were then fieeze-dried in a Virds Benchtop 3L fieeze-drier to ensure that there was no moisture in the sample. Plant samples that were hard or otherwise heterogeneous were ground with a SPEX CertiPrep 6750 freezer mill to ensure homogeneity. Other samples that were homogeneous, or those that were represented by smdl quantities were not ground. These samples were cut with scissors when packed into the mass spectrometer for stable isotope analysis.

The nuts sampled (acorn, walnut, and piiion) contain large amounts of lipids, which have diKerent stable isotope ratios that other plant biochemicals vieszen 1991). For interest's sake, the lipids were removed from a portion of the nut samples and were left in the other portion. The mo diffkrent samples from each nut were compared to iden* whether there is a large difference in stable carbon and nitrogen isotope ratios bemeen the lipid content and the totd nut meat.

Lyophylisation (lipid removal) was accomplished by following a modified version of the method outlined by Kates (1972). This involved soaking 1 gram of ground nut meat in a 2:1 solution of methanol and chloroform. This was mixed together constantly for 2 minutes, fdtered and then rinsed with double distilled water to neutdity. The lyophilised nut meat was placed in a separate vial fiom the complete nut meat. Both samples were analysed separately at the stable isotope laboratory. Bone Cohgetl

All animal and human bone samples were demineralised and treated fbr humic acids in the bone preparation laboratory, Department of Archaeology, before they were taken to the stable isotope laboratory, Department of Physics for isotopic analysis. This tratrnent removes the mineral portion of the bone and leaves the collagen portion, plus other proteins that occur in minor quantities relative to collagen.

The method used in this study was that developed by Sealy (Sealy and van der Merwe 1986). Bone demineralisation included treatment with 1% HCI. The acid was replaced every two days to provide kesh and active solution. The time of the treatment in hydrochloric acid depended upon the condition of the bone. Samples in good condition required a longer period in the acid than did damaged or degraded bone. The number of days the bone samples spent in the acid solution ranged from 9 to 65, however, the average bone took around 14 days to dernineralise. The end result of this process was collagen, the carbonate and other mindhaving been removed by the acid treatment.

After dernineralisation, the samples were neutralised with double distilled water and put into a solution of 0.125M NaOH. This removes d contaminating hurnic mated that may contribute carbon ions that are not part of the bone. This basic solution has the potential to degrade the collagen further if left for too long. Therefore, well-presemed samples were lefi in the sodium hydroxide for 20 hours and poorly preserved samples for 10-1 5 hours. The bone collagen was then rinsed to neutrality with double distilled water and placed in the fieezer. The collagen was freeze-dried in a Victis Benchtop 3L freeze-drier machine and ground with a SPEX CertiPrep 6750 freezer mill. The powdered collagen was then taken to the Stable Isotope Science Laboratory, Department of Physics at the University of Calgary. Preservation of Bone Collagen Sam~les

There are a number of methods that can be used to determine the state of preservation of bone collagen. These include the state of the collagen model, the yield relative to whole bone, and the C to N ratio. If a bone is relatively well-preserved, the collagen will maintain the shape of the bone once the mined portion has been dissolved. IF the collagen bonds are severely broken down, the resulting collagen wtll not hold together, but will appear in pieces or tendrils (Grupe 1995). It is possible that a good collagen model can result fiom bone collagen that is deteriorated and hence give the researcher a false indicator of good preservation, however a poor collagen model will only result fiom poorly preserved collagen. The yield is the percent of the bone, by weight, that remains after the mineral portion of the bone is removed. Fresh bone consists of approximately 25% coliagen by weight. The more degraded the bone, the less percent of the original protein weight will remain once the mineral portion is dissolved. Some studies have suggested that the collagen maintains its integrity and therefore has reliable 6''~ and 8% values down to 5% yield (Schoeninger and DeNiro 1982)- However, subsequent work has shown that the stable isotope values of collagen yields below 6% could depart from that of the original bone uuross et al. 1988). The ratio of carbon to nitrogen in the collagen samples should be dose to that for normal collagen, 3.2, and generally within the range of 2.9 to 3.6 (De Niro 1985). All three of these methods used to determine collagen preservation are subjectme and sated numetical boundaries between 'good' and poor' presmtion can be debated. The use of one indicator may not be sufficient to identifg poorly preserved samples. It could also lead to the exclusion of samples that are in hct dependable. The use of all three indicators will inaese the chances that poor samples are discarded and reliable samples are kept.

Bone Cdonate The methods used for the isolation of carbonate fiom bone samples followed the procedure determined to result in unaltered carbonate by Gee-Lok and Vamey (Gamie- Lok and Varney unpublished data, based on Lee-Thocpe 1989). Powdered bone (-250 mg) was put into a centrifirge tube and 10 rnL of NaOCl was added each 12 how for 48 hours. After neutraIity was reached, the bone was treated with 0.1 molar acetic acid. This concentration was found by Gamie-Lok and Vamey to be optimum for bone carbonate. Preliminary results suggest that the carbonate requires 4 hours in acid to purifjr but can be left for 24 how. If the bone is left in the acid for a prolonged period there is a greater chance of recrystalisation. This will result in a modified 6'% value. Due to the preliminary nature of the methodology study, two samples of each bone for this thesis were prepared, one left in the acetic acid for 4 hours, and one for 24 hours. The hypothesis is that these taro samples of each bone will result in similar 6°C values. The samples were rinsed to neutrality, frozen and freeze-dried using a Virtis Benchtop 3L freeze-drier.

Insects The three insect samples were cleaned, fieeze dried using the ViiBenchtop 3L fieeze-drier machine and ground with a SPEX CertiPrep 6750 freezer mill. No Wer preparation was deemed necessary. It is expected that the entire insect was consumed, and theretbre all preserved material (mainly chitin), was anaiysed for stable carbon and nitrogen isotope values.

The samples were packed into the mass spectrometer in the Stabable Isotope Science Laboratoy, Department of Physics at the University of Calmunder the supervision of Bernhatd Mayer. They were then loaded into a Continuous Flow - Elemenml Analysis - Isotope Ratio Mass Spectrometer. The elemental analysis mechanism is a Carlo Erba NA 1500, and the mass spectrometer is a Finnigan Mat Delta +XL.

A mass spectrometer analyses the amounts of isotopes by weight (figure 7-1). The sample is combusted, and CO, and N, are injected into an ion accelerator. The CO, molecules from the sample contain either '% (C1'03, or '*c(~''OJ, the N, molecules contain either "N (I4N-I4N)or "N ("N-'*N). It is unlikely that two "N atoms will bond, but also possible. Each of these different arrangements has a different molecular weight. The sample is converted from uncharged gas molecuies to ions in an ion chamber. The ions are propelled out of the ion chamber and through an accelerating magnet and then around a curve. The radius that an ion takes around this curve is determined by its weight. The heavier ions require a wider radius than lighter ions, and therefore all ions of a certain weight end up in the same area &er the curve. Collectors at the end of the curve measure the amount of each ion and kom this, produce a delta value that relates the ratio of heavy to hght isotopes of the sample to the same ratio in a standard-

Figrm 7-1. Scbanak Diagram of a Mass Spccaometer. Adapted fiom Jobstone and Rose 1996.

The samples of animal bone and human bone were subjected to daninaalisation by HCI and humic acid removal by NaOH in order to isolate bone coUlga Powdered bone was treated with NaOCl and acetic acid, which resulted in bone carbonate. Plants were ground only, with the exception of the nuts. These were lyophilised using methanol and chloroform, The carbon and nitrogen stable isotope values for collagen, plant material, and insects, and the carbon isotope dues for bone cubonate were determined in the Stable Isotope Science Laboratory at the University of Calgary. Chapter 8 - Results

Plants Table 8-1 contains the results of the carbon and nitrogen stable isotope analysis of all the botanical samples taken &om west central Chihuahua Both scientific and common names are given as well as the portion of tfie plant that was tested. For some species, Merent parts of the same plant exhibit different stable isotope dues, especially 6'% values (see MCB 37A and MCB 37B for example). Also, differences mckt between samples of the same species that were processed for different end products. The lyophilised portion of the nut samples PCB268. MB,44B) had the lipids moved, and have difKerent 6°C values trom that of the whole nut samples. The 6"~and 6% columns give the results of the stable carbon and nitrogen analysis in units % (per mil). The wtedsamples were collected in the Laguna Bustillos Basin, while the other samples were collected in the Santa Maria River Valley.

(H.B.K.) bg. EK GMim NdOSM 5.6 -13.4 C4 Table 8-1 (cont'd) SrmOkI Taxa Commorr- Pofth bcaon 61W513C WP* ~I MCB14 Sorgtnmhdapense Sorgtwm h Matd WSOSM 12.8 -12.7 C4 I (L-1 c- '~c~l~spomboluraiddesDfgmdgast seeds E d OSM 6.0 -13.9 C4 MCBSO ZeamaiEe Can kernels 7.9 -1 1.0 C4

I I I I I I I MCB 18 1- I m I stelk I 1- 1 1.81 -11.11 CAM

I MustaFd N d OSM I 114 -26.11 C3 . 1 I MC802 lasariapirmr I Mustard I*rds) NdOSM 1 5. -23.41 C3

I 1 I 1 I MCB 32 i(mcrs IL-1 benies I I I 5.81 -24-91 Table 8-1 (cont'd) la0 Cacmrorr~ Pohiorr Locdon 51W 513C Grape fnrit El F~SUJ 6 -27.7

I I 1 I I IMCB 66 Jmtia I 1 4-41 -12.51 CAM

CAM

- .- .. MCB 20 I- CAM MCB 4SA Portulaca Puslane I rn Mdel msOSM CAM In I MCB 158 I Puslarre I seeds MoEal wsOSM CAM MCB 36 Ch 254 C3 MCB 64 La Raspadra C3 I I MCB 29 I I berries N d OSM C3 MCB 10 Physalis hederaefdia - fruit N d OSM C3 MCB 11 C3

I I I I I I

MCB 27 1- Im-'dI I Ls RsI~B&~ I 3-31 -2531 C3 * Vbst.bcd rn in the ~&kof%Cemi13. Ptc&& +/- 0%

The plant samples were removed from the modem landscape, and as such, may have been exposed to some form of fixtiher. Some of these usefirl edible plants grow as weeds alongside roadways and agricultural fields. These areas ace ohinundated with runoff from agricultural fields, which are fdedwith products that contain urea or other forms of nitrogen. In these cases, the nitrogen stable isotope values may be altered fmm what they would be naturally and also what they would have been in the past. Most of the trees and cacti were collected from more remote locations along the edges of the basins or valley, in which case the danger of altemtion of nitrogen isotope values due to fdsers is diminished. It is apparent fiom this table that any differences between the stable isotope structures of the two drainages is negbgible. Those species that are represented by samples in both the Santa Maria River valley and the Iaguna Bustillos basin exhibit similar stable carbon isotope values- For emmple, five samples of prickly pear cactus taken in both locations have a narrow range of -1 1.59/m to -12596. The Cact that this CAM species does not vary in its sable carbon isotope values indicates that the environmental differences exhibited by the two regions are not significant enough to &kt photosynthetic processes. Nitrogen values, however, are not similar among species in different locations. However, 8''~values can range over small distances due to the effects of local nitrogen pools (see chapter 3). This could also be due to the use of fertilisers or effects from the pulp mill near Laguna Bustillos. The plant nitrogen dues should be used with caution.

Preservation of CoUaeen Sarn~les In this study five Eurnal samples and three human samples may not be accurate due to at least taro indicators of poor preservation (tables 8-2 and table 8-3). The higM&ted samples in tables 8-2 and 8-3 show taro of three indicators of poor presemation; donto nitrogen ratio, the percent yield, and the preservation of the coll~agenmodel. For example, sample MCF 05 had an acceptable C/N ratio, however had a low yield and only a fait collagen model remained after demininenation. However, hehighwted samples show expected trends, such as a similar sipature to other samples from the same speaes. Therefore, they will not be rejected completely, but will be discussed and interpreted with caution.

Tabk 8-2. Faunal Sampk Prammion Indicators.

I 1 1 I MCF 17 1 3.3 1 31 I G MCF 09 G-Good, F-Fair, poor^ Highlighted samples may not be accurptc Tabk 8-3- Human Sampk Pnstrrncion Indicators

MCH 01 3.3 6.35 G MCH 02 3.3 1215 G

G-Good, F-Fair, P-Poor Highlighted svnples rmy not be accurate

Fauna

Table 8-4 indudes information on the ha1samples in addition to the results of the carbon and nitrogen stable isotope analysis. The shaded samples originate horn the Laguna Bustillos Basin and all others are from the Santa Maria River Valley. The results of the carbon and nitrogen stable isotope analysis for the faunal samples help to illustrate the major contributing items to the diet of those individual animals. A 6°C value between -3096 and -19% indicates a diet based primarily on C3 plants or other animals who eat C3 plants. A value beween -121&0and 4%0represent. a diet based on C4 plants, or on other animals who eat C4 plants. Any result in be- these mo ranges generally indicates a mixed diet. The stable nitrogen isotope value indicates trophic level. M the herbivores tend to have 6'2~values below 7#., while ~orousspecies will have 6% values above 7'360. omnivores will have intermdate values

swnOls SiQ Tam CommorrNrna hUom 6- bnC Oict MCF18 NIA DumSstiriae Hercules beetle whde insect -1.0 -24.2 rotting wood, wg and humus MCF20 NIA L- Math lava whole id 7.7 -27.3 t-khhws MCF 19 NIA mi- Sphinxmoth, whole insact 9.6 -27.0 Herbivorws havulrmoth MCF 12 (21254 FW Pel, hun, W 7.6 -14.9 insects MCF 16 Ch 254 Teshrdnes Tutle Nuehal Bone 9.9 -15.5 veg, snails. worms, insects Table 2 4 Cont'd srmgk si& Too Common- Pofth 6- MCF 21 a254 S9uamata Snake skin 12.2 MCF 06 (21254 ~s~ Tukey Cen, Vert 10.4

MCF 15

1 MCF 07 Ch 2S4 PmMgbird Hunerus 8.0 -16.2 d,beCrieS,

MCF 11 Ch 254 Miadus sp. Vde Slcull8 Ma'd 5.3 MCF 13 Ch 254 Canishtrans PI, P2, metapod 8.9

- MCF 10 MCFm

I I I I I I I * Value ; stated are in the units of YW ('per mil'). Precision is +/- 02/60

Human Remains

The human remains that were sampled for this study represent a smail sample of the prehistoric population that inhabited the regions around Laguna Bustillos and the Sang. Macia River Valley one to taro thousand years ago. Table 8-5 contains the results of the stable isotope analysis of the six human skeletal samples. Samples 1 and 2 are from the Bustillos Basin, while samples 4, 5, and 6 are from the Sane Ma& River Valley. Sample 3 comes from Galeana, a site to the north of the study area that was excavated by archaeologists from the Mexican Instituto Nadonal de Arqueologia y Historia (INAH). This sample was included for comparison. It is not significant to the overall goals of this thesis due to the difficulties in comparing the stable isotope ecology of the Galeana region with that of the study region. These two areas are typified by different climate, ecology, as well as plant and animal communities.

Tabk 8-5. Human hfatcriak 6Wand 6W Results - Sample Si Pottion 61W 61WlP PCurb* Aa-co* MCH 01 Ch 202 L Femur 9.0 -1 0.6 -1 -8 8.8 MCH 02 Ch 202 L Femur 10.7 -1 3.8 -5 8.8 MCH 03 Galeana RadAJlna 9.0 -9.8 N/A N/A MCH 04 Ch 254 L Femur I1-4 -8.4 -1 -1 7.3 MCH 05 Ch 254 R Femur 10.0 -7.8 -1 -4 6.4 MCH 06 Ch 254 L Femur 12.5 -8 -5 -1 -8 6.7 * Values s ated are in he units of %o (cper mil'). PGcision is +/- 0.2%

Sample MCH 02 will not be included in the discussion due to the young age of the individual (see chapter 6 - Hwnan Remains). The diet of this young individual was not representative of the population as a whole. It is possible that this infant had not gone through the weaning process, as suggested by the higher ti1% value compared arith MCH 01 (see Table 8-5) (Katzenberg and Pfefier 1995). As was discussed in chapter 6, MCH 06 gave many indicators of paor presmtion. Although the &'%J value is higher, the 8°C value is similar to that of MCH 04 and MCH 05. This sample will be included in the discussion, but will be used +aith caution when speaking of the ti1% value and its possible implications.

Plotting stable carbon isotopes of carbonate against that of collagen groups stable isotope results into dietary categories (see figure 8-1). Following a graph prepared by Huebner (1991 afker Krueger 1985), samples MCH 01 and MCH 02 fiom the Laguna Bustillos basin plot very close to the area represented by a mixed diet composed mainly of maize. Samples MCH 04, MCH 05, and MCH 06 kom the Santa Maria river valley plot in the area represented by a diet of C4 plants and C4 meat, very close to C4 plants only. This corresponds to other evidence and data provided in this study. ,. I....,...., L

0 -

. .

Fl~&l.Humsnipmata~~co~d~(~at).Adnp~trom Hwk1991 .fta ilwger 1) C3 pknts; 2) C3 plants + C3 meat; 3) C4 plants; 4) C4 plants + C4 meat 5) marine only; 6) mixed, mainly &, 7) C3 plants + marine; 8) E hcanpastoralists [C3 plants and C4 meat]; 9) CAM plants and C3 meats.)

This chapter has presented the results of the stable isotope analysis of several samples of phe, animals, and humans from PAC sites in west cenhal Chihuahua. The stable carbon and nitro~nisotope results for plants, fauna, and human remains were presented in tables. The results presented in this chapter will be diswsed in the following chapter. Their significance for the reconstruction of prehistoric diet and for the archaeology of west central Chihuahua will be presented. The results fiom the botanical and faunal samples will be compared and contrasted with the results from the human samples in order to attempt a reconstruction of the prehistoric diet. Chapter 9 - Discussion

Initial Hy~athtsi. The initial working hypothesis of this thesis was that the prehistoric diet of wes t central Chihuahua was comprised of cultivated resources such as corn, but with a strong presence of gathered ddplants and hunted ands. This was expected due to the wide variety of resources that are available to groups living in the regions of the middle Santa Maria River Valley and around the Laguna Bustillos Basin (Appendix A). It is known that these groups were travelling to distant locations in order to gather he1 and construction mat* (Adams 1992,1998,1999,2000) and it was expected that some CO~M~and gathering of food occurred on these trips. Often there is little evidence for the consumption of a large variety of wild plant speck at the PAC sites (Adams 1999,2000), however considering that many plant species or kq$e plant remains do not survive burial (chapter 5) it is quite possible that the only evidence archaeologists have for the consumption of certain fragde wild plants such as cacti, succulents, or non-processed grasses is by way of stable carbon and nitrogen isotope analysis of human remains. Additional evidence comes hrn ethnographic and archaeological evidence from a wide range of sources and regions (chapter 5) and suggest a variey of cultivated and wild plant resources were used prehistorically by many other cultural groups.

The implications of this working hypothesis on the adaptation of prehistoric populations are many. First populations would not be dependent only on cultivated resources for sustenance. In the event of crop failure, the population would have gathered resources and had the ability to surrrive until the crops could grow or recover. Second, scheduling of activities and movements would have taken wdd resource availability patterns and locations into account. Groups would have moved around and gathered hel, construction material, and food based upon their knowledge of the availability of the resources they requited. Effort and labour would have been divided between agriculture, hunting and gathering. Third, setdements would have been located in areas that were amenable to agriculture, but stiU within reach of the wild resources they required. Many of the remains found in archaeological sites grow in higher altitudes and therefore distance to the hills and mountains would have been rninimised where possible. This pattem of site location is seen in many sites in west central Chthuahua Fourth, population sizes would have remained small to moderate. Without intensive agriculture, population density would have remained low, and settlement sizes small. This pattern of small settlement size is seen in the archaeologcal record in the regions of Santa Maria and the Bustillos basin.

Di~cusn'on This chapter will examine the results of this study and interpret them in terms of the prehistoric adaptation of the populations in west central Chihuahua The results will either fit with the working hypothesis and provide evidence for the aforementioned implications for adaptation and prehistoric lifeways, or will not tit with the working hypothesis and therefore will require alternate hypotheses that couid explain the results that were obtained from the stable isotope analysis.

Botanical Remains Most of the results obtained from the plant samples were expected, based on the knowledge of their use of the C3, C4, or CAM metabolic pathway. However, there are three 6% values that were unexpected. These are outlined in bold in table 8-1. Dasylirion wheel& sotol, (sample numbers 16A and B) and Yucca &Q, yucca, (sample number 19) are succulents, and therefore utilise the CAM metabolic pathway. While CAM plants have the ability to use both the C3 and C4 pathways, it is expected that in this hot climate CAM plants will tend to have 613Cvalues that reflect a reliance on the C4 pathway. Most of the CAM phts that were sampled do fd in the range of the C4 or CAM plants, however the aforementioned sarnpies of Dasplirion wheeleri and Yucca elata do not The 6% values for these plant samples are in the C3 range. The specific habitat of the Yucca plant sampled was d y, sandy, and at a lower elevation. The Dasplirion plant sample was located on the top of a rocky hill. Both of these samples were in habitats with other CAM plants that resulted in stable isotope ratios typical of CAM plants. The reason behind this shift to C3 metabolism is unknown. The environment is dry and hot, and C3 plana are exposed to water and heat stress. The Yucca and Dasylirion plants have the ability to use the CAM pathway in order to combat the stress caused by the hot and dry conditions. Other factors must be at work to cause these plants to shift their mode of photosynthesis to that which seems to be iess adaptive in their particular habitat. Additional samples of Yucca and Dasplirion were collected in 2000 and further research is planned in order to attempt an explanation of these results.

The nitrogen dues were more difficult to interpret, as there is not much in the literature to aid in the expectation of stable nitrogen values. In most cases, the nitrogen dues fdl between 0 and 10Y60, which seems to be normal. If the population subsisted only on plant remains theit stable nitrogen isotope signature would fall 29-60above that of the diet. For those samples that fd.I outside this range, (MCB 01,06, 14, 17,37, 40,45, 51,64,68), the reason is unknown. These may be the nahlral levels for the species, however there may be external factors that are at work. There is the possibility that some species have been affected by the application of fertilisen on crops that inundate ground water or surface run- off-The contents of the agricultural fenilisers may affect the 6''~ value. This only applies to those samples that were collected from locations affected by agricultural practices. Another possibility is that the results were erroneous due to low or high levels of nitrogen within the plant tissues. Perhaps Merresearch stemming from these results will help explain the nitrogen results obtained here.

Faunal Remans Figure 9-1 is a graphical representation of the faunal stable isotope resulrs. The human samples are also included for comparison, and in order to attempt to draw conclusions reprding human diet. snake skin UCH06 skunk Njc MCHW @el- -McH 05 * Sphinx moth Coyote MC~01 duck- --- bird Lepidoptem 0 0 f4 j -j2ckrabbit mule deer Z cottontail J vole a>telope /

FIel. F- end brrmsln -.

Most of the animal species have predictable diets, and therefore the stable carbon and nitrogen isotope results were expected 9-1 ) (Anderson and Knox Jones 1984, Barker 1964, Bellrose 1976, Brown 1982, Buechner 1950, Gallina et al. 1981, Rutgers and Norris 1970, Severson 1981, Stebbins 1%2,1985, Walker 1975). The nitrogen isotope dtsdivide the herbivorous species (rabbi&hare, deer, dents) hmthe catnivorous and omnivorous species (snake, coyote, turkey, skunk). A similar study done by Katzenbetg and Kelley (1991) tested some of the same animal species for 8°C and &"N values. Antelope and deer samples were very sirnilat, however their results for cottontain and jackrabbits were more negative. This could be due to the higher percentage of C4 grasses in west central Chihuahua than in Near Mmcico, where their study took place. Alternatively, the different populations of rabbits and hares may have different preferences for certain psspecies that grow in the ~o regions, thereby causing the variation in stable isotope results. This illustrates the importance of establishing stable isotope values for plants and animals within specific study regions.

The three insects tested had stable carbon isotope values ranging fiom -24.2 to - 27.3%. The isotopic shift from diet to insect ranges from 0 (Fry et al. 1978), to -0.1 (Ostrom et al. 1997). Therefore the plants eaten by these insects were C3 plants with signatures very close to those of the insects themselves. Some herbivorous insects will preferentially consume C3 plants due to their hlgher protein content (Boutton et al. 1978). It is not possible with this study to state whether the insect species sampled were preferentially eating C3 plants over C4 plants due to a higher protein content, or whether the C3 plants eaten were the primary dietary resources for these partidar insect species.

The stable carbon isotope results from the turkey, skunk, and coyote samples are not representative of wild diets. The behaviour and context of these species may aid in the interpretation of these resdts. Skunks are omnivorous and tend to scavenge when possible (Walker 1975). Coyotes are mainly omnivorous and are scavengers, eating rodents and other small mammals (Anderson and Knox Jones 1984). Skunks should exhibit a mid-range stable carbon isotope value, reflecting a mixed diet, while coyotes should exhibit a lower stable carbon isotope value, reflecting a diet based on C3 plant eaters. The nitrogen isotope results for coyote and skunk do conform with an omnivorous or catnivorous diet, however, the samples of skunk and coyote taken for this study exhibit more enriched donisotope values than expected. This could be caused by skunks and coyotes kquenting middens around human habitation, where corn and other C4 plant remains, or remains of C4 plant eating animals, were discarded. A diet similar to that of the human populations explains the similar 6I3Cand S"N values.

The results For the turkey were also not expected. A wild turkey diet (Rutgers and Noms 1970) should have resulted in a stable carbon isotope value in the midrange, likely in the range of-14% to -18%~~.The turkey sampled ate a large percentage of C4 plants. Either this turkey lived in an environment that was rich in C4 plants and ate only those, or it was domesticated. Domesticated turkeys kept near habitations were likely fed grains such as corn. This would lead to an enriched carbon isotope signature such as what is seen in the sample of turkey tested for this thesis. The stable nitrogen isotope value may result from the consumption of insects. Two of the three insects sampled for this study exhibited nitrogen values above 7%. .An alternate hypothesis is that the turkey frequented the middens around the settlement like the coyote and skunk. Among the animals eaten by humans were likely coyotes and turkey. Skunks were Likely avoided due to their distinctive odour. The archaeological data presents a minimum number of three skunks from excavation. Whether these were used as food, ceremonial items, or disposed of to rid the settlement areas of skunk is unclear. It is not clear if turkeys were domesticated, however either way they could have been an important part of the diet.

The results from the stable isotope analysis do not conform to the idea of a population that divided its energies between hunting, gathering many merent wild plant species, and cultivating domesticated resources such as corn and beans. Therefore, the implications outlined at the beginnkg of this chapter are not applicable to these populations.

There ace a number of possible diets that could have resulted in the human stable carbon and nitrogen values, however there are certain considerations that must be made regarding the stable isotope ecology of the region before hypothesising on the probable dietary composition. The sable isotope ecology results and the botanical sample results as shown in Table 8-1, show that the majority of the plants sampled are C3 plants, followed by CAM plants and C4 plants respectively. If groups of people were gathering wild plants, it would be worth the effort to collect ail edible resources in that area (e.g. Bettinger 1991, Hawkes etal. 1982). Thus, they would collect a wide range of resources that would include C3, C4, and CAM plants. The majority of the species flowing in the region are C3 plants (Table 8-1). Therefore, groups who were on collecting trips would likely gather a wide variety of plant species, including a majority of C3 species, followed by CAM and C4 species. Figure 9-2 is a graphical representation of the percentage of the three metabolic pathways in the Plains Grassland zone, the Madrean Evergreen Woodland zone, edible plants that could be found in west central Chihuahua, and those identified kom archaeological contexts (Adams 1992, 1998). Each ecosystem has a different percentage of C3, C4, and CAM plants. This is due to the slighdy different climatic, chemical, and physical characteristics of the three ecosystems. Therefore, the stable isotope ecology of each ecosystem is also different

Figme 9-2. -tagcs of C3, U,and CAM Plants horn DNhcnt Coam@asd on Brown 1991; hchaeologiadmPm; J based on Adoms 1992,1998,1999)

Slight diffetences can be seen between the ecological zones, and among all contexts (Fig 9-2). However, all contexts exhibit a higher percentage of C3 plants than either C4 or CAM plants. While the graphs for the two ecological zones are useful in portraying the oved stable isotope ecology, the graphs representing the edible resources and that for the archaeological remains are more useful in terms of dietary reconstruction. Although the biotic zone of Semi-Desert Grassland is not included in the overall chart, it was initially part of the research design. This biotic zone was analysed because it typities the Casas Grandes River Valley. It is useful to compare the stable isotope ecology of west central Chihuahua and the Casas Grandes River Valley because of the large skeletal collections from the Casas Grandes region, specifically from Paquimk. Eventually, these PaquirnC skeletal collections may be analysed for stable carbon and nitrogen isotopes. While the majority of plant and animal species found in the Casas Grandes region can be found in west cenaral Chihuahua, the relative proportions of C3, C4, and CAM plants is quite different bemeen the regions. This is due to the lower rainfill and the lower altitude, which defines the Semi-Desert Grassland biome along the valley bottoms. Generally, the Serni- Desert Grassland biotic zone has more C4 grasses (1000/0 of the grasses are C4, as opposed to 89% C4 grasses in the Plains Grassland biotic zone), and more CAM plants. These differences between the Casas Grandes region and west central Chihuahua preclude any direct comparison betareen skeletal stable isotope results. Any huestudies of the stable isotope ecology or human skeletal remains and prehistoric diet in the Casas Grandes regions would require a similar study of the local plants and animals.

Although stable isotopes identify the type of plants and animals that contribute to the diet, they can not identifp species. Therefore it is unknown whether the C4 signature is a result of the consumption of a wild C4 plant or the consumption of maize, or whether a C3 signature is bmbeans or a wild C3 plant There are a number of diffirent combinations of plants and animals that when eaten will result in the same stable isotope signature in human bone.

In many locations in west central Chihuahua it is possible to hd;L wide variety of edible plants, including C3, C4, and CAM species. The resulting 613C values of a mixed diet do not conform to the results of the human bone stable isotope analysis. An example of this comes from a small town in the Santa Maria River valley, Independencia, where many botanical samples were collected. On one small rocky h48 different edible resources were identified, including juniper, acorns, lemonadeberry (C3 plants), agave, Mammillaria, prickly pear, and sotol (CAM plants). A diet consisting of these items would have a 8°C value of - l9!%, considerably less enriched in 13C than any detary values seen in this study.

In any study that attempts to compare the amounts of different resources used, either in the past or in modem environments, there is a problem in how the available resources are quantified. In this study, the species were quantified as to their presence, and then to percentage C3, C4, and CAM in a specific context (Figure 9-2). The problem with this is that it does not necessariiy represent the biomass of C3, C4, and CAM resources available to gathering groups. For example, acorn is considered as one species and dropseed grass is considered as one species. However, a stand of oak trees will produce more food than a stand of dropseed grass. Therefore the adnumber of C3 species relative to C4 species does not necessarily represent the amount ofC3 food relative to C4 food avaikble to a population.

Another problem is how the population of the past perceived the resources. Certain individual species, or even portions of certain plants may have been valued or liked more than others. Others may have been taboo or avoided for reasons not apparent to the archaeologist. Another complication is the amount of processing. The required processing for different resources is not equal. Agave hearts must be roasted for days, ground into a powder and then used (Bye et d. 1975), while another resource such as cactus fits may be gathered and eaten with little processing. The amount of herequired to process certain resources may have been a factor when groups chose which resources to gather.

The problems of quantification and community choice based on preference or processing requirements are not easily solved. It is difficult to determine the percentage of the modem biomass represented by one species in a given region, and impossible to determine that of the prehistoric biomass. It is likewise difficult, if not impossible with the present state of archaeological knowledge, to interpret the prehistoric food preferences in west central Chihuahua. Quantification based on percent must therefore be used, with the realisation that biomass is not represented. The assumption that a.U edible plants were considered equal and edible must be made, while remembering that cultural factors may have complicated the issue.

Since the original working hypothesis of this study was found to be inconsistent with the data, alternate hypotheses were evaluated. These evaluations were based on the stable isotope ecology from the results of the available plant and animal resources, as well as the stable isotope results kom the human bone samples.

Dietarv Stabie Isoto~eValues In order to determine the prehistoric diet from the stable carbon and nitrogen isotopes of human bone, it is necessary to estimate what the stable isotope signatures of the prehistoric diet might have been. Although it has been demonstrated that the spacing between diet and bone collagen is 5Ym (Vogel1978, Vogel and van der Melwe l978), it is also understood from rat feeding studies that this value depends on the amount OF protein in the diet (Arnbrose and Norr 1993) and therefore the linear mixing model can not be used to infer dietary carbon isotope values fiom coUagcn (Arnbrose et al. 1997). Carbonate, on the other hand, om be used in a linear mixing model. In other words, the composition of the diet does not affect the spacing between carbonate and diet, and therefore a standard number may be added to the bone carbonate stable carbon isotope value in order to determine the stable donisotope vdue of the diet. This value is 9.4%0, which means that the carbon stable isotope value of the bone carbonate minus 9.4% equals the stable carbon isotope dueof the whole diet (Ambrose et al. 1997).

Using this model, the diet of the populations tiving in west central Chihuahua around 1000 AD can be estimated. As suggested by Ambrose and colleagues (1993, the B'% due fiom the bone carbonate of the human samples minus 9.4%0 gives an approximation of the prehistoric diet. Table 9-1 portrays these potential dietary stable carbon isotope values. It can be seen from this table that the prehistoric diet was quite enriched in '% atoms. The goal of this research is to reconstruct the prehistoric diet, however in this environment, with many sources of "C enrichment, reconstruction of the dietary composition is more difficult.

Tabk 9-1. Whok Diet Smbk Carbon Isotope Values based on Carbonate Results (6% - 9.4%o).

Sample Whole Diet 6% values* MCH 01 -11.2 MCH 02 -14.4 MCH 04 -10.5 MCH 05 -10.8 MCH 06 -1 1.2

'wsults are in units %, precision +/- 1.5%

One way to determine the composition of the prehistoric diet is to construct hypothetical diets with stable carbon isotope values, and compare these values to those from the human bone. The hypothetical diets are composed of dietary components, such as maize, or Cleating animals that are weghted with different values. These diets differ from each other in which dietary items are represented in the diet, and how much of a certain dietary item is represented. Twenty-one of these hypothetical diets were constructed and are presented in table 9-2. 'Maize' was estimated at -11.6%0 after studies done on the range of maize stable carbon isotope values piesen and Fagre 1993). The 6'% value for beans was taken kom the results of this study (-24.5%). Beans and corn were both found at Ch-254, in the Santa Maria River valley. No beans were found at Ch-202 However beans have been found in the Laguna BustiUos basin at Ch-125, therefore it is possible that there was bean consumption at Ch-202, but the evidence was not apparent in the archaeological deposits that were excavated. The value for wild plants (-221%0) incorporates averages for all 29 species tested in this study, without including beans, maize, lyophilised nut samples, and introduced species. The wild plants category includes all plants represented by this study and incorporates C3, C4, and CAM plants. Squash is considered separateiy when the hypothetical diet is composed solely of agricultural products, but is incorporated in the wild plants percentage when they make up part of the diet. Tabk 9-2. Hypothetical Diets and tbcit Rcsultiag Dietary and Bone Smbk Cadx~nIsotope Vducs.

The &st section &nes 1-7) represents vegetarian diets. These are composed of varying proportions of maize, beans, squash and wild plants. The second section (lines 8-21) represents diets of mixed vegetable and meat portions. These diets that incorporate animal and vegetable foods were formed to include W/Ovegetable resources and 20°/' animal resources. 'C4 eaters' and %3 eaters' represent meat hmanimals who subsist on C4 resources and C3 resources, respectively. The next column indicates the resulting 6I3C values of the diet as a whole, calculated by multiplying the stable carbon isotope value of the resource by its proportion in the diet, and summing these numbers for all the components. The last column represents the signatures of human carbonate resulting from each hypothetical diet. While other diets presented in this table may be probable, they are unlikely due to the stable carbon isotope values of the components. Not all potential diets have been portrayed in this table, however it is believed that the range of possibilities have been covered, and it is likely that one of the diets presented here comes close to represendng the prehistoric diet of the populations in west central Chihuahua

Comparing tables 9-1 and 9-2 indicates that most of the hypothetical diets are not enriched enough to represent the prehistoric diet The range of dietary 613C values determined by analysing the stable carbon isotope values of the bone carbonate is -10.5 to - 11.15%0 (excluding MCH 02, which is associated with problems discussed in chapter 6). While there is likely a error hctor associated with these estimated dietary values, the majority of the hypothetical diets are less enriched, and therefore likely do not represent the diet of the prehistoric population.

The hypothetical diets that are highlighted in table 9-2 are the closest to the estimated dietary values determined by analysis of the bone carbonate stable carbon isotope values. Hypothetical diets 1.2, and 4 represent diets of a community subsisting solely on agricultural products. while diet number 3 is constructed only of wild pha. Of these diets, only number 2 comes within the range expected by the stable carbon isotope values of the human bone carbonan. Hypothetical diets 5,6, and 7 represent diets mixed with agricultural and wild resources.

While one of the vegetiuian diets does come close to the expected dietary values (diet number 2). it is suggested by faunal remains in archaeological contexts that meat formed a portion of the prehistoric diet. As mentioned above, the diets numbered 8 througtr 21 represent diets composed of both vegetable and animal resources. It is usehrl to distinguish between animals that ate C3 resources fiom those that ate C4 resources because their inclusion in the diet will have effects on the stable carbon isotope dues of the human bone. Stable carbon isotope analysis of the archaeological hunal remains points to the following animals as examples of those subsisting on C4 plants; birds, turtles, hogs, cottontails, jackrabbits, skunks, coyotes, and turkeys. Animals that subsisted on C3 resources are represented in this sample set by mule deer, while tailed deer, antelope, and insects. The archaeological presence of C3 eaters and C4 eaters suggests that both groups were consumed in the past. However, the relative proportions of C3 and C4 meat in the diet will affect the resulting stable carbon isotope value and therefore also the other possible components of the diet. It can be seen horn table 9-2 that the majority of the diets with both C3 and C4 eaters have stable carbon isotope values that are too negative, with the exception of diet number 20. The presence of meat resources in the prehistoric diet is also suggested by the elevated 6*'~values of the human bone.

While it is possible to get a sufficiently enriched result with the inclusion of only C4 eaters in the diet, there is other evidence &om the human bone stable carbon isotope results that suggest that C3 eaters were an important part of the diet This evidence comes &om the spacing between the carbonate and collagen stable carbon isotope results. Table 8-3 shows the 613C,, spacing ranges from 6 to 9960. As was stated previously, a 613C,,, spacing of more than 4.4% indicates that the protein in the diet comes from a some that is less enriched than the whole diet (Ambrose et al. 1997). In other words, the dietary protein comes hma C3 source, while the whole diet is dominated by a C4 source. It is possible that the C3 dietary protein source may be beans, as beans contain more useable protein than does maize, however, it is more likely that the C3 dietary protein source is animals subsisting on C3 resources. This would hi&l&t diet number 20, composed of corn, beans, C3 eaters and C4 eaters, as the most likely representation of the prehistoric diet in the study region.

While diet numbers 9, 18, and 19 also fall within an acceptable range, they do not contain an adequate proportion of C3 protein to account for the 6"~,, spacing seen in the human bone samples. Furthermore, diet number 9 is unlikely because it represents corn agriculture without bean agriculture. There are a number of reasons why this is improbable. There are three main advantages to including both beans and corn in the diet. Firs& beans are high in the amino acid lysine, which is limiting in corn. Second, beans contain tryptophane, which is present in corn however can be removed through certain processing techniques, such as those used in making tortillas. Eating corn and beans together would provide a more complete source of amino acids than eating only corn. Third, growing beans in the same fieIds with corn will replenish the soil nitrogen because beans are legumes and therefore fix nitrogen (Kaplan 1969)- Beans are not as visible archaeologicdy, because the processing techniques used to cook beans do not result in as much charring as those that are used to cook corn. However, in areas where bean domestication has been documented, it is probable that most populations were probably subsisting on a combination of corn and beans. The proportion of corn and beans has been estimated through ethnographic observation as approximately 30 to 120 gr;uns of beans for 500 grams of corn (Kaplan 1969).

There is an alternate possibility that cannot be displayed in table 9-2 The population may have subsisted mainly on cultivated resources, such as corn, while collecting edible weeds that grew in the disturbed habitats around the fields and habitations (Widken 1970). This hypothetical diet cannot be portrayed in table 9-2 because not all of the wild plants that were sampled thrive in disturbed habitats. The hypothesis can not take into account all of the wild plants in the region, but only those that may be encountered in the disturbed habitats near the fields and settlements. Organised gthering groups that went mykom the setdement would have concentrated on the collection of he1 and construdon mated. Opportunistic gathering of edible plants occurred when they were discovered growing nearby and were harvested both to rid the field of weeds and to provide exaa sustenance. However, this hypothesis does not correspond with the stable isotope data from the plant remains and the hwnan skeletal remains. A sumey of those collected plants that flourish in disturbed habitats provides a list that includes many C3 plants as well as C4 plants. Table 9- 3 provides a short list of those species. If these gathered species were significant to the prehistoric dief then the 6% values of the human bone would reflect a larger C3 contribution to the diet Tabk 9-3. Species That Grow in Disturbed Habitus * C3 Plants c4/CAM PIants Chenopodiurn Amaran thus Lotus Portulaca Mustard Apodan them Oenotheta

From figure 9-1, it can be seen that the humans are isotopically closer to the animals eating C4 phts (turkey, skunk coyote, cottontail and jackrabbit) than those eating C3 plants (antelope and deer). The results from the bone stable carbon isotope analysis suggest that the diet was a combination of CIeating animals, some CQ-eatinganimals, beans and corn.

Although quite similar, there are slight differences between the human diets in the two regions that were sampled. While the whole diets of all individuals is ve y similar, as shown by the carbonate values, the collagen portion of the bone exhibits differences. These ~erencesmay be exhibited due to the small sample sue. The La Cruz population at Ch- 202 is represented by only one sample, and this individual was a juvenile. The differences between it and those &om Ch-254will be discussed here, however it is stressed that Mer samples need to be tested before any of these particular conclusions can be confirmed. The sample from the La CCUZsite (Ch-202,MCH 01) has collagen that is less enriched in 13C dun are the samples from the Chihuahuan Culture site (Ch-254,MCH 04,05, 06). This indicates that the protein source of the La Cruz site inhabitants contained more C3 resources. This could either come in the form of C3 plants or animals eating C3 plants, or alternately less C4 plants, or less animals eating C4 plants. The stable nitrogen isotope values give information on trophic level, or amount of meat in the diet, and in this case show that the individual living in the Bustillos Basin (MCH 01) ate less meat than did the population living in the Santa Maria valley (MCH 04,05,06). The slight differences between the regions in the stable nitrogen isotope results and the stable carbon isotope resulrs from collagen seem to indicate that the populations living at Ch-254 in the Santa Maria River valley were eating more meat than the populations living at Ch-202 in the Bustillos Basin, and those animals that were consumed were eating C4 resources. These animals may have been those which exhibited a similar isotopic value to the humans, namely turkey and canid. While the archaeological evidence su~ststhat wild plants may have had some contribution to the die&it is unlikely that they formed any major role in the everyday subsistence strategy, and that the prehistoric populations were dependent on cultigens. The edible wild plant parts most ofien found in PAC archaeological contexts became incorporated with other parts of the plant used for fuel or construction, such as the presence of juniper berries due to the use of juniper in construction and as fuel. The populations of the region probably did use wild plants to a minor degree for such things as tonics, infusions, medicines and condiments. The techniques employed here only detect the major components of the ancient diet, and do not provide evidence for or against the minor usage of plants.

It is not Wrely that insects formed a large part of the diet. As can be seen from Figure 9-1, insects have very negative 6I3C values. Any considerable consumption of insects would shift the carbon isotopic signature significantly. Although insects comprise a potentially important food source, as Bodenheimer (1951) suggested, insects were not an important food some for Northem Mdcan groups.

The importance of the freshwater mussels to the prehistoric diet in the Santa Maria river valley is unknown. It is possible that they were very important as shown by the large volume of shell collected at Ch-254. Historically and ethnographically (Wie et al. 1975), this species of freshwater bivalve has been included in the diet. However, because the mussels no longer inhabit the region, it was not possible to collect the meat or test it. These mussles were formerly found in southwestern waterways but changes in the environment, specifically the level of the watertable, have caused them to disappear (A. Vokes pers. comm.).

Therefore, the stable isotope data taken in conjunction with the archaeological data suggest a diet composed of corn, beans, and meat. Both C3 and C4 eaters were available to the prehistoric populations, and were exploited as shown by the presence of bones in the archaeologcal sites. Some C3 eaters must have been eaten to produce the carbonate- collagen spacing seen in the human bone and it is likely that C4 eaters were also consumed, due to the enriched carbon stable isotope results. It is possible that the populations in the Chihuahuan Culture site of Ch-254 ate more C4 eaters than did the La Cruz populations at Ch-202 The C4 eaters were probably the animals found around the fields and settlements such as rabbits and hares, coyotes and turkeys. This is consistent with the conclusions drawn kom a study of the zooarchaeological remains fiom El Zurdo (Hodgem 1996).

The sample MCH 02 represents a young child of unknown age. The diet of this individual may have been different than that of the other individuals that were sampled. The stable carbon isotope results of the bone carbonate of MCH 02 is much less enriched in "C than the other samples (table 8-5). If the diet of MCH 02 was composed of more C3 resources and less C4 resources than other individuals, it is possible that it may be explained by a weaning diet including more beans than the general popdation ate, or alternatively of some other specialised weaning food that was made up of C3 resources. Another explanation for the difference in stable carbon isotope results could be the lack of meat resources in the diet of MCH 02 Removing the consumption of C4 and C3 eaters fiom the diet would lower the C4 resources in the diet Although the C3 resources in the diet would also be reduced, this may account for the difference seen between MCH 02 and the other samples if the general population was eating a significant amount of C4 eaters. Hypothetical diet number 1 presents a resulting sable isotope signature of -14Y60and includes 80% corn and 20% beans. Hypothetical diet number 20 indudes the same proportion of corn and beans, but with the inclusion of C3 and C4 eaters. This diet results in a dietary stable carbon isotope signature of -13%. This is one possible explanation for the stable carbon isotope signature of human sample MCH 02

Therefore, it is suggested that hypothetical diet number 20,which is composed of 72% corn, 8% beans, 10°/o C3 eaten, and 10% C4 eaten, is the most likely representation of the prehistoric diet of populations inhabiting west central Chihuahua Wild resources provided litde contribution to the diet. This same pattern is exhibited to some degree by Medio period sites in the Babicora Basin (Abonyi and Smith n-d.). Human bone samples from El Zurdo (Ch-159) and San Juan (Ch-216) were tested for stable nitrogen and carbon isotope values, however no stable isotope information was collected from plants or animals in the region. The stable carbon isotope values of collagen from six individuals are similar to those kom Ch-254, ranging fiom -7.3 to -8.7%. The stable nitrogen isotopes fiom EL Zurdo and San Juan in the Babicora Basin are lower than those from Ch-254 (MCH 04,05,06). It is difficult to interpret this diffwence in the absence of comparable faunal stable isotope values, however it is apparent that the meat portion of the diet for these two populations (Ch-254 and Ch- 159/Ch-216)were not the same. The animals eaten at Ch-254 in the Santa Maria River valley had higher stable nitrogen isotope values, and these were then passed along to the human consumers. This may be due to a higher proportion of aquatic animals in the diet of the individuals at Ch-254 as compared with a diet of field animals such as rabbits and deer at Ch-159 (Hodgem 19%). Turkey and canid bones were recovered at both Ch-254 and Ch- 159 (Hodgetts 19%), however it is possible that the canids and turkeys around Ch-159 and Ch-216 were eating resources lower on the trophic ladder than were the canids and turkeys around Ch-254. The canid and turkey bones tested for this study Crom Ch-254 had high stable nitrogen isotope values, and this may have contributed to the high value ofthe human stable nitrogen isotope values. Chapter 10 - Conclusions This research used evidence from archaeological, faunal, botanical, and chemical sources and has provided evidence that strengthens and adds to the archaeological dietary evidence fiom west central Chihuahua The archaeological resources from sites in the Bustillos basin and in the Santa Maria river valley suggest that populations living in these areas fiom around 800 - 1300 AD were growing corn and beans and hunting local animals. The extent of wild plant gathering is unclear fkom the archaeological evidence. The sable isotope research suggests that the main contributors to the diet were corn and beans, with animal resources also of some importance. However, these results do not suggest that prehistoric populations were collecting wild plants to any large extent The conclusion drawn here differs kom the initial hypothesis of this thesis. The initial hypothesis suggested that prehistoric populations were gathering wild plants to supplement their agricultural products.

The human remains originated fiom sites that date to the Viejo period. Two radiocarbon dates from Ch-202 gave an age ranging fiom 860 to 1210 AD. The twelve radiocarbon dates fiom Ch-254 taken together result in a large time range from 760 to 1300 AD. This knowledge is useful because it is dear fkom the current study that the Viejo period and La Cruz populations in west central Chihuahua were dependant on agriculture. The comparison of the results of this study with those stable isotope results from an earlier study of human bone samples kom El Zurdo and San Juan in the Babicora Basin may help illuminate changes over space and time.

The similar carbon isotope values of Viejo, Medio and La Cruz sites indicates a stability over space and time in consumption of maize and beans. The slight differences among all sites in nitrogen stable isotope values indicates a difference in the exploitation of animal resources. Whether this is due to the resources available to each, or due to internal cultural or ideological differences is unknown. Given the similarities in other aspects of diet, and the differences between the La Cruz, Viejo and Medio mated culture, it is difficult to answer this question. The specific animals that were hunted and consumed were likely those found near to the fields such as rabbits, those animals that subsisted on C3 resources, such as deer, and those that had similar stable carbon and nitrogen values to the human values, specifically coyote and turkey. These sidaritjes could be interpreted in moways. Fiic the sirnilanties could mean that the coyotes, and turkeys were kequenting the middens around hurnan settlements and were therefore eating the same food as the humans. Whether the human populations were eating these animals or ignoring them is unclear. The proximity of the andsto human settlements would have made them mytargets for hunten, however the 6''~values of the human samples and the turkey, skunk and coyote do not display the usual

29/60 separation between trophic levels (Figure 9-1). This may imply that these animals were not being consumed by the human population. However, the small sample size of coyote, turkey, skunk, and humans precludes any conclusions on this point. Second, the humans could have been feeding these animals similar food to what they themselves were eating. This implies domestication. While domestication of skunks is unlikely, it is entirely probable that the populations here were domesticating turkeys and maybe coyotes or dogs. The turkeys may have been used for food, or for ceremonial purposes. Turkey domestication is seen in a number of sites, most notably at El Zurdo in the Babicora Basin (Hodgets 1996), and in the heas Grandes valley, specifically at Pa+& (Di Peso et al. 1974). Although there is no direct evidence for the domestication of canids in Chihuahua, the 2000 field season, a puppy was found buried in a pit in ashy midden deposits (Kelley et al. 2001). The location of this site (Ch-240)is in the Santa Maria river valley. This may indicate a degree of dog domestication, or of tolerating coyotes near the setdement and of Qbing care of the young. Domesticated dogs have been found elsewhere in the New World, and seem to date to the migrations from the Old World (Olsen 1974). It is unknown to what degree turkeys, coyotes or skunks contributed to the human diet, however it is plausible that these species were readily found near human settlements and scavenging in the middens.

The implications for the adaptive strategy of the populations living in west cenaal Chihuahua are different from what was initially expected. These populations, while not involved in intensive agriculture, were committed to an agricultural lifestyle. There is evidence that they were making trips into the surrounding mountains and hills for fuel and construction material, however food collection did not happen to any large extent Most often, sites consist of a small number of mounds which ltkely hold the remains of a small number of structures. The problem in determining the size of sites and settlements in west central Chihuahua is that there is not enough time or money to completely excavate the sites. Ch-254 in the Sanm Maria valley was only partially excavated and exposed four structures. The complete site may hold many more structures, however this will likely not be invesdgated in the near hture. The reasons for the small to moderate settlement sizes seen in west central Chihuahua is not due to a limited wild hod supply. The potential for the prehistoric populations to setde large villages was therefore not limited by subsistence strategies. Agriculture seems to have been the main source of food, and therefore the intensification of this industry could have sustained large populations. The factors limiting population size could have included soil capabilities, water availability, or in temal fktors such as ideology, kinship and marriage patterns, or politics.

The knowledg! that these populations relied on agriculture aids in site location and interpretation of regional settlement patterns. An agriculd setdement would need to be located on arable land near a water source. There is no known irrigation technology in this specific area, except for one site, (Kelley et. aL 1999b) and the fields were likely watered by rainfall. Sumey for ceramic period sites should be, and is, concentrated dong watenvays in basins and valleys and along the lower slopes of the ranges. Water and anble land are most plentiful here and this is likely where the populations would have chosen to setde. These populations would have been dependant on agricultural products. They would have been vulnerable to environmental changes that affected the viability of their subsistence strategy such as droughts, or flooding. If this was the case, then climatic fluctuation could have been the reason for the ultimate abandonment of the area before the arrival of Europeans.

Although the sample size of human bone was small, the 6'% and 6''~values of the human samples from the two regions studied (Bustillos basin and the Santa Maria river valley) will aid in the interpretation of certain points in the regional prehistory ofwest central Chihuahua. Archaeologists are attempting to understand the lack of Casas Grandes characteristics in the Bustillos basin that are present in the Santa Maria river valley. The 8°C and 6''~ values fkom the human samples were very similar, with slight differences (table 8- 5). This indicates that the populations in the two ateas had sunilar diets, likely both subsisting on corn and beans, and hunting deer, rabbits and hares around the fields, while in the Santa Maria River valley, perhaps eating or domesticating coyotes and turkeys. Potential differences lie in the source of animal protein, however conclusions regarding geographical diffaences are severely limited by the small sample sizes. The archaeological differences that are observed between these two regions are not due to a difference in adaptational strategy, because both populations were centred on agriculture and local hunting. The populations living in the Santa Maria river valley and in the Bustdlos basin ate the same items and grew the same agricultural products.

Consideration of the stable isotope ecology of the local region is important when examining the stable carbon and nitrogen isotopes for dietary reconstruction of prehistoric populations. In this case the two regions under study were similar in their stable isotope ecology. Individuals of the same species growing in the different regions had simitar carbon isotope dues. This is usefd information because hture research in west central Chihuahua can use these or other stable isotope values and apply them to their research objectives without having to test for the 6°C and 8% values of plants in another nearby region.

J-ocy This research focused on the prehistoric diet of two regions within west central Chihuahua and how this aids in the interpretation of the entire region. It was discovered that the prehistoric diet ofwest central Chihuahua centred on corn and beans, with input hmdeer, rabbit and other animals that frequented fields and settlements. This diet seems widespread across the region and is similar to that seen in the Casas Grandes valley. Appendix A - Plant Species of West Central Chihuahua

1, Phias Gmsshnd Taxon Common Name Group Met. Path. Rofemnce Comments Argemone Prickly poppies "W88dsw C3 Artemisla sp. Sagebnrsh Sh~b C3 Bender 1971 Bahia Bahia Forb C3 Brickellia Bricklebush Forb C3 Ceratoides lanata Winterfat Shrub C3 ' Chrysatharnnus (Cornpositae) Rabbittuush Shrub C3 Smlth and Epstein 1971 Ctlsium Thistle "Wee&ia C3 Cleome SpMerflower Forb C3 Gaura Gaura Forb C3 Gutiemzia Snakeweed Shrub C3 schuster el. al. 1982 ref for G. microcephala I Juniperus Junipers Shrub C3 Juniperus monosperma, J. Junipers Shrub C3 scopulorum, Juniperus osteospema J Koeleria cristata Prairie Junegrass Grass C3 Volln et all988 MiraMlis Four O'clock Forb C3 Welkie and Caldweli 1970 Oenothera Primrose Forb C3 Oryzopsis hymenoides Indian Rice Grass Grass C3 Matson and Chisholm 1981 Psoralea Scurfpea Forb C3 Ratibida Coneflower Forb C3 Rhus copallina vat, lanceolata Prairie Sumac Sh~b C3 Rosa sp, Wild rose Shrub C3 Tieszen 1994 Sphaeralcea Mallow Forb C3 Viguiera Golden-eye "Weedsm C3 Legume Atdplex canascens Four-wing Saltbush Sh~b U Katzenberg and Kelley fa01 Bouteloua gracilis Blue Grama Grass Grass U Buchmann el. el. 1886 '~outelouahinuta, 0. chondrosioides, Other Grama Grasses Grass C4 Buchmann el. af 1996 Bouteloua eriopoda, 6. curtipendula Buchloe dactyloides Buffalo Grass Grass C4 Downton 1975 Eragrostis intermedia Plains Lovegrass Grass C4 Downton 1875 Helianthus Sunflowers "Weeds" C4 Tieszen 1904 Lycurus phleoides WolftailKexas Timothy Grass C4 Downton 1975 Panicum obtusum Vine Mesquite Grass Grass C4 Had et, al. 1998 Sporobolus aimides Alkali Sacaton Grass C4 Buchrnann el. el. 1886 I Hilaria jamesii Galleta Grass Grass C4' 'ref for H.belangeri and mutica Senecio (Compositae) Groundset "Weedsw C4' Bender 1971 ref for S. gregori Asteridae Aster Forb C41C3 Welkie and Caldwell 1070 Echinocereus fendleri, Echinocereus Hedgehog Cadus CAM engelmannil var, variegatus I Opuntia Cholla Cadus CAM Opuntia imbricata, Opuntia whipplei, Cholla Cadus CAM 0,strobiliformis -15.7 0,arbuscula Opuntia macrorhiza Plains Prickly Pear Cadus CAM Bender 1971 Opuntia phaeacantha Engelmann Prickly Pear Cactus CAM Pediocactus papyracant hus Grama-grass Cadus Cadus CAM Yucca glauca Soapweed Shrub CAM 2. Madflat1 Eve~tlpefi- Woodland Tanon Common Name Group Met. Path. Reference Comments Arbutus arizonica, A, texana Madrono Tree C3 Arctosta~hvlos~unaens IPointleaf manzanita ITreeIshrub I C3 I On eroded soils .. . - 1 I m I Artemisla ludovicisna lloulsana saaebrush 1WWShruWForb 1 C3 1

I I 1 I Cassia IePtocama lSenna ll'hornscnr b I C3 I Rocky slopes

Cercocamus montanus IAlderleef mountain maho~anvITree/shrub I C3 I On eroded soils Cowanla mexicana lcliffrose 'shrub C3 On eroded soils Dalea Indlgohshes Wee d~ShnrbForb C3 Dodonaea viscosa Hopbush Tho1 ~smb C3 Rocky slopes

Eriagonum Buckwheats m Wee I/Shnrb/Forb C3 I I~wthdnaflabelliformis 1Southwestern coral bean 1Tho1ismb C3 Rocky slopes I l~~senhardtiaorthocarpa KMneywood Tho1 '~mb C3 Rocky slopes Game wriahtii WrinM's silktassel Tree 'shrub C3 On eroded soils Hibiscus IRowt-mallows lWee dfShfublForb C3 Lupinus Lupines Wee VShrubForb C3 Mimosa biuncifera Wait-a-minute Thor ~scnrb C3 Rocky slopes . m Mimosa dysocama ]Velvet-pod mimosa IThomscnrb I C3 I Rockv slopes

1 I Penstemon Penstemons WeedISh~WForb C3 '~haseolus Beans WWShrublForb C3 Rhamnus betulaefolia Birchleaf buckthorn Tmelshrub C3 On eroded soils Rhus choriophylla Meams sumac Treelshnr b C3 On eroded soils Rhus trilobata Skunkbush sumac Treelsh~b C3 On eroded soils ,Salvia sage WeedlShrublForb C3

- - . . - - - . . - - . - - .. - - - - Vauauelinia calfomica Arizona rosewood Tdshrub 1 C3 I On eroded soils ~unihrusdeppeana Alligator-bark juniper Tm C3 Pinus enalemannii A~acheoine Tree C3 Pinus lieophytla var. chihuahua Chihuahua pine Tree C3 Durango Pine 1ree C3 W Mexico Pino Triste Tree C3 W Mexico Quercus albocincta, Q. emoryi, Q. Oak Tree C3 (nuts) arizonica Quercus chihuahuensis Chihuahua oak Tree C3 (nuts) Most common Quercus chuchiuchupensis, Q. Oak-deciduous Tree C3 (nuts) santadarensis Quercus toumeyi Tourney oak Treelshnrb C3 (nuts) On eroded soils Quercus viminea, Q. Oak-high elevations Tree C3 (nuts) hypoleuciodes, Q. pennivenia, Q. epileuca, Q. fulva, Q, rugosa . Eragrostis intermedia Plains lovegrass Grass C4 Raghavendra and Lower elev,ref is Das 1978 for E. mexicana Heteropogon contortus Tanglehead Grass C4 Downton 1874 Lower elevations Leptochloa dubia Green sprangletop Grass C4 Buchmann et. al, Lower elevations 1896 Lycurus phleoides Wolftail Grass U Downton 1975 Lower elevations Schizachyriurn scoparium Little bluestem Grass C4 Volin et al 1998 Lower elevations Bouteloua curtipendula SMeoats grama Grass C4 Buchmann et. al. Lower elevations 1886 Bouteloua gracilis Blue grama Grass C4 Buchmann et. at. Lower elevations 1896 Bouteloua hirsuta Hairy grama Grass U Buchmann et. a!. Lower elevations 1886 Etyonurus barbicutmis Woolspike Grass C4* Raghavendra and Das 1078, ref for E, roy leanus Muhlenbergia emenleyi, M, toreyi, Muhlys Grass C4 Van Oevender et al. 1990 Meported Agave palmed Palmer agave Cadus/Succulent CAM Agave parryi Parry agave Cadus/Succulent CAM Coryphantha recunrata Hen and chicks cactus Cectus/Succulent CAM Echinocereus pecinatus var. Rainbow cactus Cadus/Succulent CAM rigidissirnus

Taxon Common Name Group Met. Path. Reference Comments Abies concolor White fir Tree C3 Achillea lanulosa Yarrow Forb C3 Smith and Epstein 1071 Bromus anornalus Nodding brome Grass C3 Watson and DalMtz 1092 onwads Bromus anomalus Nodding brome Grass C3 lDisturbed Bromus ciliatus Fringed brome Grass C3 Watson and DalM1992 onwards Bmmus marginatus Mountain brorne Grass C3 IDistuturbed Ceanothus fendleri Fendler ceanothus Shrub C3 Smith and Epstein 1071 Chimaphila umbellata Pipsissewa Sh~b C3 Undisturbed Deschampsia caespitosa Tufted hairgrass Grass C3 Disturbed Festuca arizonica Arizona fescue Grass C3 An el al. 1982 Frageria ovalis Wild strawberry Forb C3 Frageria ovalis Wild strawberry Forb C3 Disturbed Juniperus deppeana Alligatorbark juniper Shrub C3 - - - Koeleria cristata Prairie junegrass Grass C3 Volin et al. 1988- Lathyrus arizonicus Arizona peavine Forb C3 Legume Lathyrus graminifolius Grassleaf peavine Forb C3 Legume Lupinus sp, Lupines Forb C3 Legume Picea englemannii Engleman spnrce Tree C3 I Picea pungens Blue SPNW Tree c3 Pinus englemannii Apache pine Tree C3 - - -. - Pinus leiophylla var. chihuahuana Chihuahua pine Tree C3 Pinus ponderosa Ponderosa pine Tree C3 Pinus ponderosa Ponderosa pine Tree C3 Pinus strobiforrnis southwestern white pine Tree C3 Poa pratensis Kentucky bluegrass Grass C3 Smith and Brown 1973 Populus tremuloides ,Aspen Tree C3 Potentilla concinna Elegant cinquefoil Forb C3 Pseudotsuga menziesii Douglas-fir Tree C3 Pseudotsuga menziesii Douglas-fir Tree C3 Quercus fulva, Q, pennivenia, Q. Oaks Tree C3 arizonica, Q. grisea, Q. viminea Quercus gamelii Gambel oak Tree C3 Quercus hypoleucoides Silverleaf oak Tree C3 Quercus nrgosa Netleaf oak Tree C3 Ribes aureum Golden currant Shrub C3 Ribes pinetoam Orange gooseberry Shrub C3 Ribes viscossissimum Sticky currant Shrub C3 Sitanion hystrix Squirreltail Grass C3 Watson and Dallwitz 1992 onwards Stipa pringlei Pringle needlegrass Grass C3 Watson and DalM1992 onwards Taraxacum officinalis Dandelion Forb C3 Thomas el al, 1888 Trifolium rusbyi Rusby clover Forb C3 'Lqjume Vicia americana American vetch Forb C3 Legume

Viola adunca --Hook violet C3 UndlstuM Viola canadensis Canada violet C3 Undisturbed Mexican white pine Tree C3 Poa fendleriana Mutton bluegrass Grass C3* Smith and 'ref for P. secunda EpsteJn 1871 Blepharoneuron tricholepsis Pine dropseed Grass C4 Watson and DalW 1982 onwards Carex geophila Dryland sedge Grass C4 Smith and Epstein 1971 1 Cypenrs fendlerianus Fendler flatsedge Grass C4 Smith and Epstein 1971 Muhlenbergia minutissima Littleseed muhly Grass U Van Devender et al. f 890 Muhlenbergia montana Mountain muhly Grass C4 Van Devender et al. 1980 Muhlenbergia virescens Screwleaf muhly Grass C4 Van Devender el al. 1880 Panicum bulbosum Bulb panicurn Grass C4 Downton 1975 Agrostis scabra Rough bentgrass Grass Disturbed Arbutus arizonica Madrone Shrub Berberis repens Creeping mahonia Shrub Ceanothus huichugore Buckb~sh Shrub Erigeron divergens Spreading fleabane Forb Erigeron flagellaris Trailing fleabane Forb Erogeron macranthus, E, concinnus, Fleabanes Forb E. forosissirnus Geranium caespitosurn Purple geranium Forb I Goodyera oblongifolia W. rattlesnake plantain Shrub Undisturbed Heuchera rubescens, Haversicolor Alummots Shrub Undisturbed Holodiscus dumosus Bush rock spirea Shrub Mertensia franciscana Mountain bluebell Forb -- Physocarpus monogynus Nlnebark Sh~b Polygonum sawatchense Sawatch knotweed Forb Pseudocymopterus montanus Mountain parsley Forb Pteridum aquilinum Bracken fern Forb Pterospora andmmeda Pinedrops Forb

Pyrola virens Pyrola Shrub Undisturbed- -- Rhus glabra Smooth sumac Shwb Sambucus cerulea Blue elderberry Shrub Sam bucus velutina Velvet elder Shrub Senecio neomexicanus New Mexican groundsel Forb Smilacina racemosa Feather solomonseal Shrub Undisturbed Symphoricarpos longifolia Longflower snowberry Shnrb Symphodcarpos oreophilus Mountain snowberry Shrub Symphoricarpos oreophilus Mountain snowberry Shrub Disturbed Symphoricarpos rotundifolius Roundleaf snowberry Shrub I Symphoricarpos utahensis Utah snowberry Shrub I Thalictrum fendleri Meadownre Forb Valeriana arizonica Undisturbed

. 1970

Bufo cognatus Great plains toad RIA moths, flies, beetles, other Stebbins 1962 inseds Cnemidophorus sexlineatus viridis Prairie-lined racerunner RIA beetles, crickets, grasshoppers Barker 1964 Crotalus viridis viridis Prairie Rattlesnake RIA Carnivore-vert Cloudsley-Thompson 1091 Diadophis punctatus amyi Prairie ringneck snake RIA Worms, small rla Shaw and Campbef t 1974 Elaphe guttata Corn snake RIA Rodents Shaw and Campbell 1874 Eumeces obsoletus Great plains skink R/A insects, spiders, mollusks, Stebbins 1885 lizards Heterodon nasicus nasicus Plains hog-nose snake RIA Amph. Shaw and Campbell 1874 Holbrookia maculata Lesser Earless Lizard RIA spiders, grasshoppers, beetles, Stebbins 1962 ants, butterflies, centipedes, sm. IizaFds Masticophis flagellum testaceus Western Plains milksnake WA Carnivore-vert Cloudsley-Thompson 1981 Pituophis melanoleucus sayi Bull snake R/A Camivote-rodents Cloudsley-Thom pson 1891, Shaw and Campbell, 1874 Scaphiopus bombifmns Plains spadefoot RIA flies, bees, moths, beetles, Stebbins 1962 spiders Scoloponrs undulatus consobrinus Southern Prairie Lizard RIA fnseds, spiders, ticks, millipedes, Stebbins tQ85 snails, sm. lizards Sonora episcopa episcopa Great Plains ground snake RIA Insecls Shaw and Campbell 1974 Tantilla nigriceps Prairie blackhead snake RIA Inseds, worms Shaw and Campbell 1974 Terrapene omata Western box turtle RIA ve~,mushrooms, snails, worms, Barker 1W grasshoppers, other insects, bellies Taxon Common Name Group Diet Refs Nasua nasua Coati Mammal roots, shoots, acorns, fruit, insects, Anderson and Knox Jones 1984 crustaceans, rla, birds, sm. Mammals -- Odocoileus vimlnianus IWhite-tailed deer Mammal C3 plants Gallina et.al. 1981.

Pewnathus beileyi IBailey's pocket mouse Mammal seeds- - - - - and- - veo I Anderson and Knox Jones 1984 - - Sciunis nayariti~is~~~IAp-e squirrel Mammal ]Anderson and Knox Jones 1964 1 SV@i?Lonochrogriathus IYdlow-nosed cotton rat Mammal 'crrass, mots, seeds, berries, fruit, IAnderson and Knox Jones 1884 1 I iun~~,arthropods, sm. vert. I I Syl~ila~~~floridanus IEastem cottontail Mammal grass Anderson and Knox Jones 1884 Anderson and Knox Jones 1984 T~O~O~YSumbrinus Isouthem wcket no~her Mammal roots, tubers, fobs 1 Mammal iomnivore ]Anderson and Knox Jones 1884 1 lAmezilla violiceps IViolet crowned hurnrnin~bird Bird nectar and sm. inseds Udvardy and Knopf iAphelocoma ultramarina Mexican jay Bird acorns Udvardy and Knopf Columba fasciata Band-tailed ~iaeon Bird acorns, berrles Rutgers and Norris 1870 Cvrtonvx montezuma IMontezuma auaH Bird beds, veg, brries Rut~ersand Nonjs 1070 Bird inseds Udvardv and Kno~f Bird inseds IUdvardv and Knoof I Eugenes fulgens Rivoli's hummingbird Bird nedar and sm. insects Rutgers and Norris 1970 ~ylochadsleucotis White-eared humminabird Bird nectar Udvardy and Knopf Bird acorns Udvardy and Knopf Meleagris gallopavo mexicana Gould's turkey Bird berries, fruit, tubers, seeds, grains, Rutgers and Norris 1970 I worms, snails, insects, sm, vert, lotus Mchopsis IWhiskered owl Bird rod* Udvardy and Knopf Parus dated Mexican chickadee Bird inseds, seeds, berries Udvardy and Knopf 'parus wollweberi Bridled titmouse Bird iuniwr and elderberries Udvardv and Kno~f

Picoides arizonae Arizona woodmcker Bird-

Piranga flava Hepatic tanager Bird Ilnsectp-- --- IUdvardv and Kno~f I

Psaltri~arusminimus Bushtit Bird- linsects. seeds. berries iudvard; and noi if I Sialta mexicana lWestern bluebird Bird inseds. weed seeds IRutners and Norris 1970 I Trogon etegans Coppery tailed trogon Bird tnseds and sm. Fruit Udvardy and Knopf Vermivora crissalis Colima warbler Bird Insects Udvardy and Knopf Vireo huttoni Hutton's vireo Bird Cmtalus lepldus Rock rattlesnake RIA Carnivore-vert Cloudsley-Thompson 1881 Crotalus pricei Twin-spotted rattlesnake WA Carnivore-vert Cloudsley-Thompson 1801 Crotalus willardi Ridgenose rattlesnake WA Carnivore-vert Cloudsley-Thompson 1981 Elaphe triapsis Green rat snake WA Rodents and Mrds Shew and Campbell, 1874 Eumeces callicephalus Mountain skink WA insects and spiders Stebbins 1985 Elaphe triapsis Barking frog WA beetles, spiders, ants Stebbins 1962 tampropeltis pyromelana Sonoran mountain kingsnake RIA Carnivore-rodents Cloudsley-Thompson 1991, Shaw and Campbell 1974 Phrynosoma ditmarsi Dimafs homed lizard WA sm. insects and ants Barker 1964 Rana tarahumarae Tarahumara frog WA turtles, fish Stebbins 1882 Salvadora grahamiae Mountain patchnose snake RIA Lizards, mice Shaw and Campbell, 1974 Scleroporus clarlti Clark's spiny lizard WA insects, leaves, buds, flowers Stebbins 1985 Scleroporus jarrovi Yarrow's spiny lizard WA insects and spiders Stebbins 1985 Scleroporus scalaris Bunchgrass lizard WA insectsandspiders Stebbins 1985 Sceloporus virgatus Striped plateau lizard RIA insects, centipedeslother arthropods Stebbins 1885 Tantilla wilcoxi wilcoxi Huachuca blackhead snake WA Insects, worms Shaw and Campbell, 1974 Thamnophis eques Mexican garter snake WA Frogs Shaw and Campbell, 1974 A 3. Madna?~Montane Cor~firFotrst Taxon Common Name Group Diet Refs Comments Canis lupus Gray wolf Mammal Possibility Citellus lateralis Golden-mantled ground squirrel Mammal Possibility i .Eptesicus fuscus Big brown bat Mammal Mixed Conifer Erethizon dotsaturn Porcupine Mammal Yellow Pine Eutamias canipes Gray-footed chipmunk Mammal I Eutamias cinereicollis Gray-collared chipmunk Mammal Eutamias quadrivittatus Colorado chipmunk Mammal Eutamias umbrinus Uinta chipmunk Mammal Microtus lonicaudus Long-tailed vole Mammal Microtus mexicanus Mexican vole Mammal Micmtus montanus Montane vole Mammal Myotis auriculus Southwestern myotis Mammal Mixed Conifer Myotis evotus Lonpeared myotis Mammal Mixed Conifer . -- Myotis volans Long-legged myotis Mammal Mixed Conifer Neotoma mexicana Mexican woodrat Mammal Possibilit y Odocoileus hemionus Mule deer Mammal Possibility Odocoileus virginianus White-tailed deer Mammal Possibility Peromyscus manicuiatus Deer mouse Mammal Possibility Sciurus aberti Tassel-eared squirrel Mammal Yellow Pine

Sorex merriami Memiam shrew Mammal - Mixed Conifer Sorex nanus Dwarf shrew Mammal Mixed Conifer Sorex vagrans Vagrant shrew Mammal Mixed Conifer Sylviiagus floridanus Eastern Cottontail Mammal Possibility Sylvilagus nuttalli Nuttall's cottontail Mammal Mixed Conifer Tamiasciunrs hudsonicus Chickaree Mammal Mixed Conifer Accipiter gentilis Gashawk Bird Extend from N Aegolius acadicus Sawwhet owl Bird Extend from N .. . . - - - . Cardellina rufrifrons Red-faced warbler Bird Extend from S Carduelis pinus Pine siskin Bird Extend from N Certhis familiaris Brown creeper Bird Extend from N Cotumba fasciata Band-tailed pigeon Bird Extend from S Contopus pertinax Cones' flycatcher Bird Extend from S Cyanocitta stelleri Stellar jay Bird Extend from N Dendroica coronata Yellow-rumped warbler Bird Extend from N Dendroica graciae Grace's wehler Bird Extend from S Empidonax affinis Pine flycatcher Bird Extend from S Empidonax difncilis Western flycatcher Bid Extend from N Eugenes fulgens Rivoli's hummingbird Bird Extend from S Glaucidium gnoma Pygmy owl Bird Extend from N Hesperiphona vespertina Evening grosbeak Bird Extend from N Junco phaeonotus Yellow-eyed junco Bid Extend from S Junco spp, Juncoes Bird Extend from N Loxia curvirostra Red crossbill Bird Extend from N Meleagris gallopavo mexicana, Wild turkey Bird Extend from S M, g, merriami Myadestes obscurus Brown-backed solitaire Bird Extend from S Myadestes townsendii Townsend's solitaire Bird Extend from N Otus flammeolus Flammulated owl Bird Extend from N Parus sclateri Mexican chickadee Bird Extend from S Peucedramus taeniatus Olive warbler Bird Extend from S Piranga flava Hepatic tanager Bird Extend from S Piranga ludoviciana Western tanager Bid Extend from N Ridgwayia pinicola Aztec thrush Bird Extend from S Selasphonrs platycercus Broad-tailed hummingbird Bird Extend from N Sialia mexicana Western bluebird Bird Extend from N Sitta pygmaea Pygmy nuthatch Bird Extend from N Spizella passerfna Chipping sparrow Bird Extend from N Stdx occidentalis Spotted owl Bird Extend from N Vireo gilvus Warbling vireo Bird Extend from N Vireo solitarus Solitary vireo Bid Extend from N Ambystoma tigrinurn Tiger salamander -RIA I Aneldes hardyi Sacramento salamander RIA Crotalus pricei Twin-spotted rattlesnake RIA Crotalus viridis Western rattlesnake WA Diadophis punctatus Ringneck snake WA Eumeces callicephalus Mountain skink WA Gerrhonotus kingi Arizona alligator lizard WA Lampropeltis pyromelana Sonoran mtn. Kingsnake WA Phrynosoma douglassi Short-homed lizard WA Pituophis melanoleucus Gopher snake FUA Plethodon neomexicanus Jemez salamander RIA Salvadora grahamiae Mtn. Patch-nosed snake WA Scleroponrs jarrovi Yarrow's spiny lizard RIA Scleroponrs scalaris Bunchgrass lizard RIA Scleroponrs virgatus Striped plateau lizard RIA Thamnophis elegans Western terrestrial garter snake WA Frogs RIA Toads R/A A References Abonyi, S. and Smith, J. n.d. "Stable Isotope Analysis of Skeletons fiom Chihuahua" Unpublished manuscript on tile at the Dept. of Archaeology, University of Calgary

Adams, KR 1980. Pollen. Parched Seed. arid Prehistom A Pilot Invesktion of Prehistoric Plant Remains horn Salmon Ruin. A Chacoan Pueblo in Northwestern New Mexico. Eastern New Mexico University Contributions in Anthropology No. 9.

1992. "Archaeobotanical and Modem Ecological Perspectives on Ancient Sites in West Central Chihuahua, Medco." Preliminary Report of the 1990 and 1991 Field Seasons. Manuscript on File at the Univenity of Calgary, Calgary, Alberta.

1998. Results of macrobotanical analysis and flotation analysis bmthe 1997 field season. Unpublished, on tile at the University of Calgary.

1999. Results of macrobotanical analysis from the 1998 fled season. Unpublished, on file at the University of Calgary.

2000. Repoe on the Charred Plant Macro fossils from Ch-254. Unpublished, on tile at University of Calgary.

Altschul, DR 1973. Dm9 and Foods kom Little-Known Plan&. Notes in Harvard University Herbaria. Hamad Universicg Press, Mass.

Arnbrose, SH, and Norr, L. 1993. c'Experimend Evidence for the Relationship of the Carbon Isotope Ratios of Whole Diet and Dietary Protein to Those of Bone Collagen and Carbonate." In: Prehistoric Human Bone: Archaeol~~gat the Molecular Level. JBLarnbert, G Gmpe (eds.). Springer-Verlag. Pp. 1-37. Arnbrose, SH, Butler, BM, Hanson, DB, Hunter-Anderson, RL, Krueger, HW. 1997. ccStable Isotope Analysis of Human Diet in the Marianas Archipelago, Western Pacific." Ameniunjod ofPbysidcrJA~-@ 104343-361.

Amsden, M. 1928. Archaeolo cal Reconnaissance in Sonora. Southwest Museum Papers No. 1. Los Angela Southwest Museum. Los Angeles.

An, ZQ, Lui, JS, Siegle, Bunge, G,and Schardl, CL 1992 "Diversitg and Origins OF Endophytic Fungal Syrnbiants of the North American Grass F&xa mi@a" Tbwfta'calad Appded Gtnta'c~85(2-3):366-371.

Anderson, S and Knox Jones, J Jr- 1984. Orders and Fdesof Recent Mammals of the World. John Wdey and Sons, New York.

Ascher, R, and Clune, FJ. 1960. 'Waterfdl Cave, Southern Chihuahua, Mexico." Amnica Ank'qm-ty 26(2):270-274.

Barker, W. 1964. Famhr Re tiles and Arnnhibians of America Harper and Row. Near York.

Bass, WM. 1987. Human Osteolo~A Laboratory and Field Manual. 3" edition. Special Publication No. 2, Missouri Archaeological Society. Missouri

Begler, M and Keatinge, P. 1979. "Theoretical Goals and Methodological Realities: Problems in the Reconstruction of Prehistoric Subsistence Economies". Wodi Ambaeohgy 1 1(2):208-226.

Bellrose, FC. 1976. Ducks. Geese and Swns of North Ampria Stackpole Books. Pennsylvania Bender, MM. 1971. "Variations in the 13C/12C Ratios of Plants In Relation to the Pathway of Photosynthetic Carbon Dioxide Fixation." Pbyl~cbcmiSby 10:1239-1244.

Bennett, WC and Zingg, RM. 1976. The Tarah- An Indian Tribe of Northem Mexico, 2nd edition. Rio Grande Press, New M&co.

Bodenheirner, FS. 1951. Insects as Human Food Dr. W Junk Publishers. The Hague.

Bohrer, VL 1975. "The Prehistoric and Historic Role of the Cool-Season Grasses in the Southwest." Emnom'c Bow29(3): 199-207.

1991. "Recently Recognized Cultivated and Encouraged Plants Among the Hohokam." Kim 56(3) 227-235.

Boutton, TW.1991. "'Stable Carbon Isotope Ratios of Natural Materials: 11. Atmospheric, Terrestrial, Marine, and Freshwater Environments." In: Carbon Isoto~eTechnicpe~. DC Coleman, B fry (eds.). Academic Press, Inc. Toronto. pp. 173-185.

Boutton, TW, Cameron, GN, and Smith, BN. 1978. "Insect Herbivo y on C3 and C4 grasses." Oemhgiu 3621-32.

Brand, DD. 1933. "The Historical Geography of Northwestern Chihuahua." Unpublished Doctoral Dissertation, Department of Geography, University of CaWomia, Berkeley.

Brand, DD. 1943. TheChihuahua Culture Area." New MmbAn-h@t 6-7(3):115-158.

Bray, CM. 1983. Titcogen Metabolism in Plants." Longman Inc. New York.

Brooks, RH, Kaplan, L, Cutler, HC, Whitaker, TW. 1962 "'Plant Mated kom a Cave on the Rio Zape, Durango, Mexico." Anninn Ann'qm.9 27:356-369. . . Brown DE (ed.). 1982 Biotic Communiaes: Southwestern United Staw and Nohestem Mexic~.University of Utah Press. Salt Lake City.

Bryant, VM,Jr. 1974. "Prehistoric Diet in Southwest Tegas: The Coprolite Evidence." Amm'crm Anriqrcig 39(3):407-420.

Buchrnann, N, Brooks, Rapp, KD,and Ehrlinger, JR. 1996. "Carbon Isotope Composition of C4 Grasses is Influenced by Lght and Water Supply." Ph,ceg rmd Enthvnmmt 19392-402

Buechner, HK. 1950. '2ife History, Ecology, and Range Use of the Pronghorn Antelope in Trans-Pecos, Texas." American MihdNet 43(2):257-354.

Bye, IU,Burgess, D, Trias, AM. 1975. 'Ethnobogny of the Western Tarahumara of Chihuahua, Mexico. I. Notes of the Genus Agave." Botanical Museum Leaflets, Hamad University 24(5) :85-112

Buikstra, JEand Ubelaker, DH. (eds.). 1994. Standards for Data CoUection from Human Skeletal Remains. Proceedings of a seminar at the Field Museum of Natural Histoy. Owedby J Haas. Arkansas Survey Research Series No 44.

Carey, HA. 1931. "An Analysis of the Northwestern Chihuahua Culture." Amm'tcon Anht@oIb&t 33:325-374.

Cerquiera, m, Fry, MM., and Connor, WE. 1979. "Ihe Food and Nument Intakes of the

Tarahumara Indians of Mexico." R.nniun Jod tf Ck'nicol N~~m'iion32-9019 15.

Chapman, JA, Hockman, JG, and Edwards, WR. 1982 "Cottontails." In: Wdd Mammals of North America: Biolog?Manwent and Economics. JA Chapman and GA Feldhamer (eds.) .Johns Hopkins Universitg Press. Baltimore. Pp. 83- 123. Cloudsley-Thompson, JL1991. hvsiologp of Desert Arthro~ds- and Re~des. Springer-V-. London.

Cutler, H. 1960. "Cultivated Plant Remains fiom WatdCave, Chihuahua." Ammi.m Ad* 26(2) ;2??-279.

De Conconi, JRE, Moreno, JMP, Mayaudon, CM, Valdez, FR, Perez, MA, Prado, EE, Rodriguez, HB. 1984. "Protein Content of Some Edible Insects in Maico." Jomtdtf EthnobiorogYrogY4(1):61-72

Defoliarf GR, 1 995. "Edible Insects as Minilivestock." Bidm@ md Comm.m4:306-321.

Deines, P. 1980. "The Isotopic Composition of Reduced Organic Carbon." In: Handbook of Environmental Isoto~eGeochemistry. P Fritz and JC fontes (eds.). Amsterdam. Elsevier. Pp. 32946.

De Niro, MJ. 1985. 'Tostrnortem Presemtion and Alteration of In-vivo Bone Collagen Isotope Ratios in Relation to Paleodietay Reconstruction." NmHn 317:806-809.

Di Peso, CC. 1968. "Casas Grandes and the Gran Chichirneca." El P&o 75(4):45-61.

Di Peso, CC, Rinaldo, JB,and Fenner, Gj- 1974. GasGrartdes: A Fallen Trading Center of e Gran Chichirneca. 8 vols. Arnerind Foundation Series No. 9. Arnerind Foundation, Dragoon, and Northland Press, Flagstaff.

Doebley, JF. 1984. '"Seeds' of Wild Grasses: A Major Food of Southwestern Indians" Emnomi. Bow38 (1) 5264.

Downton, WJS. 1975. 'The Occurrence of C4 Photosynthesis Among Plants ." Pbotosyntheft'ca 9(1):96-105. Dunn, JP,Chapman, JA and Marsh, RE. 1982 "Jackrabbits." In: Wild Mammals of North encz &ologp. Manmentand Economics. JA Chapnmn and GA Feldhamer (eds.). Johns Hopkins University Press. Baltimore. Pp. 124-145.

Ebeling, W. 1986. Handbook of Indian Foods and Fibers of Arid America Univenitg of California Press. Berkeley.

Ehrlinger, m SBge, RF, Flanagan, LJ3, and Pearcy, RW. 1991. "Chte Change and the Evolution of C4 Photosynthesis." TnndF in Em& and Ewha'on 6(3):95-99.

Estados Unidos Mexicanos, Secretaria de Programiacibn y Presupuesto. 1981~Carta de predpitacih, medias anuales 1: 1,000,000. Chthuahua.

198 1b. Carta de Ternperatmu medias anuales 1: 1,000,000. Chihuahua

Facciola, S. 1990. Cornuco ia. A Source B3ok of Edible Plants. Karnpong Publications, Vita, CA.

Fosbew FR. 1960. 'Want Collecting as an Anthropological Field Method." Sl P&ko 67:125- 139.

Fralick, PW, St- JD, and MacWdiarns, AC. 1W8."Geochemistry of West-central Chihuahua Obsidian Nodules and Implications for the Derivation of Obsidian Artehcts." JodtfAhIbgri.ct/ Jim25:1023-1038.

Fry, B, Joern, A and Parker, PL. 1978. "Grasshopper Food Web Analysis: Use of Carbon Isotope Ratios to Examine Feeding Relationships Among Terrestrial Herbivores." Emha 59(3) :498-506. Gallina, S, Maury, E, and Serrano, V. 1981. "Food Habits of White-cailed Deer." In: Deer tern North America" PF FfoUiott, S Gallina (eds.). A Binational Mexico-US Man and Biosphere (MAE3) Program Investigation. Institute de Ecologia, AC Mexico DF. Pp. 133-148.

Garvie-Lok, S and Varney TL Unpublished data

Gasser, RE, and Kwiatkowslu, SM. 1991. 'Xegionai Signatures of HohohPlant Use." KIM56(3):207-225.

Goh, KM- 1991. "Carbon Dating." In: Carbon Isoto e Techniques. DC Coleman and B Fry (eds.). Acadetnic Press. Toronto. Pp. 125-146.

Grupe, G. 1995. "Preservation of Collagen in Bone From Dry, Sandy Soil".Jod of A~chucohgicdSdm~ 22: 193- 199.

Gustafkson, S. 2000. "Carbonized CereaI Grains and Weed Seeds in Prehistoric Houses - An Experimental Approach". Jomd 0fAn.bueoIb~dSa'mc~2265-70.

Hally, D. 1981. "Plant Preservation and the Content of Paleobotmical Samples: A Case Study." Rnrnican Anh'qwWp46:723-742.

Handleg, LL and Raven, JA. 1992. 'The Use of Natural Abundance of Nitrogen Isotopes in Piant Physiology and Ecology." Plarc, Ce4 and Enhnmenf 15:965-985.

Harbome, JB. 1988. Introduction to EcologCd Biochemistry. 3d Edition. Academic Press. Toronto. Hard, RJ,Maddin, RP, and Raymond, GR 1996. 'Wino Size, Stable Carbon Isotope Ratios, and Macrobotanical Remains as Multiple Lines of Evidence of Maize Dependence in the American Southwest" Jodofhhdgicd Merhad and Thq 3(4) 253-318.

Hard, RJ, .md Roney, JR. 1998. "A Massive Terraced Viage Complex in Chihuahua, Mertico, 3000 Years Before Present" Sa'encc 279: 166 1-1 664.

Harris, DR 1989. "An Evolutionary Continuum of People-Plant Interaction". In: Foe and F~Ethe evolution of plant amloitation. DR Harris and GC HilIman (eds.). Unwin Hyrnan. London.

Hawkes, K, Hi&& O'ConneU, JF. 1982 'Why Hunters Gather. optimal foraging and the Ache of Eastern Paraguay ." Rmtiim Etbnohgist 9(2):379-398.

Hendrickson, MJ. 2001. "Design Analysis of Chihuahuan Polychrome Jars from North American Museum Collections." Unpublished MA Thesis. Department of Archaeology, University of Calgary. Calgary, ,Alberta, Canada

Hinckley, TM, and Braatne, JH. 1W4."Stomata". In: Plant-Environment Interactions. RE Wfison (ed.). Marcel-Dekker Inc. New York. Pp. 323-355.

Hodgem, LM. 1996. "Faunal Evidence From EI Zurdo." Kico 62(2):149-170.

Hopkins, DW, Wheatley, RE, and Robinson, D. 1998. "Stable Isotope Studies of Soil Nitrogen." In: ht~'on of Bid& Eco1&? and Geochemical Processes, H. Griffiths (ed.). Bios Saentific Publishers. Oxford. Pp. 75- 88. Hrdlicka, A. 1908. 'Thysiological and Medical Observations Among the Indians of Southwestern United States and Northern Mexico-" Smithsonian Institution Bureau of Ethnology. Bulletin 34. Washington.

Hubick, ICT, Farquhar, GD, Shorter, R 1986. "Correlation betareen Water-Use Efficiency and Carbon Isotope Discrimination in Diverse Peanut (&chis) Germplasm-" As* JomdOjPht Physcbhgy 13(6):803-8 16.

Huebner, JA. 1991. "Cactus for Dinner, Again!: An Isotopic Analysis of Late Archaic Diet in the Lower Pecos Region of Texas." hx ers on Lower Pecos Prehistortr SA Turpin (ed.). Studies in Archeology 8. Texas Archeological Research Lab. ?he University of Texas at Austin. Pp. 175-190.

Johannessen, S. 1988. 'Tlant Remains and Culture Change: Are Paleoethnobotmical Data Better Than We Think?" In: C ultural Internretations of Archaeolo@cal Plant Remains. CA Hastorf and VS Popper (eds.) . University of Chicago Press, Chicago and London. Pp.145-1 66.

Johnstone, RAW, and Rose, ME. 1996. Mass Spectrometry for Chemists and Biochemists Tded. Cambridge Universitg Press. New York

Kaplan. 1969. 'Ethnobotmical and Nutritional Factors in the Domestication of American Beans." In: Man and His Foods CE Smith (ed.). Universitg of Alabama Press, AL. Pp. 75-85.

Kates, M. 1972 psis and identifiation of lipids. American Elsevier Publishing Co,Inc. New York.

Katzenberg MA. 1992. "Advances in Stable Isotope Analysis of Prehistoric Bone." In: Skeletal Biolo9 of Past Peoples: Research Methods. MA Katzenberg and SR Saunders (eds.) . Wrley-Liss, hc. Pp.105-119. haenberg, MA and KeIley, JH. 1991. "Stable Isotope Analysis of Rehistoric Bone from the Sierra Blanca Region of New Macico." In: &&jpllon V. COAS Pubiishing. New Mexico. Pp. 207-219.

Katzenberg MA and Pfeiffer, S. 1995. 'Witrogen Isotope Evidence for Weaning Age in a Nineteenth Century Canadian Skeletal Sample." In: Bodies of Evidence. Grauer, AL (ed). John Wdey and Sons. New York. Pp. 221-235.

KeIley, JH, St- JD, and MacWtlliams, AC. 19% 'Troyecto Arqueologico de Chihuahua: Report in the 1998 Field Season." On file at the Department of Archaeology, University of Calgary, Alberta and Instituto Nacionale de Antropologia y Historia

Kelley, JH, Stewart, JD,MacWfiams, AC, and Neff, LC- 1999b. "A West Central Chihuahuan Perspective on Chihuahuan Culture" In: The CuGrandes World. CF Schdrna and W Riley (eds.). The University of Utah Press, Salt Lake City. Pp. 63-77.

Kelley, JH, Stewart, JD,Adams, K& Burd Larkin, KT, Harf DH, and Webster, M. 2001. "The Chihuahua Archaeological Project Report on the 2000 Field Season." Inforrne aI Consejo de Arqueologia, Instituto Nacional de Anthropologia y Historia, Mexico.

Kelley, JH, and Vipando, ME. 1996. "An Overvlew of the Mexican Northwest." In:

Patterns. PR Fish and JR Rkd (eb.). Arizona State Ukersiy Anthropological Research Papers No 48. Pp. 69-77.

Kirk, DR. 1970. Wdd Edible Plants of the Western United StaaNaturegraph Publishers, California. Lafefti* JE,and van Asdall, W. 1992. "Contemporary Agncultutal Patterns in a Mountain Pima Vi." Kiw 58(2):155-175.

Laferriere, JE, Weber, CW, Kohlhepp, EA. 1991. "Use and Nutritional Composition of Some Traditional Mountain Pirna Plant Foods." Jomal ofEf%rnobiolbgy1 1 (l):93- 114.

Lee-Thorpe, JA. 1989. "Stable Carbon Isotopes in Deep Tie:The Diets of Fossil Fauna and Hominids." Unpublished Doctoral Dissertation, Department of Archaeology, University of Cape Town, Cape Town.

Lister, RH. 1960. "History of Archaeological Fieldwork in Northwestern Mexico.'' El P&#o 62118-123.

Lhpez, AM. 1992 "Arqueobo~cade la Sierra de Chihuahua" In: Historia General $e Geomhia p Amueolo~&-. A. Mirquez-Alameda (ed.). Univenidad Aut6noma de Ciudad Jukez y Gobiemo del Estado de Chihuahua Juk. Pp. 215-227.

Lumholtz, C. 1902. Unknown Mexic~.New York.

MacWGams, AC, Stewart, JD,and Kelley, JH. 1998. "A Synopsis of Chihuahuan Archaeology. Paper prepared for the 6th Biennial Southwest Symposium Hermosillo, Sonora.

Manglesdorf, P. 1958. ''Review of 'Agrtcultud Origins and Dispersals' In: Prehistoric &pmlturg. S Struever (ed.) . 197 1. Pp ,415-422

Manglesdotf, PC, and Lister, RH. 1956. c'Archaeological Evidence on the Evolution of Maize in Northwestern Mexico." Bo*nidMmwm e,Hd Unilm9 17(6):151-197. Matson, RG, and Chisholm, B. 1991. "8asketmaker I1 Subsistence: Carbon Isotopes and Other Dietary Indicator fiom Cedar Mesa, Utah." AmericaAnhqrrity 56(3):444-459.

Minnis, PE. 1982 "Macroplant Remains." In: The Galaz Rum: A Prehistoric Mirnbrgs aby R hyon and and SAIanc. University of New Mexico Press and Maxwell Museum of Anthropology. Pp. 193-200.

~mnis,PE. 1989. "Prehistoric Diet in he Northern Southwest Macroplant RdsFrom Four Corners Feces." Amm'tm Andpdy 54(3) 543-563.

OJLeary, MH. 1988. "Carbon Isotopes in Photosynthesis". Bida'ena 38(5):328-336.

OIsen, SJ. 1974. 'myDomestic Dogs in North America and Their Origins." JornoloJFieH AtChaohgy 1343-345.

Ortner, DJ and Puschar, GJ. 1985. Identification of PathoIo@calConditions in Human Skeletal Remains. Smithsonian Conmbutions to Anthropology No. 28. Smithsonian Institution Press. Washington and London.

Ostrorn, PH, Colunga-Garcia, M, Gage, SH. 1997. ''Establishing Pathways of Energy Flow for Insect Predators Using Stable Isotope Ratios: Field and Laboratory Evidence." Oecohgza 109: 108- 1 13.

Pase, CP, and Brown, DE. 1994. "Rocky Mountain (Petran) and Madrean Montane Coder . . Forests". In: . Biotic Communibes: Southwestern United States and Northwestern Mexico. DE Brown (ed.). University of Utah Press. Salt Lake City.

Pennington, CW. 1963. The Tarahurnar of Mexico. University of Utah Press, Salt Lake City. Phillips, DA Jr. 1989. 'Trehistory of Chihuahua and Sonora, Mexico." Jodof Wd Pnbistofy 3(4):373-401.

Popper, VS, and Hastorf, CA. 1988. "Introduction." In: Clurent Paleoefhnob- aIpticaI Methods and Cultt.uaI Interpretations of Archaeolo_m'cal Plant Remains. CA Hastorf and VS Popper (eds.) . Universitg of Chicago Press, Chicago and London. Pp.1-16.

Raghaven& AS, and Das, VSR 1978. "The Occurrence of C4 Photosynthesis: A Supplementary List of C4 Plants Reported During Late 1974-mid 1977." Pboto~t%rea'm12(2) :200-208.

Ramos-Elorduy, J, Moreno, JMP, Prado, EE, Perez, MA, Otero, JL,and de Guevara, OL. 1997. "Nutritional Value of Edible Insects fi-om the State of Oaxaca, Mexico." ]ommi ofFOd Con@~&on adAn4sis 10:142-157.

Ricklefi, RE. 1993. The Economy of Nm.3" Edition. WH Freeman and Co. USA.

Ruddle, K. 1973. ''The Human Use of Insects: Examples kom the Yukpa" Biotnpka 5(2):94- 101.

Rutgers, 4 and Norris, KA (4s.). 1970. Encpcloe of Avicultur~Vols. 1-3.Bkndford Press. London.

. . Sauer, C. 1952. cultural and Diswersds. American Geographical Society. New York.

Sayles, EB. 1933. ''Detail Sheets of the Gila Pueblo Chihuahua Survey." On tile at the Arizona State Museum Archives, University of Arizona, Tucson. 1936. "An Archaeological Survey of Chihuahua, Mexico." Medallion Papers XXII. Gila Pueblo Foundation, Globe, Arizona.

Schhrna, CF, and Riley, CL (eds.). l999. TheCasasThe University of Utah Press, Salt Lake City.

Schiffer,M8. 1987. Formation Processes of the Archaeol@cd Record. University of New Mexico Press. Albuquerque.

Schoeninger MJ,and DeNiro MJ. 1982 'miagenetic Ef5ects on Stable Isotope Ratios in Bone Apatite and Collagen." Abstract. AmmmcanJomd ofPbyn'cO/A~rogY57:225.

Schoeninger MJ, and DeNiro MJ. 1984. "Nitrogen and Carbon Isotopic Composition of Bone Collagen From hhheand Terrestrial Animals." Gewhimim et Cosmochikm A& 48:625-639.

Schoeninger, MJ, and Moore, K. 1992 'Bone Stable Isotope Studies in Archaeology." Jod of Wdhhistog 6(2):247-296.

Schuster, WSF, Sandquist, DR, Phillips, SL, and Ehrlinger, JR 1992 "Comparisons of Carbon Isotope Discrimination in Populations of Aridland Plant Species Differing in Lifespan." Oemhgh 91:332-337.

Sclmarcz, HI?,and Shoeninger, MJ. 1991. "Stable isotope Analyses in Human Nutritional Ecology." YhkqfP@sid Anthnzpolagy 34283-321.

Sealy, JC and van der Mme, NJ. 1986. "Isotope Assessment and the banal Mobility Hypothesis in the Southwestern Cape of South Aftica." CumntA~~hvplbgy 27(2):135-150. Severson, KE. 1981. "Food Habits and Nutritional Relationship of Mule Deer in the Southwestern United States." In: Peer Biolw mitat Requirement. and Manqgement in Western North America." PF Ffollio- S Gallina (eds.). A Binational Mexico-US Man and Biosphere (MAB) Program Investigation. Instituto de Ecologia, AC Mexico DF. Pp. 149-163.

Shaw, CE and Campbell, S. 1974. Snakes of the American West Allied A. Knopf, New York.

Smith, BN, and Epstien, S. 1971. "Two Categories of "C/12C Ratios for Higher Plants." PhtP2ysioIbgy 47:380-384.

Smith, BN, and Brown, WV. 1973. ''The Kranz Syndrome in the Gramheae as Indicated by Carbon Isotopic Ratios." Am~mJomd o/Bokmy 60(6):505-513.

Stebbins, RC. 1962. Amphibians of Western North America. U of California Press, Los Angeles. 1985. Western Reptiles and Arn~hibians.Peterson Field Guide Series. Houghton, Mi& Co. Boston.

Stewan, JD,MacWliams, AC, and Kelley, JH. 2001. "Archaeological ChronoIogy of West Central Chihuahua." In: aeDirections: The Archaeoloep o f Northwest Mexico. G. Newell and E Gabga (eds.). Cotsen Institute of Archaeology at Uubs Angeles, California.

Sutton, MQ. 1994. "Indirect Evidence in Paleonutrition Studies." In: Pdeonutrition: The Diet and Hdth of Prehistoric Ameriw KD Sobolik (ed.). Center for Archaeological Investtgations. Southern Illinois University at Carbondale. Occasional paper No. 22. Pp. 98-1 11. Thomas, SC, Jasienski, M, and Ehnaz, FA 1999, "Early vs Asymptotic GrohResponses of Herbaceous Plans to Elevated CO," Em& 80(5) :I 552-1567.

Tieszen, LL. 1991. 'Watural Variations in the Carbon Isotope Values of Plants: Implications for Archaeology, Ecology, and Paleoecology." Jod$AdaobgzidSdnn 18227- 248.

Tieszen, LL and Fagre, T. 1993. 'Carbon Isotopic Variability in Modern and Archaeological Maize." JodcfA~cbcu0Ibg"d Samm 20:25-40.

Tuross, N, Fogel, EML, and Hare, PE. 1988. "Variability in the Presemtion of the Isotopic Composition of Collagen from Fossil Bones." Geochimim md Cdsmochiimu Arto 52929-935.

Udvardy, MDF and Knopf, AA. The Audubon Society Field C.u.j&tn North America Buds. New York.

Usher, G. 1974. A Dictionam of Plants Used bv Man. Constable, USA.

Van der Mawe, NJ and Vogel, JC. 1978. "13cContent of Human Collagen as a Measure of Prehistoric Diet in Woodland North America" Natun 276:815-816.

Van Devender, TR 1990. 'late Quaternary Vegetation and Climate of the Chihuahuan Desert, United States, and Mexico." In: Packrat Middens: The kt40,000 Years of Biotic Change. JL Betancourt, TR Van Devender, and PS Martin (eds.). University of Arizona Press. Tucson. Pp. 104-133.

Van Devender, TR, and Bradley, GL 1990. 'late Quaternary Mammals from the Chihuahuan Desert Paleoecology and Latitudinal Gradients." In: Packrat ms: e.Th JLBeofco~~ TR Van Devender, and PS Martin (eds.). University of Arizona Press. Tucson. Pp. 350-362 Van Devendq TFt, Toolin, LJ and Burgess, TL. 1990. "The Ecology and Paleoecology of Gtasses in Selected Sonoran Desert Plant Communities-" In: Packrat Middens: the t 40-000Years of Biotic Chanan~.JL &tancourt, TR Van Devender, and PS Martin (eds.). University of Arizona Press. Tucson. Pp. 326-349.

Vogel, JC. 1978. c'Isotopic Assessment of the Dietary Habits of Ungulates." South Afn'cm Jod of Sa'mm 74298-301

Vogel, JC and van der Mme, NJ. 1978. " Isotopic Evidence for Early Maize Cultivation in New York State." Ammcmr Aniiquity 42238-242

Walker, EP. 1975. Mammals of the World. 3" edition. Johns Hopkins University Press. Baltimore and London.

Welkie, GW and Caldwell, M. 1970. "Leaf Anatomy of Species in Some Dicotyledon Families as Related to the C3 and C4 Pathways of Carbon Fixation." Gm&m Jomd tfBotmly 482135-2146.

Wrlke, P J, King TF, and Hammond, S. 1975. "Aboriginal Occupation at Tahquitz Canyon: Ethnohistoy and Archaeology". In: The Cahuilla Indians of the Colorado Desert Ethnobistorv and Prehsitorp, Part 2, LJ Bean (ed.). Anthropological Papers #3, BaIlena Press, Ramona, CA. Pp. 45-73.

Wren, GC. 1970. "The Ecology of Gathering in a Mexican Farming Region." ECOIIO~C BOW 24(3) :286-294.

Wmkler, BA. 1982. Wild Plant Foods of the Desert Gatherers of West Texas, New Mexico, and Northern Mexico: Some Nutritional Values, MA Thesis, U of Teas, Austin. Yoneyama, T, Fujiwara, H, Wilson, JM. 1998. 'Variations in Fractionation of Carbon and Nitrogen Isotopes in Higher Piants: Nitrogen Metabolism and Pamtioning of Phloem and Xylem." In: 9Isotows:ologic& and eoQemical Processes. H Grifiths (ed.) . Bios Sdentific Publishers. Word. Pp.99- 109.