LOCOMOTOR ADAPTATIONS IN THE LIMB SKELETONS OF NORTH AMERICAN MUSTELIDS

by

Thor Holmes

A Thesis Presented to The Faculty of Humboldt State University

In Partial Fulfillment of the Requirements for the Degree Master of Arts

June, 1980 LOCOMOTOR ADAPTATIONS IN THE LIMB SKELETONS OF NORTH AMERICAN MUSTELIDS

Approved by the Master's Thesis Committee Chairman

Approved by the Graduate Dean

TABLE OF CONTENTS Page

Acknowledgments iv

Abstract vi

Introduction 1

Materials and Methods 11

Results and Discussion 30

Intraspecific Variation 30

Species Comparisons 46

Forelimb 46

Hindlimb 68

Conclusions 91

Literature Cited 97

Appendices 105 ACKNOWLEDGMENTS

This study was partially funded by a thesis grant from the Biology Graduate Student Association at HSU. I thank the following museums and their curators for the use of materials in their collections: American Museum of Natural History; California Academy of Science; Carnegie Museum of Natural History; Field Museum of Natural History; Humboldt State University, Museum of Vertebrate Zoology; University of Kansas Natural History Museum; Los Angeles County Museum of Natural History; Museum of Zoology, University of California, Berkeley; Michigan State University, The Museum; National Museum of Natural History; San Diego Museum of Natural History; San Diego Natural History Museum; University of California at Los Angeles; University of Michigan Zoology Museum; University of Montana Department of Zoology; University of Puget Sound, Museum of Natural History; I would like to thank particularly Murray Johnson, Helen Kafka, and Shiela Kortlucke for help during the times I used their collections.

Suzanne Edwards, Judy Fessenden, Cynthia Hofmann, Rebecca Leuck, Bob Sullivan, my brother, Thomas, and my wife, Elaine helped me make measurements. Mike Gwilliam, Tim Lawlor, Steve Smith, and Bob Sullivan helped me with computer programs. Cynthia Hofmann, Elaine Holmes, and Kathy McCutcheon helped type the manuscript. Kathy typed the final draft. V

I would like to thank the members of my committee, Jake Houck, Frank Kilmer, Tim Lawlor, John Sawyer, and Jim Waters for time they invested in my thesis and my education. I would like to thank particularly my major professor, Tim Lawlor, for help, friendship, encouragement, and sundry other contributions to my life and my education far too numerous to mention here. Finally I wish to thank Elaine, my wife, for a decade of support in every sense of the word. And I wish to acknowledge that she, more than any other person, is the reason that I can look back from this point in my life and smile. ABSTRACT

The morphology and proportions of the limb skeletons of thirteen species of North American mustelids are examined.

A series of forty-nine ratios is generated for each species.

Ratios are analyzed using standard descriptive statistics; mean, standard deviation, variance, standard error, coefficient of variation, and range. Ratios are also analyzed with a closest connection (Prim) network. Qualitative comparisons of appendicular skeletons are made with drawings of each limb element. Progressive specialization from an hypothesized primitive condition to fossorial, arboreal-cursorial, aquatic, and ambulatory modes of locomotion is revealed in limb skeletons of the Mustelidae. Relationships between morphology and proportions of mustelid limb skeletons, and modes of locomotion are discussed. INTRODUCTION

The family Mustelidae, comprising twenty-five recent and some seventy fossil genera (Anderson and Jones, 1967), is one of the most diverse families of carnivores. Only its ecological counterpart in the Old World tropics, the family Viverridae, contains more extant genera. Mustelids range in size from small (35 g) to medium (37 kg). They are distributed throughout the world except for Australasia and Antarctica. The Mustelidae apparently arose from the most ancient carnivorans, family Miacidae, about 35 mybp. The origin of the Mustelidae within the miacids seems to be separate from that of the other canoid carnivores. They quickly adopted the typical mustelid specializations of a strongly carnivor- ous dentition, short powerful jaws, prominent pre- and post- glenoid processes, and a long cylindrical body (Ewer, 1973; Romer, 1966). Mustelids as a group also are characterized by a weak zygoma. Ewer (1973) and Gambaryan (1974) suggested that the weak zygoma and a long cylindrical body are adaptations to hunting small mammals within their burrows, a method of predation that still characterizes the largest and one of the most primitive living genera, Mustela (Table 1). Despite specializations of cranial and axial osteology the mustelids retain a very generalized limb structure. They do, however, show fusion of two carpals, the scaphoid 2

Table 1. -- Earliest record for ten genera of the family Mustelidae (after Romer, 1966).

Genus Time of Probable Origin Mustela Upper Miocene Martes Middle Miocene Eira Pleistocene Gulo Pleistocene Spilogale Lower Pleistocene Mephitis Pleistocene Conepatus Upper Pliocene Taxidea Upper Pliocene Lutra Lower Pliocene Enhydra Pleistocene

PLEISTOCENE Mephitis Eira Gulo Enhydra Spilogale

Conepatus Taxidea PLIOCENE Lutra

Mustela MIOCENE Martes 3 and lunar. They also have lost a third carpal, the centrale. These are interpreted as cursorial specializations and are the common heritage of all carnivores (Ewer, 1973; Vaughn, 1978). Mustelids are plantigrade to digitigrade. The extent to which they are digitigrade is never as pronounced as in the Felidae or Canidae. The mustelids are pentadactyl and all of the digits touch the substrate. Members of the family retain relatively short, stocky limbs and do not have retractile claws. Gambaryan (1974) suggested that the basic cursorial gait in the Mustelidae, the bound or half bound, is a result of their long narrow body. Variations on the basic gait include a slow ambulatory walk (Mephitis, Conepatus), a speedy trot (Taxidea, Mustela), and a bear-like shuffle (Gulo). The Mustelidae, at least as regards appendicular anatomy, more closely resemble basal fissipeds than any extant group of carnivores. While a generalized limb skeleton characterizes most mustelids, some species have evolved ambulatory, arboreal, semi-aquatic, aquatic, and fossorial habits. Mustelids, therefore, present the student an opportunity to observe a spectrum of locomotor adapta- tions in a single family. There are numerous studies on locomotor specialists. Horses, gazelles, cheetahs, whales, and moles have all been examined. Studies of this kind are valuable in that they reveal the types of adaptations to specific modes of 4 locomotion that typify specialists. I have chosen, however, to examine the array of locomotor adaptations that charac- terize the Mustelidae. No mustelid is highly specialized for a particular mode of locomotion. For that reason I think that an investigation of the Mustelidae is of particular interest because it promises to elucidate locomotor trends in types of animals often ignored in the locomotor literature. Some recent members of the Mustelidae have been the object of considerable osteological or myological study (Fisher, 1942; Howard, 1973, 1975; Leach, 1977a, 1977b; Leach and Dagg, 1976; Ondrias, 1960, 1961; Tarasoff, 1972). As yet no one has studied the entire spectrum of locomotor adaptations in the Mustelidae either myologically or osteo- logically. Some studies on the limb skeletons of other families of carnivores have been made: Hildebrand (1952, 1954), on canids; Goynea and Ashworth (1975) and Hopwood (1947), on fends; and Taylor (1970, 1974, 1976), on viverrids. Techniques used in those studies could produc- tively be applied to the Mustelidae. The burgeoning literature on primate locomotion (Ashton et al., 1971; Ashton and Oxnard, 1964; Jenkins, 1976; Lewis, 1972; Reisenfeld, 1974) contains techniques with possible applica- tions to mustelids. A similar, if somewhat older, literature on locomotion in mammals in general (Brown and Yalden, 1973, and citations therein) provides a valuable backdrop against which to compare mustelids. Finally there are studies of 5 the effect of modes of life on the skeleton, or on particular skeletal elements (Chapman, 1919; Jones, 1953; Lehmann, 1963; Taylor, 1914; Yalden, 1972). These papers are especially useful in that they elucidated the type of morphological indicators that suggest specializations to a particular mode of life. The taxonomic position of some mustelids is not well understood (Simpson, 1945), but the family lends itself to separation into four locomotor categories corresponding roughly to the four main recognized subfamilies (Fig.1 ). The Mustelinae are weasel-like forms which typically have sub-cursorial, scampering habits. This is the oldest and most primitive subfamily. Martens, fishers, and tayras, the larger members of this group, have arboreal proclivities. The mink, another member of the Mustelinae, is amphibious. The Mephitinae, the skunks, are ambulatory. The Melinae include most of the badgers; they are fossorial. Finally, the Lutrinae comprises the most aquatic fissipeds, the otters. The American badger, Taxidea, and the wolverine, Gulo, are the subject of some taxonomic debate. Nevertheless, they may be conveniently grouped with the badger and weasel subfamilies, respectively, in regard to locomotion. North American mustelids encompass all of the locomotor types that characterize the family as a whole. Hence they should constitute a representative subset of the range of locomotor specializations that characterize mustelids as a whole. It appears that the different locomotor patterns in 6

FIGURE 1

1) Hypothesized trends in the appendicular skeletons of twelve North American species of the family Mustelidae. Species are arranged according to proposed continua of progressive specializations for arboreal, cursorial (sub-cursorial), aquatic, fossorial, and ambulatory modes of locomotion. Species (continua) radiate from a hypo- thetical primitive condition simulated among extant forms by Mustela frenata. 7 8 mustelids evolved from a more or less generalized, cursorial creature that was, nevertheless, somewhat specialized to hunt small, hole-frequenting prey in their burrows. That primitive mustelid is probably best represented among living forms by the weasels. If an artificial line is drawn from the hypothetical primitive mustelid condition, simulated among extant forms by Mustela frenata, through an amphibious form (Mustela vison) and a semi-aquatic form (Lutra canadensis) to a strongly aquatic form (Enhydra lutris), a sequence toward an aquatic tendency can be observed. It follows that inspection of the limb skeletons of the animals along this line should reveal morphological and proportional changes that are related to increasing specializations for life in water. Similarly, the limb skeletons of Mustela frenata, Martes pennanti, Martes americana, and Eira barbara should show progressively greater specialization for life in the trees, because each of those animals is progressively more arboreal. The limb skeleton of the American badger should be strongly modified for fossorial life. Mustela nigripes, a subterranean, if not strictly fossorial, form obligately tied to life in prairie dog (Cynomys) towns, may have specializations of the limb skeleton intermediate between weasels and badgers. Although not a cursor in the strictest sense, the wolverine, with a home range up to 500,000 acres (Ewer, 1973), is the widest-ranging mustelid. The limb skeleton of wolverines should show specializations for 9 the life of a cursor, albeit an ungainly one. Finally a line connecting Mustela frenata, Spilogale putorius,

Mephitis mephitis, and Conepatus mesoleucus extends from small, predaceous carnivores to medium-sized, ambulatory omnivores. This line may describe an actual relaxation of locomotor specialization since there probably is no particular premium on speed or agility in striped or hognose skunks. There is, therefore, the possibility that the limb skeletons of Mephitis mephitis and Conepatus mesoleucus may be more variable anatomically than those of

Mustela frenata or any other non-mephitine mustelid. In other words, skunks (particularly Conepatus and Mephitis) may have the most generalized, although not the most primitive, skeletons in the Mustelidae. Selection in the

Mephitinae seems to have favored extreme development of circumanal glands and aposematic coloration rather than locomotor ability.

From the literature (Brown and Yalden, 1973; Gambaryan,

1974; Hildebrand, 1974; Howell, 1944; Smith and Savage,

1956) I would expect to see the following trends in the

Mustelidae. Species with cursorial tendencies should have long legs. Distal limb elements should be disproportionately long. Limb bones should be slender with long out-levers and short in-levers. Arboreal species should share many of the specializations of sub-cursorial species. This is because arboreal mustelids simply run in trees. These species should have recurved claws and mobile ankles. 10

Fossorial mustelids should have short legs, with a disproportionate shortening or distal limb elements. Limb bones of diggers should be robust and highly sculptured with short out-levers and long in-levers. The epicondyles of the humerus should be wide, and the claws should be long and powerful. Aquatic mustelids should be typified by short legs with a disproportionate shortening of proximal limb elements. Distal limb elements may be modified to be paddle-like. The pubic symphysis may be weak. The skulls of aquatic species may be foreshortened. The potential value of the comparison of the limb skeletons of all these species is enhanced by the fact that they are all phylo- genetically close.

The objectives of my study are to:

(1)describe the morphology and proportions of elements of the limb skeletons of several species of Mustelidae, and

(2)explore the relationships between modes of locomotion and the limb skeletons of those species. MATERIALS AND METHODS

A total of 558 individuals from twenty-two species of the family Mustelidae were examined. This sample encompassed sixteen genera and all of the mustelid subfamilies (Appendix

1). Nomenclature in this study follows Hall and Kelson

(1959) for North American material. The taxonomy of Old

World material is from Simpson (1945). Both males and females were included. Individuals of unknown sex were also examined, but were treated statistically only when males and females were lumped together. Large samples

(n = 30) were obtained for eight species. Eight other species were only represented by one specimen each and were, therefore, unsuited to any statistical characterization.

However, single specimens of some species were compared as individuals against the patterns of variation developed by

the better represented species. Subspecific names and locality data were noted for use in the examination of geographic variation in the locomotor

skeleton of the species studied. Because specimens for this

study were obtained from fifteen separate museum collections

(Appendix 2), and because specimens from any particular

collection often were taken at different times and from

different places, none of my samples actually represent

natural populations. So, for reasons of pragmatism, sub-

species are treated as being broadly equivalent to

geographical races. 12

There are three North American species of weasels, one of which I chose to simulate the hypothetical primitive mustelid. I chose Mustela frenata as the representative weasel for this study because it is the largest of the weasels. All three species of North American weasels lead essentially similar lives (Ewer, 1973; Powell, 1979; Rosenzweig, 1966) and are all three likely to have similar locomotor adaptations. All three species are strict carni- vores which hunt hole-frequenting prey in its burrows. Except for size differences all three species are strikingly similar. Using the largest species serves to minimize potential allometric problems arising from comparisons of animals that differ considerably in size such as weasels, otters, and wolverines. Mustela frenata is also the widest- ranging North American weasel, and is better represented in most collections than M. rixosa and M. erminea. Similarly, the three species of Spilogale examined in this study (S. gracilis, S. putorius, and S. angustifrons) probably have similar modes of locomotion. In contrast to the situation with weasels, however, the similarity of adaptation could be tested in Spilogale. The testing procedures, delineated elsewhere, justified in my mind lumping all of the species of Spilogale for my examination of limb skeletons. The decision was not taxonomic, but functional, and had the added practical effect of improving the sample size for a critical position in. my hypothetical arrangement of locomotor trends. 13

To assess limb dimensions and proportions, I measured thirty-seven structures. Dimensions for left and right sides were measured in 296 specimens, and for only one side in 262 specimens. Measurements were chosen from Hildebrand (1952, 1954), Leach (1977a), Ondrias (1961) and Taylor (1974, 1976), and are illustrated in Figs. 2-5. Measurements were made with a vernier caliper accurate to .05mm. Those measure- ments not illustrated are noted by an asterisk (*) and are briefly explained in the list.

*a) Total length of body Taken from 1 *a ) Length of tail standard museum *b) Length of hindfoot specimen tags. c) Total length of skull d) Zygomatic breadth e) Length of scapula f) Height of scapula

*g) Maximum height of scapular spine--measured perpendicular to the blade of the scapula *h) Length of acromion process--measured from the deepest point in the notch between the acromion process and the glenoid fossa i) Length of humerus

j) Posterior displacement of humeral head, consisting of two separate measures: 14

ja--the distance between the lateral aspect of the humeral head and the most medial aspect of the lesser tuberosity. jp --the distance between the medial aspect

of the humeral head and the most lateral aspect of greater tuberosity. k) Transverse width of medial epicondyles 1) Maximum diameter of humerus at midshaft m) Minimum diameter of humerus at midshaft n) Total length of ulna o) Length of olecranon process

*p) Angle of olecranon process with shaft-- measured with a protractor; the angle formed by the olecranon process and the shaft of the ulna in anterior view

q) Length of radius r) Maximum distal width of radius s) Length of third metacarpal t) Total length of pelvis u) Length of pubic symphysis v) Preacetabular length of pelvis w) Dorsoventral breadth of ilium x) Total length of femur

y) Mediolateral width of femoral condyles z) Anteroposterior width of femoral condyles A) Maximum diameter of femur at midshaft B) Minimum diameter of femur at midshaft C) Total length of tibia 15

D) Total length of tibia minus length of

medial malleolus

E) Anteroposterior width of tibial head

F) Mediolateral width of tibial head

G) Maximum diameter of tibia at midshaft

H) Minimum diameter of tibia at midshaft

I) Length of fibula

J) Postastragalar length of calcaneus

K) Length of third metatarsal

1 *a-a ) Body length--Total length minus tail length n-o) Total length of ulna minus length of

olecranon process

*i+n-o+s) Sum of length of humerus plus length of

ulna minus length of olecranon process

plus length of third metacarpal

*x+C+K) Sum of length of femur plus length of tibia

plus length of third metatarsal

I initially intended to use total length of body as a standard against which to compare limb measurements, but of the species measured only about half (232) were accompanied by external measurements from standard museum specimen tags.

For that reason I searched for a more readily available measure that might still provide a body size standard. A number of similar studies have used a measure of the combined lengths of the thoracolumbar vertebrae (Hildebrand, 1952; 16

FIGURES 2-5

2) Bones, aspects of bones, and dimensions examined in this

study. Letters are identified in text. Figures are of

Martes americana.

3) Same

4) Same

5) Same 17

Fig. 2 18 ULNA lateral aspect anterior aspect medial aspect

RADIUS lateral aspect anterior aspect

WRIST AND HAND palmar aspect dorsal aspect

Fig. 3 19 PELVIC GIRDLE dorsal aspect ventral aspect

lateral aspect

FEMUR lateral aspect posterior aspect medial aspect

Fig. 4 20 TIBIA FIBULA lateral aspect anterior aspect lateral aspect

CALCANEUM CLAW

anterior aspect fore

medial aspect hind

ANKLE AND FOOT dorsal aspect plantar aspect

Fig. 5 21

Ondrias, 1961; Thorington, 1972) as an indicator of body

size. Because of the disarticulated state of the material

I was using, such a measure in this study would have been

prohibitively tedious. I sought to find some other useful

and convenient measure of body size. The correlation coefficient was computed between length of the body and length of the skull (n = 132). A highly significant correlation was found between body length and length of skull (r = .92; p<.001) for all mustelids. I recalculated the correlation coefficient without otters (r = .97; p<.001). Otters have relatively shorter skulls than other mustelids and therefore including otters diminishes the correlation. Because of the divergent nature of the length of the skull relative to body length in otters care must be taken in the interpretation of any ratio with length of skull (c) in it. While length of skull is a good indicator of length of body in most mustelids it over-estimates the length of the body in otters. Still the correlation between length of skull and length of body is highly significant in the Mustelidae. Therefore I felt justified in using length of skull as an indicator of length of the body.

In mustelids, and particularly the Mustelinae, males are substantially larger than females (Ewer, 1973; Haley, 1975;

King, 1975; Powell, 1979). For this reason and because wide-ranging mustelids (e.g., weasels) are geographically variable (King, 1975) .I felt that it was statistically suspect to combine raw measurements from different sexes or 22 different subspecies. Yet these individuals should have proportionately similar limb dimensions despite absolute size differences. The influence of sex and subspecific variation was therefore assessed in species containing sufficiently large samples. The use of ratios is a time-honored technique in morpho- metric studies (Desmond, 1976; Howell, 1944; Tarasoff, 1972). It is important to note that ratios are derived numbers. Some of the attendant problems in the use of ratios are treated by Atchley et al. (1976) and Simpson et al. (1960). Despite some drawbacks there are several advantages to the use of ratios (Corruccini, 1977). Of particular interest to me is the value of ratios as a means of comparing the limb skeletons of animals that differ widely in size. Stahl (1962) notes, "When measured by the length of his own fore- arm every man is the same size as every other". That is precisely the quality of ratios that I wished to exploit. A total of forty-nine ratios was generated for each side of all 558 specimens. The ratios are listed here.

1 1) (a-a )/a Length of body/Total length 1 2) b/(a-a ) Length of hindfoot/Length of body 1) 3) c/(a-a Length of skull/Length of body 4) e/c Length of scapula/Length of skull 5) e/(i+n-o+s) Length of scapula/Total length of forelimb 6) f/e Height of scapula/Length of scapula 23

7) f/c Height of scapula/Length of skull 8)i/c Length of humerus/Length of skull 9)i/e Length of humerus/Length of scapula

10) i/(i+n-o+s) Length of humerus/Total length of forelimb 11) ja/jp Posterior displacement of humeral head 12) k/i Transverse width of epicondyles/ Length of humerus 13) m/1 Minimum diameter of humerus at midshaft/Maximum diameter of humerus at midshaft 14) n/c Length of ulna/Length of skull 15) n/i Length of ulna/Length of humerus

16) n/(i+n-o+s) Length of ulna/Total length of forelimb 17) o/n Length of olecranon process/Length of ulna 18) (n-o)/c Length of ulna minus length of olecranon process/Length of skull 19) (n-o)/i Length of ulna minus length of olecranon process/Length of humerus 20)(n-o)/(i+n-o+s) Length of ulna minus length of olecranon process/Total length of forelimb 24

21)q/c Length of radius/Length of skull 22) q/i Length of radius/Length of humerus 23) r/q Distal width of radius/Length of radius 24) s/c Length of third metacarpal/Length of skull 25) s/(i+n-o+s) Length of third metacarpal/Total length of forelimb 26) t/c Length of pelvis/Length of skull 27) t/(x+C+K) Length of pelvis/Total length of hindlimb 28) u/t Length of pubic symphysis/Length of pelvis 29) v/t Preacetabular length of pelvis/ Length of pelvis 30) x/b Length of femur/Length of hindfoot 31) x/c Length of femur/Length of skull 32) x/(x+C+K) Length of femur/Total length of hindlimb 33) z/y Anteroposterior width of femoral condyles/Mediolateral width of femoral condyles 34) y/x Mediolateral width of femoral condyles/Length of femur 35) z/x Anteroposterior width of femoral condyles/Length of femur 25

36) B/A Minimum diameter of femur/Maximum diameter of femur 37) D/C Length of tibia minus length of medial malleolus/Length of tibia 38) C/b Length of tibia/Length of hindfoot 39) C/c Length of tibia/Length of skull 40) C/x Length of tibia/Length of femur 41) C/(x+C+K) Length of tibia/Length of hindlimb 42) E/F Mediolateral width of tibial head/ Anteroposterior width of tibial head 43) H/G Minimum diameter of tibia/Maximum diameter of tibia 44) I/C Length of fibula/Length of tibia 45) J/K Postastragalar length of calcaneus/ Length of third metatarsal 46) J/b Postastragalar length of calcaneus/ Length of hindfoot 47) J/(x+C+K) Postastragalar length of calcaneus/ Total length of hindlimb 48) K/(x+C+K) Length of third metatarsal/Total length of hindlimb 49) b/(x+C+K) Length of hindfoot/Total length of hindlimb 26

The following standard statistics were computed for the ratios in samples of each species: range, mean, standard deviation, variance, standard error, coefficient of variation, and sample size.

To avoid complications due to age variation I used only adult animals. Adult status was determined by closure of cranial sutures and fusion of epiphyseal caps to long bones

(Hildebrand, 1952; Leach, 1977a, 1977b; Taylor, 1970, 1974,

1976). Variation between left and right sides was examined by comparing the mean + two standard errors of ratios for left and right sides of males of the same subspecies. A total of fifteen ratios (6, 8, 9, 10, 12, 13, 14, 16, 17,

19, 22, 23, 26, 39, 40) were examined for thirteen species.

Variation between males and females was examined by comparing the mean ± two standard errors of ratios for the right side of males and females of the same subspecies. A total of twenty ratios (1, 3, 6, 8, 9, 10, 12, 13, 14, 15, 17, 18,

19, 22, 23, 26, 28, 31, 36, 39, 40, 43) was examined for thirteen species. Geographic variation was examined by comparing the mean + two standard errors of ratios for the right side of males in different subspecies. The same ratios and species were examined for geographic variation as for sex variation. The ratios examined embraced fore and hindlimbs and girdles, ratios of length and robusticity within limb, and limb/body ratios. 27

Histograms of frequency distributions for over 300

ratios were visually inspected to determine whether ratios

were distributed normally about their means.

Because sample sizes were small in a number of cases, and because there were some deviations from normalcy in the frequency distributions of some of the samples a series of

Student's t-tests were performed to check the accurace of

the mean ± two standard errors as a predictor of significant difference.

Patterns among species were examined by use of Dice

grams of the mean ± two standard errors (Fig. 6), shortest

connection (Prim) networks, and qualitative appearances from drawings. Prim networks are generated by summing the

differences between the means of any given sample of ratios

for the species to be compared. The summed differences are

used to produce a closest connection network which arrays

species based on least difference (closeness). Salient to

the interpretation of a Prim network are the relative

distance between two species along the network, and the

identity of nearest neighbors in the network. The branching

pattern (e.g. angle of branching) is not important to the

interpretation of a Prim network. Prim networks were

generated using eleven species (Mustela frenata, Mustela

vison, Martes americana, Martes pennanti, Eira barbara,

Gulo luscus, Spilogale, Mephitis mephitis, Conepatus

mesoleucus, Lutra canadensis, Enhydra lutris). Nine

combinations of ratios were used to generate Prim networks 28 of the limb skeletons of mustelids (e.g. forelimb lengths, hindlimb lengths, robusticity). Networks were generated for each combination using males only, females only, and males and females combined. Networks were then compared for similarity of pattern. Similarity of networks for males only and females only was taken as evidence that the two sexes of different species are very similar in regard to the ratios used in that particular combination. By virtue of the similar patterns for males only and females only I felt justified in conducting my species-level examinations on males and females combined. Networks based upon larger numbers of species (thirteen or fifteen) were subsequently generated to examine the degree of closeness of species of

Spilogale, or to incorporate species that were only represented by males (badgers, black-footed ferrets). Of course, utilization of species consisting only of males and species consisting of males and females in the same sample reduces resolution. Yet valuable information was provided by including badgers and black-footed ferrets in networks with other species of mustelids. Limb skeletons of the twelve best-represented species were compared by standardizing the linear dimension of each limb element according to techniques developed by Hildebrand

(1952, 1954), Hopwood (1947), Jenkins and Camazine (1977), and Taylor (1974, 1976). Drawings permitted qualitative comparisons of shape, proportion, and sculpturing of various bones that might have been missed in the numerical treatment. 29

The following caveats must be given. Some of the species in this study are represented by relatively small sample sizes. Statistical characterizations of such small samples must be viewed askance and interpreted carefully.

The natural history of some of the species in this study

(Eira barbara, Conepatus mesoleucus) is poorly known, making statements about their locomotion provisional.

Finally there is a duality to the use of ratios. There are two ways to achieve a high value for a ratio: the numerator can be large, or the denominator can be small.

It is possible to get a high value for length of femur/length of hindlimb by having a relatively long femur, or by having a relatively short leg. More to the point, it is possible to get high values for length of humerus/length of skull, length of ulna/length of skull, length of femur/length of skull, etc. in Enhydra lutris not because the individual limb elements are relatively long, but because the skulls of sea otters are relatively short. This does not abrogate the value of ratios, but rather dictates caution.

Fortunately most of the limb elements I examined were treated in a series of ratios (e.g., i/c, i/e, i/(i+n-o+s)) and are therefore less likely to be misunderstood. RESULTS AND DISCUSSION

Intraspecific Variation

Histograms of frequency distributions (Appendix 4) that were plotted for samples of ratios permit the following statements regarding the normalcy of the distribution of the ratios about their mean. The effect of lumping the ratios for males and females of a species generally leads to a better approximation of a normal distribution than either sex alone. This is no doubt partly the result of increased sample size. In small mustelines the effect of lumping ratios of males and females is usually a somewhat platykurtotic curve if the denominator of the ratio is length of skull (c). This apparently results from dispro- portionate sexual dimorphism in the size of skulls of males and females. In other words, females of small mustelines have disproportionately larger skulls than males of the same species. Nevertheless, when ratios for males and females are lumped together, they are approximately normally distributed about their mean. The effect of lumping the ratios of different subspecies of a species is much the same as lumping sexes. It is interesting to note that lumping subspecies of Mustela frenata and Martes americana resulted in somewhat more platykurtotic curves than those for other species. I suspect that my larger samples for Mustela frenata and Martes americana produce this result. My sampling of subspecies 31 is better for Mustela frenata and Martes americana than the other species and leads, therefore, to a better picture of geographic variation. At the species level the distribution of ratios about their mean provides the best approximation of a normal curve of any sample of ratios examined. There is some kurtosis and some skewness, particularly in the poorly represented species (Conepatus mesoleucus, Eira barbara, Mustela nigripes). Yet lumping both sexes and all subspecies of a species has the general effect of improving the normalcy. In any case, it is at the species level that I wish to make my comparisons. Results of Student's t-tests supported by use of the mean ± two standard errors as an indicator of differences between samples. Of 122 Student's t-tests, 113 (93%) corroborated my estimates based upon the mean ± two standard errors. Of the eleven t-tests that were unsupportive, nine nonetheless showed a significant difference at the 95% level when the mean ± two standard errors suggested that the two samples were not quite significantly different at the 95% level. If there is a preferred direction in which to be wrong, it is in predicting that two samples are not signifi- cantly different when they are. This means that if I err in my interpretation of the degree of difference between two samples I will tend to underestimate it based upon the mean ± two standard errors. 32

To test for differences between the ratios for left and right sides I used my best-represented subspecies. As Fig. 7 indicates there is no significant difference between left and right sides for Martes americana. A series of fifteen t-tests showed no significant difference between any ratio for left or right sides of any species. Dice grams of the mean + two standard errors and t-tests for differences between males and females of a subspecies produced some interesting results. No sexual dimorphism was found in any ratio for any species except when (c), length of skull, was the denominator of the ratio (Figs. 7-9). In ratios which have length of skull as the denominator a significant difference is observed for small mustelines and Spilogale (Table 2). As already noted females of the small mustelines (and perhaps Spilogale) evidently have skulls that are disproportionately large relative to the size of their bodies when contrasted to males of the same species. There are some exciting resource-partitioning implications in this observation. It certainly merits further study. In species that are sexually dimorphic (e.g. Mustela frenata, Martes americana), males of different subspecies show the same pattern relative to one another that females do (Figs. 7-9). This observation improves my confidence about combining males and females in order to estimate overall patterns of variation in ratios for a subspecies or a species. 33

Dice grams and t-tests for significant difference between subspecies of a species document the existence of geographic variation. Fig. 8 illustrates perhaps the most striking example. Martes americana abietinoides and Martes americana actuosa are decidedly different animals from other martens, at least as regards relative length of olecranon process. It is compelling to postulate that since M. a. abietinoides and M. a. actuosa are residents of stunted, boreal forest, and therefore are obliged to be somewhat more cursorial than other martens, they should show a well-known cursorial adaptation (reduction of the olecranon process) relative to their conspecifics from more heavily forested situations. A number of other ratios show similar disparities between these subspecies of martens. Geographic variation also exists in some of the ratios for Mustela frenata, Mustela vison, Martes americana, Martes pennanti, Gulo luscus, Spilogale, Mephitis mephitis, Taxidea taxus, Lutra canadensis and Enhydra lutris (Table 4). It is particularly pronounced in Mustela frenata and Martes americana, the two best-represented species in this study. I suspect that analysis of large samples of other mustelids would also reveal extensive geographic variation. So while a high score in Table 4 is a good indicator of geographic variation in the ratios for a species, a low score more likely reflects insufficient data than the absence of geographic variation.. Of course, it is also likely that some of the variation in Mustela frenata and Martes 34

FIGURES 6-9

6)Dice grams of mean, ± two standard errors, and range for ratio #17 (o/n--length of olecranon process/length of ulna) for thirteen mustelids. Sample sizes are shown in parentheses. Mf, Mustela frenata; Mn, Mustela nigripes; Mv, Mustela vison; Ma, Martes americana; Mp, Martes pennanti; Eb, Eira barbara; Gl, Gulo luscus, S, Spilogale; Mm, Mephitis mephitis; Cm, Conepatus mesoleucus; Lc, Lutra canadensis, El, Enhydra lutris.

7)Dice grams of mean, ± two standard errors, and range for ratio #14 (n/c--length of ulna/length of skull) comparing sides, sexes, and subspecies of martens. Sample sizes are shown in parentheses.

8)Dice grams of mean, ± two standard errors, and range for ratio #17 (o/n--length of olecranon process/length of ulna) comparing sexes and subspecies of martens. Sample sizes are shown in parentheses.

9)Dice grams of mean, ± two standard errors, and range for ratio #12 (i/i--transverse width across epicondyles/length of humerus) comparing sexes and subspecies of martens. Sample sizes are shown in parentheses. abi, Martes americana abietinoides; act, M. a. actuosa; cau, M. a. caurina; sie, M. a. sierrae; -abi, all subspecies except M. a. abietinoides and M. a. actuosa; All, all subspecies of Martes americana. 35

Fig. 6 36 Fig. 7 37 Fig. 8 38 Fig. 9 39 americana is a reflection of the wide geographic range of these two species.

Prim networks were used to examine possible differences in the relationship between males and between females of eleven species of mustelids. Networks for males only and females only were compared for similarity of pattern using all nine combinations of ratios (Appendix 5). Figure 10 illustrates the poorest correspondence between Prim networks for males and females in this study. There are some differences between the network for males and the network for females. The relationships between species and between subfamilies are not significantly different for males and for females however. Figure 11 illustrates a better and more typical correspondence between Prim networks for males and females. This examination indicates that males and females of different species show the same relationships to each other when ratios that reflect proportions of the limb skeleton are used to generate a Prim network. It follows from this similarity then that males and females are similar to one another in appendicular anatomy, and that species comparisons by Prim network are reasonable using samples of males and females combined.

There are significant differences between males and females in some ratios (Tables 2 and 3). There are also some differences between ratios for different subspecies of a species (Table 4). Although combining sexes and different subspecies of a species tends to mask sexual and geographic 40

FIGURES 10 & 11

10)Prim networks for females (A) and males (B) using

eleven species of mustelids and eight forelimb length

ratios.

11)Prim networks for females (A) and males (B) using eleven species of mustelids and twenty-six fore and

hindlimb ratios. 41

FIGURE 10A

FIGURE 10B 42 FIGURE 11A

FIGURE 11B Table 2. -- (+) scores for significant differences (P<.05) between ratios for males and females. Data taken from best-represented subspecies in five species of Mustelidae; Mustela frenata, Martes americana, Spilogale putorius, Mephitis mephitis, Lutra canadensis.

f/c f/e i/c i/e n/c n/i (n-o)/c (n-o)/i q/c q/i

M. f. nevadensis + - + - + - + - + - 4 3 M. a. abietinoides + - + - - - + - + -

S. 2. interrupta - - + - - - - - - -

M. m. avia - - - - - - - - - -

L. c. canadensis - - - - - - - - - - 44

Table 3. -- Scores for occurrence of sexual dimorphism in

eleven species of Mustelidae. Each ratio was scored 1 point if there was a significant difference (P<.05)

between the sexes. Scores were added for each species.

For example four forelimb and four hindlimb ratios were

significantly different for males and females of

Mustela frenata.

Species Forelimb Hindlimb Combined

Mustela frenata 4 4 8

Mustela vison 4 3 7

Martes americana 4 3 7

Martes pennanti 4 0 4

Eira barbara 1 0 1

Gulo luscus 0 0 0

Spilogale spp. 2 1 3

Mephitis mephitis 0 0 0

Conepatus mesoleucus 0 0 0

Lutra canadensis 0 0 0

Enhydra lutris 1 0 1 45

Table 4. -- Scores for occurrence of geographic variation in

twelve species of Mustelidae. Each ratio was scored 1

point if there was a significant difference (P<.05)

between any two subspecies of a species. Scores for

each species were added. For example eight forelimb

and four hindlimb ratios in Mustela frenata revealed at

least one occurrence of significant differences between

subspecies.

Species Forelimb Hindlimb Combined

Mustela frenata 8 4 12

Mustela vison 1 3 4

Martes americana 8 4 12

Martes pennanti 1 0 1

Eira barbara 0 0 0

Gulo luscus 1 0 1

Spilogale spp. 4 2 6

Mephitis mephitis 1 2 3

Conepatus mesoleucus 0 0 0

Taxidea taxus 1 2 3

Lutra canadensis 3 4 7

Enhydra lutris 0 1 1 46 variation, I made species level comparisons using combined samples of males and females and all available subspecies of a species. I did this for the following reasons: (1) normalcy of the distribution of ratios about their mean results from combining males and females, or subspecies;

(2) subspecies of males and of females exhibit the same pattern of relationship to each other in Dice grams of mean

± two standard errors; males and females combined follow the same pattern (Figs. 7-9); (3) Prim networks for males, females, and males and females were similar. Appendix 6 summarizes the descriptive statistics for all ratios of males plus females and all subspecies of thirteen species of the family Mustelidae.

Species Comparisons

FORELIMB

Clavicle

The clavicle is vestigial in all of the mustelids.

Hall (1927) reported that it is absent in Taxidea taxus.

Fisher (1942) and Howard (1973) recorded the absence of the clavicle in the Lutrinae. Savage (1957) did not record a clavicle in Potamotherium, an early lutrine. Hall (1926) did not mention the occurrence of a clavicle in Spilogale or Mephitis. Klingener (1972) noted that the clavicle of mink is "a tiny vestigial bone buried between the clavo- trapezius and clavodeltoid muscle". Martes has the most 47 highly developed clavicle of all mustelids observed. This perhaps is owing to the arboreal habits of martens and fishers. Even in Martes, however, the clavicle is quite small (<1cm.), and does not articulate with the scapula

(Leach and Dagg, 1976). Ondrias (1961) did not mention the clavicle in his study of the forelimbs of European mustelids.

Scapula

The scapula in all twelve species figured (Fig. 12) is fairly uniform anatomically. The spine is well developed in all mustelids. The acromion process is located above the glenoid fossa anteriorly in the mustelines (excepting

Mustela vison), Spilogale, and Taxidea taxus. The meta- cromion process is poorly developed in the mephitines. The metacromion process is well developed in the other species examined and is particularly prominent in Mustela frenata,

Mustela vison, the lutrinae, and Taxidea taxus.

The profile of the scapula is essentially triangular in Mustela frenata but tends to become more rectangular in the Mephitinae and Taxidea taxus. The scapula of Enhydra lutris is rectangular, but it is triangular in Mustela vison, and very triangular in Lutra canadensis. The scapulae of

Martes, Eira barbara, and Gulo luscus are essentially like that in Mustela frenata but are rounder, particularly in

Martes pennanti and Eira barbara.

The triangular or sub-round profile of the scapula is a characteristic of generalized mammals (Hildebrand, 1974; 48

Jenkins, 1974; Taylor, 1974). A narrower more rectangular

profile suggests some limitation of movement, and specializa-

tion to strengthen those limited movements. A narrow

scapula can indicate fossorial or cursorial habits (Gray,

1968; Hildebrand, 1974).

Taxidea taxus, Lutra canadensis, and the larger mustelines have a prominent post-scapular fossa which extends the site of origin of the teres major muscle. The teres major contributes to posterior movement of the humerus as in digging or swimming. The presence of the post-scapular fossa in the larger mustelines is owing perhaps to their greater weight in comparison to Mustela frenata. Ewer

(1973) equated the possession of a post-scapular fossa in the ursids to the combined effects of arboreality and great weight. The absence of a post-scapular fossa in Enhydra lutris is not surprising in light of the fact that sea otters do not use the forelimb much in swimming (Tarasoff et al., 1972). Taylor (1914) noted that the forelimb in

Enhydra lutris is an organ of prehension, not propulsion.

The scapula is long relative to the body in Conepatus mesoleucus, Mephitis mephitis, and Gulo luscus. It is shortest in Mustela and Martes. The scapula is long relative to the forelimb in Enhydra lutris, but sea otters have relatively short legs (Kenyon, 1969; Taylor, 1914). The scapula is relatively short compared to the long legs of

Martes, Eira, and Gulo. The height of the scapula relative to its length is greatest in Taxidea taxus, Lutra canadensis, 49

Enhydra lutris, and Gulo luscus, which have scapulae most

unlike that of Mustela frenata of all the species examined.

The height of the scapula is least in the mephitines, particularly Conepatus mesoleucus and Mephitis mephitis.

This character suggests some restriction of forelimb mobility, and is an unusual finding in light of the locomotor habits of skunks.

There are trends in the morphology of the scapula in the Mustelidae which serve to support my notion of progressive specialization to different modes of locomotion. The scapula becomes progressively longer relative to the body in the following species sequences: Mustela frenata--Mustela nigripes--Taxidea taxus; Mustela frenata--Mustela vison--

Lutra canadensis; Mustela frenata--Spilogale--Mephitis mephitis--Conepatus mesoleucus; Mustela frenata--Martes americana--Martes pennanti--Eira barbara--Gulo luscus. The length of scapula relative to the forelimb follows essentially the same trends, except that because of their relatively long legs, the scapulae of Martes, Eira, and Gulo are relatively shorter than that of Mustela frenata.

Both indices of scapular height (relative to body length, and relative to length of scapula) show essentially the same progressive increases in height as are described above for length of scapula. The skunks show a progressive narrowing rather than widening of the scapula relative to length of scapula. 50

Humerus

The humerus of msutelids (Figs. 13, 14) is most gracile in Martes americana, Mustela frenata, Martes pennanti, Eira and Mustela vison, and is most robust in Conepatus, Taxidea,

Gulo, Lutra, and Enhydra. Trends of increasing robusticity closely follow proposed trends of locomotor specialization:

Conepatus, Taxidea, Lutra, Enhydra, and Gulo have the most robust and elaborately sculptured humeri. I am obliged to

note that there is a size increase in all of my proposed

sequences; of course, an increase in mass will lead to an increase in the robusticity of a limb element (Hildebrand,

1974; Pedley, 1977). In this case, however, increases in

robusticity and sculpturing are probably the result of both

increased size and different modes of locomotion between

the species. For instance the humerus of Spilogale is more

robust than that of Mephitis. Since Mephitis is heavier than

Spilogale, the greater robusticity of the humerus in Spilogale

cannot be attributed to greater weight. On the other hand

increasing robusticity in Martes americana, Martes pennanti,

Eira and Gulo is probably related to increased weight along

that sequence, since locomotion in those species is very

similar.

The humerus is longest relative to the body in Gulo,

Eira, Martes pennanti, Conepatus, Mephitis, and shortest

relative to the body in Mustela frenata. Ondrias (1961)

suggested that a shortening of the humerus is typical of

fossorial mammals that must turn around in narrow burrows. 51

Both Mustela nigripes and Taxidea have longer humeri than

Mustela frenata, making me suspect the accuracy of Ondrias' generalization. The humerus is long relative to the body in the long-legged Martes americana, Martes pennanti, Eira, and Gulo; short relative to the body in otters and skunks; and short in the badger, which, of course, has powerful forelimbs. No mustelid has a humerus that is longer relative to the forelimb than Mustela frenata, although the relation- ship is about the same for Enhydra. Martes and Gulo have humeri that are short relative to length of forelimb, but this is a reflection of lengthening of distal limb elements

(see below). Long legs and disproportionate lengthening of distal limb elements is a cursorial specialization (Brown and Yalden, 1973; Gray, 1968; Hildebrand, 1974).

The shaft of the humerus is curved in Lutra, Enhydra and Taxidea. Savage (1957) noted that it is curved in

Potamotherium. Ondrias (1961) reported that it is relatively straight in Meles.

The transverse width across the epicondyles of the humerus is greatest relative to length of the humerus in

Conepatus, Taxidea, Lutra, Enhydra and Mephitis (Fig. 13).

Ondrias (1961) noted that it is also great in Meles

(European badger). The transverse width across the epicondyles is narrowest in Martes americana and Mustela frenata. There is a widening trend in the epicondyles along all of the sequences I propose. A prominent medial epicondyle is indicative of powerful flexors of the manus. 52

A prominent lateral epicondyle is indicative of powerful extensors and supinators of the manus. The relatively deeper groove between trochlea and capitulum in Taxidea, Lutra,

Enhydra, Mustela frenata, and Martes americana suggests rigidity of the elbow in these species. Ondrias (1961) suggested that widening of the epicondyles was correlated with the powerful flexion of the elbow and pronation and extension of the carpus and manus, and that it is charac- teristic of fossorial and semi-aquatic specialists. The trends illustrated here corroborate that suggestion. No mustelid has a trochlea as narrow as do the cursorial

Canidae. Among mustelids, the trochlea is narrowest in Martes americana.

The posterior placement of the humeral head is somewhat more enigmatic. The head is most anterior on the humerus in

Taxidea, Conepatus, Mephitis, and, oddly enough, in Martes americana. The head is most posterior in the lutrines.

Taylor (1974) noted that the humeral head was most posteriorly placed in cursors and less so in more generalized forms. Unfortunately there are no aquatic viverrids with which to contrast otters. Ondrias (1961) said the head of

Enhydra is placed almost as far posteriorly as in the

Phocidae (seals).

The head of the humerus is divergent, suggesting mobility of the humerus, in Martes, Eira, Gulo, Lutra, and

Enhydra. The head is more firmly buttressed and less divergent in Taxidea taxus and the skunks, suggesting that greater stresses are passed through the head and along the 53 shaft of the humerus. Taylor (1974) noted from cinero- radiographs that the head of the humerus can rock in the glenoid in viverrids, making sphericity of the head a poor predictor of mobility at the shoulder. The shaft of the humerus is roundest in Martes americana, Mustela nigripes,

Eira, Martes pennanti, Mustela frenata, and Gulo, and is most elliptical in Enhydra, Lutra, Mustela vison, Taxidea, and skunks. The pectoral and deltoid ridges in Enhydra,

Lutra, Taxidea, and the skunks, are very strong and dominate the shaft of the humerus, in contrast to Martes, Eira; and

Gulo. Hildebrand (1974) noted that round shafts of the long bones can be correlated with cursorial or arboreal habits. The greater tuberosity of the humerus is prominent in Lutra, Taxidea, and the skunks, which correlates well with power in lateral rotation of the humerus. The lesser tuberosity is prominent in Enhydra. The greater and lesser tuberosities are subequal in other mustelids.

Trends in length of humerus relative to body length and other forelimb elements generally correspond to the proposed sequences, as do trends in ellipticity of the shaft.

Ulna

The ulna is gracile in Martes americana, Mustela frenata, Martes pennanti, Eira, Spilogale and robust in

Lutra, Enhydra, Mustela vison, and Gulo (Fig. 15).

Trends of increasing robusticity of the ulna generally follow proposed continua from Mustela frenata. The ulna 54 of Enhydra is slightly less robust than that of Lutra. The ulna of Taxidea is not so robust as might be expected for a fossorial mammal, but the radius of badgers is quite robust.

The length of ulna relative to body length is greatest in Gulo which suggests some cursorial specialization. The ulna is also long in Conepatus, Taxidea, and Mephitis, but that is due partly to the disproportionately long olecranon

process in these species. The ulna is relatively short in

Mustela frenata, Mustela nigripes, Mustela vison, Lutra, and

Enhydra. The length of ulna relative to the humerus is greatest in Taxidea, Conepatus, Mephitis (all three of which have long olecranon processes), Lutra, Enhydra, and Gulo.

It is important to recall the relatively short humerus of the otters when considering this relationship, because it exaggerates the length of the ulna. The humerus and ulna are about the same length in Martes and Eira. The ulna is relatively short in Mustela frenata and Mustela vison. The length of ulna relative to the forelimb shows essentially the same relationship between species as length of the ulna relative to body length. The olecranon process of Taxidea, Conepatus, and Lutra is long, providing a considerably greater mechanical advantage, in extension of the forearm compared to other mustelids. The olecranon process is short in Martes, Gulo, and Eira. A long olecranon process is often correlated

with fossorial life or swimming movements of the forearm.

The long olecranon process of Conepatus and Mephitis may be 55 an adaptation to turning over logs and rocks in search of grubs. A short olecranon process has generally been attributed to cursorial or arboreal habits (Flower, 1885;

Gambaryan, 1974). Trends in the length of the olecranon process in the Mustelidae also closely follow my proposed continua, except that the relative length of the olecranon process is about the same in Mustela frenata and Enhydra.

Ondrias (1961) stated that the length of the olecranon process in Lutra could not be correlated with semi-aquatic life. Noting the progression in length of the olecranon process in Mustela frenata, Mustela vison, and Lutra canadensis, I would respectfully disagree.

I generated ratios using as the numerator the length of the ulna minus the length of the olecranon process reasoning that such a measure was more likely an indicator of the relative contribution of the ulna to the total length of the forelimb than length of ulna. Relative to body length, length of ulna minus length of olecranon process is longest for Gulo, Eira, Martes pennanti, and Martes americana and reflects cursorial specialization in those species. Relative to body length this measure is also long for Taxidea and the skunks, albeit not as long, relatively, as suggested by measures including the length of the olecranon process. The length of the ulna minus length of olecranon process is short in Mustela frenata, Mustela vison, and Lutra. Relative to length of humerus, length of ulna minus length of olecranon process is longest in Gulo and shortest in Mustela 56 frenata. Length of ulna minus length of olecranon process relative to both body length and length of humerus follows the sequences I suggest. Relative to total length of the forelimb length of ulna minus length of olecranon process is longest in Enhydra, Taxidea, and the skunks. This relationship must be considered in light of the short limbs of the otters. Lutra and Mustela vison have the shortest length of ulna minus length of olecranon process, relative to total limb length. This ratio generally follows my proposed sequences. There is a trend toward distal broad- ening of the ulna in Taxidea, Gulo, Mustela vison, and

Lutra.

The angle between the olecranon process and the shaft of the ulna is greatest in Mephitis, Mustela nigripes,

Lutra, and Mustela frenata; the angle is smallest in Mustela vison, Martes pennanti, Conepatus, and Taxidea. The smaller angle causing the olecranon process to be more in line with the shaft of the ulna in Taxidea, Conepatus, and Mustela vison seems as though it might improve leverage relative to a greater angle. The function of the greater angle in

Mephitis, Lutra, Mustela nigripes, and Mustela frenata is a mystery to me. Taylor (1974) suggested that a smaller, more acute, angle between the olecranon process and the shaft of the ulna would lengthen the triceps, slowing its action and permitting more controlled movements of the forelimb. He also proposed that a greater angle between the olecranon process and the shaft of the ulna would shorten 57 the triceps muscle, thus leading to faster movements of the forelimb. My data neither strongly support or negate

Taylor's suggestion.

The styloid process of the ulna is most divergent in

Mustela frenata, Mustela vison, and Martes americana. The styloid process of the ulna is least divergent in Gulo,

Taxidea and the skunks.

Radius

The radius is most gracile in Martes americana, Martes pennanti, Gulo, Mustela frenata, Spilogale, and Conepatus.

A much more robust radius typifies Lutra, Enhydra, Taxidea, and Mephitis (Fig. 16). Trends from gracile to robust generally follow my proposed sequences, although the radius in Conepatus is unusual among skunks. The shaft of the radius is curved dorsoventrally in Mustela vison, Spilogale,

Conepatus, Taxidea, and Lutra. The curve is particularly noticeable in Mustela vison, Lutra, and Taxidea. The radii of other mustelids examined were more or less straight.

Hildebrand (1974) correlates bowing of the radius with power in supination of the manus.

The length of the radius relative to the length of the body is greatest in Gulo and closely parallels the relation- ships already noted for the ulna. Trends in this ratio closely follow proposed continua with even the typically unusual Enhydra conforming. The length of the radius relative to the humerus is greatest for Gulo, which is 58 followed by Taxidea, Conepatus, Mephitis, and Spilogale; the latter also have relatively short humeri. My proposed sequences are only partially supported by trends in this ratio.

The distal width of the radius is greatest in Lutra and

Taxidea, and narrowest in Mustela frenata and Martes. The trends I postulate in my sequences are supported. The only deviation is that the distal end of the radius is wider in

Mustela frenata than in Martes; probably this condition is due to the fossorial habits of Mustela frenata and selec- tive pressure to strengthen the carpus.

Carpus and Metacarpus

The wrist and hand (Fig. 17) are particularly gracile in Mustela frenata, and Martes and are robust in Taxidea,

Lutra, Mustela vison, and the skunks. The hand is particu- larly broad in Taxidea, Lutra, and the skunks. Ondrias

(1961) noted that the hand of Meles was very broad compared to that of other European mustelids. The length of the third metacarpal relative to the body is greatest in Gulo,

Martes, and Eira. The third metacarpal is shortest in

Enhydra, Taxidea, Spilogale, Mephitis, and is somewhat longer in Mustela frenata. Trends in this ratio are somewhat equivocal. Curiously, both Mustela vison and Mustela

nigripes have longer hands than Mustela frenata, even

though the hands of Enhydra and Taxidea are much shorter.

Relative to the length of the forelimb the length of the 59 third metacarpal is greatest in Mustela vison, and Lutra, and shortest in Taxidea and Enhydra. The short hand of

Taxidea is a logical correlate of the power necessary for fossorial life. The long hands of Mustela vison and Lutra are probably due to the paddle-like function of the hand.

The relatively short hand in Enhydra is probably related to the use of the hand for functions other than swimming

(Kenyon, 1969; Tarasoff, et al., 1972). The third meta- carpal is actually relatively long in Martes, Eira, and

Gulo, but seems relatively short in this ratio due to the relatively long legs of these species. The long hands of these species probably represent adaptations to running either in trees or on the ground; and correlate nicely with the tendency toward a digitigrade stance in the arboreal, sub-cursorial mustelines.

Foreclaws

The foreclaws (Fig. 18) are longest in Taxidea and are undoubtedly correlated with fossorial life. The skunks have very long claws as well. I suspect their length is related to the opportunistic feeding habits of skunks, which turn things over in search of food. The claws in Martes, Eira, and Gulo are all strongly curved and correlate well with the known arboreal tendencies of these species (Banfield,

1974; Coues, 1877, Walker et al., 1975). The foreclaws of Mustela frenata are morphologically intermediate. In

Mustela vison, the foreclaws are rather strongly curved and 60

FIGURES 12-18

12) Lateral aspect of scapulae of twelve species of Mustelidae, arrangement like that in Figure 1.

13) Anterior aspect of humeri of twelve species of Mustelidae, arrangement like that in Figure 1.

14) Lateral aspect of humeri of twelve species of Mustelidae,

arrangement like that in Figure 1.

15) Lateral aspect of ulnae of twelve species of Mustelidae,

arrangement like that in Figure 1.

16) Anterior aspect of radii of twelve species of Mustelidae, arrangement like that in Figure 1.

17) Dorsal aspect of carpus and metacarpus of ten species of

Mustelidae, arrangement like that in Figure 1.

18) Foreclaws (right) and hindclaws (left) of twelve species

of Mustelidae, arrangement like that in Figure 1. 61

Fig. 12 62

Fig. 13 63

Fig. 14 64

Fig. 15 65

Fig. 16 66

Fig. 17 67

Fig. 18 68 may aid in scrambling on stream sides or in prey capture.

The foreclaws are small in otters, particularly in Enhydra.

Bony support embracing the base of the keratinized sheath of the claws is most noticeable in Enhydra, Taxidea,

Conepatus, and Gulo.

HINDLIMB

Pelvis

The pelvis is particularly narrow and gracile in Martes americana but is fairly narrow in Martes pennanti, Eira,

Mustela frenata, Mustela vison, Spilogale, and Lutra (Fig.

19). The pelvis is wider and more robust in Mephitis, Gulo, Taxidea, and particularly in Enhydra. Taylor (1914) correlated flaring ilia with swimming movements of the hind- limb, noting that the anterior ends of the ilia of seals are almost perpendicular to the vertebral column. The angle that the ilium forms with the pubic symphysis is closest to perpendicular in Martes, Mustela, and Eira (Fig. 20).

The angle is much more acute in the skunks, Taxidea, and

Enhydra. The angle in Lutra and Gulo is intermediate in being more acute than Martes and less acute than Taxidea.

A less acute angle between the ilium and the rest of the inominate is a specialization for speed (Smith and Savage,

1956). A rodlike ilium more or less parallel to the vertebral column is a fossorial specialization (Shimer,

1903). A prominent constriction in the ilium just anterior 69 to the acetabulum is found in Taxidea, Enhydra, Lutra, Gulo,

Martes pennanti, and Eira. The constriction is less distinct in Mustela frenata and in skunks.

The length of pelvis relative to body length is great- est in otters, Conepatus, and Mephitis. Mustela, Martes, and Spilogale have a much shorter pelvis. This trend parallels my proposed sequences closely. The length of pelvis relative to length of hindlimb exhibit the same trends as length of pelvis relative to length of body.

The pubic symphysis is shortest in the skunks and

Taxidea. The pubic symphysis is longest in the mustelines.

Symphysis length in the otters is intermediate between weasels and skunks. Hall (1926) noted that the adductor mass in Spilogale and Mephitis mephitis was not so expansive as in Martes. He did not mention the pubic symphysis at all, however. Hildebrand (1974) considered a poorly fused pubic symphysis to be associated with fossorial habits.

Taylor (1914) noted that the poorly fused pubic symphysis of sea otters was structurally antecedent to the condition of the pubic symphysis in seals. The relative length of the pubic symphysis corresponds to trends I propose for aquatic and fossorial specializations. My sequences for arboreal and ambulatory specialization are not followed closely.

The preacetabular length of the pelvis is one of the least variable ratios in my study. Preacetabular length is slightly longer in Mephitis than other mustelids and slightly shorter in Taxidea and in otters. Taylor (1976) 70 noted that preacetabular length in viverrids is relatively constant.

Femur

The femur of mustelids is most gracile in Martes, Mustela frenata, Gulo, and Eira. A robust femur is found only in Enhydra and Lutra; Taxidea and skunks are intermediate

(Figs. 21, 22). Trends of increasing robusticity follow the sequences I propose. A constricted neck between the head and shaft of the femur characterizes members of the Mustelinae and Enhydra. Skunks, Lutra, and Taxidea, have a thicker neck; the head of the femur is therefore more firmly buttressed.

The length of femur relative to hindfoot length is greatest in the skunks and Taxidea. Otters and Mustela vison have the shortest femora. The hindfeet of otters

(and to a lesser degree mink) are somewhat longer than those of other mustelids. The trends in this ratio follow my proposed sequences except for skunks, which do not differ appreciably among themselves. The length of femur relative to the body is greatest in Conepatus, Eira, Gulo,

Martes pennanti, and Mephitis. The femur is shortest in

Lutra, Mustela vison, and Mustela frenata. The long femur in arboreal species and runners (Eira Barbara, Gulo luscus, and Martes pennanti) follows well-established trends for cursorial specialization (Hildebrand, 1974; Howell, 1944;

Smith and Savage, 1956). The long femur of Conepatus and Mephitis is mystifying. Relative to body length all 71

other mustelids have longer femora than Mustela frenata.

The femur is longest relative to hindlimb length in Taxidea, suggesting that the distal limb elements have become shortened in this species. The femur is shortest relative to total length of the limb in the otters. This ratio follows my proposed sequences closely.

Ratios examining the relative width across and depth of the femoral condyles (z/y, y/x, z/x) show that otters,

Taxidea, Mustela vison, and skunks have femoral condyles

widened mediolaterally, whereas the condyles are narrow in

Mustela frenata, Martes, and Eira. The femoral condyles

are deep anteroposteriorly in otters and Mustela vison and

shallow in Martes americana, Martes pennanti, Eira, and

Spilogale. These ratios follow my proposed continua fairly

closely. The shaft of the femur is roundest in Martes,

Eira, Gulo, and Mustela frenata. The shaft of the femur is most elliptical in the otters, Mustela vison, Taxidea,

Mustela nigripes, and Spilogale. The shaft of the femur is expanded mediolaterally in Lutra and particularly in Enhydra.

Round shafts on long bones are correlated with running and arboreal habits, while more elliptical shafts are typical of aquatic and fossorial specialization (Hildebrand, 1974).

This ratio follows my proposed continua for running,

arboreal, and aquatic specializations. Skunks, Taxidea,

and Mustela nigripes do not conform to my continua.

Mustela nigripes and Spilogale both have more elliptical 72 femora than Taxidea taxus; Conepatus and Mephitis do not differ appreciably from Taxidea.

Tibia

The tibia is most gracile in Mustela frenata, Martes,

Eira, Spilogale, and Gulo. The tibia is much more robust in Taxidea, Lutra, Enhydra, and Mustela vison (Fig. 23).

The tibia is fused proximally to the fibula in Gulo and

Enhydra. This fusion likely restricts motion at the ankle to flexion and extension of the pes (Barnett and Napier,

1953ab; Walmsley, 1918). The length of the medial malleolus is greatest in Enhydra, Lutra, Mustela vison, Taxidea, and

Mustela nigripes, and is probably also an indication of reduced mobility at the ankle of those species. A shorter medial malleolus is characteristic of Martes, Eira, and

Gulo, which are decidedly more agile beasts than badgers or otters. Trapp (1972) mentioned the ability to rotate the hindfoot in Martes and other arboreal carnivores as an adaptation permitting head-first descent from trees. Taylor

(1976) recorded more potential movement in the ankle of

Nandinia, an arboreal viverrid, than in any other African species of the family.

The length of tibia relative to hindfoot length is greatest in skunks, and least in the badger and otters. The extraordinary claws of badgers explain partially the relative shortness of the badger tibia in this ratio, because the length of hindfoot measure that I used included 73 claws. Shortening of distal limb elements is a fossorial adaptation (Smith and Savage, 1956). The long, paddle-shaped feet of otters may account in part for the condition of this ratio in otters. The tibia is longest relative to the body in skunks but is also long in Martes, Eira, and Gulo.

A shorter tibia occurs in Taxidea, Mustela nigripes, and

Mustela frenata. The length of tibia relative to length of femur is one of the classical relationships of locomotor studies (Desmond, 1976) and has been widely used to illus- trate cursorial adaptation. Gregory (in Desmond, 1976) suggested that the higher the ratio of length of tibia/length of femur (T/F) the faster an animal is structurally capable of running. Desmond (1976) reported a T/F ratio of 0.92 in race horses and 1.25 in gazelles. All of the species I examined have a T/F ratio greater than 0.92 except Taxidea, and Enhydra has a T/F ratio of more than 1.25. Mustelids, and certainly otters, are not specialized cursors. Taylor

(1976) gave T/F ratios of 1.02-1.26 for viverrids. These high T/F ratios point up one of the pitfalls of making hasty comparisons. The femora of all carnivores are shorter relative to their body lengths than the femora of ungulates and render the comparison of T/F ratios between carnivores and ungulates suspect.

Trends in the ratios of tibia length follow proposed sequences except in skunks, which have surprisingly long distal limb elements. The length of the tibia relative to the length of the hindlimb is greatest in Lutra, Mephitis and Conepatus. The tibia is shortest in Taxidea. 74

The mediolateral width of the proximal end of the

tibia is greatest in otters, and correlates well with the

wide femur of these species. The anteroposterior depth of

the proximal end of the tibia is greatest in Gulo. Trends

in widening or deepening of the proximal end of the tibia

do not fit my proposed sequences well.

The tibia of mustelids is most round in Mustela vison

and Martes, and most elliptical in the otters, Taxidea, and

Mustela frenata. Ellipticity of the tibia in Mustela

frenata is greater than that in any mustelids except

Taxidea and otters. Trends in ellipticity of the tibia do not follow my sequences.

The lengthening of distal elements in the limb of

skunks is not reported in the literature to the best of my

knowledge . It seems reasonable that specializations for increasing the length of stride in cursorial species would be selectively advantageous in ambulatory species as well.

An increase in the length of stride should reduce the energy investment to move a unit of distance regardless of speed.

Fibula

The fibula of mustelids is gracile in Martes, Mustela,

Eira, Gulo, and the skunks. The fibula is more robust in

Taxidea, Lutra, and Enhydra (Fig. 24). Trends in robusticity of the fibula follow my proposed sequences in the mustelines, and in Lutra and Enhydra. The fibula of the three 75 mephitises I examined are almost identical. The fibula is longest relative to the tibia in Martes, Eira, Gulo and

Spilogale. Mustela nigripes, Mustela vison, Taxidea, Lutra, and Enhydra have short fibulas.

Calcaneus

The calcaneus is gracile in Martes, Gulo, Mustela vison and Conepatus. A more robust calcaneus typifies Mustela frenata, Taxidea, and Enhydra (Fig. 25). Postastragalar length of the calcaneus is greatest in Conepatus, Taxidea, and Mephitis. The postastragular length is much less in Mustela frenata, Martes americana, and Enhydra. My proposed sequences conform very well with trends in the postastragular length of the calcaneus except, as usual, Enhydra is very unlike other aquatic mustelids. The postastragalar length relative to length of the third metatarsal and relative to length of hind foot are essentially similar ratios. The postastragalar length relative to length of hindlimb is greatest in Taxidea, Lutra, Gulo, and Conepatus. The postastragalar length is least in Mustela frenata and

Martes americana. This ratio parallels my proposed sequences except in the case of Enhydra in which the postastragalar length relative to hindlimb length is essentially the same as in Mustela vison. Stains (1976) noted that the calcanea of mustelids were at least subfamilially distinct, but drew no functional conclusions from his work. Probably an increase in postastragalar length increases the power of 76 extension of the pes in otters, badgers, and relatively heavy-bodied sub-cursorial forms such as Gulo.

Pes

The hindfoot is most gracile in Mustela, Martes, and

Spilogale. The hindfoot of Taxidea, Lutra, Conepatus, and

Enhydra is much more robust (Fig. 26). Trends in robust- ness of the hindfoot follow my proposed sequences closely.

The length of the third metatarsal relative to the total length of the hindlimb is greater by far in Enhydra, which has large paddle-like feet and short legs. The third meta- tarsal is much shorter in Eira, Spilogale, Mephitis,

Conepatus, and Taxidea. Trends in skunks, arboreal mustelines, Gulo, and fossorial mustelids correspond to my proposed sequences.

Hindfoot length relative to length of hindlimb is greatest in Enhydra and least in Spilogale and Mephitis.

Sample sizes for this ratio were the smallest in this study.

The length of the hindfoot relative to length of body is greatest in Enhydra and Gulo. The hindfoot is shortest relative to length of body in Mustela vison and Spilogale.

The long hindfoot of Gulo could be an adaptation to sub-cursorial locomotion in this wide-ranging mustelid.

However, the size of hindfoot may be a reflection of the large size and massiveness of Gulo compared to other smaller mustelids. The long hindfoot of Enhydra may be a function of the size of sea otters as well. Sea otters, 77

however, are not particularly adept at overland travel

(Kenyon, 1969; Tarasoff et al., 1972) and the long hindfoot

is most likely an adaptation to aquatic locomotion. The

relatively small hindfoot of Lutra correlates well with the

fact that more of the propulsive forces in river otters are

provided by the forelimb and tail than in sea otters

(Tarasoff et al., 1972). Indeed, terrestrial locomotion

is much more common in river otters than in sea otters. The

ratio of hindfoot length to body length in Lutra is more

similar to terrestrial mustelids than to Enhydra. The

smallest hindfeet in the Mustelidae belong to Spilogale,

Mustela frenata, Mustela vison, and Mustela nigripes, which implies along the same line suggested for Gulo luscus that

little animals have relatively small feet.

Hindclaws

The hindclaws in the Mustelidae follow essentially the

same patterns described for the foreclaws (Fig. 18). In

skunks and badgers the hindclaws are much shorter than the foreclaws. The structure of foreclaws and hindclaws is

very similar.

Tail

Ratio number 1, body length/total length documents, a

short tail in Taxidea, Gulo, and Enhydra. Long tails

characterize Lutra, Conepatus, and Mephitis. Short tails

are typical of fossorial mammals (Hildebrand, 1974; Shimer,

1903; Vaughan, 1978). Tarasoff et al. (1972) noted that 78

FIGURES 19-26

19) Dorsal aspect of pelvic girdles of twelve species of

Mustelidae, arrangement like that in Figure 1.

20) Lateral aspect of pelvic girdles of twelve species of

Mustelidae, arrangement like that in Figure 1.

21) Medial aspect of femora of twelve species of Mustelidae,

arrangement like that in Figure 1.

22) Posterior aspect of femora of twelve species of

Mustelidae, arrangement like that in Figure 1.

23) Anterior aspect of tibiae of twelve species of

Mustelidae, arrangement like that in Figure 1.

24) Lateral aspect of fibulae of twelve species of

Mustelidae, arrangement like that in Figure 1.

25) Anterior (left) and medial (right) aspects of calcanea

of twelve species of Mustelidae, arrangement like that in Figure 1.

26) Dorsal aspect of tarsus and pes of eleven species of

Mustelidae, arrangement like that in Figure 1. 79

Fig. 19 80

Fig. 20 81

Fig. 21 82

Fig. 22 83

Fig. 23 84

Fig. 24 85

Fig. 25 86

Fig. 26 87 the tail was important in aquatic locomotion to both Lutra and Enhydra. That information makes the short tail of

Enhydra somewhat enigmatic. The long bushy tail of skunks is well known and serves more as a warning device than a locomotor aid. The long tail of Martes pennanti is not surprising in an arboreal runner and leaper (Hildebrand,

1974; Taylor, 1970). What is peculiar is the decidedly shorter tail of the equally, if not more, arboreal Martes americana (Powell, pers. comm.).

Figure 27 summarizes the results of Prim networks for various aspects of the limb skeletons of thirteen species of Mustelidae.

Prim networks show a strong similarity of form in the limb skeletons of otters, badgers, and skunks. These three subfamilies of the Mustelidae are particularly close with regard to the forelimb skeleton and robusticity ratios. The hindlimbs of otters are more reminiscent of members of the genus Mustela than of skunks. Otters are always relatively distant from whatever species they join in the networks.

Considering both limbs and robusticity, it is clear that otters are closest to skunks and badgers. This similarity in form and function between swimmers and diggers is not a new observation (Gray, 1944, 1968; Hildebrand, 1974; Smith and Savage, 1956). One interesting observation about otters from the Prim networks is that in regard to forelimbs, hindlimbs, and robusticity, Lutra canadensis, is more distantly connected to other mustelids than is Enhydra 88 lutris. The implication is that Enhydra lutris, at least regarding appendicular osteology, is more generalized than Lutra canadensis. 89

FIGURE 27

Prim networks for males and females combined using thirteen species and (A) twenty-six fore and hindlimb ratios;

(B) fifteen forelimb ratios; (C) nineteen hindlimb ratios;

(D) eleven robusticity ratios. 90 CONCLUSIONS

Taken as a whole my proposed sequences are borne out by the data. However, there are some interesting divergences between my predictions and my observations. Enhydra lutris is not on the same continuum of locomotor specialization as

Mustela vison and Lutra canadensis. Enhydra is more aquatic, and presumably more specialized for aquatic life, than

Lutra. Enhydra emphasizes different bone-muscle systems in aquatic locomotion than Lutra or Mustela vison.

There are two problems with my proposed continua for arboreal specialization. First, the species are not in the appropriate order. Martes americana is, if anything, a bit more specialized for arboreal life than Martes pennanti or Eira. Second, arboreal and cursorial speciali- zations are very similar in the Mustelinae. This statement is demonstrated by the tendency of Martes, Eira, and Gulo to group closely together in the majority of my ratios.

Gulo does have more pronounced cursorial adaptations (e.g. increase in length, disproportionate increase in length of distal limb elements) than other mustelids. Martes americana, however, is nearly as specialized for running as Gulo, even though Martes americana is a more arboreal mustelid; Eira and Martes pennanti are intermediate between Mustela frenata and Martes americana.

My data for skunks present some surprises. Skunks have combined cursorial specializations (e.g. lengthening 92 of distal limb elements) and fossorial specializations (e.g. robust skeletons, long claws, powerful forelimbs). This combination of specializations suggests a lack of channeliza- tion to any particular mode of locomotion in skunks. In oter words, skunks are more generalized in locomotor tendencies with specializations characteristic of several modes of locomotion.

The data for fossorial and aquatic locomotion (ignoring for a moment Enhydra) provide strong support for my proposed sequences. Mustela vison is intermediate between

Mustela frenata and Lutra. Mustela nigripes is inter- mediate between Mustela frenata and Taxidea.

The apparent similarity of form and function between the skunks and badgers, and between the larger mustelines, is probably at least partly a reflection of phylogenetic closeness between the Mephitinae and the Melinae, and between Martes, Gulo, and Eira (Anderson, 1970; Simpson,

1945; Winge, 1941). Still, there is little doubt in my mind that the Prim networks, the drawings, and the statis- tical estimates of similarity reflect actual similarities in mode of locomotion. My confidence is strengthened by the following comparisons between New and Old World species.

Meles meles, the European badger, has generally similar ratios to Taxidea taxus. The single specimen of Meles has a longer, narrower scapula, a shorter humerus with wider epicondyles, and a shorter ulna than Taxidea taxus. Meles meles also have a longer pelvis, pubic symphysis, and ilium 93 than Taxidea taxus. Meles also has a slightly longer femur, tibia, and hindfoot. Meles appears to be somewhat more fossorial than Taxidea taxus.

Ratios for Mellivora sagulata (the ratel or honey badger) are more similar to Taxidea taxus than Meles moles.

Ratios for Helectis moschata, the ferret badger, are inter- mediate between those for Taxidea taxus and Mustela nigripes.

Finally, the ratios for Arctonyx collaris, the hog badger, are very close to those for both Taxidea taxus and Mellivora sagulata.

The ratios for Amblonyx cinerea (the Oriental small clawed otter) are more like Lutra canadensis than any other

North American mustelid. Amblonyx differs from Lutra in having a shorter, wider scapula, a shorter humerus with wider epicohdyles, a shorter ulna with a longer olecranon process, and a radius that is wider distally. The pelvis of Amblonyx is shorter than that of Lutra as is the tibia, whereas the femur is a bit longer. The ratios of Pteronura brasiliensis, (the giant otter of South America) are more like Amblonyx than Lutra.

The ratios for Mustela putorius, the European polecat, are similar to those for Mustela frenata, Mustela vison, and

Mustela nigripes which makes both functional and taxonomic sense.

The implication to me, from my North American data and the relatively scanty data on other mustelids, is that a 94 larger sample of mustelids worldwide would strengthen the generality of my proposed sequences.

There clearly are different locomotor patterns among species of Mustelidae. These locomotor patterns are followed in type and degree by patterns of specialization in the limb skeletons of the Mustelidae. Patterns of specialization in the family are revealed by sampling North American forms. The more cursorial forms show an increase in the length of the limb bones, particularly the distal limb bones, relative to more generalized species. Species with cursorial (and arboreal) tendencies have longer bones with rounder shafts compared to fossorial or aquatic species.

In mink and otters, and in black-footed ferrets and badgers, there are progressive decreases in the length of long bones.

Mink and otters on one line, and black-footed ferrets and badgers on another, show progressive increases in the length of in-levers (olecranon process, calcaneus) and progressive decreases in the length of out-levers (forearm, hindfoot) compared to weasels. Certainly the specializations for running in mustelids are not so pronounced as in ungulates or even canids. Neither are fossorial adaptations as pronounced as in moles, nor aquatic specializations as spectacular as in pinnipeds. Trends are evident, however, and to a considerable extent they appear to progress from the hypothetical generalized condition observed in weasels.

Skunks appear to be quite generalized. Hall (1926) noted that the muscular anatomy of Mephitis mephitis was 95

primitive (generalized?) compared to that of Martes which

he felt showed specializations for speed and agility.

Hall's view contradicts subsequent positions taken by Leach

(1976, 1977a, 1977b) and Ondrias (1961), who felt that the

anatomy of Martes was very generalized. When contrasted

to ungulates or dogs, the appendicular anatomy of martens and fishers is generalized. In comparison to Mephitis, and

I presume other skunks as well, the opposite seems to be

true. The more or less central position of skunks in the

Prim networks suggests a generality in their limb skeletons,

although martens and fishers are often centrally located

in the networks as well.

Coefficients of variation were examined for all species

having samples of n>9 for all ratios (Appendix 6). The

most variable species for each of the 49 ratios was noted.

The number of instances in which each species exhibited the

highest coefficient of variation is as follows: Mustela frenata, 4; Mustela vison, 5; Mustela nigripes, 0; Martes americana, 1; Martes pennanti, 0; Eira Barbara, 1; Gulo luscus, 0; Spilogale, 6; Mephitis mephitis, 16; Conepatus mesoleucus, 0; Taxidea taxus, 6; Lutra canadensis, 2;

Enhydra lutris, 8. A relative indication of variability at

the subfamilial level can be computed by dividing the number of occurrences of the highest coefficient of variation in a

subfamily by the number of species examined in that subfamily.

Values for that computation are: Mustelinae, 1.57: Mephitinae,

7.33; Melinae, 6.0; Lutrinae, 5.0. This index suggests that 96 the Mephitinae are the most variable subfamily of mustelids while the Mustelinae are the least. The variability in the

Mephitinae is actually underestimated in this calculation because the sample of Conepatus mesoleucus is small

(n = 6); hence Conepatus was not scored although it has the highest coefficient of variation in nine of the ratios. The high coefficient of variation characteristic of skunks suggests that they are generalized. I would argue that the generalized limb skeletons of skunks and their variability suggest that there are few selective pressures to be swift or agile in skunks (particularly M. mephitis and C. mesoleucus) compared to other mustelids. LITERATURE CITED

Anderson, E. 1970. Quaternary evolution of the genus Martes (Carnivora, Mustlidae). Acta Zoologica Fennica, Helsinki-Nelssingfors, 132pp. Anderson, S. and J. K. Jones. 1967. Recent mammals of the world; a synopsis of families. Ronald Press, New York, pp335-338. Ashton, E. H. and C. E. Oxnard. 1964. Functional adapta- tions of the primate shoulder girdle. Proc. Zool. Soc. London, 142:49-66. Ashton, E. H., R. M. Flinn, C. E. Oxnard, and T. F. Spence. 1971. The functional and classificatory significance of combined metrical features of the primate shoulder girdle. J. Zool., London, 163:319-350. Atchley, W. R., C. T. Gaskins, and D. Anderson. 1976. Statistical properties of ratios. I Empirical results. Syst. Zool., 25:137-148. Banfield, A. W. F. 1974. The mammals of Canada. University of Toronto Press, Toronto, pp315-346. Barnet, C. H. and J. R. Napier. 1953a. The rotary mobility of the fibula in eutherian mammals. J. Anat., 87:11-21. . 1953b. The form and mobility of the fibula in metatherian mammals. J. Anat., 87:207-213. Brown, C. J. and D. W. Yalden. 1973. The description of mammals. II Limbs and locomotion of terrestrial mammals. Mamm. Rev. , 3(4):107-134. 98

Brown, J. H. and R. C. Lasiewski. 1972. Metabolism of weasels: the cost of being long and thin. Ecology, 53(5):939-943. Chapman, R. N. 1919. A study of the correlation of the pelvic structure and the habits of certain burrowing mammals. Amer. J. Anat., 25:185-219. Corruccini, R. S. 1977. Correlation properties of morpho- metric ratios. Syst. Zool., 26:211-217. Coues, E. 1877. Fur-bearing animals: a monograph of North American Mustelidae. Government Printing Office, Washington, 348pp. Desmond, A. J. 1976. The hot-blooded dinosaurs; a revolution in paleontology. Dial Press, New York, 238pp. Ewer, R. F. 1973. The Carnivores. Cornell University Press, New York, 494pp. Fisher, E. M. 1942. The osteology and myology of the California river otter. Stanford University Press, California. Flower, W. H. 1885. An introduction to the osteology of the Mammalia. MacMillan and Co., London, 373pp. Gambaryan, P. P. 1974. How mammals run. John Wiley and Sons, New York, 367pp. Goynea, W. and R. Ashworth. 1975. The form and function of retractile claws in the Felidae and other representa- tive carnivorans. J. Morph., 145:229-238. Gray, J. 1944. Studies in the mechanics of the tetrapod skeleton. J. Exper. Biol., 20:88-116. 99

1968. Animal locomotion. Weidenfeld and Nicholson, London, 479pp. Haley, D. 1975. Sleek and savage: North America's weasel family. Pacific Search Books, Seattle, 128pp. Hall, E. R. 1926. The muscular anatomy of three mustelid mammals, Mephitis, Spilogale, Martes. Univ. California Publ. Zool., 30:7-38. . 1927. The muscular anatomy of the American badger (Taxidea taxus). Univ. California Publ. Zool., 30:205-219.

. 1951. American weasels. Univ. Kansas Publ. Mus. Nat Hist., 4:1-466. Hall, E. R. and K. R. Kelson. 1959. The mammals of North America. Ronald Press, New York, 2:897-950. Hildebrand, M. 1952. An analysis of body proportions in the Canidae. Amer. J. Anat., 90:217-256. . 1954. Comparative morphology of the body skeleton in Recent Canidae. Univ. California Publ. Zool., 52:399-470.

. 1974. Analysis of vertebrate structure. John Wiley and Sons, New York, 710pp. Hopwood, A. T. 1947. Contributions to the study of some African mammals. III Adaptations in the bones of the forelimbs of the lion, leopard, cheetah. J. Zool., London, 41:259-271. Howell, A. B. 1944. Speed in animals. University of Chicago Press, Chicago, 270pp. 100

Howard, L. D. 1973. Muscular anatomy of the forelimb of the sea otter (Enhydra lutris). Proc. California Acad. Sci., 20:411-500. . 1975. The muscular anatomy of the hindlimb of the sea otter (Enhydra lutris). Proc. California Acad. Sci., 12:335-416. Jenkins, F. A. Jr. 1970. Limb movements in a monotreme (Tachyglossus aculeatus): a cineroradiographic analysis. Science, 168:1473-1475. Jenkins, F. A. Jr. (ed.). 1974. Primate locomotion. Academic Press, New York, 390pp. . 1976. The movement of the shoulder girdle in claviculate and aclaviculate mammals. J. Morph., 144(1):71-83. Jenkins, F. A. Jr. and S. M. Camazine. 1977. Hip structure and locomotion in ambulatory and cursorial carnivores. J. Zool., London, 181(3):35l-370. Jones, F. W. 1953. Some readaptations of the mammalian pes in response to arboreal habits. Proc. Zool. Soc. London, 123:33-41. Kenyon, K. W. 1969. The sea otter in the Eastern Pacific Ocean. N. Amer. Fauna, 68:1-341. King, C. M. (ed.). 1975. Biology of mustelids; some Soviet research. British Library Lending Division, 266pp. Klingener, D. 1972. Laboratory anatomy of the mink. W. C. Brown Co., Dubuque, Iowa, 99pp. 101

Leach, D. and A. I. Dagg. 1976. The morphology of the

femur in marten and fisher. Can. J. Zool., 54:559-565.

Leach, D. 1977a. The descriptive and comparative post-

cranial osteology of marten (Martes americana Turton)

and fisher (Martes pennanti Erxleben): the appendicular

anatomy. Can. J. Zool., 55:199-214.

. 1977b. The forelimb musculature of marten

(Martes americana Turton) and fisher (Martes pennanti

Erxleben). Can. J. Zool., 55:31-41.

Lehmann, W. H. 1963. The forelimb structure of some

fossorial rodents. J. Morph., 113:59-76.

Lewis, 0. J. 1972. Osteological features characterizing

the wrists of monkeys and apes with a reconsideration

of this region of Dryopithecus (Proconsul) africanus.

Amer. J. Phys. Anthrop., 36(l):45-58.

Ondrias, J. C. 1960. Secondary sexual variation and body

skeletal proportions in European Mustelidae. Arkiv

Zool. 12:577-583.

. 1961. Comparative osteological investigations

on the front limbs of European Mustelidae. Arkiv

Zool., 13:311-320.

Pedley, T. J. (ed.). 1977. Scale effects in animal loco-

motion. Academic Press, New York.

Peterka, H. E. 1937. A study of the myology and osteology

of tree sciurids with regard to adaptation to arboreal,

glissant, and fossorial habits. Trans. Kansas Acad.

Sci., 39:313-332. 102

Powell, R. A. 1979. Mustelid spacing patterns: variations on a theme by Mustela. Z. Tierpsychol., 50:153-165. Riesenfeld, A. 1974. Metatarsal robusticity in Primates and a few other plantigrade mammals. Primates, 15(1):1-25. Romer, A. S. 1966. Vertebrate paleontology, 3rd ed. University of Chicago Press, Chicago, 468pp. Rosenzweig, M. L. 1966. Community structure in sympatric Carnivora. J. Mamm., 47:602-612. Savage, R. J. G. 1957. The anatomy of Potamotherium an Oligocene lutrine. Proc. Zool. Soc. London, 129:151-244. Shimer, H. W. 1903. Adaptations to aquatic, arboreal, fossorial, and cursorial habits in mammals. III Fossorial adaptations. Amer. Nat., 37:819-825. Simpson, G. G. 1945. The principles of classification and a classification of mammals. Bull. Amer. Mus. Nat. Hist., 85:105-120. Simpson, G. G., A. Roe, and R. C. Lewontin. 1960. Quanti- tative Zoology. Harcourt, Brace and Co., New York, 440pp. Smith, J. M. and R. J. G. Savage. 1956. Some locomotory adaptations in mammals. J. Zool., 42:603-622. Sokal, R. R. and F. J. Rohlf. 1969. Biometry. The

principles and practice of statistics in biological research. W. H. Freeman, San Francisco. 103

Stahl, W. R. 1962. Similarity and dimensional methods in biology. Science, 137:205-212. Stains, H. J. 1976. Calcanea of members of the Mustelidae. Pt. 1, Mustelinae. Pt. 2, Mellivorinae, Mephitinae, and Lutrinae. Bull. So. Calif. Acad. Sci., 75(3): 237-257. Tarasoff, F. J. 1972. Comparative aspects of the hind- limbs of the river otter, sea otter, and seals. In: Functional anatomy of marine mammals. R. J. Harrison

ed., Academic Press, New York, pp333-359. • Tarasoff, F. J., A. Basaillon, J. Pierard, and A. P. Whitt. 1972. Locomotory patterns and external morphology of the river otter, sea otter, and harp seal (Mammalia). Can. J. Zool. 50:915-•929. Taylor, W. P. 1914. The problem of aquatic adaptation in the Carnivora, as illustrated in the osteology and evolution of the sea otter. Univ. California Publ. Geol. Sci., 7:465-495. Taylor, M. E. 1970. Locomotion in some East African viverrids. J. Mamm., 51(1):42-51. . 1974. The functional anatomy of the forelimb of some African Viverridae (Carnivora). J. Morph., 143:307-336. . 1976. The functional anatomy of the hindlimb of some African Viverridae (Carnivora). J. Morph., 148:227-254.- 104

Thorington, R. W. 1972. Proportions and allometry in the

gray squirrel, Sciurus carolinensis. Nemouria: Occ.

Pap. Delaware Mus. Nat. Hist., 8:1-17.

Trapp, G. R. 1972. Some anatomical and behavioral

adaptations of ringtails, Bassariscus astutus. J.

Mamm., 53(3):549-557.

Vaughan, T. A. 1978. Mammalogy, 2nd ed. W. B. Saunders

Co., Philadelphia, 522pp.

Walker, E. P. et al. 1975. Mammals of the world. 3rd ed.

Johns Hopkins University Press, Baltimore, 150pp.

Walmsley, T. 1918. The reduction of the mammalian fibula.

J. Anat., 52:326-331.

Winge, H. 1941. The interrelationships of the mammalian

genera. Rodentia, Carnivora, Primates. Copenhagen:

C. A. Reitzels Forlag, 376pp.

Yalden, D. W. 1970. The functional morphology of the

carpal bones in carnivores. Acta Anat., 79:481-500.

. 1972. The form and function of the carpal bones

in some arboreally adapted mammals. Acta Anat.,

82:383-406. Appendix 1. -- Listing of specimens used for this study. Specimens are arranged taxonomically and separated by sex. Specimens of unknown sex are listed in a separate column (?).

MUSTELIDAE

Mustelinae MALES FEMALES ? TOTAL Mustela frenata goldmani 2 - - 2 longicauda 1 - - 1 munda 9 1 - 10 nevadensis 23 17 - 40 nigriauris 9 2 - 11 noveboracensis 19 - - 19 olivacea 4 2 - 6 primulina 2 - - 2 other ssp. - 1 - 1 Total 69 23 0 92

Mustela nigripes subspecies 7 - - 7

Mustela vison aestuarina 16 5 - 21 energumenos 14 9 - 23 evagor 1 - - 1 ingens 2 - - 2 letifera 1 - - 1 Total 34 14 - 48 106

MALES FEMALES ? TOTAL Martes americana abietinoides 18 18 - 36 actuosa 18 - - 18 caurina 13 7 - 20 humboldtensis 1 - - 1 sierrae 21 5 - 26 vancouverensis 1 - - 1 Total 72 30 - 102

Martes pennanti columbiana 6 9 2 17 pacifica 4 4 2 10 pennanti 12 - - 12

other ssp. 2 2 _- 4 Total 24 15 4 43

Eira barbara biologie 1 - 1 2 peruana 1 - - 1 poliocephala 1 2 - 3 rara 1 - - 1 senex - - 1 1 other ssp. 3 1 - 4 Total 7 3 2 12 107

MALES FEMALES ? TOTAL Gulo luscus

luscus 15 8 1 24 luteus 1 2 - 3 Total 16 10 1 27

Mephitinae

Spilogale gracilis amphialus 2 - - 2 latifrons 21 2 - 23 microrhina 3 - - 3 phenax 5 4 - 9 saxatilis 1 1 - 2 Total 32 7 0 39

Spilogale putorius interrupts 16 9 - 25 putorius 3 1 - 4 Total 19 10 - 29

Spilogale anguistifrons elata - 1 - 1 TOTAL 51 18 0 69 108

MALES FEMALES ? TOTAL Mephitis mephitis avia 16 11 - 27 elongata 2 - - 2 estor - 2 - 2 major 4 - - 4 nigra 5 1 1 7 occidentalis 6 5 2 13 spissigrada 1 - - 1 Total 34 19 3 • 56

Conepatus mesoleucus mearnsi 1 - - 1 nicaraguae 1 1 - 2 sonorensis 1 1 - 2

other ssp. 1 - ____- _____1 Total 4 2 0 6

Melinae Taxidea taxus

berlanderi 7 - - 7 taxus 17 - - 17 Total 24 0 0 24 109

MALES FEMALES ? TOTAL Lutrinae Lutra canadensis brevipilosus 3 3 - 6 canadensis 14 15 - 29 exeva - 1 - 1 pacifica 2 - - 2 periclyzomae 2 1 - 3 other ssp. 3 - - 3 Total 24 20 0 44

Enhydra lutris lutris 5 1 - 6 nereis 9 5 1 15 Total 14 6 1 21

Mustelinae Mustela putorius - 1 - 1

Mellivorinae Mellivora sagulata - 1 - 1

Melinae Meles meles - 1 - 1 Helectis moschata 1 - - 1 Arctonyx collaris 1 - - 1 110

MALES FEMALES ? TOTAL Lutrinae

Amblonyx cinerea 1 1

Pteronura brasiliensis 1 - 1

Total Old World 3 4 0 7

Total North America 380 160 11 551

GRAND TOTAL 383 164 11 558 APPENDIX 2

CONTRIBUTING INSTITUTIONS

American Museum of Natural History (AMNH)

Mustela nigripes 1

Eira barbara 1

Martes pennanti 3

California Academy of Science (CAS)

Mephitis mephitis 3

Carnegie Museum of Natural History (CMNH)

Mustela frenata 19

Field Museum of Natural History (FMNH)

Eira barbara 3

Martes pennanti 2

Conepatus mesoleucus 2 Taxidea taxus 4

Humboldt State University MVZ (HSU)

Mustela frenata 1

Mustela putorius 1

Martes pennanti 1

Lutra canadensis 1

Enhydra lutris 1

Los Angeles County Museum of Natural History (LACMNH)

Eira barbara 1 112

(LACMNH)

Martes pennanti 3

Spilogale putorius 1

Conepatus mesoleucus 1

Taxidea taxus 5

Lutra canadensis 2

Michigan State University, the Museum (MSU)

Taxidea taxus 5

National Museum of Natural History (NMNH)

Mustela nigripes 2

Eira barbara 6

Martes pennanti 3

Gulo luscus 2

Enhydra lutris 1 -

Mellivora sagulata 1 Meles meles 1

Helectis moschata 1

Arctonyx collaris 1

Amblonyx cinerea 1

Pteronura brasiliensis 1

San Diego Natural History Museum (SDNHM)

Gulo luscus 2

University of California, Berkeley, MVZ (UCB)

Mustela frenata 71

Mustela vison 43 113

(UCB)

Mustela nigripes 3

Martes americana 58

Martes pennanti 12

Eira Barbara 1

Gulo luscus 9

Spilogale 28

Mephitis mephitis 20

Conepatus mesoleucus 3

Taxidea taxus 9

Lutra canadensis 10

Enhydra lutris 9

University of California, Los Angeles (UCLA)

Enhydra lutris 1

University of Kansas Museum of Natural History (KU)

Spilogale putorius 22

Mephitis mephitis 27

University of Michigan Museum of Zoology (UMich)

Martes americana 10

Martes pennanti 10

Gulo luscus 8

Lutra canadensis 28

University of Montana Department of Zoology (UMont)

Martes americana 21

Martes pennanti 9 114

(UMont)

Spilogale 18

University of Puget Sound, Puget Sound Museum of

Natural History (UPS)

Mustela frenata 1

Mustela vison 5

Martes americana 13

Gulo luscus 6

Taxidea taxus 1

Lutra canadensis 2

Enhydra lutris 6 Appendix 3. -- Groupings of samples for descriptive statistics. Groupings are listed taxonomically and divided by sex and side.

RIGHT LEFT Mustela frenata males munda munda

nevadensis nevadensis nigriauris nigriauris

noveboracensis -

All subspecies All subspecies 1

females nevadensis nevadensis 15

All subspecies All subspecies

both sexes nevadensis nevadensis All save nev. All save nev. All subspecies All subspecies

Mustela nigripes males All All

Mustela vison males aestuarina aestuarina

energumenos energumenos RIGHT LEFT

Mustela vison males ingens -

All subspecies All subspecies females aestuarina aestuarina

energumenos energumenos All subspecies All subspecies

both sexes aestuarina aestuarina

energumenos energumenos All subspecies All subspecies 11 6

Martes americana males abietinoides abietinoides

actuosa - caurina caurina sierrae sierrae All save abi. All save abi.

All subspecies All subspecies

females abietinoides abietinoides RIGHT LEFT Martes americana females caurina - sierrae - All save abi. - All subspecies All subspecies both sexes abietinoides abietinoides caurina - sierrae -

All save abi. All save abi. 11

All subspecies All subspecies 7

Martes pennanti males columbiana - pacifica pacifica pennanti - All subspecies All subspecies females columbiana - pacifica pacifica All subspecies All subspecies RIGHT LEFT Martes pennanti both sexes columbiana -

pacifica pacifica pennanti -

All subspecies All subspecies

Eira barbara males All subspecies All subspecies

females All subspecies All subspecies both sexes All subspecies All subspecies 1 18

Gulo luscus males luscus luscus All subspecies All subspecies

females luscus -

All subspecies All subspecies

both sexes luscus luscus luteus

All subspecies All subspecies RIGHT LEFT Spilogale gracilis males latifrons - All subspecies - females All subspecies - both sexes latifrons - phenax -

All subspecies

- Spilogale putorius males interrupta 1 19

All subspecies - females interrupta - All subspecies - both sexes interrupta - putorius - All subspecies -

Spilogale all species males All subspecies All subspecies females All subspecies - RIGHT LEFT Spilogale all species both sexes All subspecies -

Mephitis mephitis males avia - major major occidentalis occidentalis nigra - All subspecies All subspecies females occidentalis

occidentalis 12

avia - 0 All subspecies All subspecies both sexes avia - occidentalis occidentalis nigra - All subspecies All subspecies Conepatus mesoleucus males All subspecies All subspecies females All subspecies - both sexes All subspecies All subspecies RIGHT LEFT

Taxidea taxus males berlanderi berlanderi taxus taxus

All subspecies All subspecies

Lutra canadensis males canadensis -

All subspecies All subspecies females canadensis - All subspecies All subspecies 1 2 both sexes brevipilosus brevipilosus 1 canadensis - periclyzomae periclyzomae

All subspecies All subspecies

Enhydra lutris males nereis -

lutris -

All subspecies All subspecies RIGHT LEFT

Enhydra lutris females nereis - All subspecies All subspecies both sexes nereis - lutris - All subspecies All subspecies 12 2 Appendix 4. -- Groups of samples used to generate histograms

of frequency distributions for each ratio. Groups are

listed taxonomically. Groups are either entire

species samples or well represented subspecies. Groups

are also separated into males, females, and male +

females samples.

Mustela frenata nevadensis only, males nevadensis only, females

nevadensis only, males + females

noveboracensis only, males

all subspecies, males

all subspecies, females

all subspecies, males + females

Mustela vison all subspecies, males all subspecies, males + females

Martes americana abietinoides only, males +

females

abietinoides + actuosa, males

abietinoides + actuosa, males +

females

all subspecies save abietinoides + actuosa, males

124

Martes americana all subspecies save abietinoides

+ actuosa, males + females

all subspecies,subspecies, female males

sl subspecies,emales

all subspecies, males + females

Martes pennanti all subspecies, males all subspecies, males + females

Gulo luscus all subspecies, males + females

Spilogale gracilis all subspecies, males

all subspecies, males + females

Spilogale putorius all subspecies, males all subspecies, males + females

Spilogale gracilis + putorius all subspecies, males + females

Mephitis mephitis avia only, males + females

all subspecies, males

all subspecies, males + females

Taxidea taxus all subspecies, males 125

Lutra canadensis canadensis only, males + females

all subspecies, males all subspecies, males + females

Enhydra lutris all subspecies, males + females

Appendix 5. -- Dimensions (number of species, number of

ratios) for Prim networks. Sexes were examined

separately and in a male + female sample. Prim networks

were generated for nine combinations of ratios. Those

nine combinations of ratios are the major subdivisions

of this appendix.

Number of spp. Number of ratios NO SKULL

15,24 ratios: 1, 2, 3, 4, 5, 7, 8, males + females 13,24 10, 14, 16, 18, 20, 21, 24,

11,24 25, 26, 27, 30, 31, 38, 39,

46, 49, 50.

15,24

males only 13,24

11,24

females only 13,24

11,24

LENGTH RATIOS

males + females 15,27 ratios: 5, 6, 9, 10, 12, 15,

13,27 16, 17, 19, 20, 22, 23, 25,

27, 28, 29, 30, 32, 37, 38,

40, 41, 44, 45, 46, 47, 48. 127

LENGTH RATIOS (cont.)

males 15,18 ratios: 6, 9, 12, 15, 17, 19,

males + females 13,18 22, 23, 28, 29, 32, 37, 40,

11,18 41, 44, 45, 47, 48.

15,18

males only 13,18

11,18

females only 13,18

11,18

FORELIMB RATIOS, NO SKULL

males + females 13,15 ratios: 5, 6, 9, 10, 11, 12,

13, 15, 16, 17, 19, 20, 22,

23, 25.

males + females 13,10 ratios: 6, 9, 11, 12, 13, 15,

11,10 17, 19, 22, 23.

males only 13,10

11,10

females only 11,10 128

FORELIMB LENGTHS

15,13 ratios: 5, 6, 9, 10, 12, 15,

males + females 13,13 16, 17, 19, 20, 22, 23, 25. 11,13

15,8 ratios: 6, 9, 12, 15, 17, 19,

males + females 13,8 22, 23.

11,8

15,8

males only 13,8

11,8

females only 13,8

11,8

HINDLIMB

15,14 ratios: 27, 28, 29, 30, 32,

males + females 13,14 37, 38, 40, 41, 44, 45, 46,

11,14 47, 48.

15,10 ratios: 28, 29, 32, 37, 40,

males + females 13,10 41, 44, 45, 47, 48.

11,10 129

HINDLIMB (cont.)

15,10

males only 13,10

11,10

females only 13,10

HINDLIMB RATIOS, NO SKULL

males + females 13,19 ratios: 27, 28, 29, 30, 32, 33, 34, 35, 36, 37, 40, 41,

42, 43, 44, 45, 46, 47, 48.

males + females 13,16 ratios: 28, 29, 32, 33, 34,

11,16 35, 36, 40, 41, 42, 43, 44, 45, 47, 48.

males only 13,16

11,16

females only 11,16

females only 11,16 130

ROBUSTICITY 15,11 ratios: 11, 12, 13, 23, 29, males + females 13,11 33, 34, 35, 36, 42, 43. 11,11

15,11 males only 13,11 11,11

females only 13,11 11,11

SKULL ONLY males + females 12,11 ratios: 3, 4, 7, 8, 14, 18, 9,11 21, 24, 26, 31, 39.

males only 11,11 9,11

females only 9,11

SIX SKULL RATIOS 15,6 ratios: 9, 14, 18, 21, 31, males + females 13,6 39. 11,6 Appendix 6. -- Descriptive statistics for species comparisons

Range Mean SD SE n CV 1) Length of body/Total length

Mf .57- .69 .639 .023 .003 65 3.676 Mn .761 1 My .64- .69 .669 .014 .003 25 2.076 Ma .64- .71 .769 .020 .003 35 2.915 Mp .58- .63 .601 .021 .009 6 3.500 G1 .73- .81 .775 .026 .008 10 3.400 Eb .602 1 S .57- .73 .652 .046 .008 32 7.082 Mm .43- .62 .544 .045 .011 17 8.250 Cm .59- .60 .594 .005 .002 4 .802 Tt .78- .86 .819 .025 .007 12 3.850 Lc .59- .64 .623 .016 .005 12 2.521 El .73- .79 .766 .020 .007 9 2.558

2) Length of hindfoot/Length of body

Mf .15- .27 .178 .017 .002 60 9.503 Mn .145 1 My .15- .19 .174 .009 .002 24 4.890 Ma .19- .24 .212 .014 .003 26 6.480 Mp .19- .22 .203 .013 .006 5 6.563 G1 .21- .24 .224 .016 .006 7 6.951 Eb .175 1 S .14- .20 .167 .013 .002 31 7.920 Mm .18- .31 .210 .032 .008 17 15.265 133

Range Mean SD SE n CV Cm .19- .21 .196 .012 .006 4 6.031 Tt .17- .20 .187 .011 .003 12 6.102 Lc .12- .20 .176 .021 .006 12 12.218 El .21- .25 .222 .011 .004 9 5.156

3) Length of skull/Length of body Mf .17- .29 .191 .016 .002 61 8.188 Mn .171 1 My .16- .18 .170 .005 .001 23 3.116 Ma .18- .20 .191 .006 .001 32 3.161 Mp .18- .20 .188 .007 .003 6 3.702 G1 .19- .21 .195 .006 .002 9 3.026 Eb

S .18- .24 .201 .011 .002 30 5.533 Mm .17- .32 .213 .035 .009 14 16.324 Cm .18- .21 .186 .017 .009 4 9.290 Tt .19- .22 .209 .009 .003 11 4.436 Lc .15- .17 .157 .008 .002 12 5.205 El .12- .14 .131 .006 .002 9 4.238

4) Length of scapula/Length of skull Mf .45- .54 .494 .019 .002 83 3.858 Mn .53- .58 .544 .018 .007 6 3.223 My .51- .62 .546 .024 .004 41 4.366 Ma .48- .56 .524 .017 .002 79 3.291 Mp .53- .66 .570 .029 .005 36 5.044 134

Range Mean SD SE n CV

G1 .67- .71 .689 .016 .004 18 2.282

Eb .57- .64 .609 .034 .013 7 5.578

S .51- .63 .583 .025 .003 55 4.302

Mm .64- .80 .704 .040 .006 48 5.633

Cm .63- .84 .762 .074 .030 6 9.759

Tt .55- .66 .616 .031 .007 18 5.014

Lc .59- .69 .648 .027 .004 41 4.140

El .79-1.00 .899 .049 .011 21 5.394

5) Length of scapula/Length of forelimb

Mf .32- .37 .348 .009 .001 38 2.553

Mn .35- .35 .354 .002 .001 3 .432

My .35- .39 .368 .010 .002 16 2.669

Ma .29- .32 .302 .007 .001 27 2.470

Mp .30- .34 .316 .012 .002 27 3.660

G1 .31- .33 .320 .007 .002 8 2.203

Eb .32- .34 .329 .006 .002 7 1.701

S .36- .43 .387 .016 .003 26 4.124

Mm .37- .45 .410 .019 .003 32 4.614

Cm .374 1

Tt .34- .40 .373 .019 .006 12 5.160

Lc .41- .46 .439 .012 .003 22 2.833

El .49- .54 .512 .016 .006 6 3.066 135

Range Mean SD SE n CV 6) Height of scapula/Length of scapula

Mf .48- .61 .531 .024 .003 86 4.446 Mn .49- .54 .515 .017 .006 7 3.288 My .50- .60 .564 .020 .003 38 3.568 Ma .50- .60 .546 .019 .002 78 3.500 Mp .49- .63 .574 .027 .004 42 4.727 G1 .57- .67 .604 .024 .005 27 3.937 Eb .56- .62 .580 .016 .005 10 2.739 S .35- .62 .559 .037 .005 60 6.611 Mm .44- .64 .518 .039 .005 51 7.487 Cm .50- .57 .532 .027 .010 7 5.089 Tt .57- .68 .623 .031 .006 24 4.922 Lc .57- .69 .619 .026 .004 37 4.193 El .57- .71 .627 .038 .008 .21 0.138

7) Height of scapula/Length of skull

Mf .22- .29 .263 .015 .002 81 5.858 Mn .27- .29 .279 .008 .003 6 3.001 My .26- .35 .307 .019 .003 34 6.186 Ma .25- .31 .287 .014 .002 75 4.720 Mp .27- .50 .330 .035 .006 35 G1 .38- .45 .415 .019 .004 20 4.584 Eb .32- .37 .353 .017 .006 7 4.807 S .28- .37 .329 .021 .003 55 6.404 Mm .31- .41 .365 .025 .004 47 6.811 Cm .34- .45 .409 .038 .015 6 9.185 136

Range Mean SD SE n CV Tt .33- .41 .377 .025 .006 18 6.578 Lc .34- .45 .402 .024 .004 38 5.900 El .49- .63 .564 .045 .010 21 7.938

8) Length of humerus/Length of skull

Mf .60- .73 .663 .024 .003 79 3.668 Mn .70- .72 .710 .009 .004 6 1.282 My .65- .75 .699 .026 .004 39 3.671 Ma .66- .84 .782 .028 .003 78 3.557 Mp .76- .91 .823 .024 .004 36 2.867 G1 .86- .97 .930 .025 .005 21 2.701 Eb .83- .90 .866 .031 .011 8 3.548 S .64- .76 .707 .027 .004 57 3.849 Mm .75- .87 .800 .030 .004 48 3.710 Cm .79- .89 .839 .034 .014 6 4.020 Tt .69- .87 .757 .048 .011 18 6.344 Lc .65- .76 .697 .025 .004 42 3.645 El .77- .92 .846 .044 .010 21 5.183

9) Length of humerus/Length of scapula Mf 1.24-1.45 1.342 .040 .004 82 2.969 Mn 1.29-1.34 1.317 .020 .008 7 1.537 My 1.20-1.38 1.290 .035 .005 42 2.699 Ma 1.30-1.55 1.488 .035 .004 81 2.327 Mp 1.30-1.55 1.447 .051 .008 43 3.517 G1 1.24-1.42 1.358 .037 .007 27 2.729 139

Range Mean SD SE n CV 13) Ellipticity of humerus Mf .65- .96 .799 .058 .006 89 7.282 Mn .74- .90 .829 .055 .021 7 6.661 My .63- .84 .730 .054 .008 47 7.338 Ma .71- .95 .856 .049 .005 84 5.746 Mp .71- .92 .811 .048 .007 43 5.890 G1 .70- .86 .775 .039 .007 28 5.014 Eb .74- .89 .815 .057 .017 11 7.037 S .60- .86 .699 .056 .007 62 8.051 Mm .53- .85 .639 .058 .008 53 9.074 Cm .52- .64 .576 .041 .016 7 7.199 Tt .66- .84 .734 .043 .009 24 5.922 Lc .50- .69 .574 .039 .006 42 6.748 El .49- .65 .576 .044 .010 21 7.634

14) Length of ulna/Length of skull Mf .54- .65 .600 .025 .003 78 4.168 Mn .681 .001 .001 2 .208 My .58- .74 .654 .031 .005 39 4.705 Ma .68- .82 .756 .031 .004 69 4.128 Mp .78- .91 .819 .021 .004 34 2.537 G1 .91-1.01 .973 .025 .005 22 2.577 Eb .82- .88 .844 .022 .008 7 2.623 S .64- .76 .713 .026 .004 52 3.639 Mm .77- .93 .846 .028 .004 45 3.346 Cm .86- .97 .918 .034 .014 6 3.650 140

Range Mean SD SE n CV Tt .81- .95 .864 .038 .009 17 4.415 Lc .65- .76 .704 .023 .004 39 3.232 El .80- .98 .872 .044 .010 20 5.054

15) Length of ulna/Length of humerus Mf .86- .95 .903 .020 .002 81 2.225 Mn .95- .99 .971 .024 .014 3 2.428 My .81- .97 .930 .027 .004 39 2.867 Ma .92-1.01 .956 .022 .003 73 2.304 Mp .96-1.07 .998 .021 .003 41 2.101 Gl 1.01-1.15 1.049 .026 .005 28 2.521 Eb .94- .99 .968 .016 .005 10 1.639 S .96-1.08 1.011 .021 .003 57 2.067 Mm 1.01-1.13 1.061 .028 .004 49 2.683 Cm 1.05-1.12 1.094 .024 .010 6 2.210 Tt 1.04-1.19 1.146 .034 .007 22 2.983 Lc .93-1.06 1.009 .024 .004 39 2.412 El 1.00-1.06 1.034 .016 .004 20 1.569

16) Length of ulna/Length of forelimb Mf .41- .44 .428 .006 .001 38 1.407 Mn .45- .46 .449 .005 .003 3 1.142 My .40- .44 .431 .009 .002 17 2.095 Ma .40- .45 .438 .009 .002 28 1.945 Mp .44- .46 .452 .004 .001 27 .946 G1 .46- .46 .459 .002 .001 9 .361 141

Range Mean SD SE n CV Eb .44- .46 .452 .006 .002 7 1.372 S .40- .51 .459 .031 .006 27 6.771 Mm .40- .50 .477 .034 .006 32 7.045 Cm .510 1 Tt .51- .54 .530 .010 .003 12 1.907 Lc .45- .50 .469 .010 .002 22 2.041 El .48- .50 .492 .006 .003 6 1.249

17)Length of olecranon process/Length of ulna Mf .11- .17 .146 .012 .001 84 8.100 Mn .17- .18 .171 .006 .004 3 3.566 My .14- .20 .162 .011 .002 43 6.731 Ma .11- .14 .121 .007 .001 74 5.891 Mp .11- .14 .127 .007 .001 41 5.779 G1 .10- .14 .120 .009 .002 28 7.311 Eb .12- .15 .129 .011 .003 10 8.230 S .13- .17 .150 .008 .001 57 5.347 Mm .13- .18 .163 .011 .002 50 6.585 Cm .21- .23 .218 .011 .005 6 5.276 Tt .21- .24 .222 .011 .002 22 4.828 Lc .19- .25 .215 .016 .003 39 7.367 El .13- .16 .146 .008 .002 20 5.449

18)Length of ulna minus length of olecranon process/Length of skull Mf .46- .57 .512 .025 .003 78 4.815 142

Range Mean SD SE n CV Mn .56- .57 .564 .007 .005 2 1.254 My .46- .61 .547 .028 .005 39 5.138 Ma .60- .73 .664 .030 .004 69 4.535 Mp .68- .78 .717 .021 .004 34 2.866 G1 .80- .90 .857 .026 .006 22 3.082 Eb .70- .77 .734 .025 .009 7 3.403 S .53- .65 .607 .024 .003 52 3.965 Mm .65- .79 .709 .028 .004 45 3.889 Cm .67- .76 .718 .033 .013 6 4.457 Tt .63- .74 .670 .033 .008 17 4.890 Lc .46- .60 .550 .026 .004 39 4.759 El .68- .83 . 47 .038 .008 20 5.044

19) Length of ulna minus length of olecranon process/Length of humerus Mf .73- .81 .771 .020 .002 81 2.625 Mn .78- .82 .804 .025 .014 3 3.820 My .65- .82 .778 .029 .005 39 3.729 Ma .81- .91 .848 .025 .003 73 2.961 Mp .83- .95 .871 .023 .004 41 2.607 G1 .88- .95 .920 .019 .004 28 2.065 Eb .82- .86 .843 .014 .004 10 1.629 S .80- .92 .860 .020 .003 57 2.267 Mm .84-1.03 .889 .033 .005 49 3.748 Cm .83- .89 .857 .026 .011 6 3.093 Tt .83- .93 .889 .026 .006 22 2.975 143

Range Mean SD SE n CV Lc .64- .84 .789 .035 .006 39 4.480 El .86- .91 .883 .015 .003 20 1.641

20) Length of ulna minus length of olecranon process/Length of forelimb Mf .35- .44 .394 .033 .005 38 8.326 Mn .37- .38 .373 .006 .004 3 1.640 My .32- .37 .361 .010 .003 17 2.888 Ma .37- .40 .387 .006 .001 28 1.508 Mp .38- .41 .394 .005 .001 27 1.311 G1 .40- .41 .404 .003 .001 9 .743 Eb .39- .40 .395 .003 .001 7 .758 S .38- .43 .403 .010 .002 27 2.524 Mm .40- .43 .411 .006 .001 32 .1.452 Cm .393 1 Tt .40- .43 .410 .008 .002 12 1.850 Lc .32- .38 .366 .013 .003 22 3.490 El .42- .43 .419 .004 .001 6 .865

21) Length of radius/Length of skull Mf .43- .52 .471 .021 .002 77 4.512 Mn .51- .53 .522 .013 .010 2 2.576 My .45- .54 .500 .021 .003 40 4.281 Ma .56- .68 .619 .028 .003 68 4.502 Mp .64- .74 .672 .018 .003 34 2.710 G1 .75- .83 .797 .021 .004 22 2.598 144

Range Mean SD SE n CV Eb .65- .72 .681 .026 .009 8 3.815 S .50- .61 .569 .023 .003 52 3.993 Mm .62- .74 .675 .025 .004 46 3.642 Cm .64- .73 .696 .033 .013 6 4.745 Tt .61- .70 .647 .025 .006 17 3.817 Lc .48- .54 .514 .016 .003 40 3.113 El .63- .73 .679 .031 .003 19 4.576

22) Length of radius/Length of humerus Mf .67- .75 .709 .018 .002 81 2.526 Mn .73- .76 .744 .015 .008 3 1.958 My .67- .75 .712 .016 .003 40 2.270 Ma .75- .84 .793 .022 .003 72 2.818 Mp .78- .87 .818 .019 .003 41 2.356 G1 .83- .89 .856 .015 .003 28 1.749 Eb .76- .81 .787 .017 .005 11 2.126 S .77- .86 .807 .020 .003 57 2.494 Mm .81- .90 .846 .023 .003 50 2.690 Cm .80- .85 .832 .019 .007 7 2.328 Tt .77- .90 .863 .026 .006 22 3.029 Lc .71- .77 .739 .018 .003 40 2.387 El .77- .83 .807 .015 .003 19 1.877

23) Distal width of radius/Length of radius Mf .14- .81 .178 .011 .001 81 6.442 Mn .19- .20 .196 .005 .003 3 2.297 145

Range Mean SD SE n CV My .15- .23 .194 .014 .002 44 7.065 Ma .15- .18 .164 .007 .001 73 4.086 Mp .15- .23 .166 .013 .002 41 7.724 G1 .18- .21 .195 .008 .001 29 4.043 Eb .18- .22 .200 .017 .005 11 8.322 S .17- .23 .194 .013 .002 57 6.442 Mm .18- .23 .202 .012 .002 51 5.992 Cm .20- .24 .211 .015 .006 7 6.925 Tt .22- .26 .232 .011 .002 22 4.908 Lc .21- .25 .234 .011 .002 40 4.509 El .18- .23 .207 .012 .003 19 6.003

24) Length of third metacarpal/Length of skull Mf .19- .26 .224 .013 .002 39 5.614 Mn .25- .26 .253 .004 .003 3 1.723 My .23- .27 .250 .014 .003 19 5.618 Ma .26- .31 .284 .012 .002 28 4.303 Mp .26- .30 .277 .010 .002 21 3.637 G1 .31- .33 .323 .006 .003 5 1.893 Eb .23- .27 .250 .016 .008 4 6.258 S .19- .25 .207 .014 .003 25 6.979 Mm .19- .23 .211 .011 .002 32 5.213 Cm .237 1 Tt .19- .22 .205 .007 .002 9 3.595 Lc .24- .26 .248 .007 .002 22 2.866 El .17- .20 .187 .012 .005 6 6.153 146

Range Mean SD SE n CV 25) Length of third metacarpal/Length of forelimb Mf .15- .17 .159 .005 .001 38 3.314 Mn .16- .17 .164 .003 .002 3 1.956 Mv .16- .19 .170 .007 .002 17 3.893 Ma .15- .17 .162 .004 .001 28 2.242 Mp .14- .17 .153 .005 .001 27 3.251 G1 .15- .17 .154 .007 .002 9 4.706 Eb .13- .14 .137 .004 .002 7 3.111 S .13- .16 .136 .007 .001 27 4.866 Mm .11- .14 .122 .006 .001 32 5.167 Cm .140 1 Tt .11- .14 .123 .007 .002 12 5.631 Lc .15- .17 .165 .005 .001 22 3.081 El .10- .11 .105 .004 .002 6 3.929

26) Length of pelvis/Length of skull Mf .52- .67 .599 .028 .003 82 4.647 Mn .68- .69 .682 .009 .004 5 1.298 My .64- .76 .702 .028 .004 43 4.035 Ma .57- .73 .656 .030 .003 97 4.541 Mp .71- .82 .741 .025 .004 35 3.307 G1 .82- .90 .863 .019 .004 20 2.173 Eb .71- .85 .794 .040 .015 7 4.999 S .63- .83 .744 .043 .005 62 5.729 Mm .85-1.00 .911 .032 .005 48 3.544 Cm .85-1.07 1.009 .084 .035 6 8.282 147

Range Mean SD SE n CV Tt .74- .85 .789 .034 .008 17 4.343 Lc .89-1.09 1.001 .053 .008 43 5.340 El 1.25-1.50 1.397 .061 .014 20 4.396

27)Length of pelvis/Length of hindlimb Mf .31- .35 .330 .009 .001 42 2.797 Mn .37- .38 .378 .008 .004 3 1.987 My .34- .47 .389 .041 .010 18 10.498 Ma .27- .31 .293 .010 .002 40 3.243 Mp .31- .35 .330 .010 .002 27 3.159 G1 .35- .38 .365 .012 .003 13 3.302 Eb .34- .39 .360 .020 .009 5 5.682 S .37- .43 .403 .013 .002 31 3.213 Mm .38- .45 .421 .015 .003 33 3.591 Cm .416 1 Tt .45- .49 .473 .012 .004 9 2.598 Lc .48- .55 .525 .020 .004 27 3.765 El .56- .58 .568 .006 .002 7 .998

28)Length of pubic symphysis/Length of pelvis Mf .22- .34 2.81 .019 .002 86 6.622 Mn .24- .27 .260 .011 .005 6 4.304 Mv .19- .27 .231 .023 .005 23 9.857 Ma .27- .37 .328 .021 .003 53 6.268 Mp .21- .33 .307 .025 .005 23 8.169 G1 .24- .28 .254 .013 .003 16 5.296 148

Range Mean SD SE n CV Eb .29- .34 .314 .016 .006 8 5.076 S .10- .19 .142 .022 .003 42 15.722 Mm .06- .11 .092 .012 .002 37 12.870 Cm .09- .12 .104 .012 .005 6 11.238 Tt .11- .15 .127 .010 .002 22 7.655 Lc .16- .20 .180 .017 .008 5 9.421 El .16- .24 .213 .022 .008 16 10.155

29)Preacetabular length of pelvis/Length of pelvis Mf .50- .57 .541 .015 .002 88 2.685 Mn .53- .55 .542 .006 .002 6 1.116 Mv .50- .59 .529 .017 .002 47 3.220 Ma .50- .55 .523 .011 .001 102 2.113 Mp .50- .57 .539 .016 .002 41 2.886 G1 .48- .54 .520 .013 .002 27 2.428 Eb .50- .54 .522 .014 .004 10 2.706 S .48- .57 .527 .016 .002 66 3.008 Mm .50- .76 .573 .033 .004 54 5.762 Cm .51- .57 .539 .019 .008 6 3.592 Tt .47- .50 .487 .009 .002 23 1.917 Lc .42- .45 .438 .009 .001 43 2.138 El .43- .48 .448 .011 .003 20 2.569

30)Length of femur/Length of hindfoot Mf .62- .86 .754 .047 .006 62 6.289 Mn .875 1 149

Range Mean SD SE n CV My .69- .83 .733 .032 .006 24 4.340 Ma .72- .90 .778 .046 .009 25 5.881 Mp .78- .90 .811 .043 .018 6 5.295 G1 .76- .92 .844 .067 .025 7 7.968 Eb .987 1 S .83-1.20 .942 .077 .013 35 8.137

Mm .87-1.02 .936 .043 .010 17 4.587 Cm .95-1.01 .991 .030 .015 4 3.024 Tt .74- .99 .882 .100 .032 10 11.373 Lc .57- .63 .603 .023 .007 12 3.825 El .47- .54 .504 .022 .008 8 4.336

31) Length of femur/Length of skull Mf .64- .80 .706 .034 .004 82 4.771 Mn .73- .90 .809 .078 .030 7 9.684 My .66- .86 .750 .036 .006 41 4.820 Ma .79- .93 .872 .028 .003 95 3.195 Mp .83- .99 .913 .028 .005 35 3.118 Gl .93-1.02 .983 .021 .005 21 2.148 Eb .84-1.03 .954 .066 .022 9 6.926 S .71- .88 .794 .034 .004 64 4.271 Mm .86-1.02 .925 .036 .005 47 3.849 Cm .89-1.06 .999 .058 .024 6 5.829 Tt .73- .86 .783 .036 .009 17 4.574 Lc .66- .77 .706 .028 .004 44 3.946

E1 .77- .94 .852 .043 .009 21 5.076 150

Range Mean SD SE n CV 32) Length of femur/Length of hindlimb Mf .38- .40 .392 .005 .001 42 1.264 Mn .41- .42 .411 .004 .002 4 .888 My .38- .40 .393 .005 .001 20 1.327 Ma .38- .41 .394 .007 .001 40 1.811 Mp .40- .41 .402 .004 .001 28 .891 G1 .42- .43 .422 .004 .001 13 .835 Eb .42- .45 .440 .013 .005 6 2.960 S .42- .44 .427 .005 .001 31 1.263 Mm .42- .44 .428 .006 .001 33 1.412 Cm .43- .43 .433 .001 .001 2 .327 Tt .46- .48 .471 .004 .001 9 .769 Lc .36- .37 .364 .005 .001 27 1.246 El .33- .36 .340 .011 .004 9 3.137

33) Anteroposterior width of femoral condyles/Mediolateral width of femoral condyles Mf .72- .96 .871 .041 .004 89 4.716 Mn .82- .94 .866 .042 .016 7 4.823 My .82- .96 .895 .034 .005 44 3.755 Ma .74- .93 .844 .035 .004 101 4.178 Mp .76- .95 .863 .032 .005 42 3.684 G1 .77- .90 .833 .032 .006 28 3.812 Eb .74- .92 .803 .046 .014 11 5.772 S .70- .89 .792 .043 .005 68 5.371 Mm .74- .93 .827 .033 .004 53 3.951 151

Range Mean SD SE n CV Cm .75- .94 .807 .062 .023 7 7.634 Tt .76- .89 .827 .033 .007 22 3.988 Lc .79- .91 .837 .030 .005 43 3.570 El .79- .93 .877 .029 .007 20 3.324

34)Mediolateral width of femoral condyles/Length of femur Mf .18- .22 .198 .009 .001 89 4.595 Mn .20- .21 .205 .003 .001 7 1.704 My .21- .26 .223 .012 .002 45 5.317 Ma .17- .20 .182 .006 .001 101 3.181 Mp .17- .21 .188 .007 .001 42 3.948 G1 .20- .24 .217 .011 .002 28 4.959 Eb .18- .23 .198 .016 .005 11 7.996 S .19- .24 .208 .012 .001 68 5.808 Mm .20- .26 .225 .012 .002 53 5.366 Cm .21- .25 .225 .014 .005 7 6.447 Tt .22- .26 .235 .010 .002 22 4.325 Lc .27- .32 .297 .012 .002 43 4.067 El .29- .35 .310 .016 .003 21 5.168

35)Anteroposterior width of femoral condyles/Length of femur Mf .14- .19 .173 .009 .001 89 4.936 Mn .17- .19 .178 .008 .003 7 4.241 My .17- .24 .199 .010 .002 44 5.247 Ma .14- .18 .154 .007 .001 100 4.242 Mp .14- .18 .162 .007 .001 42 4.380 152

Range Mean SD SE n CV G1 .17- .20 .180 .009 .002 28 4.742 Eb .14- .20 .160 .020 .006 11 12.527 S .15- .18 .164 .008 .001 68 4.573 Mm .16- .21 .186 .010 .001 53 5.497 Cm .17- .21 .181 .019 .007 7 10.294 Tt .18- .21 .194 .008 .002 22 4.354 Lc .23- .28 .248 .010 .002 43 4.110 El .24- .31 .271 .014 .003 21 5.051

36) Ellipticity of femur Mf .75- .96 .867 .043 .005 90 4.942 Mn .74- .82 .784 .023 .009 7 2.958 My .73- .96 .835 .047 .007 46 5.637 Ma .79- .95 .877 .031 .003 102 3.510 Mp .86- .97 .926 .021 .003 42 2.313 G1 .86- .95 .913 .024 .005 28 2.649 Eb .78- .91 .857 .039 .011 12 4.587 S .68- .88 .781 .047 .006 68 6.041 Mm .63- .91 .821 .054 .007 53 6.553 Cm .73- .92 .816 .075 .028 7 9.234 Tt .71- .88 .815 .051 .011 23 6.302 Lc .68- .88 .783 .046 .007 43 5.932 El .68- .81 .749 .041 .009 21 5.435 153

Range Mean SD SE n CV 37) Length of tibia minus length of medial malleolus/Length of tibia Mf .93- .98 .952 .007 .001 82 .698 Mn .93- .95 .994 .006 .003 6 .679 My .90- .95 .941 .009 .001 46 .934 Ma .95- .97 .959 .004 .000 92 .456 Mp .94- .97 .953 .005 .001 40 .503 G1 .95- .97 .954 .007 .001 29 .717 Eb .95- .96 .955 .005 .001 11 .487 S .94- .97 .952 .007 .001 65 .736 Mm .94- .97 .953 .007 .001 51 .755 Cm .93- .96 .947 .009 .003 7 .975 Tt .88- .96 .939 .014 .003 23 1.499 Lc .92- .95 .937 .007 .001 43 .727 El .91- .94 .926 .007 .002 21 .293

38) Length of tibia/Length of hindfoot Mf .67- .92 .824 .048 .007 55 5.866 Mn .891 1 My .77- .91 .812 .030 .006 23 3.680 Ma .76-1.01 .839 .054 .011 25 6.407 Mp .82- .96 .872 .051 .021 6 5.861 G1 .24- .91 .839 .063 .024 7 7.495 Eb .923 1 S .85-1.20 .961 .078 .013 34 8.139 Mm .93-1.06 .992 .042 .010 17 4.186 154

Range Mean SD SE n CV Cm .96-1.01 .974 .026 .013 4 2.703 Tt .61- .85 .749 .074 .022 11 9.893 Lc .71- .78 .747 .023 .007 12 3.142 El .61- .69 .649 .025 .008 9 3.908

39) Length of tibia/Length of skull Mf .70- .85 .772 .035 .004 74 4.564 Mn .76- .77 .763 .005 .002 5 .664 My .75- .94 .829 .034 .005 42 4.101 Ma .85-1.03 .951 .037 .004 88 3.859 Mp .92-1.07 .968 .027 .005 33 2.839 G1 .91-1.02 .966 .025 .005 22 2.564 Eb .88- .97 .926 .036 .013 8 3.840 S .73- .90 .814 .037 .005 60 4.581 Mm .89-1.07 .969 .040 .006 46 4.077 Cm .90-1.07 1.014 .060 .025 6 5.966 Tt .60- .73 .653 .033 .008 18 5.007 Lc .82- .93 .872 .025 .004 43 2.907 El .99-1.18 1.091 .050 .011 21 4.624

40) Length of tibia/Length of femur Mf 1.03-1.14 1.092 .023 .003 81 2.103 Mn 1.01-1.04 1.027 .013 .005 6 1.311 My 1.07-1.17 1.106 0.22 .003 44 1.984 Ma 1.01-1.13 1.089 .024 .002 92 2.176 Mp 1.03-1.10 1.065 .016 .002 40 1.464 155

Range Mean SD SE n CV Gl .96-1.03 .983 .015 .003 28 1.541 Eb .91-1.07 .967 .052 .017 10 5.405 S .98-1.08 1.026 .022 .003 65 2.171 Mm 1.01-1.11 1.049 .022 .003 50 2.143 Cm 1.00-1.05 1.020 .019 .007 7 1.858 Tt .81- .87 8.34 .014 .003 21 1.699 Lc 1.17-1.31 1.240 .027 .004 43 2.196 El 1.18-1.33 1.282 .034 .007 21 2.615

41) Length of tibia/Length of hindlimb Mf .39- .47 .415 .020 .003 42 4.869 Mn .42- .43 .422 .008 .002 4 .895 My .42- .44 .432 .005 .001 20 1.062 Ma .41- .45 .431 .007 .001 40 1.686 Mp .42- .44 .430 .004 .001 28 .894 G1 .41- .42 .415 .002 .001 13 .506 Eb .41- .44 .421 .012 .005 6 2.773 S .42- .46 .442 .006 .001 31 1.366 Mm .43- .46 .446 .005 .001 33 1.148 Cm .44- .46 .446 .013 .009 2 2.854 Tt .39- .40 .393 .005 .002 9 1.180 Lc .44- .48 .452 .008 .001 27 1.709 El .43- .44 .433 .005 .002 9 1.065 156

Range Mean SD SE n CV 42) Anteroposterior width of head of tibia/Mediolateral width of head of tibia

Mf .79- .95 .868 .031 .003 90 3.601 Mn .85- .94 .880 .034 .013 7 3.851 My .77- .93 .862 .035 .005 47 4.038 Ma .77- .90 .838 .027 .003 95 3.281 Mp .82- .93 .878 .023 .004 42 2.611 G1 .88-1.01 .933 .031 .006 29 3.279 Eb .79- .91 .840 .037 .011 12 4.453 S .74- .90 .821 .037 .005 64 4.472 Mm .77- .90 .841 .030 .004 53 3.571 Cm .81- .90 .853 .029 .011 7 3.372 Tt .89- .92 .851 .034 .007 23 4.005 Lc .66- .80 .746 .033 .005 42 4.376 El .65- .85 .782 .039 .008 21 4.936

43) Ellipticity of tibia

Mf .54- .95 .694 .071 .008 89 10.250 Mn .70- .76 .731 .024 .009 7 3.283 My .67- .89 .775 .050 .007 47 6.458 Ma .63- .90 .783 .053 .005 95 6.724 Mp .70- .83 .773 .036 .006 40 4.647 G1 .67- .82 .742 .044 .008 29 5.945 Eb .70- .83 .777 .043 .013 11 5.482 S .55- .92 .749 .080 .010 65 10.706 Mm .59- .85 .707 .061 .008 52 8.660 157

Range Mean SD SE n CV Cm .70- .79 .752 .042 .016 7 5.651 Tt .57- .73 .651 .038 .008 23 5.769 Lc .53- .72 .624 .047 .007 43 7.511 El .54- .78 .671 .062 .013 21 9.186

44)Length of fibula/Length of tibia Mf .87- .96 .919 .012 .001 78 1.343 Mn .70- .91 .816 .110 .049 5 13.441 My .72- .93 .894 .047 .007 42 5.257 Ma .92- .96 .936 .008 .001 91 .833 Mp .89-1.00 .924 .017 .003 39 1.811 G1 .87- .94 .918 .014 .003 28 1.488 Eb .91- .94 .924 .010 .003 10 1.032 S .87- .99 .928 .021 .003 64 2.231 Mm .87- .94 .913 .012 .002 43 1.331 Cm .89- .94 .910 .017 .006 7 1.869 Tt .86- .93 .894 .018 .004 20 2.008 Lc .87- .91 .890 .010 .002 39 1.152 El .85- .89 .870 .012 .003 20 1.368

45)Postastragalar length of calcaneus/Length of third metatarsal Mf .28- .37 .337 .021 .003 43 6.252 Mn .40- .48 .432 .034 .017 4 7.794 My .38- .53 .439 .040 .009 21 9.159 Ma .33- .41 .359 .018 .003 40 5.084 158

Range Mean SD SE n CV Mp .38- .48 .411 .022 .004 27 5.246 G1 .51- .60 .551 .025 .007 13 4.463 Eb .45- .56 .509 .036 .013 8 7.065 S .48- .64 .537 .035 .007 25 6.464 Mm .55- .77 .646 .046 .008 34 7.064 Cm .69- .73 .709 .028 .019 2 3.887 Tt .62- .74 .700 .036 .011 10 5.571 Lc .47- .58 .503 .024 .005 27 4.854 El .32- .37 .347 .013 .004 9 3.867

46) Postastragalar length of calcaneus/Length of hindfoot Mf .10- .14 .117 .009 .001 40 7.641 Mn .155 1 My .13- .17 .142 .010 .002 22 7.267 Ma .12- .15 .128 .009 .002 19 7.083 Mp .13- .16 .145 .012 .005 6 8.059 G1 .16- .21 .185 .020 .008 7 11.043 Eb .136 1 S .14- .20 .161 .018 .005 13 11.406 Mm .18- .20 .185 .009 .003 10 4.678 Cm .17- .19 .178 .009 .005 3 4.993 Tt .16- .20 .183 .012 .004 11 6.815 Lc .14- .23 .162 .023 .007 12 13.973 El .10- .13 .117 .006 .002 9 5.445 159

Range Mean SD SE n CV 47)Postastragalar length of calcaneus/Length of hindlimb Mf .05- .07 .061 .004 .001 42 6.560 Mn .07- .08 .072 .005 .002 4 6.529 My .07- .09 .076 .006 .001 20 8.290 Ma .06- .07 .064 .003 .000 40 3.946 Mp .06- .08 .068 .003 .001 28 4.798 G1 .08- .10 .090 .003 .001 13 3.334 Eb .06- .08 .070 .006 .002 6 8.132 S .07- .08 .071 .004 .001 25 6.217 Mm .06- .09 .077 .009 .002 33 11.281 Cm .08- .09 .086 .004 .003 2 4.933 Tt .08- .10 .095 .006 .002 9 6.413 Lc .09- .10 .094 .003 .001 27 3.294 El .07- .08 .078 .003 .001 9 4.219

48)Length of third metatarsal/Length of hindlimb Mf .17- .19 .180 .006 .001 42 3.224 Mn .16- .17 .167 .003 .002 4 1.914 My .17- .18 .174 .005 .001 20 2.587 Ma .17- .19 .177 .005 .001 40 2.935 Mp .16- .18 .168 .004 .001 28 2.314 G1 .16- .17 .163 .004 .001 13 2.199 Eb .13- .15 .139 .005 .002 6 3.344 S .13- .14 .131 .004 .001 31 2.965 Mm .12- .14 .127 .005 .001 33 3.967 Cm .11- .13 .121 .011 .008 2 9.350 160

Range Mean SD SE n CV Tt .13- .15 .136 .006 .002 9 4.293 Lc .17- .19 .186 .006 .001 27 2.980 El .21- .24 .225 .011 .004 9 4.769

49) Length of hindfoot/Length of hindlimb Mf .48- .59 .529 .076 .006 23 5.132 Mn My .48- .55 .523 .021 .007 10 3.985 Ma .52- .53 .524 .007 .004 4 1.397 Mp .44- .51 .475 .044 .031 2 9.230 G1 .564 1 Eb .452 1 S .39- .49 .453 .029 .009 11 6.328 Mm .42- .48 .449 .022 .009 6 4.835 Cm Tt .49- .64 .543 .058 .026 5 10.760 Lc .39- .60 .535 .097 .048 4 18.071 El .65- .69 .675 .022 .011 4 3.212