Palaeontologia Electronica NEW PLEISTOCENE CAVE FAUNAS OF
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Palaeontologia Electronica http://palaeo-electronica.org NEW PLEISTOCENE CAVE FAUNAS OF THE ANDES OF CENTRAL PERÚ: RADIOCARBON AGES AND THE SURVIVAL OF LOW LATITUDE, PLEISTOCENE DNA Bruce J. Shockey, Rodolfo Salas-Gismondi, Patrice Baby, Jean-Loup Guyot, María Cristina Baltazar, Luis Huamán, Andrew Clack, Marcelo Stucchi, François Pujos, Jenna María Emerson, and John J. Flynn ABSTRACT Peruvian citizens have led our team to their discoveries of Pleistocene cave fau- nas in the central Andes of Perú. These caves (Jatun Uchco, Departamento de Huá- nuco; Cueva Roselló, Departamento de Junín; and Trigo Jirka, Departamento de Huánuco) preserve numerous carnivorans (Puma, a sabercat [Smilodon populator], an unnamed large extinct felid, fox [Lycalopex sp.], hognose skunk [Conepatus sp.]), deer (cf. Pudu and cf. Hippocamelus), vicuña, an extinct horse (†Onohippidium devillei), a chinchillid rodent (cf. Lagidium), bats (Anoura, Desmodus, and Platalina), and sloths (†Megatherium, †Scelidodon, and, †Diabolotherium). Bats were found only in the low- est cave (Jatun Uchco, 2,150 m), and ungulates were found only at Cueva Roselló— the only cave studied in a region of flat terrain. Trigo Jirka preserved ancient feces of a large animal and the keratin claw of †Diabolotherium. Collagen for radiocarbon dating and DNA for phylogenetic studies have been iso- lated from bone from Cueva Roselló (3,875 m) and Trigo Jirka (2,700 m). Conventional radiometric ages from Cueva Roselló are 23,340 ± 120 and 22,220 ± 130 years before present and that of Trigo Jirka is 29,140 ± 260. Ancient DNA (aDNA) from †Onohippid- ium of Cueva Roselló (12° South latitude) and †Diabolotherium of Trigo Jirka (10° South) is being used in phylogenetic studies. The successful recovery of aDNA sug- gests that the cool temperatures, low humidity, and the shield from UV radiation of caves at high elevation can permit aDNA studies at low latitudes. Previously, such studies have been limited to latitudes greater than 35° for Pleistocene samples. Bruce J. Shockey. Manhattan College, Manhattan College Parkway, New York City, NY, USA, 10471 and Division of Paleontology, American Museum of Natural History, New York, NY, USA. [email protected] Rodolfo Salas-Gismondi. Departamento de Paleontología de Vertebrados, Museo de Historia Natural– UNMSM, Av. Arenales 1256, Lima 14, Perú, [email protected] Patrice Baby. Laboratoire des Mécanismes et Transferts en Géologie, IRD, Université de Toulouse, CNRS, OMP, 14 Av. E. Belin, F-31400 Toulouse, France, [email protected] PE Article Number: 12.3.15A Copyright: Society for Vertebrate Paleontology December 2009 Submission: 11 February 2009. Acceptance: 6 November 2009 Shockey, Bruce J., Salas-Gismondi, Rodolfo, Baby, Patrice, Guyot, Jean-Loup, Baltazar, María Cristina, Huamán, Luis, Clack, Andrew, Stucchi, Marcelo, Pujos, François, Emerson, Jenna María, and Flynn, John J. 2009. New Pleistocene Cave Faunas of the Andes of Central Perú: Radiocarbon Ages and the Survival of Low Latitude, Pleistocene DNA. Palaeontologia Electronica Vol. 12, Issue 3; 15A: 15p; http://palaeo-electronica.org/2009_3/189/index.html Shockey, et al.: NEW ANDEAN CAVE FAUNAS Jean-Loup Guyot. Laboratoire des Mécanismes et Transferts en Géologie, IRD, Université de Toulouse, CNRS, OMP, CP 7091 Lago Sul, 71619-970 Brasilia DF, Brazil, [email protected] María Cristina Baltazar. Instituto Nacional de Cultura, Lima, Perú, [email protected] Luis Huamán. Laboratorio de Palinología y Paleobotánica, Universidad Peruana Cayetano Heredia, Lima, Perú, [email protected] Andrew Clack. McMaster Ancient DNA Centre, Department of Anthropology, McMaster University, Hamilton, Ontario L8S 4K1, Canada, [email protected] Marcelo Stucchi. Asociación para la Investigación y Conservación de la Biodiversidad – AICB, Av. Vicús 538, Lima 33, Perú, [email protected] François Pujos. Departamento de Geología y Paleontología, Instituto Argentino de Nivología Glaciología y Ciencias Ambientales (IANIGLA), CCT–CONICET–Mendoza, Avenida Ruiz Leal s/n, Parque Gral. San Martín, 5500 Mendoza, Argentina. [email protected] Jenna María Emerson. Carroll College, Biology Department. 1601 N. Benton Ave., Helena, MT 59625, USA. [email protected] John J. Flynn. Division of Paleontology, American Museum of Natural History, Central Park West at 79th St., New York, NY, USA. [email protected] KEY WORDS: Pleistocene; cave fauna; Great American Biotic Interchange; South American mammals; Ancient DNA; palynology; radiocarbon ages INTRODUCTION Pleistocene megafaunal extinctions 10-15,000 years ago. For the greatest part of the Cenozoic (the last Recent discoveries of new cave faunas in the 65 million years), South America has been an iso- Andes of central Perú provide rare opportunities to lated continent, home to a peculiar endemic fauna sample mammals from this post-GABI / pre-mega- that consisted mostly of marsupials, xenarthrans faunal extinction period (Salas and Stucchi 2005; (armadillos, glyptodonts, anteaters, and sloths), Anonymous 2006; Shockey et al. 2007; Figure 1). and several groups of the now extinct native “ungu- Their location is particularly fortuitous because lates” (Simpson 1980). This “splendid isolation” these caves preserve samples of Pleistocene ended about three million years ago with the for- mammals from low latitudes (from 9° to just over mation of the Panamanian land bridge that now 12° South), whereas much of the knowledge of connects South and North America (Stehli and Pleistocene South America comes from high lati- Webb 1985). This resulted in a mixing of the fau- tude localities in Argentina (>30°). The drier condi- nas of both continents that reached its peak diver- tions and cooler temperatures at high elevation sity after the beginning of the Great American negated the usual disadvantage of low latitude Biotic Interchange (GABI), but before the late Pleistocene fossils—the destruction of organic Figure 1. The Discoverers. The initial discoveries of the cave faunas in this study were accomplished by responsible local individuals: Iván Solano (left) was instrumental in discovering fossils in Jatun Uchco; Gonzalo Roselló (left in center photo) and his crew discovered the cave and fossils at Cueva Roselló; and Don Magno (right) discovered the cave and fossils at Trigo Jirka. 2 PALAEO-ELECTRONICA.ORG molecules in warm and humid environments (Aus- sidad Nacional Mayor de San Marcos (MUSM) in tin et al. 1997; Wayne et al. 1999). Also, the loca- Lima, Perú. Representative samples from all taxa tion of the fossils within the ground provided some are being stored in a freezer at the MUSM to pre- protection against damaging ultraviolet radiation. serve organics for future molecular studies. Identifi- Most Pleistocene fossils known from the cation of the fossil vertebrates was accomplished Andes of Perú have come from caves (Pujos and by comparing them to specimens in the mammal Salas 2004; Salas and Stucchi 2005). Gervais departments at the Museo de Historia Natural- (1855) reported fossils from Sansón-Machay near UNMSM and the American Museum of Natural His- Cerro de Pasco in the central Andes, and Norden- tory as well as comparative collections in the verte- skiöld (1908) reported and described remains of brate paleontology collections of these two various taxa from Casa del Diablo Cave located on institutions. the Altiplano of southern Perú at 3,819 m. Other Sediment samples from Jatun Uchco and Peruvian Andean cave faunas include Santa Rosa, Cueva Roselló and “coprolites” (ancient feces) near Celdín, in northern Perú (Pujos 2002); Huargo from Trigo Jirka were submitted for palynological Cave in the Departamento de Huánuco, central analysis using the palynology collection of the Lab- Perú (Cardich 1973); Tres Ventanas in the Depar- oratorio de Palinología y Paleobotánica de la Uni- tamento de Lima at about 4,000 m, and Pikim- versidad Peruana Cayetano Heredia under the achay cave in the Ayacucho Valley at 2,800 m (see direction of LH. Angiosperms were identified from Pujos and Salas 2004 for a summary of these and pollen, and spores were used to identify ferns and other Andean faunas of Perú). Of these, only a few club mosses (i.e., Lycopodium). have been radiometrically dated. These include Beta Analytical (Miami) performed the radio- Tres Ventanas, with a 14C age estimated to be carbon analyses. Bone samples were washed in greater than 40,000 BP (Engel 1970); Huargo, de-ionized water, and the outermost layers were cave bed 8, with a 14C age of 13,490 ± 700 BP removed by scraping. The remaining bone materi- (Cardich 1973); and Pikimachay with 14C age esti- als were then crushed and washed repeatedly in mates of 14,150 ± 180 and 19,620 ± 3,000 BP HCl until the mineral apatite was eliminated. (McNeish et al. 1970). As far as we know, no previ- Throughout this acid treatment, the remaining col- ous radiocarbon analyses of Andean faunas of lagen was inspected for rootlets, which were Perú were accomplished using accelerator mass removed if detected. The quality of the bone pres- spectrometry (AMS). ervation and quantity of collagen obtained permit- The purpose of this work is to summarize the ted an alkali pretreatment in which the collagen results of our field studies of the three caves that was washed in NaOH to ensure that all organic contain Pleistocene faunas (a fourth cave that con- acids were removed. Accelerator mass spectrome- tained remains of a mid-Holocene spectacled bear, try (AMS) was performed at one of the six Interna- Tremarctos ornatus, is documented elsewhere tional Consortium of Accelerator Laboratories [Stucchi et al. 2009]). This summary includes the (ICAL) on graphite (100% C) that had been basic locality data for the caves, a faunal list of taxa reduced from the collagen samples. recovered with figures of some of the more instruc- In addition to 14C content, stable carbon iso- tive specimens, results of radiocarbon dating from tope ratios (13C/12C) were obtained to verify the bone samples from two of the caves, and a list of purity of the collagen and to apply the standard plant taxa of which pollen or spores were found in correction to Measured Radiocarbon Age to obtain sediment or fecal samples.