LATE PLEISTOCENE EQUIDS in EASTERN BERING/A: DENTAL CHARACTERISTICS and MORTALITY PROFILES of Equus Lambei from the BLUEFISH CAVES, YUKON TERRITORIES, CANADA
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Ll / LATE PLEISTOCENE EQUIDS IN EASTERN BERING/A: DENTAL CHARACTERISTICS AND MORTALITY PROFILES OF Equus lambei FROM THE BLUEFISH CAVES, YUKON TERRITORIES, CANADA Ariane BURKE* and Jacques CINQ-MARS'"* Summary Résumé Zusammenfassung The Bluefish Caves of northem Les Équidés du Pleistocène tardif de Spiitpleistoziine Equiden in der ostli Yukon, Canada, have yielded the earli l'est de la Béringie : caractéristiques chen Beringregion: Zahnmerkmale est evidence of human occupation ol dentaires et courbes de mortalité de und Sterbealtesprofile von Equus lam Eastern Beringia. They have also pro Equus lambei des grottes Bluefish, bei aus den Bluefish-Hohlen im vided us with the larges! and most com Territoires du Yukon, Canada. Yukongebiet, Kanada. plex in situ late Pleistocene fàuna ever Les grottes Bluefish, dans le nord du Die Bluefish Caves in Nord Yukon, recovered in this region, if not in ail of' Yukon, Canada, recèlent les témoins les Kanada, erbrachten den frühesten Beringia. This paper presents research plus anciem d'occupation humaine dans Nachweis menschlicher Besiedlung im results Oil an important component of la Béringie de l 't'st. De plus, ces grottes ostlichen Beringge!Jiet. Ehenso lieferten the Bluefïsh jàuna, the equids (Equus contiennent une faune parrni les plus sie uns den umfàngreichsten und kom lambeiJ. More specijïcalh'. it presents grandes et les plus complexes du plexesten pleistoziinen in situ - data derived .flwn the stucfr of a rela Pléistocène tardifjamais découvertes in Faunenkomple.r, der in dieser Region tive/y large swnple of' horse teeth recov situ dans cette région. Cet article présen bekannt geirnrden ist. Dieser Beitrag ered from the tlzree ca1·es. As well as te les résultats d'une recherche sur un behandelt die Forschungsergebnisse zu contributing to the reconstruction of membre important de la faune de einer bedeutenden Komponente der Full and Late Glacial landscapes in the Bluefish, le cheval (Equus lambeiJ. Cette Bluefish-Fauna, den Equiden (Equus Bluefish Basin, Eastern Beringia, this recherche est spécifiquement orientée lambei). Das Schwergewicht liegt au{ research contributes to our knowledge vers l'étude de la dentition de ce cheval, Daten, die anhand einer groj3en Menge of the Late Pleistocene Beringian equid. témoin relativement abondant dans les von Pf'erdeziihnen aus den drei Hohlen Equus lambei. trois grottes. Tout en approfondissant gewonnen werden konnten. Die nos connaissances sur Equus lambei, cet Ergebnisse erweitern unser Wissen über article vise à contribuer à la reconstitu die hach- und spiitglaziale Landschaft tion de l'environnement dans le Bassin im Bluefish-Becken und das spiitpleisto Bluefish. ziine Pferd, Equus lambei. Key Words Mots clés Schlüsselworte Equus lambei, Blucfïsh caves, Equus lambei. Grottes Bluefïsh, Plé Equus lambei, Bluefish-Hdhlen, Full/Late Glacial, Skeletto-chronology, niglaciaire, Tardiglaciaire, Squeletto Hoch- und Spiitglazial, Skeletto-Krono Eastern Beringia. chronologie, Béringie orientale. logie, Ôstliches Beringgebiet. Introduction They have been the focus of several multi-disciplinary pro The paleoenvironmental record for Eastern Beringia is jects, such as the Yukon Research Programme, the Yukon preserved intact in numerous deposits in the northern Refugium Project, and long-terrn study of Pleistocene ver Yukon, Northwest Territories and Alaska. These deposits tebrate fossils undertaken by the Canadian Museum of provide us with a continuous record of environmental con Nature (C. R Harington). ditions during the last glacial period, or Wisconsinan Eastern Beringia, including the interior basins, (Hughes et al., 1981; Harington, 1979; Morian, 1980). unglaciated lowland areas such as the Bonnet Plume, Old * Dept. of' AmhropologY, Uni1·ersity of Manitoba, 435 Fletcher Argue Hldg, Winnipeg, Manitoha, Canada. ** Archaco/ogicaf Survns of' Canada, Canadian Museum of' Civilization, I OO rue Laurier, Hull, Québec, Canada. ANllJ/WPOLOOLOG!C\. /997. N° 25. 26 218 Crow, Bluefish and Bell basins, played a part in the histo appears in pre-late Wisconsinan deposits in Dawson, Old ry of habitation in the New World, particularily during Crow and Alaska, and in Illinoian age deposits in Alaska. the maximum expansion of the Cordilleran and At Bluefish, Equus lambei specimens have been radiocar Laurentide ice sheets. For this reason archaeologists seek bon dated to approximately 22-23 Kyrs bp at the earliest better understanding of Late Pleistocene environments in and 12 Kyrs bp at the latest. Eastern Beringia. A relatively small, broad-skulled horse, Equus lambei The floral and faunal communities of Pleistocene strongly resembles Late Pleistocene equids from Siberia Eastern Beringia are still poorly known but appear to have (Harington, 1977; see also Eisenmann, 1986: 72). The type differed fundamentally from present tundra communities specimen, from Gold Run Creek, Alaska, was first (Harington, 1979; Guthrie, 1980, 1982, 1985; Matthews, described by Hay in 1917. 1982). A better understanding of Pleistocene faunal com Originally described as a member of the genus munities in Eastern Beringia has been hampered by the Asinus, E. lambei is now assigned to the caballine group Jack of in situ, identifiable biocenoses (Matthews, 1982; on the basis of physical traits described by Harington Guthrie, 1985). For example, the Mammoth Fauna, an (1989) and multivariate analyses carried out by apparently widespread Pleistocene fauna, is believed to be Eisenmann (1980, 1986). Eisenmann noted close similari dominated by bison, horse and mammoth (Guthrie, 1980, ties between Equus lambei, late Pleistocene Siberian 1982, 1985; Matthews, 1982; Vereshchagin and horses, Equus przewalskii and modern Arabian breeds. Baryshnikov, 1982), and only loosely associated with ele Similarily, Forsten (1988a: 163) states that E. lambei, the ments such as Saiga, Ovibos. At the Bluefish Caves, north Yukon horse, was "the easternmost representative of a ern Yukon, however, elements of the Mammoth Fauna are circumpolar species of small, caballoid, horse of which found together with both Saiga and Ovibos, in close strati Przelwalski' s horse and the tarpan were the last wild graphie association. Eurasian survivors." The presence of abundant faunal and palynological The Bluefish Caves have yielded 505 horse cheek remains in situ in the three caves which make up the teeth, so far: 306 maxillary and 218 mandibular. The teeth Bluefish Caves complex, make this an invaluable assem were sorted into anatomical positions, and the total number blage for furthering our knowledge of animal communities of teeth for each anatomical position was calculated. The and their environment in East Beringia. dental MNI (Minimum Number of Individuals) based on This paper adds to our knowledge of a dominant mem cheek teeth is 51 individuals. Twenty-five individuals from ber of the Mammoth Fauna: the horse. Preliminary Cave 1, 13 from Cave II and 13 from Cave III. research on the dental morphology of Equus lambei and Mandibular cheekteeth were measured on 7 dimen thin-sectioning of equid teeth from the Bluefish Caves for sions, maxillary teeth on 5 dimensions. Measurements the purposes of establishing season of death is presented. were taken following Turnbull (1986), at the occlusal sur Dental morphology is believed to be a useful tool for mak face for ease of comparison with Eisenmann's morphomet ing taxonomie determinations of Pleistocene fossil horses ric data (Eisenmann, 1980). (Azzaroli, 1990: 341; Prat, 1976, 1980; Eisenmann, 1980, In this paper, the quantitative data are used to confirm 1986, 1991 ). the taxonomie affiliation of E. lambei, to describe the den tal characteristics of E. lambei more fully and to construct The Horses at Bluefish Caves age profiles for horse for each cave using eruption/wear Horses have been discovered at Bluefish Caves in a data and tooth-height tables, after Levine (1982). A series stratigraphie context spanning the last 15,000 years of the of qualitative observations were also made on the cheek late Pleistocene. These fossils have potential for establish teeth following Eisenmann (1986: fig. 19). ing the relationship between the behaviour and morphology A representative sample of teeth (equal to dental MNI of Beringian equids, and paleoenvironmental changes minus poorly-preserved teeth) was taken from each cave occuring during the late Pleistocene. for thin-sectioning. Thirty-eight samples were taken, 18 from Cave 1, 7 from Cave II and 13 from Cave III. The Dating of E. lambei remains in Eastern Beringia sampled teeth were set in resin blocks, and thin-sectioned Equus lambei, the horse represented in the Bluefish using standard petrographic methodology (Burke, 1992; fauna, was the dominant equid form in the steppe-like ter Burke and Castanet, 1995). The resulting thin-sections rain of East Beringia during the late Wisconsinan (Sher, were viewed under transmitted, polarized light and deter 1971: 153; Harington and Clulow, 1973: 724). E. lambei minations of season of death were made. Section II: America, Eastern Asia, Pacifie 219 Results E. kiang, E. hemionus, and E. asinus (fig. 1, 2). The data Qualitative dental characteristics of E. lambei are only show that E. lambei most closely resembles other roughly similar to those of E. przewalskii, which Pleistocene caballoids, rather than the stenonid group (of Eisenmann considers typical of wild horses (1986: fig.19). which E. kiang, E. hemionus, and E. asinus are part). Mean The average number of