Pleistocene Mustelidae (Mammalia, Carnivora) from Fairbanks, Alaska
Total Page：16
File Type：pdf, Size：1020Kb
PLEISTOCENE MUSTELIDAE (MAMMALIA, CARNIVORA) FROM FAIRBANKS, ALASKA ELAINE ANDERSON! Abstract. Five of Mustela species mustelids, presidency of C. E. Bunnell, initiated its cf. erminea, Mustela vison, Mustela eversmanni well known program of collecting the fossils beringiae ssp. no\-., Gulo guJo, and Taxidea taxus, the The are reported from late Pleistocene deposits near exposed during mining operations. Fairbanks, Alaska. This is the first record of the university had little money for such ven- steppe ferret in the New World. It is closely related tures, but Childs Frick of the American if not Mustela the to, conspecific with, nigripes, Museum of Natural History agreed to fi- black-footed ferret. The northernmost occurrence nance the program, and his support con- of Taxidea taxus is reported. The woI\ erine, bad- tinued until the middle 1950's ger and ferret material is characterized by large (except the war little size, and some of tlie specimens are the largest during years when mining was known for the The Fairbanks area was done . Geist in col- species. ) Otto W. was charge of never and the of this glaciated, grassy steppes lecting the fossils. Thousands of specimens refiigium supported a large assemblage of Pleisto- were collected, but because cene mammals. unfortunately, of the methods of collection, stratigraphic INTRODUCTION infonnation is almost entirely lacking. Since the Universitv of Alaska had neither the Remains of Pleistocene mammals are space nor the comparative material, almost abundant in the frozen sediments of central all of the specimens were shipped to the Alaska, and at least 39 species are known. Frick Laboratory at the American Museum Many species of carni\'ores were associated of Natural History. There, a few groups with the large assemblage of herbivores that were studied, but most of the material was inhabited the Alaskan refugium in the late put in storage. The Mustelidae was one of Pleistocene. Large carnivores, Arctodus si- the neglected groups, and until 1973, when mtis, Ursus arctos. Panthera ho atrox, Homo- Anderson reported the presence of ferret, fherium serum, and Canis lupus dominated only badger and wolverine were recorded the scene, but the small carnivores—foxes, in the faunal lists (Pewe, 1957). dhole, lyn.x, and the mustelids—were an im- The Fairbanks area, where the fossils were portant part of the fauna. Five species of collected, lies between 64°45' and 65° N lat- mustelids, Mustela cf. erminea, Mustela itude, and is situated on the north side of the broad Tanana River at the base of vison, Mustela eversmanni beringiae ssp. valley the hills that make of the Yukon- nov., Gulo gulo, and Taxidea taxus are now up part known from the Fairbanks area. Tanana Ri\'er upland (see Fig. 1). Rising 380 to 545 meters above the nearly flat Fossil collecting began in the Fairbanks of the Chena and Tanana area with the advent of gold mining in 1928. floodplain rivers, are the low rounded hills of the In 1929, the University of Alaska, under the uplands. Loess, derived from the floodplain and the ^730 Magnolia St., Den\er, Colorado 80220. glacial outwash plains, covers the ridges Bull. Mus. Comp. Zool., 148(1): 1-21, April, 1977 1 Bullcfiii Miiscrun of Comparative Zoology, Vol. 148, No. 1 I48°00 65*00 kilometsrs — Moin Roads Figure 1. Map of the Fairbanks area. from a depth of about a meter on tlie sum- valleys, and was subsequently covered with mits to about 30 meters on the middle more loess, and the entire mass became fro- slopes. The upland valleys are filled with zen. Today permafrost covers much of the from three to 30 meters of gravel overlaid Fairbanks area. Needless to say, mining by three to 90 meters of colluvial silt. The and collecting fossils in this perennially floodplain is underlaid by several hundred frozen muck was, and still is, difficult. The feet of interbedded lenses of silt, sand, and fossils were exposed as the miners, using gravel (Pevve, 1957). The Fairbanks area hydraulic methods, removed the frozen was never glaciated, but glaciers from overburden from the gold-bearing gravels. the Alaska Range to the south came within Since most of the bones were transported 80 kilometers of the present cit\ of Fair- before burial, mummies and complete skele- banks. tons are rare, and most of the specimens are The Quaternary in central Alaska is char- disarticulated. Although a few pre-Wiscon- acterized by alternating periods of deposi- sinan deposits are known (Pewe and Hop- tion and erosion of gravel and silt, by kins, 1967), the majority of specimens are of the and warming and cooling climate, by late Wisconsinan in age. the formation and of the melting perma- The mustelid material is generally well frost. Gold-bearing gravels were deposited preserved, although some of the teeth are in the creek valleys early in the Quaternary, broken. The bones vary in color from light and were later covered by loess and organic to dark brown, and there is no trace of the debris which became perennially frozen. blue mineral, vivianite, on of the mate- Solifluction, the movement of moisture-sat- any rial I examined. The consist en- urated soil downhill during periods of thaw- specimens of skulls and mandibles. A femur of ing, was a major factor in the entombment tirely of animal and plant remains. The fossil- Giilo was listed in the field notes, but the laden silt eventually came to rest in the specimen could not be found. Pleistocene Mustelidae • Anderson ACKNOWLEDGEMENTS UA—Unixersity of Alaska UCM—University of Colorado Museimi I wish to express appreciation to — my deep USNM National Museum of Natural History Dr. Richard H. for Tedford letting me study I —incisor i ' the Alaskan mustelids in the Frick Col- C—canine with superscript (upper) or P— ( lection. Berv'l Ta>lor and George Krochak premolar subscript (lower) tooth M—molar ' of the Frick American Museum Laboratory, max.—maxillary of Natural History, assisted me in locating R—right specimens and field data. Russell D. Guth- L—left N—number in rie, University of Alaska, showed me some sample O.R.—observed range of the collecting areas near Fairbanks, and M—mean I would like to thank him and his wife for S.D.—standard deviation their generous hospitality during my visit to Fairbanks. For permission to study col- Mustela sp. cf. M. erminea Linnaeus lections in their care, I am indebted to John Short-tailed Weasel or Ermine A. \Miite, Idaho State University; Peter Figure 2 A Robinson, University of Colorado Museum; Material: Late Pleistocene, F:AM 49340 L ramus Charles S. Churcher, University of Toronto; w/C-M.; F:AM 49341 R ramus w/C-M.; F:AM and C. R. Harington, National Museum of 49348 R ramus w/C-Mi; F:AM 49349 frag. L Canada. My sincere thanks go to Barbara ramus w'Pa-i, Fairbanks area, Alaska. Lawrence and Charles Mack, Museum of Comparati\'e Material: Mustela erminea arctica, Alaska AMNH 21921- Comparative Zoology; John L. Paradiso and Recent, 17939, 21917-19, 22, 31369, 31379. KU 2975-76. Mtisiela rixosa Clyde Jones, Bureau of Sport Fisheries and eskimo Recent, Alaska AMNH 31383-84, 42811- National Museum of Natural His- Wildlife, 13, 42815-18. Northwest Territory AMNH tory; Richard G. Van Gelder, American 29212. Museum of Natinal Histoiy; William H. Four small weasel mandibles were found Burt, University of Colorado Museum; and in the collections from the Fairbanks area. Robert S. Hoffmann, Museum of Natural Guthrie (personal believes History, University of Kansas, for making communication) they were preserved in the nests of comparative material available to me. Bjorn ground The coro- Kurten, University of Helsinki, permitted squirrels, Spermophilus parryi. noid is in all of me to use some of his raw data on Giilo process missing the speci- mens. The teeth of three of the giilo. Erica Hansen, Idaho State University, specimens are but 49348 made the illustrations for Figures 1-3; Ms. slightly worn, F:AM shows Dehlin, formerly of the Frick Laboratory, moderately worn dentition. Comparison executed Figures 4 and 5 for Childs Frick with Recent specimens of Mustela erminea arctica Merriam and Mustela rixosa es- some years ago. This research was sup- ( ) ported by NSF Grant GB 31287 awarded to kimo (Stone), the two subspecies found in Professor Bryan Patterson, Harvard Univer- central Alaska today, shows that the Pleisto- cene most sity, and is part of a study of Pleistocene specimens closely resemble Mus- mammals of North America. tela erminea arctica. Table 1 shows that measurements of tooth row ABBREVIATIONS length, length of Ml, length of trigonid of M,, and width AMXH—American Museum of Natural Histoiy, of the talonid of Mi of die Pleistocene man- F:AM—Frick American Museum of Collection, dibles fall within the observed range of Natural History Mustela erminea arctica and exceed the ISUM—Idaho State University Museum KU—Museum of Natural History, University of observed range of Mustela rixosa eskimo. Kansas In his monograph on American weasels, MCZ—Musemn of Comparative Zoolog\', Harvard Hall noted that the basilar University (1951) length NMC—National Musemns of Canada of the skull of Mustela erminea measures 4 BtiJIcliii Museum of Comparative Zoology. Vol. 14S, Ko. 1 Table 1. Measurements, in mm, of Mustela 30cin ERMINEA AND MvSTELA RIXOSA FROM ALASKA. Pleistocene Mustelidae • Anderson Table 2. Measurements, in mm, of Mustela surements of the specimen fall within the Alaska. visoN FROM observed range of Mustela vison ingens (Osgood), the extant subspecies found in N OR. M S.D. the area today. It is the largest .subspecies Depth of ramus of Mustela vison. No moiphological differ- below P3-4 — — ences were observed between the specimen F:AM 30821 1 7.8 and the comparative material.