THE CAPE DECEIT FAUNA EARLY PLEISTOCENE MAMMALIAN ASSEMBLAGE FROM THE ALASKAN ARCTIC
THE CAPE DECEIT FAUNA EARLY PLEISTOCENE MAMMALIAN ASSEMBLAGE FROM THE ALASKAN ARCTIC
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DOI：
10.1016/0033-5894(71)90060-3
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发表时间：
1971-01-01
期刊：
影响因子：
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通讯作者：
MATTHEWS J V JR
中科院分区：
文献类型：
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作者：
GUTHRIE R D;MATTHEWS J V JR
更新世暴露位于Kotzebue Sound（阿拉斯加）南海岸的德赛特角附近，包含一系列复杂的有机沉积物，这些沉积物产生了具有分类学、进化和动物地理学意义的脊椎动物化石。德赛特角当地动物群来自德赛特角组，是该遗址三个主要地层单位中最低的一个，包括犬属、驯鹿属、鹿属、鼠兔属、旅鼠属、田鼠属、上鼠属的代表，以及一个新描述的属和种，即Predicrostonyx hopkinsi-现存Dicrostonyx属的前身。除了P. hopkinsi，Ochotona，Pliomys和Microtus的新种也在Cape Deceit当地动物群中被描述。在此基础上，对四川田鼠Microtus deceitensis sp. n.和P. hopkinsi sp. n.这表明Cape Deceit地层至少是前克罗默时代的。这一假设得到了上覆的Inmachuk和Deering地层的证实，来自这些单位的化石（包括Dicrostonyx torquatus和D。henseli）和C-14日期。因此，德赛特角当地动物群，包含了最早的北美记录的几个所包括的属，除了唯一的北美记录Pliomys.Stratigraphic功能在曝光表明，德赛特角当地动物群哺乳动物生活在一个无树（苔原）的环境，当代苔原哺乳动物区系有一个漫长的北极适应的进化历史。我们假设存在于欧亚大陆东北部和阿拉斯加的更新世，最近的“白令纪”哺乳动物领域，有时有助于更南部地区的古北和新北的动物群。适应北极或源自北极的白令纪哺乳动物的南迁发生在欧洲和北美的不同时期（有些人解释为表明存在“白令纪过滤桥”），我们认为，这在很大程度上是由于白令纪地区以南的大陆自然地理和更新世地理的差异。
Pleistocene exposures located near Cape Deceit on the south shore of Kotzebue Sound (Alaska) contain a complex sequence of organic sediments which have yielded fossil vertebrates of taxonomic, evolutionary, and zoogeographic significance. Cape Deceit Local Fauna from the Cape Deceit Formation, lowermost of three major stratigraphic units recognized at the site, contains representatives of the genera Canis, Rangifer, Cervus, Ochotona, Lemmus, Microtus, Pliomys, and a newly described genus and species, Predicrostonyx hopkinsi-predecessor of the extant genus Dicrostonyx. In addition to P. hopkinsi, new species of Ochotona, Pliomys, and Microtus are described from the Cape Deceit Local Fauna. the stage of evolution of Microtus deceitensis sp. n. and P. hopkinsi sp. n. indicate that the Cape Deceit Formation is at least of pre-Cromerian age. This assumption is substantiated by the stratigraphy of the overlying Inmachuk and Deering formations, fossils from these units (including Dicrostonyx torquatus and D. henseli), and C-14 dates. The Cape Deceit Local Fauna, therefore, contains the earliest North American record of several of the included genera in addition to the only North American record of Pliomys.Stratigraphic features at the exposure indicate that the Cape Deceit Local Fauna mammals lived in a treeless (tundra) environment showing that the contemporary tundra mammalian fauna has a lengthy arctic-adapted evolutionary history. We postulate the existence in northeastern Eurasia and Alaska of a Pleistocene-Recent “Beringian” mammalian realm which has at times contributed to the fauna of more southern regions of the Palaerctic and Nearctic. The fact that this southern movement of arctic-adapted or arctic-derived Beringian mammals occurred at different times in Europe and North America (interpreted by some as indicating the existence of a “Beringian filter-bridge”) is, we think, due largely to differences of continental physiography and Pleistocene geography south of the Beringian area.