The fossil record of the short-faced bears (Ursidae, Tremarctinae) from Venezuela. Systematic, biogeographic, and paleoecological implications
The fossil record of the short-faced bears (Ursidae, Tremarctinae) from Venezuela. Systematic, biogeographic, and paleoecological implications
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委内瑞拉短面熊（Ursidae、Tremactinae）的化石记录。
DOI：
10.1127/0077-7749/2007/0244-0287
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发表时间：
2007
影响因子：
0.8
通讯作者：
A. Rincón
中科院分区：
文献类型：
--
作者：
L. Soibelzon;A. Rincón
ROYO y GOMEZ 于 1960 年在委内瑞拉首次记录了 Tremarctinae 熊。此后，在两个地点采集了三个新标本，但没有报道。本文的目的是讨论这些记录的分类学、生物地层学和生物地理学含义。 Tremarctinae 亚科中的熊属仅分布在美洲。在南美洲，仅记录了一种化石属，Arctotherium，包括五个物种：A. angustidens，仅限于阿根廷和玻利维亚的恩塞纳丹（早至中更新世）； A. vetustum，仅记录于巴西和阿根廷的波奈纪（中更新世）；两个博纳里安和卢贾安（中更新世 - 早全新世）物种，A. bonariense（仅在阿根廷有记录）和 A. tarijense（出现在阿根廷、玻利维亚、乌拉圭和智利）；和 A. wingei，仅在卢迦纪（更新世晚期 - 全新世早期）有确定记录。经过本研究，我们得出结论：（1）A. wingei 是委内瑞拉唯一有记录的物种，（2）所有已知标本均源自卢贾尼亚。在委内瑞拉以外，该物种是在玻利维亚和巴西记录的，但没有精确的地层数据。尽管 A. wingei 是最拟形的 Arctotherium 物种之一，但在更新世晚期之前的沉积物中尚未记录到它。这可以解释为物种对低纬度热带或亚热带环境的偏好，而这些环境在早更新世大陆沉积物中很少得到体现。
The first record of a Tremarctinae bear in Venezuela was made by ROYO y GOMEZ in 1960. Since then, three new specimens from two localities have been collected but not reported. The purpose of this contribution is to discuss the taxonomy, biostratigraphy, and biogeographic implications of these records. The bear genera included in the subfamily Tremarctinae are distributed exclusively in America. In South America only one fossil genus is recorded, Arctotherium, comprising five species: A. angustidens, restricted to the Ensenadan (early - middle Pleistocene) of Argentina and Bolivia; A. vetustum, recorded only in the Bonaerian (middle Pleistocene) of Brazil and Argentina; two Bonaerian and Lujanian (middle Pleistocene - early Holocene) species, A. bonariense (recorded only in Argentina), and A. tarijense (occurring in Argentina, Bolivia, Uruguay and Chile); and A. wingei, recorded with certainty only in the Lujanian (late Pleistocene - early Holocene). After the present study we conclude that (1) A. wingei is the only species recorded in Venezuela, and (2) all known specimens have Lujanian provenance. Outside Venezuela, this species is recorded from Bolivia and Brazil but without precise stratigraphic data. Although A. wingei is one of the most plesiomorphic Arctotherium species, it has not been recorded in sediments older than late Pleistocene. This could be interpreted as species preference for low latitude tropical or subtropical environments, which are poorly represented in early Pleistocene continental sediments.