A Late Pleistocene third molar of Hylochoerus (Suidae, Mammalia) from Rusinga Island, Kenya: paleoenvironmental implications and a note on the hypsodonty of African forest hogs
A Late Pleistocene third molar of Hylochoerus (Suidae, Mammalia) from Rusinga Island, Kenya: paleoenvironmental implications and a note on the hypsodonty of African forest hogs
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DOI：
10.1080/08912963.2021.1887861
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发表时间：
2021-04
影响因子：
1.4
通讯作者：
Ignacio A. Lazagabaster;T. Cerling;J. Faith
中科院分区：
文献类型：
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作者：
Ignacio A. Lazagabaster;T. Cerling;J. Faith
非洲林猪（学名：Hylochoerus）是现存的非洲热带猪科动物，栖息于各种森林环境和茂密的林地，主要是食草动物。Hylochoerus可能是从更新世的Kolpochoerus majus类祖先进化而来，但其最近的进化历史几乎是未知的。在这里，我们描述了一个部分右下第三磨牙从晚更新世Wasibrium床的Rusinga岛（~50-36 ka）。冠部近远中侧压缩，呈丘齿状，排列成柱状，类似现存的Hylochoerus。我们提供了从计算机断层扫描获得的关于现存Hylochoerus的高齿指数（HI）的准确数据，并表明Rusinga第三臼齿牙冠与现代臼齿牙冠一样高（HI = 1.8-2.0）。稳定碳同位素分析表明，鲁辛加标本的饮食（δ 13 C = −17.0 ‰）也与现存的森林猪（δ 13 C平均值= −17.6 ‰）相似。这个极负的值与鲁辛加其他大型食草动物化石的值（δ 13 C平均值为-0.7 ‰）形成鲜明对比。在对这种异常的潜在解释中，最有可能的是晚更新世古环境比以前认为的更不均匀，可能包括鲁辛加高地的封闭树冠林地。
ABSTRACT African forest hogs (genus Hylochoerus) are extant Afro-tropical suids that inhabit a variety of forest environments and thick bushlands and are predominantly herbivores. Hylochoerus likely evolved from a Pleistocene Kolpochoerus majus-like ancestor, but its recent evolutionary history is virtually unknown. Here, we describe a partial right lower third molar from the Late Pleistocene Wasiriya Beds of Rusinga Island (~50-36 ka). The crowns are mesiodistally compressed in a bunolophodont fashion and arranged in columnar pillars that resemble those of extant Hylochoerus. We provide accurate data derived from computed tomography on the hypsodonty index (HI) of extant Hylochoerus and show that the Rusinga third molar crown was as tall as those of its modern counterpart (HI = 1.8–2.0). Stable carbon isotope analyses suggest that the diet of the Rusinga specimen (δ13C = −17.0 ‰) was also like that of extant forest hogs (δ13C average = −17.6 ‰). This extremely negative value contrasts strikingly with those of other fossil large herbivores at Rusinga (δ13C average = −0.7 ‰.). Among the potential explanations for this anomaly, the most likely is that the Late Pleistocene paleoenvironments were more heterogeneous than previously considered and may have included closed-canopy woodland in the highlands of Rusinga.