Large Mesozoic mammals fed on young dinosaurs
Large Mesozoic mammals fed on young dinosaurs
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DOI：
10.1038/nature03102
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发表时间：
2005-01-13
期刊：
影响因子：
64.8
通讯作者：
Li, CK
中科院分区：
文献类型：
--
作者：
Hu, YM;Meng, J;Li, CK
中生代的哺乳动物通常被描绘成鼩 鼱或老鼠大小的动物，主要是食虫的，可能是夜行性的，生活在恐龙的阴影下（1-5）。已知最大的中生代哺乳动物化石是Repenomamus robustus，它是中国辽宁早白垩世的一种三齿类哺乳动物（6，7）。一个R.粗壮种的体型和弗吉尼亚负鼠差不多在这里，我们报告了一个新种的属，代表的骨架与大部分的头骨和postcranium保存在关节。新种比R.粗壮的头骨长度。此外，胃内容物与骨架的R。粗壮恐龙揭示了一只幼年鹦鹉龙的遗骸，鹦鹉龙是一种角龙类恐龙。我们的发现构成了第一个直接证据，证明一些三齿哺乳动物是食肉动物，以小型脊椎动物为食，包括年轻的恐龙，也表明中生代哺乳动物的体型范围比以前所知的要大得多。我们认为中生代哺乳动物占据了不同的生态位，一些大型哺乳动物可能与恐龙争夺食物和领土。
Mesozoic mammals are commonly portrayed as shrew- or rat-sized animals that were mainly insectivorous, probably nocturnal and lived in the shadow of dinosaurs(1-5). The largest known Mesozoic mammal represented by substantially complete remains is Repenomamus robustus, a triconodont mammal from the Lower Cretaceous of Liaoning, China(6,7). An adult individual of R. robustus was the size of a Virginia opossum. Here we report a new species of the genus, represented by a skeleton with most of the skull and postcranium preserved in articulation. The new species is 50% larger than R. robustus in skull length. In addition, stomach contents associated with a skeleton of R. robustus reveal remains of a juvenile Psittacosaurus, a ceratopsian dinosaur. Our discoveries constitute the first direct evidence that some triconodont mammals were carnivorous and fed on small vertebrates, including young dinosaurs, and also show that Mesozoic mammals had a much greater range of body sizes than previously known. We suggest that Mesozoic mammals occupied diverse niches and that some large mammals probably competed with dinosaurs for food and territory.