古生物学家认为，鸟类是由恐龙进化来的，而且许多恐龙也是凶猛的肉食动物，那么，刚披上羽毛的恐龙能飞上树吗？近日，美国《国家科学院院刊》在线发表中科院古脊椎动物与古人类研究所的最新发现：它们可以飞上树！因为它们能逮食树栖动物。
那是1.2亿年前的一只小盗龙，古生物学家在我国辽宁早白垩世的地层中发现了它的化石。“在它的腹部，竟然保存了一件不完整的树栖动物残骸。”论文第一作者、古脊椎所美籍博士后邹晶梅说，“从骨骼化石的保存特点和相对位置推测，该动物很可能是被小盗龙活捉了吞下肚子的。”
这件标本解开了一些谜团。古鸟类专家、中科院古脊椎所研究员周忠和告诉，这只已经成年的小动物残存下了两只脚，从脚趾看，属于典型的树栖类动物。“要想抓住这只麻雀个头的原始小动物，小盗龙至少要能在树枝间滑翔自如。”
小盗龙吃的会是掉在地上的死尸吗？“可能性不大！”恐龙专家、古脊椎所研究员徐星认为，一般食腐动物会将尸体撕成一块块地慢慢吃，而这只树栖小动物的骨骼排列却似整只被囫囵吞下。只有在生擒了猎物、生怕其逃走的情况下，小盗龙才会如此心急地进食。（生物谷Bioon.com）
doi:10.1073/pnas.1117727108
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Additional specimen of Microraptor provides unique evidence of dinosaurs preying on birds
O'Connor, Jingmai; Zhou, Zhonghe; Xu, Xing
Preserved indicators of diet are extremely rare in the fossil record; even more so is unequivocal direct evidence for predator–prey relationships. Here, we report on a unique specimen of the small nonavian theropod Microraptor gui from the Early Cretaceous Jehol biota, China, which has the remains of an adult enantiornithine bird preserved in its abdomen, most likely not scavenged, but captured and consumed by the dinosaur. We provide direct evidence for the dietary preferences of Microraptor and a nonavian dinosaur feeding on a bird. Further, because Jehol enantiornithines were distinctly arboreal, in contrast to their cursorial ornithurine counterparts, this fossil suggests that Microraptor hunted in trees thereby supporting inferences that this taxon was also an arborealist, and provides further support for the arboreality of basal dromaeosaurids.
