CRANIAL ANATOMY OF STENONYCHOSAURUS-INEQUALIS (SAURISCHIA, THEROPODA) AND ITS BEARING ON THE ORIGIN OF BIRDS
CRANIAL ANATOMY OF STENONYCHOSAURUS-INEQUALIS (SAURISCHIA, THEROPODA) AND ITS BEARING ON THE ORIGIN OF BIRDS
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DOI：
10.1139/e85-173
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发表时间：
1985-01-01
影响因子：
1.4
通讯作者：
CURRIE, PJ
中科院分区：
文献类型：
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作者：
CURRIE, PJ
近年来发现的额外的头骨材料的罕见的食肉恐龙Stenonychosaurus不等提示第一次彻底描述这种动物。本种只在北美洲的白垩纪地层中发现，与蒙古的两个已描述的蜥鸟龙属物种密切相关，但又有区别。一个衍生的特徴，一个膨胀的parasphenoic胶囊，发现在sauronithoidids和ornithomimids，强烈建议共同的祖先。中耳腔是明确的，并连接到至少两个系统的鼻窦在头骨。像这样的周期性鼻窦在兽脚亚目恐龙中还没有被描述过，它们的假定缺失被用作反对鸟类的兽脚亚目祖先的证据。虽然狭爪龙的这些和其他颅骨特征并不能证明鸟类是兽脚亚目恐龙的后代，但它们加强了小型食肉恐龙比假鳄目或鳄鱼更可能是鸟类祖先的说法。
The discovery in recent years of additional skull material of the rare carnivorous dinosaur Stenonychosaurus inequalis prompts the first thorough description of this animal. This species, known only from the Upper Cretaceous strata of North America, is closely related to, but distinct from, the two described species of Saurornithoides from Mongolia. A derived characteristic, an inflated parasphenoic capsule, is found in both the sauronithoidids and ornithomimids, strongly suggesting shared ancestry. The middle ear cavity is well defined and is connected to at least two systems of sinuses in the skull bones. Periotic sinuses like these have not been described in theropods, and thier presumed absence has been used as evidence against theropod ancestry of birds. Although these and other cranial characteristics of Stenonychosaurus do not prove that birds descended from theropods, they strengthen the claim that small carnivorous dinosaurs are more plausible bird ancestors than either psedosuchians or crocodiles:.