一种侏罗纪哺乳形动物游泳者与哺乳动物咽部的演化转变
A Jurassic mammaliaform swimmer and transformation of the mammalian pharynx.
文献信息
| PMID | 42844474 |
|---|---|
| 原文 | 在 PubMed 查看原文 ↗ |
| 发表日期 | 2026 |
| 作者 | Y Li |
| 作者单位 | College of Paleontology, Shenyang Normal University, Shenyang, China. |
| 期刊 | Nature |
| SCI 分区 | Q1 |
| IF | 56.7 |
| 研究类型 | 基础研究 · 基础／转化 |
| 所属专科 | 咽喉科 |
中文摘要
在中国中侏罗世发现的一件保存完好的哺乳形动物化石，为摄食器官的演化转变以及中生代哺乳动物的生态多样性提供了证据。哺乳形动物是现代哺乳动物（Mammalia）的演化前身1-3，其形态学为哺乳动物的演化起源提供了首要线索。该哺乳形动物中罕见地保存了类似兽亚纲的咽穹（喉部通道）和舌骨骨骼解剖结构（喉部骨骼），提示类似兽亚纲的吞咽、饮水和吮吸行为所需的关键软组织解剖结构，早在现代哺乳动物兴起之前就已在齿兽目（Docodonta）与哺乳动物的共同祖先中演化出来。该化石展现出大量适应游泳的特化特征，填补了早期哺乳动物骨盆和后肢解剖知识的重要空白。其特征为高度独特的犬齿和用于肉食性饮食的伪裂齿型切割齿。我们将其解释为一种半水生哺乳形动物，在水中游泳和觅食，生活方式与现生鸭嘴兽类似。该物种是侏罗纪哺乳形动物中体型最大的。它扩展了齿兽类的体型范围，并增添了越来越多的证据，表明多种齿兽类占据了包括半水生及其他生态形态型在内的多样生态位。齿兽类是在恐龙主导的中生代生态系统中，远在现代哺乳动物多样化之前，半水生及其他生态形态型重复演化的一个早期例证。
英文摘要
The discovery of a well-preserved mammaliaform fossil from the Middle Jurassic period of China reveals evidence on the evolutionary transformation of the feeding apparatus and the ecological diversity of Mesozoic era mammals. Mammaliaforms are evolutionary predecessors to modern Mammalia1-3, and their morphologies provide primary insights into the evolutionary origin of mammals. The rare preservation of a therian-like pharyngeal vault (throat passage) and hyoid skeletal anatomy (throat bones) in this mammaliaform suggests that critical soft-tissue anatomy for therian-like swallowing, drinking and suckling behaviours had evolved in the common ancestors of Docodonta and Mammalia, long before the rise of modern mammals. This fossil exhibits a wealth of features specialized for swimming, filling in a major gap of anatomical knowledge of pelvis and hindlimb for early mammals. It is characterized by highly distinctive canines and pseudo-carnassial sectorial teeth for a faunivorous diet. We interpret that this mammaliaform was semiaquatic, swimming and foraging in water, with a lifestyle analogous to the extant platypus. This species is the largest of Jurassic mammaliaforms. It expands the body size range of docodontans, and adds to a growing body of evidence that multiple docodontans exploited diverse niches with semiaquatic and other ecomorphotypes. Docodontans are an early example of replicated evolution of the semiaquatic and other ecomorphotypes in the Mesozoic ecosystem dominated by dinosaurs, long before the diversification of extant mammals.