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进化过程. 刚德瓦纳的白纪早期的一条四足蛇
David M Martill1, Helmut Tischlinger2, Nicholas R Longrich3
1School of Earth and Environmental Sciences, University of Portsmouth, Portsmouth PO1 3QL, UK.
概括
有四个四肢的化石蛇揭示了早期的蛇形进化. 这一发现表明蛇起源于挖洞的祖先,并可能在贡德瓦纳进化,影响了我们对爬行动物进化的理解.
科学领域:
- 古生物学
- 进化生物学
- 脊椎动物学
背景情况:
- 蛇的进化起源在很大程度上是未知的,尽管它们的现有多样性.
- 之前发现的双腿蛇已经揭示了到蛇的转变,但四肢蛇的化石却没有被描述.
- 人们对早期蛇的生态和祖先环境的了解很少.
研究的目的:
- 描述一个新发现的四肢蛇从早期的白纪克拉托形成的巴西.
- 根据化石证据推断早期蛇的生态适应和进化起源.
- 调查蛇头的早期多样化和地理来源.
主要方法:
- 一个四肢化石蛇的形态分析,专注于身体规划,四肢结构和头骨特征.
- 与现存和灭绝的爬行动物进行比较解剖学,以确定适应性.
- 分析肠道内容以确定饮食和捕食行为.
主要成果:
- 一个四肢蛇的描述,它具有蛇形的身体平面和小的,可抓的四肢.
- 根据头骨和身体比例以及神经脊柱减少的证据证明了化石适应 (挖掘).
- 在肠道中存在掠食性特征 (牙,关节) 和脊椎动物的猎物,表明早期的食肉行为.
- 肢体结构表明捕捉猎物或交配的功能.
结论:
- 这条四肢蛇提供了从到蛇的转变的关键见解.
- 化石适应表明蛇是从挖掘而不是海洋祖先进化而来的.
- 这一发现,与其他基底蛇一起,支持冠状蛇的冈多瓦起源.
- 早期的蛇是脊椎动物的捕食者,表明食肉类在蛇类历史的早期发展.
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