基本的骨证据表明,皮克罗多类哺乳动物不是干长类灵长类动物
Jordan W Crowell1,2, John R Wible3, Stephen G B Chester1,2,4
1Department of Anthropology, The Graduate Center, City University of New York, 365 Fifth Avenue, New York, NY 10016, USA.
Biology letters
|January 9, 2024
概括
皮克罗多类哺乳动物不是早期的灵长类动物. 新的头骨数据显示,它们的基本头骨特征与plesiadapiforms不同,这表明牙特征的独立进化.
科学领域:
- 古生物学的古生物学
- 脊椎动物古生物学 脊椎动物古生物学
- 哺乳动物进化 哺乳动物进化
背景情况:
- 北美古世中期的神秘胎盘哺乳动物Picrodontidae具有不确定的遗传亲属关系.
- 以前的分类将Picrodontidae与各种群体结合在一起,通常基于牙特征,表明与plesiadapiforms的联系.
- 皮克罗登类的化石记录主要是牙和鼻,可供研究的头骨材料有限.
研究的目的:
- 通过微型计算机断层扫描 (μCT) 来研究皮克罗多类哺乳动物*Zanycteris paleocenus*的基本形态.
- 为了比较Z. paleocenus*与其他哺乳动物群体的基本骨特征,以澄清皮克罗登蒂的遗传位置.
- 将新的形态学数据整合到克拉迪斯学分析中,以重新评估Picrodontidae的进化关系.
主要方法:
- 微计算机断层扫描 (μCT) 扫描 *Zanycteris paleocenus* (AMNH 17180) 的部分头骨,以揭示内部和外部形态.
- 详细描述和对Z. paleocenus*基本骨解剖学的比较分析.
- 遗传学分析将新的头骨数据与早期哺乳动物现有的形态数据集结合起来.
主要成果:
- *Zanycteris paleocenus*的基本骨形态与已知的plesiadapiforms显著不同.
- *Z. paleocenus*的头骨特征与阿帕特米科 (Apatemyidae) 和尼克蒂瑟里科 (Nyctitheriidae) 等古人种类型有相似之处.
- 克拉迪斯蒂克分析表明,皮克罗多类不是干长类灵长类动物或幼龙类哺乳动物,与plesiadapiforms共享的牙特征可能是homoplasies (独立进化).
结论:
- 皮克罗多类从灵长类动物和Euarchonta的直接祖先中被移除.
- 提出的将皮克罗登蒂科与Plesiadapiforms联系在一起的牙突合形态被重新解释为独立进化.
- 这项研究强调了在有有限的化石证据和高度的autapomorphy的种群中仔细审查拟议的synapomorphies的重要性.
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