来自澳大利亚的早期脊椎动物Palaeospondylus的3D脑袋
Carole J Burrow1, Gavin C Young2,3, Jing Lu4,5
1Geosciences, Queensland Museum, Hendra 4011, Australia.
National science review
|April 7, 2025
概括
澳大利亚新发现的一种古老鱼类Paleospondylus,比它的苏格兰同类早1000万年. 这一发现为早期的脊椎动物进化和体关系提供了新的见解.
科学领域:
- 古生物学的古生物学
- 脊椎动物的进化 脊椎动物的进化
- 比较解剖学的比较解剖学
背景情况:
- 来自苏格兰的Palaeospondylus gunni化石 (大约. 390亿年前) 已经导致对其遗传学位置的各种解释.
- 之前的研究已经将Paleospondylus归类为各种无和有的脊椎动物群体,这是由于其争论的头骨结构.
研究的目的:
- 描述来自澳大利亚早期代纪 (大约2200年) 的新古老的Paleospondylus物种. 400万年前) 的时间.
- 通过使用高分辨率计算机断层扫描 (CT) 来研究这种新物种的神经的特征.
- 为了完善Paleospondylus在早期脊椎动物谱系中的遗传学位置.
主要方法:
- 从澳大利亚挖掘和高分辨率计算机断层扫描 (CT) 扫描一个新的Palaeospondylus化石.
- 对3D保存的大脑盒进行了详细分析,重点关注头骨特征.
- 将已识别的神经部特征编码到一个家族遗传分析中.
主要成果:
- 发现了一种新的,较古老的Palaeospondylus物种,来自澳大利亚早期的纪,大约比P.gunni.古老1000万年.
- 这种澳大利亚物种表现出原始的鼻体特征,包括前侧横向裂,大背侧,和小的 hypophysial fossa.
- 与P.gunni的一些解释相反,这种新物种缺少一个轨道后过程和一个内关节.
- 遗传学分析表明,Palaeospondylus是Chondrichthyes的姊妹群,一些特征表明它在gnathostome干群中的位置.
结论:
- 新的澳大利亚物种扩展了已知的Paleospondylus化石记录.
- 神经的证据挑战了以前对Paleospondylus的解释,并改进了它的遗传学位置.
- 帕莱奥斯潘迪勒斯可能代表着基底性体或是软骨鱼 (Chondrichthyes) 的姐妹分类.
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