相关实验视频
Updated: May 23, 2025

04:32
Dissection, MicroCT Scanning and Morphometric Analyses of the Baculum
Published on: March 19, 2017
7.5K
评论:缺失的 sabertooth baculum-在什么时候没有证据可以合理地被认为是缺席的证据?
1Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA.
Anatomical record (Hoboken, N.J. : 2007)
|May 22, 2025
概括
已灭绝的 saber-toothed 猫 (machairodonts) 的骨化骨 (阴茎骨) 的化石证据仍然难以捉摸. 尽管在像拉布里亚牧场这样的丰富化石遗址进行了广泛的搜索,但这种骨头的缺失可能表明这些掠食性哺乳动物中并不存在.
科学领域:
- 古生物学的古生物学
- 比较解剖学的比较解剖学
- 进化生物学 进化生物学
背景情况:
- 大多数食肉动物和所有现代类动物 (猫家族) 都具有骨化.
- 骨是许多哺乳动物的阴茎中发现的骨,有助于交配.
- 在任何已灭绝的machairodont (刀牙猫) 物种中,从未发现过任何.
研究的目的:
- 为了研究在已灭绝的牙动物中存在或缺少牙的可能性.
- 为了调和基于相关物种的的预期存在与缺乏化石证据.
主要方法:
- 分析了大量的化石收藏,特别是来自Rancho La Brea Tar Pits (RLB) 的化石,这些化石以丰富的食肉动物化石而闻名.
- 详细检查了*Smilodon fatalis*的化石遗骸,包括小而脆弱的骨头.
- 化石矩阵的微观分类,以识别微化石和罕见的骨元素.
主要成果:
- 尽管在RLB发现了大量的*Smilodon fatalis*骨和数千个微化石,但尚未确定任何baculum.
- 其他小骨头,如关节骨和骨,已经从同样的化石沉积物中恢复.
- 密集的搜索努力,包括化石分类器的视觉辅助工具,未能找到一个machairodont baculum.
结论:
- 马基罗登化石中持续缺少体是值得注意的,特别是在像RLB.这样的异常丰富的遗址中.
- 潜在的解释包括像"坑磨损" (地震活动造成的磨损) 这样的语音学因素,粉碎了不那么密集的骨头.
- 缺乏证据迫使人们考虑这种缺失是否有意义,可能表明machairodonts缺乏,挑战进化假设.
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