Muséum National d'Histoire Naturelle, CNRS UMR 7207, Centre de Recherche en Paléontologie-Paris, CR2P, Sorbonne Université, Paris, France.
Faculty of Biosciences, University of Heidelberg, Heidelberg, Germany.
Sci Rep. 2024 Jul 31;14(1):17744. doi: 10.1038/s41598-024-67357-3.
The biology of extinct animals is usually reconstructed from external morphological characters and comparison with present-day analogues. Internal soft organs are very rarely preserved in fossils and require high-tech approaches for visualization. Here, we report the internal anatomy of a female and male of the ~ 162 Myr-old lobster Eryma ventrosum from the Jurassic La Voulte-sur-Rhône Konservat-Lagerstätte in France using X-ray synchrotron tomography. The Erymidae is an extinct, species-rich, widespread and ecologically important Mesozoic family of decapod crustaceans. Our investigation revealed the anatomy of the locomotory, respiratory, circulatory, excretory, digestive, nervous and sensory, and reproductive systems at a resolution resembling low-magnification histology. Particularly notable is the detailed preservation of the small brain and the fragile hepatopancreas, the main metabolic organ of decapods that decays rapidly post-mortem. The remarkable preservation shows that the internal anatomy of Eryma ventrosum is closer to that of Nephropidae (clawed lobsters) than Astacidae (freshwater crayfish), their closest living relatives based on skeletal morphology. The microanatomy of the gonads and hepatopancreas indicates that the two specimens investigated were a young, well-nourished female and male prior to sexual maturity. The analysis of the soft anatomy reveals remarkable conservatism over 160 Myr and offers new insights into feeding, reproduction, life history and lifestyle of an important component of the macrozoobenthos of Middle Jurassic seas.
灭绝动物的生物学通常是通过外部形态特征和与现代类似物的比较来重建的。内部软组织很少在化石中保存下来，需要高科技手段才能进行可视化。在这里，我们报告了来自法国侏罗纪拉沃尔蒂-sur-Rhône 保存库化石床的 1.62 亿年前雌性和雄性龙虾 Eryma ventrosum 的内部解剖结构，使用了同步辐射断层扫描技术。Erymidae 是一种已灭绝的、物种丰富的、分布广泛的、生态上重要的中生代十足目甲壳类动物科。我们的研究揭示了运动、呼吸、循环、排泄、消化、神经和感觉以及生殖系统的解剖结构，分辨率类似于低倍放大组织学。特别值得注意的是小大脑和脆弱的肝胰腺的详细保存，肝胰腺是十足目动物的主要代谢器官，死后迅速分解。显著的保存表明，Eryma ventrosum 的内部解剖结构与 Nephropidae（有爪龙虾）比 Astacidae（淡水小龙虾）更接近，后者是基于骨骼形态的最接近的现存亲属。性腺和肝胰腺的微观解剖表明，所研究的两个标本在性成熟前是年轻、营养良好的雌性和雄性。软组织解剖分析揭示了超过 1.6 亿年的显著保守性，并为 Middle Jurassic 海洋中大型底栖动物的一个重要组成部分的进食、繁殖、生活史和生活方式提供了新的见解。
