The oldest dairoidid crab (Decapoda, Brachyura, Parthenopoidea) from the Eocene of Spain
The oldest dairoidid crab (Decapoda, Brachyura, Parthenopoidea) from the Eocene of Spain
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DOI：
10.1002/spp2.1494
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发表时间：
2023-05
影响因子：
2.3
通讯作者：
F. Ferratges;J. Luque;J. L. Domínguez;À. Ossó;M. Aurell;S. Zamora
中科院分区：
文献类型：
--
作者：
F. Ferratges;J. Luque;J. L. Domínguez;À. Ossó;M. Aurell;S. Zamora
Eubrachyurans，或“更高”的真正螃蟹，是十足类甲壳动物中最具物种的一组，并有丰富的化石记录，一直延伸到早白垩世。然而，大多数现存的科是在古近纪，特别是始新世的化石记录中首次发现的。不幸的是，许多早期真短尾类的化石往往是零碎的，只有少数研究结合了灭绝和现存的类群在系统发育的背景下使用不同的最优标准。在此，我们报道了一种新的蟹类--箭形吻蟹Phrynolambrus sagittalis sp. nov.，一种来自韦斯卡（西班牙北方）始新世晚期的神秘真短尾龙，其完整性和精致的保存允许在系统发育背景下对其解剖结构进行检查。戴氏蟹科以前被认为是最古老的石蟹（Eriphioidea）或肘蟹（Parthenopoidea），这两种不同且关系遥远的真正螃蟹群体生活在今天。化石材料的机械制备和计算机断层扫描显示了几个诊断特征，可以与整个螃蟹生命树的家庭进行详细的比较，并测试有关其系统发育亲和力的假设。Phrynolambrus sagittalis是该属在伊比利亚半岛的第一个记录，代表了世界上最古老的冠单性蟹类之一，扩大了我们的知识肘蟹在古近纪的地理分布，以及它们的早期起源，解剖多样性和系统的亲和力。了解始新世真短尾类的差异对于解开冠科之间的系统关系，以及解释导致现代动物群演化的时空模式至关重要。
Eubrachyurans, or ‘higher’ true crabs, are the most speciose group of decapod crustaceans and have a rich fossil record extending into the Early Cretaceous. However, most extant families are first found in the fossil record in the Palaeogene, and particularly in the Eocene. Unfortunately, fossils of many early eubrachyuran groups are often fragmentary, and only a few studies have combined extinct and extant taxa in a phylogenetic context using different optimality criteria. Here, we report the dairoidid crab Phrynolambrus sagittalis sp. nov., an enigmatic eubrachyuran from the upper Eocene of Huesca (northern Spain), whose completeness and exquisite preservation permit examination of its anatomy in a phylogenetic context. Dairoidids have previously been considered among the oldest stone crabs (Eriphioidea) or elbow crabs (Parthenopoidea), two disparate and distantly related groups of true crabs living today. Mechanical preparation and computed tomography of the fossil material revealed several diagnostic features that allow a detailed comparison with families across the crab tree of life, and test hypotheses about its phylogenetic affinities. Phrynolambrus sagittalis is the first record of the genus in the Iberian Peninsula, and represents one of the oldest crown parthenopoidean crabs worldwide, expanding our knowledge of the biogeographical distribution of elbow crabs during the Palaeogene, as well as their early origins, anatomical diversity and systematic affinities. Understanding the disparity of Eocene eubrachyurans is pivotal to disentangling the systematic relationships among crown families, and interpreting the spatio‐temporal patterns leading to the evolution of modern faunas.