Marramà Giuseppe, Carnevale Giorgio, Kriwet Jürgen
Dipartimento di Scienze della Terra Università degli Studi di Torino via Valperga Caluso 35 Turin 10125 Italy.
Department of Palaeontology University of Vienna Althanstrasse 14 Vienna 1090 Austria.
Lethaia. 2021 Dec;54(5):736-751. doi: 10.1111/let.12436. Epub 2021 Jul 22.
Over the last few years, the morphology, taxonomy and systematics of the cartilaginous fish taxa of the two main sites of the Bolca Lagerstätte, Italy, (Pesciara and Monte Postale sites) have been extensively discussed in a series of papers, resulting in a complete revision of this neglected component of the Eocene Tethyan ichthyofauna. Here, we provide a comprehensive overview of the diversity, palaeoecology and palaeoenvironmental significance of the two chondrichthyan assemblages of the Pesciara and Monte Postale sites. The assemblages include 14 shark species (Lamniformes and Carcharhiniformes) and batoids (Torpediniformes, Rhinopristiformes, Myliobatiformes, Platyrhinidae and Zanobatidae), as well as a single putative chimaeriform. The Pesciara and Monte Postale sites are characterized by eight chondrichthyan taxa each, but the taxonomic compositions are distinctly different reflecting the dissimilarities in the overall composition of both fish assemblages. Palaeoecological interpretations and habitat preferences of the two chondrichthyan assemblages are consistent with previously hypothesized palaeoenvironmental settings based on sedimentological, palaeontological and geochemical evidence. The chondrichthyan assemblages of the two sites appear to be constituted by ecologically vicariant taxa, with both characterized by a predominance of benthic species with durophagous/cancritrophic feeding modes. Taxonomic composition, habitat preferences and palaeobathymetric analyses support the hypothesis that both assemblages occupied tropical marine shallow waters (likely up to 50 m deep) of the inner portion of the Lessini Shelf. The taxonomic composition of both sites is considerably different from that of any other contemporaneous Tethyan and Boreal chondrichthyan assemblages.
在过去几年里，意大利博尔卡化石库两个主要地点（佩夏拉和蒙特波斯塔莱地点）的软骨鱼类分类群的形态学、分类学和系统学在一系列论文中得到了广泛讨论，从而对始新世特提斯鱼类区系这一被忽视的组成部分进行了全面修订。在此，我们全面概述了佩夏拉和蒙特波斯塔莱地点的两个软骨鱼类组合的多样性、古生态学和古环境意义。这些组合包括14种鲨鱼（鼠鲨目和真鲨目）和鳐类（电鳐目、犁头鳐目、鲼形目、扁鲨科和 Zanobatidae），以及一种疑似银鲛目鱼类。佩夏拉和蒙特波斯塔莱地点各有8个软骨鱼类分类群，但分类组成明显不同，反映了两个鱼类组合整体组成的差异。根据沉积学、古生物学和地球化学证据，对这两个软骨鱼类组合的古生态学解释和栖息地偏好与先前假设的古环境背景一致。这两个地点的软骨鱼类组合似乎由生态替代分类群组成，两者都以底栖物种为主，具有食硬壳动物/食蟹动物的摄食模式。分类组成、栖息地偏好和古深度分析支持了这样的假设，即这两个组合都占据了莱希尼陆架内部的热带海洋浅水区域（可能深度达50米）。这两个地点的分类组成与任何其他同期特提斯和北方软骨鱼类组合的分类组成有很大不同。
