A revision of the theropod dinosaur Camarillasaurus cirugedae from the Early Cretaceous of Spain

在上侏罗世和下白垩世，欧洲主要被陆表海覆盖，因此陆地动物群主要局限于几个较大的岛屿。然而，最近的生物地理分析表明，当时欧洲是亚洲、非洲和北美洲之间陆地动物群的一个重要的“转盘”。伊比利亚岛是下白垩纪的重要岛屿之一，包括今天的西班牙和葡萄牙的大部分地区。在过去的30年里，来自西班牙的下白垩世恐龙变得更为人所知，特别是鸟腿类和蜥脚类恐龙已经为我们了解当时的欧洲恐龙群及其生物地理关系提供了重要的数据。然而，兽脚类恐龙要鲜为人知得多；除了保存极其完好的鸟龙似鹈鹕龙和来自拉斯霍亚石灰岩叠层的碳齿龙Concavenator外，最近在巴雷米亚石灰岩建造中发现的另一个分类单元--Camarillasaurus cirugedae--被发现。后者基于一个不完整的后颅骨骼，并被鉴定为一个基本的角龙，对该支系的进化和多样性具有重要意义。然而，申请人对这份材料的初步研究突出了对遗骸的原始解释和作为角龙的鉴定存在的几个问题。此外，对通过表面收集恢复原始材料的地点的访问表明，有可能恢复该分类单元的更多材料。因此，本项目的目标是根据原始遗骸和新发现的元素，全面挖掘Camarillasaurus的类型地点，并修订该类群的解剖学和系统发育地位。这将有助于更好地了解其对我们了解早白垩世欧洲恐龙动物群及其生物地理关系的重要性。

Europe was mainly covered by epicontinental seas during the Upper Jurassic and Lower Cretaceous, so that terrestrial faunas were mainly restricted to several larger islands. Nevertheless, recent biogeographic analyses indicate that Europe represented an important "turntable" of terrestrial faunas between Asia, Africa, and North America at that time. One of the important islands in the Lower Cretaceous was Iberia, which included most of present day Spain and Portugal. Lower Cretaceous dinosaurs from Spain have become better known in the past 30 years, and especially ornithischian and sauropod dinosaurs have already yielded important data for our understanding of European dinosaur faunas of that time and their biogeographic relationships. However, theropod dinosaurs are much more poorly known; apart from the exceptionally preserved ornithomimosaur Pelecanimimus and the carcharodontosaur Concavenator from the laminated limestones of Las Hoyas, only one further taxon, Camarillasaurus cirugedae, has recently been described from the Barremian Camarillas Formation. This latter taxon is based on a fragmentary postcranial skeleton and was identified as a basal ceratosaur, with important implications for the evolution and diversity of this clade. However, a preliminary study of this material by the applicant highlighted several problems with the original interpretations of the remains and the identification as a ceratosaur. Furthermore, a visit to the site, from where the original materials were recovered by surface collection, demonstrated that there is potential to recover more material of this taxon. The objectives of the current project are thus a complete excavation of the type locality of Camarillasaurus and a revision of the anatomy and phylogenetic position of this taxon, based on both the original remains and newly discovered elements.This will lead to a better understanding of its importance for our knowledge of Early Cretaceous European dinosaur faunas and their biogeographic relationships.