Deslongchampsina gen. nov.
Yvridiosuchus gen. nov.
Teleosauroidea was a clade of successful, morphologically diverse, ancient crocodylomorphs that were integral in coastal marine/lagoonal environments during the Jurassic. Within Teleosauroidea, the macrophagous/durophagous tribe Machimosaurini evolved specialized feeding strategies (e.g. hypertrophied jaw musculature and blunt, heavily ornamented dentition) and large body sizes (> 7 m), becoming an important component of Middle and Late Jurassic ecosystems. These ocean-dwelling giants are well known from the Callovian (Lemmysuchus) of Europe and the UK, and from the KimmeridgianâTithonian (Machimosaurus) of Europe and northern Africa. There are reports of fragmentary machimosaurin material from the Bathonian of Africa, but the overall Bathonian teleosauroid material is poorly understood. While multiple specimens were described during the 19th and 20th centuries, little research has been done since. Here we re-describe two historically important Bathonian species from near Oxford, UK. We demonstrate that both 'Steneosaurus' larteti and 'Steneosaurus' boutilieri are valid taxa and we establish neotypes for both species and two new genera, Deslongchampsina and Yvridiosuchus. Our cladistic analysis finds Yvridiosuchus boutilieri as a basal member of Machimosaurini and Deslongchampsina larteti to be closely related to Steneosaurus heberti. Interestingly, four distinct teleosauroid ecomorphotypes are present in the Bathonian of Europe and teleosauroid ecomorphological diversity continued throughout the Callovian and Kimmeridgian/Tithonian in Europe and England.
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Ane De Celis, ÂIvÃn NarvÃez Â& Francisco Ortega (2019)
Spatiotemporal palaeodiversity patterns of modern crocodiles (Crocodyliformes: Eusuchia).
Zoological Journal of the Linnean Society, zlz038Â
(advance online publication)ÂÂ
doi:
https://doi.org/10.1093/zoolinnean/zlz038
Eusuchia is a crocodyliform clade with a rich and diverse fossil record dating back to the Mesozoic. There are several recent studies that analyse crocodyliform palaeodiversity over time, but none of them focuses exclusively on eusuchians. Thus, we estimated subsampled eusuchian palaeodiversity species dynamics over time not only at a global scale, but also by continents and main crocodylian lineages (Alligatoroidea, Crocodyloidea and Gavialoidea). These estimates reveal complex spatiotemporal palaeodiversity patterns, in which two maxima can be detected: the first during the Palaeocene and the second, which is also the biggest, in the middle-late Miocene. The Palaeocene shift is related to a North American alligatoroid diversification, whereas the middle-late Miocene maximum is related to a diversification of the three main Crocodylia lineages in Gondwanan land masses, but especially in South America. Additionally, a model-based study using generalized least squares was carried out to analyse the relationships between different abiotic and sampling proxies and eusuchian palaeodiversity. The results show that palaeotemperature is the most important factor amongst the analysed proxies, in accordance with previous studies. However, the results suggest that, along with palaeotemperature, other abiotic and/or biotic factors might also be driving eusuchian palaeodiversity dynamics.
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The fossil record provides evidence of a long evolutionary history of European lizards. Since fossil lizards are regularly represented by bone remains, the knowledge of the origins of extant taxa and their distribution in time and space is hindered by the fact that their comparative osteology is not yet completely and adequately known. In spite of a rising interest in this topic since the end of the 20th century, a gap in our knowledge is still evident. We here report the first broad-scale comparative osteological analysis of the skulls of extant European lizards, highlighting significant differences that can be used in identification. This comparative study, including as many European species as possible, leads to the creation of a detailed diagnostic key for each single bone. Also, our data significantly improve the recognizability of extant European non-snake squamates, with 54% of the current diversity to be recognized based on the new results contra the previously estimated 31%. This recognizability is expected to further increase in the future, with new studies focusing on species that are either missing or poorly represented here, or applying promising advanced methodologies.ÂÂ