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101.
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Two associated incomplete thyreophoran dorsal vertebrae from the Callovian Marnes de Dives Formation of the Vaches Noires cliffs, on the Normandy coast, are referred to an indeterminate stegosaur that appears to be different from Lexovisaurus, previously reported from the Callovian of western France. These vertebrae are the first evidence of thyreophorans from the Vaches Noires and complement the dinosaur assemblage from this locality, which hitherto consisted of several theropod taxa and an indeterminate sauropod. The dinosaur record from the Vaches Noires is heavily dominated by theropods and this imbalance is difficult to explain. A possible explanation may be that the dinosaur sample from the Vaches Noires is too small to be statistically significant and representative of the original faunal assemblage from which it is derived. 相似文献
103.
The fossil record provides direct empirical data for understanding macroevolutionary patterns and processes. Inherent biases in the fossil record are well known to confound analyses of this data. Sampling bias proxies have been used as covariates in regression models to test for such biases. Proxies, such as formation count, are associated with paleobiodiversity, but are insufficient for explaining species dispersal owing to a lack of geographic context. Here, we develop a sampling bias proxy that incorporates geographic information and test it with a case study on early tetrapodomorph biogeography. We use recently-developed Bayesian phylogeographic models and a new supertree of early tetrapodomorphs to estimate dispersal rates and ancestral habitat locations. We find strong evidence that geographic sampling bias explains supposed radiations in dispersal rate (potential adaptive radiations). Our study highlights the necessity of accounting for geographic sampling bias in macroevolutionary and phylogenetic analyses and provides an approach to test for its effect. 相似文献
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《Comptes Rendus Palevol》2019,18(8):1073-1082
The present study investigates the inner structural organization of the two mandible specimens Tighenif 1 and Tighenif 2 from the late early Pleistocene site of Tighenif, Algeria. Using (micro)tomographic scans, we built a new protocol to investigate the cortical bone topography at the post-canine level. We selected two cross-sectional slices placed between the P3/P4 and M1/M2 on the right and left sides and assessed the cortical bone thickness topography (CBT) on each slice. Our analyses demonstrate that the mandibles from Tighenif exhibit higher CBT and a different topographic distribution pattern at the molar level than in modern humans, resulting in a proportionally more robust inner structure, while a similar signal is observed between the fossil and extant specimens at the premolar level. Further studies need to be done in order to determine if this feature is related to functional constraints during mastication or paramasticatory activities; or if it is related to any independent evolutionary process. 相似文献
105.
Raúl O. Gómez Fernando F. Garberoglio Guillermo W. Rougier 《Comptes Rendus Palevol》2019,18(7):771-781
Madtsoiids constitute a successful group of extinct snakes widely distributed across Gondwana and the European archipelago during Late Cretaceous times, surviving in reduced numbers to the Pleistocene. They are renowned for including some of the largest snakes that have ever crawled on earth, yet diverse small madtsoiids are also known. Uncovering the evolutionary trends that led these snakes into disparate body sizes has been hampered mainly by the lack of phylogenetic consensus and the paucity of taxa with novel combinations of features. Here we describe a new large madtsoiid snake based on isolated vertebrae from the La Colonia Formation (Maastrichtian–Danian) of Patagonia, Argentina. A comprehensive phylogenetic analysis recovers Madtsoiidae as a basal ophidian lineage and the new snake as sister to a clade of mostly big-to-gigantic taxa, providing insights into early stages and evolutionary trends towards madtsoiid gigantism. 相似文献
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Anne-Marie Lundsgaard Jacob B. Holm Kim A. Sjøberg Kirstine N. Bojsen-Møller Lene S. Myrmel Even Fjære Benjamin A.H. Jensen Trine S. Nicolaisen Janne R. Hingst Sine L. Hansen Sophia Doll Philip E. Geyer Atul S. Deshmukh Jens J. Holst Lise Madsen Karsten Kristiansen Jørgen F.P. Wojtaszewski Erik A. Richter Bente Kiens 《Cell metabolism》2019,29(1):50-63.e4
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Alexandro Bonifaz Berenice Córdoba-García Tania Simancas-Llanos Marco A. Hernández Erick Martínez-Herrera Andrés Tirado-Sánchez 《Revista iberoamericana de micología》2019,36(1):30-33