Asian mock vipers of the genus Psammodynastes and African forest snakes of the genus Buhoma are two genera belonging to the snake superfamily Elapoidea. The phylogenetic placements of Psammodynastes and Buhoma within Elapoidea has been extremely unstable which has resulted in their uncertain and debated taxonomy. We used ultraconserved elements and traditional nuclear and mitochondrial markers to infer the phylogenetic relationships of these two genera with other elapoids. Psammodynastes, for which a reference genome has been sequenced, were found, with strong branch support, to be a relatively early diverging split within Elapoidea that is sister to a clade consisting of Elapidae, Micrelapidae and Lamprophiidae. Hence, we allocate Psammodynastes to its own family, Psammodynastidae new family. However, the phylogenetic position of Buhoma could not be resolved with a high degree of confidence. Attempts to identify the possible sources of conflict in the rapid radiation of elapoid snakes suggest that both hybridisation/introgression during the rapid diversification, including possible ghost introgression, as well as incomplete lineage sorting likely have had a confounding role. The usual practice of combining mitochondrial loci with nuclear genomic data appears to mislead phylogeny reconstructions in rapid radiation scenarios, especially in the absence of genome scale data.
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RBINS Staff Publications 2024
Bioerosional marks are frequently recognized as indicators of the dynamic interactions between the organisms and their surrounding environments. In the fossil record, these structures are frequently manifest in the skeletal remains of vertebrates, being commonly associated to predation activity, scavenging, or post-mortem degradation processes. In the case of the turtles, their shells offer a distinctive substrate, exposed for the development of bioerosional processes throughout the organism life, unlike other vertebrate osseous structures. These bioerosions can indicate the type of habitat in which the turtles live, their behavioral patterns, and even their state of health. Sea turtles, as other marine vertebrates, have been extensively studied in the realms of the biology, evolution, and conservation. However, relatively scarce information is available regarding the pathologies and infectious diseases affecting their shells, especially when extinct taxa are analyzed. The aim of this study is to analyze the diverse types of bioerosional marks on the shells of two sea turtle individuals, attributable to taxa, from the Lutetian (middle Eocene) of Belgium. One of them corresponds to the shell of the holotype of Eochelone brabantica (IRSNB R 0001). Its carapace exhibits multiple erosive anomalies on several costal plates. The second specimen is a carapace of Puppigerus camperi (IRSNB R 0004). It displays different typologies of shell deviations, also of erosive character. The analyses of these specimens have been performed through both the detailed macroscopic examination and the study of the cross-sectional images provided by CT scanning in the case of Eochelone brabantica, and a 3D model obtained through a surface scanner for Puppigerus camperi. As a result, insights into the shell modifications of these two turtle individuals induced by various external agents have been provided, enhancing our understanding of the physical stressors affecting these organisms in ancient marine environments and the organisms responsible for these changes.
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RBINS Staff Publications 2025
