Morphology and ontogeny of the plagiosaurid temnospondyl Plagiosternum granulosum from the Middle Triassic of Germany

Plagiosaurids form a small but highly disparate clade of Triassic temnospondyls that are characterized by extremely flattened and wide skulls, large orbits and a knobby to pustular ornamentation. The largest European taxon is Plagiosternum granulosum from the Middle Triassic of Germany. Originally k...

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Detalhes bibliográficos
Autores: Schoch, Rainer|||0000-0002-0312-2877, Gastou, Stéphanie, Steyer, Sébastien J., Mujal, Eudald|||0000-0002-6310-323X, Moreno, Raphael, Witzmann, Florian
Formato: artículo
Fecha de publicación:2025
País:España
Recursos:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:323045
Acesso em linha:https://ddd.uab.cat/record/323045
https://dx.doi.org/urn:doi:10.1007/s12542-025-00748-7
Access Level:acceso abierto
Palavra-chave:Plagiosauridae
Phylogeny
Stereospondyli
Temnospondyli
Triassic
Descrição
Resumo:Plagiosaurids form a small but highly disparate clade of Triassic temnospondyls that are characterized by extremely flattened and wide skulls, large orbits and a knobby to pustular ornamentation. The largest European taxon is Plagiosternum granulosum from the Middle Triassic of Germany. Originally known from fragmentary bonebed material only, recent finds add well-preserved specimens that reveal the structure of the skull, mandible and pectoral girdle in great detail. The humerus and atlas of P. granulosum are described for the first time, and a putative cleithrum is identified. Ontogenetic changes include a proportional extension of the orbit, a more convex occipital margin, elongation of the parietal, proportional increase of the occipital condyles and formation of pustular ornament at nodal points of reticulate ridges. The presence of gastral scales can be inferred from the structure of the interclavicle, but there is no evidence of osteoderms. Plagiosternum granulosum was the most salt-tolerant temnospondyl in the Ladinian palaeoenvironments, where it dwelled brackish lagoons and lakes and formed a community with nothosaurids and other euhaline taxa.