Criteria for inferring seafloor arrival position in teleosauroid carcasses (Crocodylomorpha: Thalattosuchia) and comparison with other marine vertebrates
Johnson, Michela (Staatliches Museum für Naturkunde Stuttgart)
Mujal, Eudald (Institut Català de Paleontologia Miquel Crusafont)
Cooper, Samuel L. A. (Universität Hohenheim)
Maxwell, Erin (Staatliches Museum für Naturkunde Stuttgart)

Fecha:	2025
Resumen:	The Lower Jurassic (Toarcian) Posidonienschiefer Formation of southwestern Germany is a classic konservat lagerstätte, yielding some of the world's best-preserved fossils of marine vertebrates, including ichthyosaurs, thalattosuchian crocodylomorphs, plesiosaurs and fishes. Despite numerous studies concentrating on the taphonomy of ichthyosaurs in this formation, less taphonomic work has focussed on the thalattosuchians of the assemblage. Multiple thalattosuchian species displaying a wide range of body sizes have been recovered. We investigated indicators for seafloor arrival position in thirteen Macrospondylus bollensis and one Platysuchus multiscrobiculatus specimens representing various body sizes using three-dimensional (3D) photogrammetric models. False-colour depth maps were used to interpret the relative topography (depth level) of bone penetration into the sediment and were aligned on the XY plane, making them parallel to the stratigraphic plane. Our results show both headfirst and non-headfirst seafloor arrivals in observed specimens, with headfirst seafloor arrivals exhibiting deeply buried skulls, displacement of select cervical vertebrae and/or characteristic fractures in the cranium and mandible. We (1) interpret seafloor landing types in teleosauroids; (2) recognize and list specific characteristics that are consistently attributed to either a headfirst or non-headfirst seafloor arrival; (3) discuss possible factors that may have contributed to these features, such as body shape and size, substrate and velocity; and (4) provide a new definition for headfirst seafloor arrival that can be readily attributed to other marine vertebrates from various formations. Lastly, our results show that observers must carefully consider how historical specimens might have been prepared, as this may influence taphonomic interpretations.
Derechos:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original.
Lengua:	Anglès
Documento:	Article ; recerca ; Versió publicada
Materia:	Teleosauroidea ; Early Jurassic ; Toarcian ; Posidonienschiefer Formation ; Taphonomy ; Fossil lagerstätte ; Photogrammetric models
Publicado en:	Geological Magazine, Vol. 162 (July 2025) , art. e19, ISSN 1469-5081

DOI: 10.1017/S0016756825100058

18 p, 4.9 MB

El registro aparece en las colecciones:
Documentos de investigación > Documentos de los grupos de investigación de la UAB > Centros y grupos de investigación (producción científica) > Ciencias > Institut Català de Paleontologia Miquel Crusafont (ICP)
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