The sternum and interclavicle of Aelurognathus tigriceps (Broom & Haughton, 1913) (Therapsida: Gorgonopsia), with comments on sternal evolution in therapsids

• DOI: 10.5852/cr-palevol2024v23a6
• Publication Date: 2024-02-08T09:10:53Z
• Authors: Christian A. SIDOR; Arjan MANN
• Keywords: Sternum; Broom

Understanding the origin and evolution of unique mammalian respiratory system hinges on our knowledge osteological changes in pectoral apparatus (i.e., scapulocoracoid, cleithrum, clavicle, interclavicle, sternum) throughout synapsid fossil record. Among non-mammalian therapsids, documentation this anatomy is woefully incomplete, with groups such as dinocephalians gorgonopsians remaining poorly documented. Here we provide a detailed anatomical description an articulated sternum interclavicle well-preserved specimen Aelurognathus tigriceps (Broom & Haughton, 1913) from Lopingian upper Madumabisa Mudstone Formation, Luangwa Basin Zambia. The sternal morphology reveals new details attachment sites for ribs, showing three distinct facets, previously undescribed depression ventral surface interclavicle. We also preliminary discussion morphological variation these elements both within Gorgonopsia across Therapsida.