Original paper
Ontogeny and adult osteology of the Middle Triassic temnospondyl Trematolestes hagdorni
Schoch, Rainer R.; Mujal, Eudald
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen Band 306 Heft 3 (2022), p. 265 - 286
47 references
published: Dec 28, 2022
manuscript accepted: Dec 2, 2022
manuscript received: Oct 25, 2022
ArtNo. ESP155030603004, Price: 29.00 €
Abstract
The slender-skulled temnospondyl Trematolestes hagdorni Schoch, 2006 forms a regular component of Lower Keuper lake faunas. New material extends the size range by larval, juvenile and large adult specimens, and also reveals new features of the palate, mandible and postcranium. In early juveniles, the head was wider but the ornament consistent with that of later stages. In juveniles and adults, the preorbital region grew isometrically, whereas the interorbital region and postorbital skull table were subject to positive allometry. The postfrontal and postorbital expanded markedly, whereas the unpaired frontal became narrower. In the basicranial region, tooth patches were replaced by dermal ornament, articular facets became proportionately much larger and heterodonty increased, with minute marginal teeth and enlarged fangs. In the adult mandible, the large size and relatively close position of the meckelian and adductor fenestrae give a greatly reduced, strut-like prearticular. The stapes has a straight and slender shaft, a tiny foramen and a large footplate that abruptly curves dorsomedially. The interclavicle is consistent through development in the possession of a narrow aligned ornamented area, a sagittally straight clavicular overlap and a broadened anterior end. The humerus was short but massive and of semilunar shape. The trunk intercentra were taller in adults and fused to or firmly sutured with pleurocentra in the anterior region. Larval specimens had a well differentiated ilium and femur, indicating fast development of limbs as contrasted by basal temnospondyl larvae. Adults of T. hagdorni were aquatic predators in nutrition-rich freshwater lakes whereas its larvae and juveniles preferred small water bodies with less diverse predator faunas.
Keywords
Amphibia • ossification • skull • Stereospondyli • Temnospondyli • Trematosauroidea • Triassic