Postcranial skeleton of Birgeria liui (Osteichthyes, Actinopterygii) from the Longobardian (Ladinian, Middle Triassic) of Xingyi, Guizhou, South China

Abstract

The large carnivorous ray-finned fish Birgeria liui Jin, 2001 from the Middle Triassic marine Zhuganpo Member, was previously briefly described based on an incomplete specimen, which lacked the skull and the anterior part of the body, hence with many of its morphological characteristics missing or misidentified. Herein, we report a new well preserved specimen of B. liui from the early Late Ladinian of South China, which shows the most complete and articulated postcranial skeleton for an adult specimen of Birgeria. The new informations relate to the number of neural arches and their changes along the vertebral column, the articulation between the neighboring haemal spines in the caudal region, the presence of ribs, the endoskeleton and the pattern of lepidotrichia of all fins and the covering of scales. We also update some characters of the postcranial skeleton of a few of other Birgeria species, based on direct observations.