New insights into Tibetodus gyrodoides Young & Liu, 1954 (Actinopterygii, Pycnodontiformes) from the Qinghai-Xizang Plateau based on micro-CT data

The Pycnodontiformes is a distinctive group of fossil actinopterygian (ray-finned) fishes from the Late Triassic to Palaeogene. Tibetodus gyrodoides, reported in 1954, represents the only known fossil record of this group in China, holding significant scientific and historical importance. In this study, non-destructive techniques such as scanning electron microscopy (SEM) and micro-computed tomography (micro-CT) were utilised to reexamine the specimen, providing new insights into both the surface morphology and internal structures of the vomer and its teeth and investigating the process of tooth wear. A tooth covered by matrix was also discovered. Furthermore, an Elliptical Fourier Analysis (EFA) was conducted to quantitatively analyse the morphology of the palatal teeth in this specimen, adding new data for future research on pycnodontiforms and their feeding behavior.