Ontogenetic variation in the skull of Stenopterygius quadriscissus with an emphasis on prenatal development.

ABSTRACT: The availability of a large sample size from a range of ontogenetic stages makes Stenopterygius quadriscissus a good model to study ontogenetic variation in a fossil sauropsid. We qualitatively examined pre- and postnatal ontogenetic changes in the cranium of S. quadriscissus. The prenatal ossification sequence is similar to other diapsids, exhibiting delayed chondrocranial ossification compared to the dermatocranium. In the dermatocranium, the circumorbital area is more ossified earlier in development relative to other elements, especially those of the skull roof where ossification is comparatively weaker across prenatal stages. Perinatally all cranial elements are ossified, and many scarf and step joints are already closed. We propose four prenatal and three postnatal stages in S. quadri

SUBMITTER: Miedema F 

PROVIDER: S-EPMC8807662 | biostudies-literature | 2022 Feb

REPOSITORIES: biostudies-literature