Data for: Three-dimensional fossils of a Cretaceous collared carpet shark (Parascylliidae, Orectolobiformes) shed light on skeletal evolution in galeomorphs

A rich fossil record of teeth shows that many living shark families’
origins lie deep in the Mesozoic. Fossils of the sharks to whom these
teeth belonged are far rarer and, when they are preserved, are often
flattened, hindering understanding of the evolutionary radiation of living
shark groups. Here we use computed tomography to describe two articulated
Upper Cretaceous shark skeletons from the Chalk of the UK, preserving
three-dimensional neurocrania, visceral cartilages, pectoral skeletons,
and vertebrae. These fossils display skeletal anatomies characteristic of
the Parascylliidae, a family of Orectolobiformes now endemic to Australia
and the Indo-Pacific. However, they differ in having a more heavily
mineralised braincase and a tri-basal pectoral fin endoskeleton, while
their teeth can be attributed to a new species of the problematic taxon
Pararhincodon. Phylogenetic analysis of these new fossils confirms that
Pararhincodon is a stem-group parascylliid, providing insight into the
evolution of parascylliids’ distinctive anatomy during the late
Mesozoic-Cenozoic shift in orectolobiform biodiversity from the Northern
Atlantic to the Indo-Pacific. Meanwhile, both Pararhincodon and extant
parascylliids have a distinctive vertebral morphology previously described
only in Carcharhiniformes, contributing a skeletal perspective to the
picture emerging from macroevolutionary analyses of coastal, small-bodied
origins for galeomorphs.