Dapediidae

Dapediidae is an extinct family of neopterygian ray-finned fish, likely belonging to the clade Ginglymodi and thus distantly related to modern gars. They lived from the Middle Triassic to the Late Jurassic. Its members were historically placed within the ginglymodian family Semionotidae, but were moved to their own family in 1966, and subsequently to the separate order Dapediiformes in 2016.

Description

Dapediids had deep, laterally flattened circular bodies covered in thick ganoid scales, which gave them a resemblance to the pycnodontiforms, a group they may or may not be related to. Their teeth were adapted towards a durophagous diet; some dapediids fed on hard-shelled invertebrates, while at least one genus may have been herbivorous.

Classification

Dapediids are usually considered to be either basal ginglymodians or stem group representatives of the wider clade Holostei, but some studies have found them to be early-diverging stem-teleosts instead. In 2025 the Ladinian Guizhoubrachysomus was identified as an early-diverging dapediid, and the group was recovered within Semionotiformes as the sister group of Macrosemiidae.