Obaichthyidae

Obaichthyidae is an extinct family of ginglymodian ray-finned fish that lived in what is now Africa and South America during the Cretaceous period (Aptian–Cenomanian ages). It was erected in 2010 by Lance Grande to include the genera Dentilepisosteus and Obaichthys. In 2012, it was defined as a stem-based taxon containing all taxa more closely related to Obaichthys than to the genera Lepisosteus, Pliodetes or Lepidotes. Afrocascudo, initially described as the earliest known armored catfish, might represent a juvenile obaichthyid, possibly a junior synonym of Obaichthys, though this has been disputed based on the complete ossification of the bones indicating full maturity and the absence of important holostean characters.

Obaichthyids were close relatives of the modern gars of the family Lepisosteidae, with the two groups making up the superfamily Lepisosteoidea. They are also known as spiny gars, referencing their close resemblance and relationship to modern gars, with one difference being their spiny scales. They also differ from extant gars in their highly specialized jaws, with a prominent overbite, teeth concentrated at the tip, and a very small gape, indicating that they likely fed on small invertebrates, in contrast to all lepisosteids which are adapted to feed on other vertebrates.