Obaichthyidae is an extinct family of ginglymodian ray-finned fish that lived in what is now Africa, South America, and southern Europe during the Cretaceous period (Aptian–Cenomanian ages).

[2][3] They also differ from extant gars in their highly specialized jaws, with a mobile maxilla & a reduced lower jaw leading to 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.

[4] Like modern gars, they appear to have preferred freshwater & brackish environments but were tolerant of marine conditions, allowing them to disperse across oceanic habitats.

[2][6] 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.

[1] Afrocascudo, initially described as the earliest known armored catfish, might represent a juvenile obaichthyid, possibly a junior synonym of Obaichthys,[7] though this has been disputed based on the complete ossification of the bones indicating full maturity and the absence of important holostean characters.