Nhanulepisosteus

Nhanulepisosteus (nhanu, Mixteca for "old" + Lepisosteus) is an extinct genus of gar known from the Late Jurassic of Oaxaca, Mexico. It contains a single species, N. mexicanus. It is the oldest species of true gar known from fossil remains.

Nhanulepisosteus is known from disarticulated cranial remains and ganoid scales from the Kimmeridgian-aged Llano Yosobé deposits of the Sabinal Formation. Although retaining some traits of basal Ginglymodi, it has certain derived features such as jaw structure that more closely resemble modern gar, indicating that gar are a highly morphologically conservative group.

Nhanulepisosteus inhabited a fully marine environment, contrasting with modern gar that are largely freshwater taxa, with only occasional sightings in marine environments. This indicates that gar may have originally been marine fish before invading freshwater environments prior to the Early Cretaceous.