Aktiogavialis

Aktiogavialis is an extinct genus of crocodylian from the Oligocene Epoch some thirty million years ago. Only one species in the genus, Aktiogavialis puertoricensis, has been described so far.

As a typical gavialoid, Aktiogavialis followed the standard crocodilian body plan. An elongated, squat quadrupedal body terminates in a long, laterally-flattened tail at one end and a specialized, narrow snout at the other. As with the other members of its family, the snout of Aktiogavialis was extremely long and narrow, tapering into a thin structure past the eye sockets. Based on the fragmentary remains recovered, the species was differentiated from other members of its family by unique positioning and geometry of its skull elements.

Aktiogavialis has been placed in the family Gavialidae, whose only living members are the Indian gharial and, possibly, the false gharial of Southeast Asia. Phylogenetic analysis indicates that its closest relatives were the extinct gavials Gryposuchus and Siquisiquesuchus.

The type species of the genus, A. puertoricensis was described in 2007. The holotype, designated UPRMP 3094, was discovered in Puerto Rican deposits dating from the Oligocene Epoch some thirty million years old. The deposits, part of the San Sebastián Formation along the Rio Guatemala in Puerto Rico, have been an adequate supply of other crocodylian fossils. Aktiogavialis remains recovered were extremely fragmentary, consisting of an incomplete skull featuring elements of the braincase and other scattered cranial elements.

Marine sediments and nanofossils form part of the deposits where the specimen was found, indicating a marine distribution for Aktivogavialis puertoricensis. This is in contrast with the living members of the family Gavialidae, which reside entirely in the freshwater rivers of South Asia. While there is a possibility that fossils found in prehistoric deltaic sediments have been washed onto the delta from inland sources, the Aktiogavialis specimen found so far was from a location that had essentially been islandic. This has led to conclusions that the members of the family Gavialidae were partially or primarily saltwater reptiles prior to the evolution of the family's two extant species.

The genus' name, Aktiogavialis is derived from the Greek words aktios (river) and gavialis (gavial). This roughly translates to "shore gavial", referring to Aktiogavialis' rather estuarine distribution. The sole species' name, Aktiogavialis puertoricensis, mean "shore gavial from Puerto Rico", in reference to the specimen's country of origin.