COELACANTH REMAINS FROM THE LATE JURASSIC-?EARLIEST CRETACEOUS OF URUGUAY: THE SOUTHERNMOST OCCURRENCE OF THE MAWSONIIDAE

Mawsonia, the largest actinistian, was a non-marine form common in continental and estuarine deposits of the Tithonian-Cenomanian of western Gondwana. The genus has been recently reviewed, and only two species are recognized as valid: M. gigas and M. tegamensis. Herein we describe new material that can be referred to this genus, including two basisphenoids, a coronoid, a pterygoid, a metapterygoid, one operculum, and two posparietals. The Uruguayan record represents the southernmost occurrence of Mawsonia and the Mawsoniidae in the world, and strengthens the Late Jurassic-Early Cretaceous age proposed for the unit.