The first record of Abelisauridae (Theropoda: Ceratosauria) from Uruguay (Late Jurassic, Tacuarembó Formation)

An incomplete albeit well preserved tooth from the Late Jurassic Tacuarembó Formation (Uruguay) shows a character combination only found in abelisaurid theropods, i.e. irregular enamel, hooked distal denticles, interdenticular sulci, lanceolate cross-sectional shape, and straight distal border. Its referral to Abelisauridae was tested via a phylogenetic analysis, with the Uruguayan taxon deeply nested within the clade. This is the first record of abelisaurids in Uruguay and one of the few Jurassic records of the group worldwide. Abelisaurids occur together with ceratosaurids and megalosaurines in the Tacuarembó Formation, revealing a rich Late Jurassic theropod assemblage.