Yaguarasaurinae

Yaguarasaurinae Temporal range: Late Cretaceous 89.3–85.8 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Skull of Romeosaurus fumanensis.
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Squamata
Clade:	†Mosasauria
Family:	†Mosasauridae
Clade:	†Russellosaurina
Subfamily:	†Yaguarasaurinae Palci et al., 2013
Genera
Romeosaurus Russellosaurus Yaguarasaurus

The Yaguarasaurinae are a subfamily of mosasaurs, a diverse group of Late Cretaceous marine squamates. Members of the subfamily are informally and collectively known as "yaguarasaurines" and have been recovered from North and South America and Europe.^[1] Three genera, Yaguarasaurus, Russellosaurus and Romeosaurus are known. Yaguarasaurus and Russellosaurus were previously considered part of the Tethysaurinae until they were grouped with Romeosaurus as yaguarasaurines.^[2]

Like the closely related tethysaurines, all yaguarasaurines were plesiopedal (meaning primitive and not as well adapted to marine life as later mosasaurs). They generally retained relatively small sizes compared to later giant mosasaurs, though Yaguarasaurus itself might have grown rather large. The yaguarasaurines appeared during the Turonian and might have survived into the Santonian, though they were extinct by the Campanian when more derived and hydropedal mosasaurs had appeared. The etymology of this group derives from the genus Yaguarasaurus (after the town Yaguará and sauros, Greek for "lizard").