What is "sphenotitan"

Sphenotitan is an extinct genus of basal opisthodontian sphenodontian reptile known from the Late Triassic Quebrada del Barro Formation of northwestern Argentina. It was first described and named by Ricardo N. Martínez, Cecilia Apaldetti, Carina E. Colombi, Angel Praderio, Eliana Fernandez, Paula Santi Malnis, Gustavo A. Correa, Diego Abelin and Oscar Alcober in 2013 and the type species is Sphenotitan leyesi.