Evidence of large theropods from the Middle Jurassic of the Mahajanga basin, NW Madagascar, with implications for the ceratosaurian pedal ungual evolution.

Two large theropod remains from the Middle Jurassic (Isalo IIIb, Bathonian) of the Mahajanga Basin, NW Madagascar, are here described. They consist of a large tooth crown and a pedal ungual. The tooth is similar to the teeth of some basal tetanuran theropods, but we cautiously refer it to Theropoda incertae sedis. The pedal ungual, pertaining to a close relative of the abelisauroids but not to a member of the Abelisauroidea, shows that non-abelisauroid ceratosaurian theropods were present in the Middle Jurassic of Madagascar and provides new insight into the evolution of the ceratosaurian pedal unguals. Both remains reveal the large body size attained by the Middle Jurassic Malagasy theropods.