Tropeognathus (meaning "keel jaw") is a genus of large pterosaurs from the late Early Cretaceous of South America. This genus is considered to be a member of the Ornithocheiridae, a diverse group of pterosaurs known for their keel-tipped snouts and large size. Tropeognathus is regarded as the largest pterosaur found in the Southern Hemisphere, only rivaled by the huge azhdarchids.^[1] The type and only species is Tropeognathus mesembrinus. Fossil remains of Tropeognathus have been recovered from the Romualdo Formation, which is a Lagerstätte located in the Santana Group of the Araripe Basin in northeastern Brazil.

Tropeognathus mesembrinus. Crested beak fisher pterosaur. Cretaceous Santana Formation of Brazil.