Platonismina

Platonismina is a term used in the field of paleontology to describe a group of extinct, flightless birds that lived during the late Cretaceous period, approximately 70 million years ago. The name "Platonismina" is derived from the Greek word "platon," meaning "flat," and "ismina," referring to the Ismina Formation in Egypt, where the first fossils were discovered. These birds are notable for their unique anatomical features, including a flat, broad sternum and a long, narrow tail, which is believed to have been used for display purposes.

Platonismina is classified within the order Pterosauria, which includes pterosaurs, but it is distinct from them in several ways. Unlike pterosaurs, Platonismina had feathers and were not capable of flight. They are also believed to have been ground-dwelling birds, feeding on insects and small vertebrates.

The most well-known species of Platonismina is Ismavis, which was named after the Ismina Formation. Ismavis had a wingspan of about 1.5 meters and is one of the largest known non-avian dinosaurs. Its fossils have provided valuable insights into the evolution of birds and the transition from pterosaurs to modern birds.

Despite their unique features, Platonismina is not considered a direct ancestor of modern birds. Instead, they are thought to have evolved independently from pterosaurs, representing a separate branch of the avian evolutionary tree. Their discovery has contributed to our understanding of the diversity and complexity of the avian radiation during the Cretaceous period.