Gastornis
Article
July 5, 2022
Gastornis is an extinct genus of large, flightless birds closely related to the anseriformes. It was distributed in both present-day Eurasia and North America from the Middle Paleocene to the Middle Eocene 62 to 43 million years ago. The first fossils of the genus Gastornis were discovered near Paris in 1855 and were first described in the same year. The oldest North American finds date back to 1876 and were originally placed in the genus Diatryma. For a long time, both genres were considered independent, which is partly due to an incorrect reconstruction from the end of the 19th century. Only in the early 1990s was it recognized that Diatryma and Gastornis are closely related, new bone finds from France finally led to the synonymization of Diatryma with Gastornis. For a long time, Gastornis was regarded as an agile, carnivorous predator that mainly hunted smaller mammals and, combined with its size, which ranged to just over 2 m, represented a top predator of its time. The view was accompanied by a skeletal structure resembling the South American "terror birds" (Phorusrhacidae), which was worked out on the basis of a nearly complete skeleton find from Wyoming discovered in 1916. In part, however, this similarity was based on incorrect assumptions about the length of individual bones in the foot skeleton. It was not until the 1970s that the image of the agile runner could be corrected by new discoveries of foot bones. According to this, Gastornis represented a rather slow-moving, ground-dwelling bird due to its physique. The diet was unclear for a long time. In addition to the specialization in meat food, a purely plant-based diet was repeatedly discussed, which resulted primarily from anatomical considerations such as the size of the animal and the structure of the beak. For the time being, several independent studies from 2013 confirm the view of specialization in plant food.