Archaeopteryx or "Allosaurus", which had a crocodile-like anatomy of the brain and inner ear. Newer research shows that while the "Archaeopteryx" brain was more complex than that of more primitive theropods, it had a more generalized brain volume among Maniraptora dinosaurs, even smaller than that of other non-avian dinosaurs in several instances, which indicates the neurological development required for flight was already a common trait in the maniraptoran clade. Recent studies of flight feather barb geometry reveal that modern birds possess a larger barb angle in the trailing vane of the feather, whereas "Archaeopteryx" lacks this large barb angle, indicating potentially
Archaeopteryx or trunk-climbing lifestyle. This has been interpreted as evidence of theropod ancestry. In 1988, Gregory S. Paul claimed to have found evidence of a hyperextensible second toe, but this was not verified and accepted by other scientists until the Thermopolis specimen was described. "Until now, the feature was thought to belong only to the species' close relatives, the deinonychosaurs." The Thermopolis Specimen was assigned to "Archaeopteryx siemensii" in 2007. The specimen is considered to represent the most complete and best-preserved "Archaeopteryx" remains yet. The discovery of an eleventh specimen was announced in 2011, and it was described in 2014. It