 As such they would be regarded as transitional fossils between the reptile-like "Archaeornithes" like "Archaeopteryx" and modern birds.They were described by Romer as birds with essentially modern anatomy, but retaining teeth.Unlike the dinosaur-like "Archaeornithes", the various types of birds assigned to the Odontognathae had short tails with a plowshare-shaped pygostyle and a well developed carina for flight muscle.