Lesser Bennu

If it walks like a duck and quacks like a duck… it might still be a Martian. Bennus are members of a fascinating clade of periostracan antitrematans, the Nothornitha, which evolved a warm-blooded metabolism and have learned to walk in an erect gait on their hands. Their periostracum has grown even thicker than in more primitive relatives like the Kratox and, to better conserve body-heat, has developed a short pelt of hair-like fibres, similar to those found on the shells of some Earth-gastropods. This further conceals the form and sutures of the underlying skeleton, which is more like that of a lophophoran than a vertebrate.

The Lesser Bennu is a chicken-sized omnivore that wanders through the shrublands and steppes in search of anything edible, which it cracks open with its fairly robust beak. Its tunicine tail is curiously strongly reduced, though it still sports bristles. Despite its bird-like physique, it is a largely silent animal, capable of only faint hisses and snorts. Most of the communication is instead done over the striped dewlap hanging from the proboscis and clattering sounds made by clapping the scolecodont beak. When encountered by our astronauts, these bennus show little fear and are rather inquisitive. The Portuguese and Dutch may have observed similar behaviour when first encountering the dodo. Curiously though, these animals do have natural predators and other bennu species do show an appropriate fear-response when seeing us, so one wonders why this one does not.