Eosinopteryx

Type Species: Eosinopteryx brevipenna

Classification: Dinosauria – Saurischia – Theropoda – Coelurosauria – Maniraptora – Paraves – Avialae - Anchiornithidae

Time Period: Late Jurassic

Location: China

Diet: Carnivore 

The paravian theropod Eosinopertyx was originally classified as a troodontid, but further study convinced researchers it was a paravian that belonged with the anchiornithids. Eosinopertyx is known from a single adult specimen. It measured only twelve inches long, and its snout was very short. Its wings were about the same size as its cousin Anchiornis, with the primary wing feathers longer than the humerus (upper arm bone). It had an unusual arrangement of wing bones that would’ve prevented a flapping motion. It had a short tail, and its feet and toes were slender; the feet lacked curved claws for predation or climbing. The short tail lacks feathers, and the hind legs lacked the ‘hind wings’ common in many paravians. Its anatomy implies it couldn’t fly, and the reduced feathers on its legs enabled it to have a wide range of movement when running. Thus scientists are certain that Eosinopertyx was cursorial (running about on the ground). The feathers may have served as insulation, but it’s also likely the arm feathers enabled it to glide as it hopped off tree trunks to either escape predators or chase small prey. It likely fed on insects, lizards, and early mammals.