When did the sinosauropteryx live?
Sinosauropteryx
The length of the filaments varies across the body. On the type specimen, they are shortest just in front of the eyes, with a length of 13mm (0.51in). Going further along the body, the filaments rapidly increase in length until reaching lengths of 35mm (1.4in) over the shoulder blades. The length remains uniform over the back, until beyond the hips, when the filaments lengthen again and reach their maximum length midway down the tail at 40mm (1.6in). The filaments on the underside of the tail are shorter overall and decrease in length more rapidly than those on the dorsal surface. By the 25th tail vertebrae, the filaments on the underside reach a length of only 35mm (1.4in). The longest feathers present on the forearm measured 14mm (0.55in).[1]