[1] The fossil of Docofossor brachydactylus, holotype BMNH 131735, along with that of Agilodocodon scansorius, was originally found by farmers near Nanshimen in the province of Hebei in a layer of the Chinese Tiaojishan Formation (Oxfordian) and acquired by the Beijing Museum of Natural History.

The type species Docofossor brachydactylus was named and described by Zhe-Xi Luo, Meng Qingjin, Ji Qiang, Liu Di, Zhang Yuguang, and April I. Neander in the journal Science in 2015.

It had shovel-like fingers for digging, short and wide upper molars typical of mammals that forage underground, and a sprawling posture indicative of subterranean movement.

The sprawling is proven by a short hindlimb of just twenty-three millimetres, a massive olecranon as an adaptation for digging and a projecting parafibula forcing the knee joint into a bent position.

[3] The spines and ribs of Docofossor also show evidence for the influence of genes seen in modern mammals, since they feature a gradual thoracic to lumbular vertebrae transition.

However, Docofossor and numerous other fossils – including Castorocauda, a (related) swimming, fish-eating mammaliaform – provide strong evidence that forms ancestral to the true mammals adapted to wide-ranging environments despite competition from dinosaurs.