A small antiarch, Minicrania lirouyii gen et sp nov, from the early Devonian of Qujing, Yunnan (China), with remarks on antiarch phylogeny

A new Early Devonian (Lochkovian) yunnanolepiform-like antiarch Minicrania lirouyii gen. et sp. nov. is described from Qujing, Yunnan, southeastern China. This tiny antiarch possesses both a preorbital depression and a preorbital recess. It is characterized by a long and narrow skull-roof, short obstantic margin, large orbital fenestra, fairly short dorsal wall of the trunk-shield and a close fusion of the dermal plates. It shows some neurocranial structures, observed here for the first time in an antiarch. A growth series of the skull-roof shows a slight allometric growth. The phylogeny of antiarchs is discussed on the basis of new character combinations observed in this new form. It is suggested that Minicrania is the sister-group of euantiarchs plus sinolepids, sharing with them the preorbital recess. The Yunnanolepidae would be the sister-group of the Chuchinolepidae (i.e., ''procondylolepids''), and the Yunnanolepiformes are re-defined here to include only these two groups.