A SMALL ANTIARCH, MINICRANIA-LIROUYII GEN-NOV ET SP-NOV, FROM THE EARLY DEVONIAN OF QUJING, YUNNAN (CHINA), WITH REMARKS ON ANTIARCH PHYLOGENY

A new Early Devonian (Lochkovian) yunnanolepiform-like antiarch Minicr ania lirouyii gen. et sp. nov. is described from Qujing, Yunnan, south eastern China. This tiny antiarch possesses both a preorbital depressi on and a preorbital recess. It is characterized by a long and narrow s kull-roof, short obstantic margin, large orbital fenestra, fairly shor t dorsal wall of the trunk-shield and a close fusion of the dermal pla tes. It shows some neurocranial structures, observed here for the firs t time in an antiarch. A growth series of the skull-roof shows a sligh t allometric growth. The phylogeny of antiarchs is discussed on the ba sis of new character combinations observed in this new form. It is sug gested that Minicrania is the sister-group of euantiarchs plus sinolep ids, 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 thes e two groups.