Minjinia turgenensis is a species of placoderm from the Devonian of Mongolia. It is known from a single specimen preserving part of the skull, including remains of endochondral bone, which indicates that a mineralised endoskeleton evolved before the split between bony and cartilaginous fish, and that it was lost in the latter group.[1]
In the phylogenetic analysis ran by Brazeau et al., M. turgenensis was found as the sister taxon of a clade formed by Entelognathus, Ramirosuarezia, Janusiscus and the crown gnathostomes. A cladogram simplified from their analysis is shown below:[1]