Qilinyu in Yunnan

Qilinyu rostrata is a “maxillate” placoderm from the late Ludlow epoch of Qujing, Yunnan, 419 million years ago.

Specimen and taxonomy

The holotype and paratype of Q. rostrata are two exquisitely preserved specimens both featuring a domed cranium and a curved rostrum presenting a “dolphin-like profile.”

The researchers’ cladistic diagram show that Q. rostrata is the sister taxon of Entelognathus and all other crown gnathostomes (i.e., bony and cartilaginous fishes, and their descendants).

Evolutionary significance

Q. rostrata, together with Entelognathus, demonstrate additional irrefutable proof that modern gnathostomes evolved from arthrodire placoderms.