''Jiuchengia longoccipita'' is a coccosteid

arthrodire Arthrodira (Greek for "jointed neck") is an Order (biology), order of extinct armored, jawed fishes of the class Placodermi that flourished in the Devonian period before their sudden extinction, surviving for about 50 million years and penetratin ...

placoderm Placoderms (from Ancient Greek πλάξ 'plax'', ''plakos'''Plate (animal anatomy), plate' and δέρμα 'derma'''skin') are vertebrate animals of the class (biology), class Placodermi, an extinct group of prehistoric fish known from Pal ...

from the Late Emsian

epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided b ...

of Wuding,

Yunnan Yunnan; is an inland Provinces of China, province in Southwestern China. The province spans approximately and has a population of 47.2 million (as of 2020). The capital of the province is Kunming. The province borders the Chinese provinces ...

. Its skull is similar in form to those of ''

Watsonosteus ''Watsonosteus'' is an extinct genus of coccosteid arthrodire placoderm from the Late Givetian stage of the Middle Devonian period. Fossils are found in the Orkney Islands, Scotland. It was a small placoderm with a total body length of , with th ...

'' and ''

Dickosteus ''Dickosteus'' is an extinct genus of coccosteid arthrodire placoderm from the Late Eifelian to Early Givetian stages of the Middle Devonian period. Fossils are found in Orkney and Caithness, Scotland. It was a small placoderm with a total body ...

'', though ''J. longoccipita'' can be easily distinguished from them in that its skull is longer, and has anatomical features in common with homostiids.

References

Coccosteidae Placoderms of Asia Paleontology in Yunnan Prehistoric animals of China Fossil taxa described in 1983 Arthrodire genera {{Placoderm-stub