Myllokunmingia

Myllokunmingia is an extinct genus of primitive jawless fish that lived in during the Cambrian period, approximately 518 million years ago, in what is now the Yunnan Province of China. It was discovered alongside Haikouichthys, another genus of primitive jawless fish, in 1999 and is considered to be among the earliest known vertebrate animals in the fossil record. The holotype of the type species, Myllokunmingia fengjiaoa — and the only uncontroversial specimen thereof — was found in the Yuanshan member of the Qiongzhusi Formation in the Eoredlichia Zone near Haikou at Ercaicun, Kunming City, Yunnan, China.

== Description == The holotype is 28 mm long and 6 mm high. The animal has a distinct head and body with a forward, sail-like (1.5 mm) dorsal fin and a ventral fin fold further back (probably paired). The head has five or six gill pouches with hemibranchs. In the body, there are 25 muscle segments (myomeres) with rearward-facing, double-V-shaped chevrons. There is a notochord, a pharynx and a digestive tract that may run all the way to the rear tip of the animal. A mouth cannot be clearly identified. There may be a pericardial cavity. There are no fin radials. The tip of the tail in the holotype is buried in sediment.