Taxonomy

Phylum: Priapulida

Class: Palaeoscolecida

Order：uncertain

Family: Cricocosmiidae

Genus：Cricocosmia

Specie: Cricocosmia jinningensis

Description: 

The elongate, slender body can be divided into an anterior proboscis and a trunk. The proboscis can be sub-divided into an introvert, collar, everted pharynx, and digestive tract. The introvert has the same width as the trunk, with a slight taper toward the anterior, and is covered by elongate, slightly curved spines. The collar is short, smooth, and cone-shaped. The pharynx is elongate and can be completely everted. Three sections of the pharynx are recognized based on the constriction between each section and the difference in pharyngeal teeth morphology and arrangement. The elongate trunk is distinctly annulated and tapers slightly toward the posterior end. The anterior‐most part of the trunk has narrow annuli (about 40 per centimeter), but without any ornament. The main body of the trunk has relatively wider annuli (20-24 per centimeter), each of which bears one pair of lateral sclerites. A pair of curved hooks is situated at the posterior termination of the body. The gut is straight, flat, and stands out as a black band extending from the proboscis to the posterior end of the trunk.

Age & Localities

Age:Cambrian Series 2, Stage 3, Eoredlichia-Wutingaspis Zone

Principal localities: Chengjiang biota(Yu’anshan Member of the Chiungchussu Formation), eastern Yunnan Province, China