Ercaivermis

Ercaivermis
Temporal range:
Scientific classification
Kingdom: Animalia
Phylum: Priapulida
Class: Priapulimorpha
Order: Priapulimorphida
Family: Priapulidae
Genus: Ercaivermis
Species:
E. sparios
Binomial name
Ercaivermis sparios
Wang et al., 2023

Ercaivermis is an extinct genus of priapulid that lived during Cambrian Stage 3. It is closely related to the genera Louisella and Ottoia.[1]

Description

Unusual octagonal symmetry is observed in Ercaivermis sparios, the type species. Ercaivermis is characterised by a vermiform body divided into an introvert and annulated trunk. The introvert is armed with scalids in longitudinal rows and circles, with each circle containing eight scalids. The scalids on the second to ninth circles exhibit a quincunx pattern, resulting in sixteen longitudinal rows in Zone I. The eight scalids around the first circle, meanwhile, are out of alignment from the longitudinal rows. The pharynx is inverted, and the densely distributed teeth of Ercaivermis are tiny and decrease in size posteriorly. Ercavermis also possesses a straight gut running from middle trunk to anus, along with four pairs of bilaterally arranged bicaudal hooks around the posterior end.[2]

References

  1. ^ Liu, Chunxiao; Liu, Jianni (2025). "New observation on Corynetis from the early Cambrian Guanshan Biota reflect burrowing life". Royal Society Open Science. 12 (10) 251357. Bibcode:2025RSOS...1251357L. doi:10.1098/rsos.251357. ISSN 2054-5703. PMC 12503955. PMID 41063726.
  2. ^ Wang, Deng; Vannier, Jean; Sun, Jie; Yu, Chiyang; Han, Jian (15 September 2023). "A New Chengjiang Worm Sheds Light on the Radiation and Disparity in Early Priapulida". Biology. 12 (9): 1242. doi:10.3390/biology12091242. ISSN 2079-7737. PMC 10525141. PMID 37759641.