Biology:Emmonsaspis

From HandWiki
Short description: Extinct genus of Cambrian organisms

Emmonsaspis
Scientific classification e
Domain: Eukaryota
Kingdom: Animalia
Phylum: incertae sedis
Genus: Emmonsaspis
1886

Emmonsaspis is a fossil that was found in the Cambrian-age Parker Slate of Vermont in the late 19th century.

Description

Emmonsaspis is described as a tadpole or worm-like animal. No trace of a spinal cord is present.

There are two species: Emmonaspis worthanella and Emmonaspis cambriensis (Walcott(?) 1886(?) 1911(?)).

E. cambrensis has been described as a graptolite, a chordate, an arthropod and as a frond-like organism.[1][2]

Affinities

It was interpreted by paleontologist C. D. Walcott in 1911 as a polychaete worm. Although some paleontologists regard it as an early chordate allied with Pikaia et al., Conway Morris suggested in 1993 that it might be a Cambrian descendant of the Vendian form Pteridinium, and a frondose morphology is the current vogue.[3]

Notes

  1. "Cambrian Primitive Chordate Fossil". http://www.fossilmuseum.net/Cambrian-Explosion/Chordate/Chordate.htm. 
  2. "Duffy: Chordate Origins". http://www.biology.ualberta.ca/courses.hp/biol606/OldLecs/Lecture2K.08.Duffy.html. 
  3. Shu, D. -G.; Morris, S. C.; Zhang, X. -L. (1996). "A Pikaia-like chordate from the Lower Cambrian of China". Nature 384 (6605): 157–158. doi:10.1038/384157a0. 

Wikidata ☰ Q5373604 entry