Emmonaspis

"Emmonaspis" is a fossil that was found in the Cambrian-age Parker Slate of Vermont in the late 19th Century.

Description

"Emmonaspis" 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. [ [http://www.fossilmuseum.net/Cambrian-Explosion/Chordate/Chordate.htm Problematic Cambrian Fossil, Possibly a Primitive Chordate Fossil] ] ] [ [http://www.biology.ualberta.ca/courses.hp/biol606/OldLecs/Lecture2K.08.Duffy.html The quest for chordate origins] ]

What it is thought to be

It was interpreted by paleontologist C. D. Walcott in 1911 as a Polychaete worm. Conway Morris suggested in 1993 that it might be a Cambrian descendant of the Vendian form "Pteridinium". Some paleontologists regard it as an early chordate allied with "Pikaia" et al.

Notes