Emmonaspis is a fossil found in the Lower Cambrian Parker Slate of Vermont in the late 19th Century. It may be present in the Burgess Shale of British Columbia as well. Descriptions are somewhat vague and confusing. It was interpreted by 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 alied with Pikaia et. al.
Emmonaspis is described as a tadpole-like or worm-like animal. It is apparently segmented, but no trace of a spinal cord is present. It is said to have at least 46 segments with two filamentous branches (walking legs?) on the body segments. Faint jointed appendages are said to extend forward from the front of the head. The fossil apparently has not been restudied. No modern interpretation is available.
There are two species:
Emmonaspis Worthanella
Emmonaspis Cambriensis Walcott(?) 1886(?) 1911(?)