|
|
|
|
|
AmiskwiaAmiskwia is a small, probably gelatinous animal of unknown affinity known from fossils of the Middle Cambrian Burgess shale formation in British Columbia. The preservation of the five known specimens leaves much to be desired. Fossil size is up to 1 inch in length. The head contains two short tentacles, and the unsegmented trunk has two small, stubby side fins and a flattened tail. The gut runs straight from the head almost to the tail. Amiskwia was originally categorized by Paleontologist Charles Walcott. Walcott thought he saw three buccal spines in the fossils, and therefore categorized Amiskwia as a chaetognath worm (arrow worm). However, since Amiskwia appears to lack the characteristic grasping spines and teeth of other Burgess fossil arrow worms, so later scientists suggested it was more likely a nemertean (ribbon worm). Conway Morris, who did a re-examination of the Burgess Shale fauna in the 1970s, described it as being the single known species in an otherwise unknown phylum. Amiskwia is rare in the Burgess formation. This, along with the fins and tail, suggest it was a swimming animal that was inadvertently trapped in the turbid sediment flows that formed the Burgess deposits. Only one species, Amiskwia sagittiformis, has been described. External link - http://www.nmnh.si.edu/paleo/shale/pamisk.htm
|
 |
|
| Copyright 2005-2009 OnPedia.com. All Rights Reserved |
|
|