Monday, August 17, 2009

Waptia fieldensis Plus an Anomalocaris

This picture shows a Middle Cambrian Period (500 million years ago) fossil stored at the Cincinnati Museum Geier Collection Center. It is a Waptia fieldensis from the Stephen Formation in the Burgess Shale Member. The fossil came from Burgess Pass in British Columbia, Canada.

This creature was a crustacean that resembles today's shrimp. The famed paleontologist Charles Doolittle Walcott named this species in 1912. His notoriety comes from his 1909 discovery the Cambrian fossils in Burgess Shale in the Canadian Rockies.



This next fossil is also in Burgess Shale but I am not sure what the creature was called. Looking at this website: http://www.trilobites.info/gallery.html. I would say this is an Anomalocaris described by Walcott as a "strange shrimp". Apparently, it was quite the predator of the Cambrian seas.

2 comments:

Anonymous said...

Yep, Anomalocaris

Anonymous said...

Yes, an anomalocarid for sure. These are fairly wide-ranging geographically, and also occur in older rocks than the Burgess. I've emailed you a photo of a specimen from Lower Cambrian rocks. There are (at least) two genera of anomalocarids in the Cambrian rocks of British Columbia, Anomalocaris and Laggania. See http://www.trilobites.info/species3.html

Apparently, Laggania appendages have long, multiple bristles in place of the shorter, simpler spines of Anomalocaris.

There seems to be quite a range of spine shapes in anomalocarid specimens. I have one specimen from the Lower Cambrian with single, relatively thick spines; the specimen in your photo obviously has narrower, longer, double spines.

Cheers,
--Howard
Calgary, AB, Canada