Burgess Shale's Weird Wonders
The fossils found in the Burgess Shale include the 500-million-year-old ancestors of most modern animals
- By Smithsonian.com
- Smithsonian.com, July 16, 2009

(J.B. Caron, with permission of the Royal Ontario Museum and Parks Canada © ROM)
Sidneyia inexpectans is thought to be a carnivorous animal about four inches long that ate prey larger than trilobites and lived at the bottom of the ocean during the Cambrian Period. Sidneyia is potentially an ancestral member of a group of arthropods that include today’s spiders and horseshoe crabs.













Comments (5)
Pikaia has a notocord and fish-like body form Making it our oldest ancestor. It likely evolved into the toothless hagfish of the Ordovician Period, following the Cambrian.
A good drawing can be found in WONDERFUL LIFE by Stephen J. Gould, page 322
Posted by Bee G. Gwynn,MD on February 27,2012 | 03:00 PM
@ John -- I can tell you one thing: None of the creatures in this painting are our early ancestors. They were more than likely very early fish. None of these creatures are early fish. They are primarily invertebrates and many of them either die out or evolve into the invertebrate sea creatures or bugs we see today.
Posted by twilight guardian on April 23,2011 | 07:18 PM
This is the time of tools... evolving them, testing them, wearing them...
Posted by fairlyunbalanced on December 14,2010 | 02:24 AM
its so pretty
Posted by malik on October 6,2010 | 10:22 AM
Which creature is most likely to have been our ancestor? Do you have a rendering of it?
Posted by John Grannell on November 13,2009 | 11:50 AM