Page 57 - The Restless Earth Fossils

56 Fossils

look like tiny, crawling fortresses. Walcott, accompanied by his
family and various students, returned to the Canadian Rockies
and hunted fossils in the Burgess shale for many summer field
seasons. He ultimately collected more than 65,000 specimens of
a shallow water community that was entombed in a landslide
some 530 million years ago.
Walcott’s discoveries showed the early Cambrian to be a time
of rapid experimentation in body forms and survival strategies

The Predator Found in Pieces

Charles Doolittle Walcott found many species in the Burgess Shale,
most of which were new to science. He discovered something
that looked like the rear end of a shrimp and was given the name
Anomalocaris by its first discoverer in 1892, and something that
looked like a pineapple ring. Walcott named this latter fossil Peytoia.
Walcott thought Peytoia might have been some sort of primitive
jellyfish. A third fossil, named Laggania, resembled a sea cucumber
(a starfish relative) that had been smashed like roadkill. It had a
roughly circular mouth surrounded by a ring of plates. All these fos-
sils became part of Walcott’s collection at the Smithsonian.
Some seventy years later, three researchers began looking at the
Burgess Shale fossils in more detail and made some amazing discov-
eries. In 1978, Simon Conway Morris studied a specimen of Laggania
and found an example of Peytoia about where Walcott had described
an “indistinct mouth.” In 1979, Derek Briggs realized, after studying
hundreds of fossils, that Anomalocaris was not an entire animal at all,
but some leg or other body part. Finally, in 1981, H.G. Whittington
decided to risk damaging a large, indistinct example of Laggania, by
taking it slowly apart to better see some partly hidden structures.

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