Feb 11 2014

New Burgess Shale Find

Published by under Evolution
Comments: 8

For those familiar with the Burgess Shale, the news of a new “phyllopod bed” is exciting.

A century ago Charles Walcott discovered (in what is now called Walcott quarry) an amazing fossil bed from the Cambrian era. These were soft-bodied fossils preserved in shale from the very dawn of multicellular life, the Cambrian explosion. From 570 to 530 million years ago multicellular plant and animal life appeared in fossils and diversified. Every major group we see today is represented in Cambrian fossil beds, along with phyla that are now extinct. Walcott Quarry is by far the most prolific and best preserved such fossil bed.

Now researchers report on the discovery of another fossil bed 40 km southeast of the Walcott quarry, in Kootenay National Park. The report:

The assemblage, discovered in 2012, occurs at the top of the Burgess Shale Formation and is significantly younger than the localities of the type area. In situ excavation and talus collections from a two-meter thick interval have so far yielded 3053 specimens representing at least 52 taxa. Among these, half are known from the Walcott Quarry and at least 15 are new.

Wow. This is a massive find from somewhat later in the Cambrian, perhaps showing even more early diversity of multicellular life. Already they are finding new species and more details about known species. It may be a little early to speculate, but the researchers feel that this find could be even bigger than the Walcott Quarry.

What the Burgess Shale documents is an entire ecosystem of creatures, living in the shallow seas at that time. What you won’t find in Cambrian fossil beds are modern fish, crustaceans, mollusks or anything else contemporary. You will only find primitive fauna, weird looking to our modern eyes. Some contain features that clearly indicate that they were ancestors to modern groups, while other resemble nothing alive today.

In other words – the Burgess Shale and Cambrian fossil beds in general are a dramatic line of evidence for the evolutionary history of life on earth. Such a find could have, in a single stroke, provided dramatic falsification of current evolutionary theory. Instead it provided powerful confirmation.

Still, creationists try to twist the significance of Cambrian fossils to their end, claiming the “explosion” represents the “sudden appearance of complex forms.” Of course by “explosion” paleontologists mean 40 million years. The complex forms are also clearly primitive early forms – nothing close to modern. The power of motivated reasoning and self-deception never ceases to amaze.

I can’t wait to see what new discoveries come out of the Kootenay fossil bed. This is something on which to definitely to keep an eye.

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