Deep-Sea Fossil Hunting
Sea Urchin. Photo Credit: Ed Kwon, Flickr Creative Commons
My dad is a fossil guy. He hunts for them, cleans them, collects them, and donates the good ones to museums. Occasionally, he even takes his daughter (that’s me!) with him on these hunting expeditions. I am not particularly obsessed with encased ancient organisms, but I think the fossilized dinosaur poop my dad has is pretty cool.
Today, as I was browsing Eurekalert! yet again for cool story ideas, I stumbled upon a press-release discussing an article on newly discovered fossils published online October 10th, in PLoS ONE. The article, entitled “Ancient Origin of the Modern Deep-Sea Fauna”, may redefine what we know about the evolution and survival of mysterious deep sea creatures.
Previously, researchers thought organisms such as sea urchins and sea stars developed after periods of mass extinction and low oceanic oxygen levels, when shallow water organisms moved deeper and replaced the pre-existing fauna that were wiped out.
In this study, a researcher out of the University of Göttingen in Germany, and his team studied a collection of 74 well-preserved fossils from 114 million years ago gathered from deep-sea sediments just off the coast of Florida. This collection is much older than the fossils already on record.
Fossil Comparison. Credit: Thuy B, et al. (2012) Ancient Origin of the Modern Deep-Sea Fauna. PLoS ONE 7(10)
Comparing ancient sea stars to their modern-day relatives, researchers found striking structural similarities among other things, suggesting that the organisms were able to survive periods of extinction and climate change. Other organisms, such as ancient sea-urchins, were not so lucky. The fossils of these groups did not provide sufficient evidence to compare to their modern counterparts. However, based on phylogenetic analysis, the researchers were able to determine that the urchins evolved earlier than previously believed, and possibly in deeper waters as well.
These findings are important for understanding ocean stability and biodiversity. By suggesting that these ancient deep-sea creatures were less impacted by climate changes and more resilient to extinction events, the scientists are also suggesting that modern sea-creatures may also be more robust than we think.
Based solely on fossil evidence, I would not make that leap in logic. However, I would be interested to see what other studies on modern deep-sea dwellers have to say about their ability to survive major events in geologic time.
Until then, I’ll go back to listening to my dad tell stories of how he excavated a trilobite or how he was hiking and happened to trip over a rock that turned out to be a rare fish fossil whose name I can never seem to remember. Some guys just have all the luck, I guess.
Cassie Writes Science 
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