WALKING TRILOBITES???!!!! Our followers are probably familiar with Tiktaalik, a Devonian-aged fossil

WALKING TRILOBITES???!!!! Our followers are probably familiar with Tiktaalik, a Devonian-aged fossil from the Canadian Arctic found almost 10 years ago. That fossil is commonly called a “fishopod”; it looks like a fish that has legs and marks the transition when vertebrate life began moving onto land. The rocks where Tiktaalik was found were 375 million years old, but that isn’t the first time life moved onto land. Plants lived on land well before that, possibly as long as several hundred million years before that. New research from scientists at the University of Saskatchewan suggests these plants may not have been alone. In fact, the kings of the Cambrian world, the Triolobites, made brief voyages onto land. Trilobites are arthropods, part of the phylum of life which today includes spiders and insects. They were one of the dominant species in the Cambrian period which started 543 million years ago, and thanks to their hard shells, over 20,000 distinct species have been identified. While scientist Gabriela Mángano was investigating rocks of the Rome Formation in southeastern Tennessee, she realized something interesting. The rocks were 525 million years old and contained Trilobite fossils in a very unusual place. The rocks were sediments deposited in a tidal flat; in an area near a shoreline where water moved in and out every day, just as it does today. But tidal flats aren’t deep water, and in fact, they have lots of areas that stand above high tide. By looking closely, she and her colleagues verified that the sediments containing the trilobites were above water lines by finding impressions made by raindrops and cracks that formed when the mud dried up. The trilobites may not have been able to stay very long and they may not have been able to survive well out of the water, but these little critters crawled out of the oceans 150 million years before the first vertebrates pulled it off. WALKING TRILOBITES! -JBB Image credit:http://upload.wikimedia.org/wikipedia/commons/d/d9/Trilobite_tracks_at_World_Museum_Liverpool_d1.jpg Original paper:http://geology.geoscienceworld.org/content/42/2/143.full Read more:http://tiktaalik.uchicago.edu/meetTik.htmlhttp://science.psu.edu/news-and-events/2001-news/Hedges8-2001.htmhttp://www.trilobites.info/trilobite.htmhttp://www.popsci.com/science/article/2012-12/new-evidence-revives-controversy-about-when-life-first-came-land -- source link
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