The crayfish is a modern arthropod. Image courtesy of Wikipedia.
Joel Kontinen
Fossil discoveries have often challenged the belief in millions of years. For instance, soft tissue found in T. rex bone suggests that dinosaurs can hardly be millions of years old. Moreover, soft tissue was also found in an 18-million-year-old salamander fossil.
Researchers have also found DNA in mammoths, further weakening the reliability of dating methods.
The newest challenge comes from arthropods (Arthropoda) that supposedly already lived in the Paleozoic era. According to Physorg, researchers have found remains of “chitin-protein complex - structural materials containing protein and polysaccharide”- in them.
The external skeleton of a crab or crayfish is formed of chitin. For a long time, researchers believed that chitin couldn’t be preserved for tens of millions of years since microorganisms break them apart.
However, George Cody at the Carnegie Institution and colleagues recently found remains of chitin in a scorpion assumed to be 310 million years old and from a scorpion-like arthropod estimated to be 417 million years old.
It is becoming increasingly difficult to believe that the ages assigned to fossils are correct.
Source:
Unexpected exoskeleton remnants found in Paleozoic fossils. Physorg.com 7 February 2011.
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