Australian scientists have been testing a theory that some ancient animals couldn’t chew their food, and it appears the idea has legs.
University of New England researchers have been looking at now-extinct trilobites, which were common in the oceans in the Cambrian era about 500 million years ago.
The creatures had an armour-like shell but didn’t have jaws or other structures in the mouth to chew.
Instead, they used spines on their many pairs of legs to grind up or shred prey in a similar fashion to modern-day horseshoe crabs.
But despite being aware of this spectacular anatomical detail, nobody had ever tested whether trilobite species could potentially crush, or “chew,” shells with their spiny legs.
Using advanced modelling techniques, the researchers compared the legs of two ancient trilobite species to the legs of the modern horseshoe crab, which is a known clam eater.
The modelling confirmed the trilobite species Sidneyia inexpectans was, indeed, capable of crushing shells, as indicated by its fossilised gut contents. However, it could not do this very effectively.
On the other hand Redlichia rex — Australia’s most menacing Cambrian trilobite, spanning 25cm and armed with bulky legs — was effectively built like a tank.
As such, it was probably highly capable of shell-crushing destruction.
Past research has suggested Redlichia rex also ate other trilobites, including its own kind, making it one of the oldest known cannibals.
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