User:Abyssal/Portal:Ordovician/DYK/3


 * ...that eighty years on, scientists are still debating whether the Palæozoic fossils known as Chitinozoans (SEM image pictured) represent plants, animals or eggs?
 * ... that small shells of Trigonoconcha are triangular?
 * ... that a fossil of Concavodonta described in 1843 has been lost?
 * ... that one species of the extinct bivalve Similodonta was found in 108.90 m down a Welsh borehole?