User:Abyssal/Portal:Ordovician/DYK/1


 * ...that fossil Thelodont fish (depiction pictured) surprised scientists by showing that stomachs evolved before jaws?
 * ... that Aegirocassis is the earliest example of massive filter-feeder animals discovered?
 * ... that members of the extinct bivalve genus Hemiconcavodonta are unique in the subfamily Concavodontinae in that their teeth point in two directions?
 * ... that the extinct Argentinian bivalve Cuyopsis symmetricus was named for the symmetry of its rectangular shells?
 * ... that the extinct bivalve subfamily Praenuculinae can be told apart from its sister subfamily by looking at teeth?