User:Abyssal/Portal:Silurian/DYK/3


 * ...that ostracoderms are the earliest known vertebrate animals?
 * ... that fossils of the extinct bivalve family Praenuculidae have been found on every continent except Antarctica?
 * ... that Arthropleuridea is an extinct class of myriapods which includes, at over 2 meters long, the largest terrestrial arthropods that ever lived?