The Palaeontological Twelve Days of Christmas - Day 9

Following on from the Twelve Geology Days of Christmas, this year we have a palaeontological version.

On the ninth day of Christmas my true love sent to me, nine Nigersaurus nibbling,
eight evolutionary digits encroaching,
seven seismosaurus stomping,
six snakes aslithering,

fiiiiive fossilllll fishhhhhhh,

four fossil footprints following,
three Tribrachidium tripartiting
two trilobites tasting,

and a Cambrian Lagerstätte.