This is part of a trilobite from the Ordovician period. As far as I can ascertain this is Cryptolith
This is part of a trilobite from the Ordovician period. As far as I can ascertain this is Cryptolithus, in the order Ptychopariida. The perforations above are part of the head shield, which may have functioned as a sieve. Water would rush through the perforations and small bits of food would be strained out. Collected in northern Kentucky. Description from the National Audubon Society Field Guide to North American Fossils (Chanticleer Press, 1995). -- source link
Tumblr Blog : aquaticbugs.tumblr.com