Take a gander at this unusual trilobite, Hypodicranotus striatulus (Walcott, 1875), with his gloriously bulbous head shield. Missing from this specimen is the wonderful forked hypostome from the dorsal exoskeleton that marks him as H. striatulus. He’s from outcrops in the Verulam Formation, Bowmanville, Ontario, Canada. He lived in a deep subtidal environment as a nektobenthic deposit feeder some 460.9 to 449.5 million years ago.

These extinct pelagic trilobites are in the order Asaphida in the family Remopleuridae. Specimens have been found in Middle Ordovician marine outcrops from Ontario, Canada, the Northwest Territories, Quebec and in New York State, United States. Some of his sister taxa also in Remopleurididae (Hawle and Corda, 1847)  have been found in the Northwest Territories, Quebec, the UK and in Iowa, Wisconsin and Nevada. Photo credit: Marc R. Hänsel