Semadiscus

Semadiscus; Temporal range: Lower Botomian PreꞒ Ꞓ O S D C P T J K Pg N ↓
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Trilobita
Order:	Agnostida
Suborder:	Eodiscina
Superfamily:	Eodiscoidea
Family:	Weymouthiidae
Genus:	Semadiscus; Romanenko, 1978
species
	S. sollennis Romanenko, 1978 (type species) ;

Semadiscus is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It has been collected from the Lower Cambrian (early Botomian) of Canada (Newfoundland), Russia (Siberia, Gorno-Altaysk), and the United States (New York State). Only the headshield (or cephalon) is known, and it may well be that it would be better to include it in Serrodiscus.^{[according to whom?]}