Chidleyenoceras

Chidleyenoceras Temporal range: Middle Ordovician
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Subclass:	Nautiloidea
Order:	Tarphycerida
Suborder:	Barrandeocerina
Family:
Genus:	Chidleyenoceras Shimizu & Obata, 1935

Chidleyenoceras is a Middle Ordovician tarphyceroid with a closely coiled, evolute shell; whorl section subquadrate, widest just above a broadly rounded venter; dorsum with a broad shallow impression; sutures moderately spaced, weakly sinuous; siphuncle large, subventral, apparently orthochoantitic with tubular segments.

The tubular, subventral siphuncle separates Chidleyenoceras from the Apsidoceratidae (Sweet, 1964) where it had been included and puts it well into the (Flower, 1984).

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