Ascocerida

Ascocerida
Temporal range:
The ontogeny of Ascoceras, an Ascoceridian
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Orthoceratoidea
Order: Ascocerida
Kuhn, 1949

The Ascocerida are comparatively small, bizarre Orthoceratoids known only from Ordovician and Silurian sediments in Europe and North America, uniquely characterized by a deciduous conch consisting of a longer juvenile portion and an inflated short adult portion that separate sometime in maturity.