Stenolaemata

Stenolaemata are a class of exclusively marine bryozoans. Stenolaemates originated and diversified in the Ordovician, and more than 600 species are still alive today. All extant (living) species are in the order Cyclostomatida, the third-largest order of living bryozoans.

Fenestrida is an extinct order of bryozoans in the class Stenolaemata.