Eulithostraca (lit. "true Lithostracans") are a clade of Lithostraca.
Description[]
Of all modern clades of Tentaclostoma, Eulithostracans have diverged the least from the first Tentaclostomes, retaining most if not all of the ancestral traits. Like all Lithostracans, Eulithostracans are benthic predators, with eight fins used for locomotion, six oral tentacles, two sensory stalks, two gill surfaces, and a single orifice.
Eulithostraca has retained the ancestral calcium carbonate shell, which it can retract its limbs into as a defense mechanism. Eulithostracans generally live in the open seabed away from Anthostoma reefs, where their shell is most advantageous.
Eulithostraca
