BlastozoaW
Blastozoa

Blastozoa is a subphylum of extinct animals belonging to Phylum Echinodermata. This subphylum is characterized by the presence of specialized respiratory structures and brachiole plates used for feeding. This subphylum ranged from the Cambrian to the Permian.

CinctaW
Cincta

Cincta is an extinct class of echinoderms that lived only in the Middle Cambrian epoch. Homostelea is a junior synonym. The classification of cinctans is controversial, but they are probably part of the echinoderm stem group.

CtenocystoideaW
Ctenocystoidea

Ctenocystoidea is an extinct clade of echinoderms, which lived during the Cambrian and Ordovician periods. Unlike other echinoderms, ctenocystoids had bilateral symmetry, or were only very slightly asymmetrical. They are believed to be one of the earliest-diverging branches of echinoderms, with their bilateral symmetry a trait shared with other deuterostomes. Ctenocystoids were once classified in the taxon Homalozoa, also known as Carpoidea, alongside cinctans, solutes, and stylophorans. Homalozoa is now recognized as a polyphyletic group of echinoderms without radial symmetry. Ctenocystoids were geographically widespread during the Middle Cambrian, with one species surviving into the Late Ordovician.

CystoideaW
Cystoidea

Cystoidea is a class of extinct crinozoan echinoderms, termed cystoids, that lived attached to the sea floor by stalks. They existed during the Paleozoic Era, in the Middle Ordovician and Silurian Periods, until their extinction in the Devonian Period.

DizygocrinusW
Dizygocrinus

Dizygocrinus, also known as the feather star, is a genus of extinct sea lily from the Batocrinidae family.

EocrinoideaW
Eocrinoidea

The Eocrinoidea are an extinct class of echinoderms that lived between the Early Cambrian and Late Silurian periods. They are the earliest known group of stalked, arm-bearing echinoderms, and were the most common echinoderms during the Cambrian.

HomalozoaW
Homalozoa

Homalozoa is an obsolete extinct subphylum of Paleozoic Era echinoderms, prehistoric marine invertebrates. They are also referred to as carpoids.

Soluta (echinoderm)W
Soluta (echinoderm)

Soluta is an extinct class of echinoderms that lived from the Middle Cambrian to the Early Devonian. The class is also known by its junior synonym Homoiostelea. Soluta is one of the four "carpoid" classes, alongside Ctenocystoidea, Cincta, and Stylophora, which made up the obsolete subphylum Homalozoa. Solutes were asymmetric animals with a stereom skeleton and two appendages, an arm extending anteriorly and a posterior appendage called a homoiostele.

StylophoraW
Stylophora

The stylophorans are an extinct, possibly polyphyletic group allied to the Paleozoic Era echinoderms, comprising the prehistoric cornutes and mitrates. It is synonymous with the subphylum Calcichordata. Their unusual appearances have led to a variety of very different reconstructions of their anatomy, how they lived, and their relationships to other organisms.