Disparida Temporal range:
| |
---|---|
Synbathocrinus from the Mississippian of Missouri, USA | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Echinodermata |
Class: | Crinoidea |
Infraclass: | Inadunata |
Parvclass: | †
Disparida Moore & Laudon, 1943 |
Orders [1] | |
Disparida is an parvclass of extinct marine animals in the class Crinoidea. [2] [3] [1] Disparids are a speciose and morphologically diverse group of crinoids distinguished by their monocyclic calyx and slender arms without pinnules. They range from the Early Ordovician ( Tremadocian) to Middle Permian, reaching their highest diversity during the Late Ordovician. [4]
While many disparids had a generalized shape typical of other stalked crinoids, some subgroups achieved strange forms. The long-lasting Calceocrinidae were recumbent forms, with a flattened crown bent back onto a stalk which rested on the seafloor. Other unusual disparid families include the armless Zophocrinidae, the spiral-armed Myelodactylidae, and the diminutive, simplified Pisocrinidae. Disparids have long been classified by the structure of their radial plates and different planes of symmetry, but a cumulative phylogenetic approach has failed to confirm the validity of many proposed subgroups. Nevertheless, Disparida itself is well-supported as a distinct monophyletic group. [4]
Major traits of Disparida include: [1] [5]
Disparida classification is undergoing revision. Many proposed families are paraphyletic or polyphyletic. [5] [6] [4]
Family Acolocrinidae
Family Allagecrinidae
Family Alphacrinidae
Family Anamesocrinidae
Family Anomalocrinidae
Family Aptocrinidae
Family Athenacrinidae
Family Belemnocrinidae
Family Calceocrinidae
Family Catillocrinidae
Family Cincinnaticrinidae (i.e. Heterocrinidae, paraphyletic / polyphyletic)
Family Columbicrinidae
Family Dulkumocrinidae
Family Eustenocrinidae
Family Haplocrinitidae
Family Homocrinidae (paraphyletic / polyphyletic)
Family Iocrinidae (paraphyletic)
Family Maennilicrinidae
Family Myelodactylidae
Family Pisocrinidae
Family Pygmaeocrinidae (polyphyletic)
Family Synbathocrinidae
Family Tetragonocrinidae
Family Zophocrinidae
Disparida Temporal range:
| |
---|---|
Synbathocrinus from the Mississippian of Missouri, USA | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Echinodermata |
Class: | Crinoidea |
Infraclass: | Inadunata |
Parvclass: | †
Disparida Moore & Laudon, 1943 |
Orders [1] | |
Disparida is an parvclass of extinct marine animals in the class Crinoidea. [2] [3] [1] Disparids are a speciose and morphologically diverse group of crinoids distinguished by their monocyclic calyx and slender arms without pinnules. They range from the Early Ordovician ( Tremadocian) to Middle Permian, reaching their highest diversity during the Late Ordovician. [4]
While many disparids had a generalized shape typical of other stalked crinoids, some subgroups achieved strange forms. The long-lasting Calceocrinidae were recumbent forms, with a flattened crown bent back onto a stalk which rested on the seafloor. Other unusual disparid families include the armless Zophocrinidae, the spiral-armed Myelodactylidae, and the diminutive, simplified Pisocrinidae. Disparids have long been classified by the structure of their radial plates and different planes of symmetry, but a cumulative phylogenetic approach has failed to confirm the validity of many proposed subgroups. Nevertheless, Disparida itself is well-supported as a distinct monophyletic group. [4]
Major traits of Disparida include: [1] [5]
Disparida classification is undergoing revision. Many proposed families are paraphyletic or polyphyletic. [5] [6] [4]
Family Acolocrinidae
Family Allagecrinidae
Family Alphacrinidae
Family Anamesocrinidae
Family Anomalocrinidae
Family Aptocrinidae
Family Athenacrinidae
Family Belemnocrinidae
Family Calceocrinidae
Family Catillocrinidae
Family Cincinnaticrinidae (i.e. Heterocrinidae, paraphyletic / polyphyletic)
Family Columbicrinidae
Family Dulkumocrinidae
Family Eustenocrinidae
Family Haplocrinitidae
Family Homocrinidae (paraphyletic / polyphyletic)
Family Iocrinidae (paraphyletic)
Family Maennilicrinidae
Family Myelodactylidae
Family Pisocrinidae
Family Pygmaeocrinidae (polyphyletic)
Family Synbathocrinidae
Family Tetragonocrinidae
Family Zophocrinidae