Errantia
Subclass of annelid worms
From Wikipedia, the free encyclopedia
Errantia is a diverse group of marine polychaete worms in the phylum Annelida. Traditionally a subclass of the paraphyletic class Polychaeta,[4] it is currently regarded as a monophyletic group within the larger Pleistoannelida, composed of Errantia and Sedentaria.[2] These worms are found worldwide in marine environments and brackish water.
| Errantia Temporal range: [1] | |
|---|---|
| |
| Alitta virens | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Annelida |
| Clade: | Pleistoannelida |
| Subclass: | Errantia Audouin & H Milne Edwards 1832 |
| Orders[2][3] | |
Phylogeny
The phylogeny of polychaetes is slowly being resolved. Errantia and Sedentaria are the two biggest clades of polychaetes, and together they compose clade Pleistoannelida.[5] Two groups are nested within Errantia: Aciculata (Eunicida + Phyllodocida) and Protodriliformia (small meiofaunal worms such as the Protodrilida).[6][3][2]
Historically, the order Amphinomida was part of this subclass. However, phylogenetic analyses place Amphinomida inside a basal clade with Sipunculida and Lobatocerebrum, and this clade is the sister group to Pleistoannelida.[3]
| |||||||||||||
| Pleistoannelida | |||||||||||||
Some taxa, such as Spintheridae and Myzostomida, are still difficult to place due to their long branching, but they likely belong to either Errantia or Sedentaria.[3]
Classification
Historical
Errantia is, along with Sedentaria, one of the two old orders of the paraphyletic class "Polychaeta". In 1977 the zoologist Kristian Fauchald split Errantia into three orders: Phyllodocida, Amphinomida and Eunicida, giving way to this classification.[7]
- Order Amphinomida – 2 families (Amphinomidae, Euphrosinidae)
- Order Eunicida
- Superfamily Eunicea – 7 families (Onuphidae, Eunicidae, Lumbrineridae, Iphitimidae, Arabellidae, Lysaretidae, Dorvilleidae)
- Superfamily incertae sedis – 2 families (Histriobdellidae, Ichthytomidae)
- Order Phyllodocida
- Suborder Phyllodociformia – 4 families (Phyllodocidae, Alciopidae, Lopadorrhynchidae, Pontodoridae)
- Suborder Aphroditiformia
- Superfamily Aphroditacea – 6 families (Aphroditidae, Polynoidae, Polyodontidae, Pholoididae, Eulepethidae, Sigalionidae)
- Superfamily Chrysopetalacea – 2 families (Chrysopetalidae, Palmyridae)
- Superfamily Pisionacea – 1 family (Pisionidae)
- Suborder Nereidiformia – 6 families (Hesionidae, Pilargiidae, Syllidae, Calamyzidae, Nereididae, Antonbmunidae)
- Suborder Glyceriformia – 3 families (Glyceridae, Goniadidae, Lacydoniidae)
- Suborder incertae sedis – 5 families (Iospilidae, Nephtyidae, Sphaerodoridae, Tomopteridae, Typhloscolecidae)