Errantia is a diverse group of marine life polychaete worms in the phylum Annelida. Traditionally a subclass of the paraphyletic class Polychaeta,
Phylogeny
The
phylogeny of
is slowly being resolved. Errantia and
Sedentaria are the two biggest
of polychaetes, and together they compose clade
Pleistoannelida.
Two groups are nested within Errantia:
Aciculata (
Eunicida +
Phyllodocida) and
Protodriliformia (
progenesis meiofaunal worms such as the
Protodrilida).
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.
Some taxon, such as Spintheridae and Myzostomida, are still difficult to place due to their long branching, but they likely belong to either Errantia or Sedentaria.
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.
-
Order Amphinomida – 2 families (Amphinomidae, Euphrosinidae)
-
Order Eunicida
-
Order Phyllodocida
-
Suborder Phyllodociformia – 4 families (Phyllodocidae, Alciopidae, Lopadorrhynchidae, Pontodoridae)
-
Suborder Aphroditiformia
-
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)
