Phylogenetic Classification of Spiralian Animals
Guide to levels:
phylogenetic sub-subgroups
basal spiralians (no definite name)
-
Orthonectida (traditionally considered to be a class of the phylum
Mesozoa)
-
Dicyemida (traditionally considered to be a class of the phylum
Mesozoa)
-
Platyhelminthes
(This class taxonomy is according to Ehlers
1985, which was still considered valid in 1998.
Some authors suggest that Acoelomorpha and possibly Catenulida should
be elevated to the phylum level.
This phylum is classified to much lower levels to show where the flukes
and tapeworms are now being placed.)
-
Catenulida
-
Acoelomorpha
-
Rhabditophora
-
Macrostomida
-
Polycladida
-
Neophora
-
Lecithoepitheliata
-
Prolecithophora
-
Seriata
-
Proseriata
-
Tricladida (inlcuding planarians)
-
Rhabdocoela
-
Typhloplanoida
-
Dalyelloida
-
Temnocephalidea
(everything above this line is traditionally listed under the class
Turbellaria!)
-
Neodermata (parasitic flatworms)
-
Udonellidea
-
Trematoda (yes, the flukes are no longer a separate class, but some kind
of sub-order)
-
Cercomeromorphae
-
Monogenea (This taxon used to be combined with the Digenea to form the
"class" Trematoda)
-
Cestodaria (yes, the true tapeworms are no longer a separate class, but
some kind of infra-order)
The next four phyla are now believed to form a monophyletic group above
phylum level - Gnathifera - based on the similar, elaborate structure of
their chitinous jaws [except for the greatly simplified, entirely parasitic
Acanthocephala].
-
Monogononta
-
Bdelloidea
-
Seisonidea
-
Acanthocephala
-
Archiacanthocephala
-
Paleoacanthocephala
-
Eoacanthocephala
Rotifera and Acanthocephala have been proposed for combination in a new
phylum, Syndermata, based on synapomorphies of the lorica.
-
Gnathostomulida
-
Filospermoidea
-
Bursovaginoidea
Lophotrochozoa
-
Mollusca
-
Aplacophora
-
Monoplacophora
-
Polyplacophora
-
Bivalvia (=Pelecypoda)
-
Gastropoda
-
Prosobranchia
-
Opisthobranchia
-
Pulmonata
-
Scaphopoda
-
Cephalopoda
-
Sipuncula
-
Sipunculidea
-
Phascolosomatidea
-
Annelida
-
Polychaeta
-
Aeolosomatida
-
Pogonophora (still treated as a separate phylum by many authors)
-
Perviata
-
Vestimentifera (= Obturata)
-
Echiura (still treated as a separate phylum by many authors)
-
Clitellata
-
Oligochaeta
-
Lumbriculida
-
Haplotaxida
-
Moniligastrida
-
Branchiobdellida (incorrectly treated as an order of Hirudinida by Meglitsch
and Schramm)
-
Hirudinida
-
Hirudinea
-
Acanthobdellida
-
Cycliophora
(not usually placed here, but the describers in 1995 thought that its
closest relationships were probably with Kamptozoa and Bryozoa)
-
Kamptozoa
(Sometimes considered a lophophorate, and sometimes placed with other
acoelomates in "basal spiralians," probably closely related to Cycliophora)
From here to bottom of page are the tradtionally lophophorate phyla,
which are probably not a monophyletic group.
-
Bryozoa (probably more closely related to Polychaeta than to other
lophophorates)
(older references include Kamptozoa under this name)
-
Phylactolaemata
-
Stenolaemata
-
Gymnolaemata
-
Phoronida (closest related to Brachiopoda)
Maintained by Sam Mozley (click
to send me E-mail)
Last modified on January 5, 2004