(sea gooseberry ctenophore) |
BASAL METAZOA
modified from
|
(sea butterfly ctenophore) |
============================================= Porifera (sponges) | <<=M=| ================================================== TO CNIDARIA ===> |===E=====| | ===C========================= Ctenophora (comb-jellies) M= METAZOA ==1===| E= EUMETAZOA ============================= Bilateria (all higher animals)
Back to Zool 250 tree for animal phyla
TRAITS SUPPORTING EACH CLADE
(** plesiomorphic- a primitive state, not unique to clade):
b) blind gut** c) giant compound cilia form comb rows d) colloblast cells e) pair of elongate tentacles in tentacle sheaths f) biradial symmetry g) multiciliated cells* |
(Obelia polyps + medusa) |
(hydrozoan medusa) |
PHYLUM CNIDARIA
(= anemones, jellyfish, etc) (tree and traits from Ruppert et al. 2003- 7th ed.) |
(anthozoan polyp) |
(scyphozoan medusa) |
==2============== Hydrozoa (hydroids, siphonophores, hydrocorals, etc.) | <<==1===| ==4========= Anthozoa$ (anemones, corals, gorgonians, etc.) ==3==| | ===6=== Cubozoa (sea wasps) ==5==| ===7=== Scyphozoa (jellyfish)
Back to Zool 250 tree for animal phyla
TRAITS SUPPORTING EACH CLADE (** plesiomorphic- a primitive state, not unique to clade):
b) nematocyst with operculum c) diploblastic** d) radial symmetry** b) stenotele nematocyst c) simple bell margin in medusa, no rhopalia** d) simple gastrovascular cavity in polyp** e) medusa by simple budding f) medusa has simple manubrium g) cnidocytes strictly epidermal** h) mesoglea lacks cells i) gastrodermis lacks cnidocytes** j) gonads epidermal b) gastrodermal cnidocytes in both polyp & medusa stage c) gastric filaments with cnidocytes d) gastrodermal gonads e) septate gastrovascular cavity in polyp |
b) nematocysts lack operculum c) tubular pharynx with siphonoglyph in polyp b) funnel-shaped polyp c) medusae produced by strobilation d) medusa with 4 septa and septal funnels e) 8 gonadal bands on septae f) rhopalia b) small polyps lack septae c) tentacles on pedalia at corners of bell d) 4 rhopalia with complex ocelli e) velarium (velum-like structure in medusae) f) highly venomous nematocysts b) large manubrium on medusae c) 8-fold notched bell margin with rhopalia |
$Molecular data suggest Anthozoa are the sister group to the Medusozoa (=Hydrozoa + Cubozoa + Scyphozoa) and some morphological data support this relationship (Martindale et al. 2002. Molec Phylog. Evol. 24: 358).