(Beroe ctenophore)

BASAL METAZOA modified from Tree of Life; traits & tree after Ruppert & Barnes 1994 p. 1052)

(sea butterfly ctenophore)

     ============================================= Porifera (sponges)
     |
<<=M=|         ================================================== TO CNIDARIA ===>
     |===E=====|
               |     ===C========================= Ctenophora (comb-jellies)
 M= METAZOA    ==1===|
 E= EUMETAZOA        ============================= Bilateria (all higher animals)

TRAITS SUPPORTING EACH CLADE
(** plesiomorphic- a primitive state, not unique to clade):

1: a) acetylcholine / acetylcholinesterase system C (Ctenophora): a) diploblastic** 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)

TRAITS SUPPORTING EACH CLADE (** plesiomorphic- a primitive state, not unique to clade):

1 (Cnidaria): a) epidermal cnidocytes with nematocysts b) nematocyst with operculum c) diploblastic** d) radial symmetry** 2 (Hydrozoa): a) velum in medusa stage 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 3: a) mesoglea lacks cells b) gastrodermal cnidocytes in both polyp & medusa stage c) gastrodermal gonads d) septate gastrovascular cavity in polyp

4 (Anthozoa): a) medusa stage absent b) nematocysts lack operculum c) tubular pharynx with siphonoglyph in polyp 5 (Medusozoa): a) medusa stage dominant b) funnel-shaped polyp c) medusae produced by strobilation d) medusa with 4 septa and septal funnels e) 8 gonadal bands on septae e) gastric filaments with cnidocytes f) rhopalia 6 (Cubozoa): a) cubic-shaped medusae 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 7 (Scyphozoa): a) medusa stage dominant** b) polyps possess 4 septae b) large manubrium c) 8-fold notched bell margin with rhopalia