Revised clade from Tree of Life for Kingdom Animalia

PHYLUM PORIFERA (sponges; from "Tree of Life" on WWW)

          ==== Calcarea (includes ascon, sycon & leucon grades, calcareous spicules)
          |
          |=== Sclerospongia (coralline sponges; leucon type, silica & calcareous spicules)
<<=abcde==|
          |=== Demospongia (most living sponge species; leucon type, silica spicules)
          |
          ==== Hexactinellida (glass sponges; no regular canal system, silica spicules)

Traits supporting each sponge clade (** plesiomorphic- a primitive state, not unique to clade):

a) water canal system with pumping choanocytes (monociliated cells** with diplosome**)
b) porocytes (pore cells)
c) pinacoderm (epithelium-like layer) lacking basal lamina & intercellular junctions
d) reversible differentiation of most cell types
e) transport of sperm to egg via choanocyte

Back to Zool 250 version of tree for animal phyla

Back to Zool 250 Home Page