Clades for Phylum PORIFERA
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) <<==1=====| |=== 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):
1: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.
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Copyright © 1999 by A. Richard Palmer. All rights reserved.
(revised Jan. 9, 1999)