Phylum Archeocyathida
Range:  Lower to Upper Cambrian

Some place this phylum under the sponges - structurally and
functionally similar - others place this group as a separate phylum.

1.  organisms with calcareous (microgranular calcite) skeleton
2.  invested cup erect or curved, held to substrate with holdfast
3.  skeleton may consist of a single porous wall - Monocyathida
     more commonly as two concentric porous walls, an inner and
     outer wall separated by a space (intervallum)
4.  inner wall surrounds a central cavity
5.  intervallum may contain various radial elements:
   porous septa - subdivide intervallar space tabulae - transverse porous skeletal elements of variable curvature
   non-porous bars, rods, dissepiments
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Sponges:  Phylum Porifera

Latin porus - pore fera - to bear
Range: PreCambrian - Recent

Characteristics:
  1.  cellular grade organization
  2.  dominantly marine
  3.  metazoa
  4.  asymmetrical or radially symmetrical
  5.  without organs, mouth or nervous system
  6.  with a body permeated with pores, canals and chambers (inlets and
   exits.)
  7.  water flows through openings by action of numerous flagellate
   cells that line that internal cavities
  8.  Larvae free swimming
  Adults sessile
  9.  Reproduction usually sexual; freshwater sponges asexual
10.  internal skeleton
  crystalline spicules - Si0₂
  organic fibers


Phylum Porifera (Tasch, 1980)

CLASS 1.  Demospongea  Range Cambrian to Recent skeletons spongin, siliceous spicules;  spicule rays meet at 60^o or 120^o

CLASS 2.  Hyalospongea  Range Pre-Cambrian to Recent siliceous spicules - skeletal spicule rays form right angles common spicule stauract - four rays in one plane

CLASS 3.  Calcispongea  Range Cambrian to Recent calcareous spicules; diacts, triacts, tetracts (tuning fork type spicules may be interlocking to form)

CLASS 4.  Sclerospongea Range Ord - Permian (?)  Tr - Rec coralline sponge with compound skeleton of siliceous spicules,  organic fibers and aragonite



Phylum Porifera: (Boardman, 1987)

Subphylum - Symplasma

CLASS - Demospongia (C - Rec) knobby siliceous spicules fused  together.  Girtycoelia.  Burgess Shale

CLASS - Hexactinellida (C - Rec)  six-rayed spicules, more   advanced forms have fused spicules to make a three-   dimensional rectilinear pattern.  Hydnoceras


Subphylum - Cellularia

CLASS - Calcarea (L Perm - Rec) calcium carbonate spicules.   Reef formers in the late Paleozoic.    Astreosponggium, Stellispongia, Peronidella

CLASS- Sclerospongea (ord-Perm (?), Tr - Rec) coraline sponge with   compound skeleton of siliceous spicules, organic fiber and   aragonite

CLASS - Stromatoporata* (?C, Ord-K)

CLASS- Chaetetida* (Ord - Rec
   May belong to Demospongia or Calcarea           

CLASS (Order) Sclerospongia


New class; Hartman & Goreau, 1970; symp. Zool. Soc. London, 1969,  v. 25, p. 205-243

Group of living sponges (coralline sponges)basal skeleton mass of aragonite (all other calc. sponges calcite), also contain silica and spongin fibersfrom Christmas Islands, Cuba, Jamaica;  flourish in deep shade under fore-reef projections (10m - 100m and deeper), twilight to total darkness.

Merlia (similar to certain tabulates of Chaetitidae (sponges?)),
Ceratoporella, Stromatospongia, Goreaviellabeige, red vermillion colorsymbiotic with serpulids imbedded and attachedrapid growth

Morphology: elongate depressions converging on osculum, transparentAffinities:  stromotoporoids, chaetitids