Lophophorates
Several phyla included in this group - see textbook (we’re only looking at two).
They all
have a similar structure surrounding the mouth - ciliated tentacles called a “lophophore”.
Other structures (e.g., no distinct head, U-shaped digestive tract) also suggest a
relationship.
Phylum Bryozoa (5,000? species)
- (book calls these “Ectoprocta”; stick with Bryozoa)
- colonial animals that resemble mosses (have a hard “exoskeleton”)
- “air ferns”
- aquatic, sessile, some are important reef builders
-
[Fig., not in book, but see fig. 33.14a, p. 677]
Phylum Brachiopoda (330 living species - 30,000 fossil species) - lamp shells
- resemble clams and other mollusks of the class bivalvia
- shells are dorsal and ventral, not side to side (symmetry is along a
different axis)
- looking at one shell, it looks bilateral
- the two shells often differ somewhat in size
- NOT related to Bivalves.
- filter feeders, sessile
-
[Fig., not in book, but see fig. 33.14b, p. 677]
Comment - these used to be considered transitional between protostomes and
deuterostomes, butt recent evidence puts them pretty much in the protostomes.
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- Spring '08
- BIRCHARD
- Ordovician, Sea urchin, Bryozoa, sea cucumbers, center Sea
-
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