Unit 5: The Evolutionary History of Diversity
Animations
Extras
Study Guide
Chapter 33
Invertebrates
Review
Notes
Point
Invertebrates
do not have a
backbone
, and account for 95% of known
animal
species.
Phyla
Calcarea
and
Silicea
are the multicellular
sponges
(formerly Porifera) that lack true tissues.
Phylum
Cnidaria
belongs in the clade with true tissues called
Eumetazoa
.
Most Eumetazoa belong to the clade
Bilateria
and exhibit
bilateral
symmetry and
triploblastic
embryonic development.
Phylum
Platyhelminthes
are flatworms with a gastrovascular cavity.
Phylum
Nematoda
are roundworms with a
pseudocoelom
.
Phylum
Mollusca
are soft-bodied animals.
Phylum
Annelida
are segmented worms with a true
coelom
.
Phylum
Arthropoda
have
segmented
bodies.
Phylum
Echinodermata
are
deuterostomes
.
Summary: