Phylum
Arthropoda
Champions of
variations in appendages
Exoskeleton
(outside skeleton) made of
chitin and protein
First phylum to
venture into the air
Pioneered jointed legs
More species than
any other phylum
Complete digestive tract
with two ends
Bilateral phylum
that added segmentation
Phylum
Mollusca
Feeding device like a
toothed, rasping tongue
( r a d u l a )
Most have a
calcium-carbonate shell
Muscular “foot” used to slide,
dig, or jump
Some propel, using their
siphon as a water jet
Mantle of tissue
covering the body
Complete digestive
tract with two ends
Phylum
Echinodermata
Five-part radial symmetry
Tube feet used
for locomotion
Some spines are
little pincers (pedicellaria)
Hard but flexible bodies with
interlocking plates under
thin skin
All members
live in the ocean
Complete digestive
tract with two ends
Phylum
Chordata
All have notochord; most
have backbone
Increased complexity made
possible by much more DNA
Most have inside
skeleton of bones
Phylum to which
humans belong
Jaws and skulls
important in their evolution
Complete digestive
tract with two ends
Bilateral phylum
that added segmentation
Phylum
Porifera
No symmetry or
consistent body shape
Water flows through its
b o d y, full of canals
Spicules act as a skeleton to
give it structure
No locomotion;
stationary animal
Specialized cells,
but not organized into
organs or tissues
Phylum
Cnidaria
First muscles and nerves
Some have stinging
structures (nematocysts)
Some free-drifting medusae
Some non-swimming polyps
Hollow body cavity for food
Digestive tract with the
entrance being the exit
Phylum
Platyhelminthes
Some of the simplest animals
with bilateral symmetry
Tubular mouth (pharynx) at
m i d - b o d y
Three tissue layers, but no
body cavity
Digestive tract with the
entrance being the exit
Most members are parasitic
Phylum
Annelida
Bilateral phylum that
added segmentation
Complete digestive tract with
two ends
Fluid-filled compartments
used for locomotion
Their active burrowing has
affected global climate
Body design basically
a tube within a tube
A c t i v i t i e s
P A G E 24
F L AT WO R M S A N N E L I D SC N I DA R I A N SS P O N G E S
P hylum Comparison Chart Key
E C H I N O D E R M SM O L L U S C SA RT H RO P O D S C H O R DAT E S
