Animal Diversity

Animal Diversity

Figure 32.4 A traditional view of animal diversity based on body-plan grades

Figure 32.8 Animal phylogeny based on sequencing of SSU-rRNA

Figure 32.5 Body symmetry

Figure 32.13x Burgess Shale fossils

Figure 32.13 A sample of some of the animals that evolved during the Cambrian explosion

Figure 33.1 Review of animal phylogeny

Phylum Porifera • Sponges • “colony” of flagellated cells • individual cells can potentially regenerate into a new individual

Figure 33.3 Anatomy of a sponge

Radial

Phylum Cnidaria • Hydras, jellyfish, sea anemones, corals • gastrovascular cavity • stinging cells • Radiata

Figure 33.4 Polyp and medusa forms of cnidarians

Figure 33.5 A cnidocyte of a hydra

Table 33.1 Classes of Phylum Cnidaria

Phylum Ctenophora • Comb jellies • comblike ciliary plates • gastrovascular cavity • Radiata

Bilateral

Figure 32.6 Body plans of the bilateria

Phylum Platyhelminthes • Flatworms • dorsoventrally flattened • no segmentation • gastrovascular cavity • bilateral, no coelom, protostome

Table 33.2 Classes of Phylum Platyhelminthes

Figure 33.10 Anatomy of a planarian

Figure 33.12 Anatomy of a tapeworm

Phylum Rotifera • Ciliated crown • no digestive system • bilateral, pseudocoelomates, protostome

Figure 33.13 A rotifer

Phylum Nematoda • Roundworms • unsegmented • no circulatory system • bilateral, pseudocoelomate, protostome

Figure 33.25a Free-living nematode

Lophophorates - several phyla • Bryozoans, lampshells (brachiopods) • bilateral, coelomate, protostome

Figure 33.14 Lophophorates: Bryozoan (left), brachiopod (right)

Phylum Mollusca • Clams, snails, squids • foot, visceral mass, mantle • bilateral, coelomate, protostome

Figure 33.16 Basic body plan of mollusks

Table 33.3 Major Classes of Phylum Mollusca

Figure 33.18 The results of torsion in a gastropod

Figure 33.21 Anatomy of a clam

Phylum Annelida • Segmented worms • bilateral, coelomate, protostome

Figure 33.23 Anatomy of an earthworm

Table 33.4 Classes of Phylum Annelida

Phylum Arthropoda • Crustaceans, insects, spiders • segmented body, jointed appendages, exoskeleton • bilateral, coelomate, protostome

Figure 33.26 External anatomy of an arthropod

Table 33.5 Some Major Arthropod Classes

Figure 33.30b Spider anatomy

Figure 33.33 Anatomy of a grasshopper, an insect

BilateralDeuterostomes

Figure 32.7 A comparison of early development in protostomes and deuterostomes

Phylum Echinodermata • Starfish, sea urchins • bilateral, coelomate, deuterostome

Figure 33.38 Anatomy of a sea star

Phylum Chordata • Lancelets, tunicates, vertebrates • notochord, nerve cord • bilateral, coelomate, deuterostome

Figure 34.2 Chordate characteristics

Figure 34.3 Subphylum Urochordata: a tunicate

Figure 34.4a Subphylum Cephalochordata: lancelet anatomy

Table 33.7 Animal phyla

Animal Diversity