STUDY GUIDE
Taxonomy, Animal Phyla, and Vertebrate Classes
Organizing Organisms:
To see how living things are related to each other, we organize them into groups called taxa
(singular: taxon) based on clues to their evolutionary history, such as their DNA sequences and
phenotypes. Some taxa, such as divisions and kingdoms, classify living things into broad groups. For
example, the kingdom Animalia includes all the animals. Other taxa, such as genera (singular: genus)
and species, classify living things into more specific groups. For example, the species Homo sapiens
refers only to humans.
Study Question 1:
Put the following categories in order from broadest to most specific: Class, Domain, Family,
Genus, Kingdom, Order, Phylum, Species.
Study Question 2: Complete the following table using your text, lecture notes, and/or Internet
sources. Many spots have more than one possible answer.
Level of Taxon
Genus
Species
Example of Taxon
Rattus (rat genus)
Carnivora
Canidae
Eukarya
Kingdom
Chordata
Amphibia
Evolution of Animal Phyla:
The animal kingdom is divided into broad groupings called phyla. To understand animal life,
it's necessary not only to know the features of these phyla, but also how those traits reflect the
evolution of animals and their move onto land. For example, bilateral symmetry makes directed
movement and digestion of food easier.
The phyla we cover in this class are the Porifera (sponges), Cnidaria (jellyfish and allies),
Platyhelminthes (flatworms; you can simply say "flatworms" on a test), Nematoda (roundworms),
Annelida (earthworms), Mollusca (mollusks, such as cephalopods, gastropods, and bivalves),
Arthropoda (animals with jointed exoskeletons, such as crustaceans, insects, and arachnids),
Echinodermata (starfish, sea urchins, sea cucumbers), and Chordata (tunicates, lancelets, and
vertebrates). Other animal phyla exist, but are somewhat less recognizable.
STUDY GUIDE
Taxonomy, Animal Phyla, and Vertebrate Classes
Study Question 3:
The major features that we have as chordates are: specialized tissues, bilateral symmetry, a complete digestive
tract, a true coelom, segmentation, and a dorsal nerve cord and notochord. In addition, some phyla have developed
other adaptations. One example of an adaptation chordates do not have is an exoskeleton. Complete the following
table to show which phyla share these features. (Boxes in the last seven columns should say 'yes' or 'no.')
Phylum
Example
member
Porifera
Sea sponge
Coral
Specialized
tissues?
Bilateral
symmetry?
Complete
digestive
tract?
No
True
coelom?
Segmented?
Exoskeleton?
No
Yes
Dorsal nerve
cord and
notochord?
No
No
Platyhelminthes
No
Nematoda
Octopus
Yes
Arthropoda
Starfish
Shark
Yes
Yes
Yes
Yes
No
No
STUDY GUIDE
Taxonomy, Animal Phyla, and Vertebrate Classes
Vertebrate Classes:
The vertebrates are chordates with a spine and cranium (skull). In lecture, we discussed several of the major
vertebrate classes: the cartilaginous fish, the bony fish (with a focus on ray-finned fish), the amphibians, the reptiles
(including birds), and the mammals. Within the mammals, we find three orders: the monotremes (egg-laying
mammals), the marsupials (pouched mammals), and the eutherians/placental mammals (such as us.)
Study Question 4: Complete the following table (all but the first two columns should say 'yes' or 'no.'
Group
Example
member
Backbone?
Hard
skeleton?
Tetrapod limbs
(vertebrate legs)?
Amniote
egg?
Endothermy?
Hair?
Embryo kept
in placenta?
Yes
Yes
Yes
No
No
No
No
Tunicates (not
vertebrates!)
Shark
Bony Fish
Reptiles
(excluding birds)
Birds (special
group of reptiles)
Monotreme
mammals
Placental
mammals