Key Concepts in Animal Phylogeny and Development

Segmentation

Adaptation that allows for specialization.

Subphylum Hexapoda

Arthropod taxon with three body regions.

Chilipoda

Members are carnivores.

Diplopoda

Members are detritivores.

Phylum Arthropoda

Unique among invertebrate phyla for possessing members that have wings.

Protostomes

Characterized by determinate cleavage, blastopore becomes the mouth, and spiral cleavage.

Deuterostomes

Characterized by indeterminate cleavage, blastopore becomes the anus, and radial cleavage.

Lophotrochoan phyla

Ordered by species diversity from lowest to highest: Annelida, Platyhelminthes, Mollusca.

Choanoflagellates

Specialized cells in sponges.

Porifera

Have internal fertilization.

Cnidarians

Have external fertilization.

Spiral cleavage

Type of cleavage found in protostomes.

Animals

Multicellular organisms that move under their own power and eat other organisms.

Endothermy

Trait shared by mammals and birds that explains their frequent eating habits.

Heartworm

Caused by a member of Phylum Nematoda.

Mammals

Do not exhibit radial symmetry.

Deuterostomes

Share key features of embryonic development.

Species diversity order

From least diverse to most diverse: Echinoderma, Cnidaria, Annelida, Mollusca.

Subphylum Crustacea

Characteristic of having two pairs of antennae.

Protists

Group to which choanoflagellates belong.

Subphylum Bivalvia

Group of mollusks that feeds by siphoning water over their gills.

Parasite

Reproduces in its final host.

Vertebrates and tunicates

Share a muscular, post-anal tail.

Depth perception

Made possible by the movement of eye placement to the front of the head.

Blastula

The 'hollow ball of cells' stage in embryonic development.

Phylum Urochordata

Describes a chordate that is a filter feeder with siphons.

Complete metamorphosis

Describes the life cycle stages of a caterpillar, pupae, and adult butterfly.

Acoelomate

Represents a type of organism with no coelom.

Crustacea

Group to which pill bugs belong.

Annelida

Members have a true coelom.

Gnathostome

Term that describes organisms with a jaw.

Embryonic development

Diploblastic: no coelom, radial symmetry, neutral net; Triploblastic: cephalization, coelom, central nervous system.

Jellyfish Apocalypse

Not a well-documented problem that conservation organizations need to address.

Chordates

Not the same as vertebrates.

Monotremes and marsupials

Have some embryonic development outside the uterus.

Embryonic stages order

Fertilized egg, First cleavage, Blastula, Gastula.

Pseudoceolmates

Some deuterostomes are not classified as such.

Class Bivalvia

Does not have terrestrial members.

Echinoderms

Includes both marine and fresh-water species.

Lampreys and hagfish

Do not have jaws.

Subphylum Gastropoda

Clade to which a terrestrial mollusk without a shell belongs.

Dorsal hollow nerve cord

Describes the blue line in a diagram that lies on top of the red notochord.

Chondrichthyes

Best described as sharks, skates, and rays.

Nematodes

Organism that is NOT in Phylum Annelida.