Vertebrate Comparative Anatomy - Key Terms (VOCABULARY flashcards)

Vocabulary flashcards covering key terms from the vertebrate comparative anatomy lecture notes.

Comparative Anatomy

The study of the variation in form, function, anatomy, physiology, and evolution among vertebrate animals.

Chondrichthyes

Cartilaginous fishes with jaws; skeleton made of cartilage (e.g., sharks and rays).

Osteichthyes

Bony fishes; skeleton primarily of bone.

Amphibia

Class including frogs, salamanders, and caecilians; life cycle often includes aquatic and terrestrial stages.

Reptilia

Class of reptiles (lizards, snakes, turtles, crocodilians, etc.); primarily terrestrial and amniote vertebrates.

Aves

Birds.

Mammalia

Mammals.

Gnathostomata

Jawed vertebrates.

Cyclostomata

Jawless fishes, including hagfishes and lampreys.

Amniota

Vertebrates that lay eggs with an amnion; includesSauropsida (reptiles/birds) and Synapsida (mammals).

Sauropsida

Reptiles and birds.

Synapsida

Mammals and their extinct relatives.

Tetrapoda

Vertebrates with four limbs.

Archosauria

Clade that includes birds and crocodilians (and their dinosaur ancestors).

Theria

Mammals excluding monotremes; includes marsupials and placentals.

Monotremes

Egg-laying mammals (e.g., platypus and echidnas).

Metatheria

Marsupials.

Eutheria

Placental mammals.

Cladistics

Phylogenetic systematics; groups organisms based on shared derived characters to form clades.

Clade

A monophyletic group consisting of a common ancestor and all its descendants.

Synapomorphy

A shared derived character that defines a clade (homologous in origin).

Symplesiomorphy

A shared ancestral character; provides little information about relatedness.

Plesiomorphy

An ancestral character.

Apomorphy

A derived character.

Outgroup

A lineage used to root a phylogenetic tree; less closely related than the ingroup.

Ingroup

The group of organisms being studied in a phylogenetic analysis.

Crown group

Extant or with all the defining characteristics of a clade.

Stem group

Extinct lineage leading to the crown group; ancestral forms.

Geologic Timescale

Timeline of Earth's history in millions of years, divided into eras, periods, epochs, and ages.

Hagfishes

Cyclostomata; jawless fishes (Myxiniformes).

Lampreys

Cyclostomata; jawless fishes (Petromyzontiformes).

Mass extinctions

Five major extinction events in the Phanerozoic where large numbers of species disappeared.