Phylogenetic Tree of Animals

These flashcards cover key terms and concepts from the lecture about the phylogenetic tree of animals, focusing on the major groups, characteristics, and evolutionary processes.

Eumetazoa

A clade that includes animals with true tissues.

Bilateria

Organisms with bilateral symmetry and three germ layers (triploblastic).

Choanoflagellata

Single flagellate motile organisms that can form colonies.

Acoelomates

Animals without a coelom, classified under Metazoa.

Radiata

Animals exhibiting radial symmetry and possessing two germ layers (diploblastic).

Parazoa

Animals without true tissues, such as sponges.

Protostomia

A clade of animals including those in which the mouth forms before the anus.

Ecdysozoa

A group of protostomes that undergo molting.

Lophophore

A crown of tentacles used for feeding in some aquatic invertebrates.

Echinodermata

Phylum that includes sea stars, sea urchins, and sea cucumbers, characterized by radial symmetry and a water vascular system.

Cephalochordata

A subphylum of chordates commonly known as lancelets.

Urochordata

A subphylum that includes tunicates, which have specialized sessile adults.

Paedomorphosis

An evolutionary process where juvenile characteristics of an ancestor are carried into adult forms of its descendants.

Madreporite

An external structure in echinoderms that serves as a water inlet for the water vascular system.

Pedicellariae

Minute pincers on the aboral surface of echinoderms used for protection and cleaning.

Dermal Branchiae

Projections of the coelomic cavity in echinoderms used for respiration and excretion.

Notochord

A dorsal elastic supporting rod present in all chordates at some stage of development.

Nerve Cord

A hollow dorsal structure in chordates that develops into the brain.

Pharyngeal Pouches

Funnel-like openings in chordates that originally served as filter-feeding devices.

Endostyle

An organ in chordates that secretes iodinated hormones.

Cephalization

The evolutionary trend toward the concentration of sensory organs and nervous tissue at the anterior end of the body.