Protosomes - Week 8

Biramous

Double-branched appendages

Ecdysis

Shedding or molting of skin

Arthropod

“Jointed feet”; represents the most successful anad abundant organisms in the animal kingdom

Trilobites

Ancient arthropods that are now extinct; were dorsoventrally flattened and divided into longitudinal sections

Book gills

Primitive gills of horseshoe crabs located on the lower abdomen

Cephalothorax

Fused head and thorax; a body region in arthropods

Carapace

Hard shell that functions as a protective or defensive covering

Abdomen

Posterior part of the body; segment behind the thorax

Chelicerae

One of a pair of claw-like feeding appendages characteristic of chelicerates

Palp

Appendage that functions as a sensory organ (touch and taste)

Telson

Last segment of abdomen

Antennae

Sensory appendage on the head of animals

Antennule

First pair of antennae

Chelipeds

Pair of legs that possesses a pincer-like chela (a pincer-like organ)

Rostrum

Beaklike appendage; a piercing mouthpart

Swimmerets

Elongated appendages in crustaceans located on the lower abdomen; used in sexual reproduction

Maxillae

Paired structures used for testing or manipulating food

Maxillipeds

Appendages modified for feeding that are located behind the maxillae

Green gland

Excretory organ found in some crustaceans, located in the head region

Digestive gland

Structure that secretes digestive enzymes

Gastric mill

Series of plates or ossicles that are moved by muscles and function as a grinding apparatus

Insects

Most speciose and ecologically dominant group of animals on the earth; successful because of small size, ability to fly, exoskeleton, and metamorphic life stage development

Compound eyes

Type of eye composed of repeating units of cornea, lenses, and photoreceptor cells

Uniramous

Single-branched appendages