Arthropods, Echinoderms, and Chordates Lecture Review

Flashcards covering the vocabulary and key concepts of Phylum Arthropoda, Echinodermata, Chordata, and the classes of fishes, amphibians, reptiles, birds, and mammals based on the provided lecture notes.

Arthropoda

A phylum meaning "joint-footed" characterized by metameric segmentation, jointed appendages, and an exoskeleton.

Trilobita

A subphylum of extinct arthropods named for their trilobed body.

Chelicerata

A subphylum defined by having chelicerae instead of mandibles, four pairs of walking legs, and no antennae.

Merostomata

A class including horseshoe crabs, described as "living fossils" with appendages that have gills and a sharp telson.

Arachnida

A class including spiders, mites, ticks, and scorpions, named after "Arachne" in Greek mythology.

Hemolytic venom

A type of venom possessed by black widow and brown recluse spiders.

Arachnophobia

An intense fear of spiders.

Chiggers

Mites that bite through skin and inject enzymes that liquify skin cells.

Myriapoda

A subphylum containing centipedes and millipedes, characterized by a head followed by a series of trunk segments.

Centipedes

A member of Myriapoda with flat bodies and one pair of appendages per body segment; they are predators with venom claws.

Millipedes

A member of Myriapoda with round bodies and two pairs of appendages on most body segments; they are typically herbivorous.

Crustacea

A subphylum including lobsters and crabs, characterized by two pairs of antennae, two pairs of maxillae, and biramous appendages.

Ecdysis

The process of shedding the carapace or shell to allow for growth.

Ommatidia

The individual units that make up the many-faceted compound eye of crustaceans.

Hemocoel

The open circulatory system found in crustaceans.

Hexapoda

A subphylum where members have unbranched (uniramous) appendages and three pairs of legs.

Holometabolous

Complete metamorphosis consisting of four stages: egg, larvae, pupa, and adult.

Hemimetabolous

Incomplete metamorphosis consisting of egg, nymph (or naiad if aquatic), and adult.

Pheromones

External hormones used for chemical communication, such as sex attractants or trail markers.

Stridulation

The process of rubbing body parts together to make sounds to attract mates, commonly seen in crickets.

Bioluminescence

The animal production of light, seen in insects like lightning bugs.

Echinodermata

A marine phylum featuring radial symmetry (usually with 5 points), tube feet, and no head or brain.

Asteroidea

The class containing sea stars (starfishes) which exhibit pentaradial symmetry.

Ophiuroidea

The class containing brittle stars and basket stars with five arms clearly distinct from the central disc.

Echinoidea

The class containing sea urchins and sand dollars, which have a compact body in a shell called a test.

Holothuroidea

The class containing sea cucumbers, named for their vegetable-like appearance and leathery body wall.

Crinoidea

The class containing sea lilies and feather stars, characterized by a stalk that attaches them to the substrate.

Hemichordata

Worm-like bottom-dwellers, such as acorn worms, with a body consisting of a proboscis, collar, and trunk.

Chordata

A phylum characterized by a dorsal hollow nerve cord, notochord, pharyngeal gill slits, postanal tail, and an endostyle.

Urochordata

Known as "tail chordates" or tunicates, protected by a non-living coat called a tunic.

Cephalochordata

Known as "head chords" or lancelets, which use an atriopore to send water out of the body cavity.

Paedomorphosis

The maturing of reproductive structures while the body remains in a juvenile condition.

Cyclostomata

A clade of jawless fishes (Agnatha) including lampreys and hagfishes.

Myxini

A group of marine jawless fish known as hagfishes that are very slimy.

Gnathostomata

A group of vertebrates with jawed mouths and paired appendages.

Chondrichthyes

The class of cartilagenous fish, including sharks, featuring placoid scales and heterocercal tails.

Squalene

Fats used by Chondrichthyes to maintain neutral buoyancy in the absence of a swim bladder.

Osteichthyes

The class of bony fishes, characterized by a bony skeleton, homocercal tail, and an operculum covering the gills.

Sarcopterygii

A subclass of lobe-finned or fleshy-finned fishes believed to be ancestral to amphibians.

Countercurrent system

In fish respiration, the flow of water in the opposite direction of blood flow to maximize oxygen exchange.

Catadromous

A migration pattern, such as in eels, where adults swim from freshwater to the sea to spawn.

Anadromous

A migration pattern, such as in salmon, where adults swim from the sea to freshwater to spawn.

Preadaptation

The concept that adaptations for preserving life in drying pools (like lungs and dragging limbs) served as a preparation for life on land.

Rhipidistians

A group of lobe-finned fishes believed to be ancestral to amphibians due to skull and tooth similarities.

Anura

The order of amphibians containing frogs and toads, characterized by the absence of a tail in adults.

Amplexus

The grip a male frog uses to hold onto a female until she lays eggs for fertilization.

Amniotic egg

A shelled egg with four extraembryonic membranes, allowing for reproduction away from water.

Testudines

The order containing turtles, characterized by a bony case made of a dorsal carapace and a ventral plastron.

Squamata

The order of reptiles containing lizards and snakes, characterized by a kinetic skull and epidermal scales.

Jacobson's organ

Organs in the roof of the snake's mouth used to detect chemical information from the forked tongue.

Pit vipers

Snakes such as rattlesnakes that use heat-sensitive loreal pits to detect prey.

Osteoderms

Bones embedded in the skin of crocodilians for protection.

Archaeopteryx

The earliest known bird fossil, meaning "ancient wing," displaying both avian and reptilian characters.

Pygostyle

The shortened tail structure found in birds.

Contour feathers

Feathers that cover and streamline the bird's body; the flight feathers.

Elliptical wings

Wings with a low aspect ratio seen in birds that maneuver in forests, such as sparrows.

Precocial

Hatchlings that are ready to go with parents immediately at hatching, like ducks.

Altricial

Hatchlings that are naked, helpless, and require significant care, like many songbirds.

Mammalia

A class of homeothermic organisms characterized by hair and mammary glands.

Metatheria

A subclass of mammals including marsupials that keep young in a pouch for development.

Vibrissae

Whiskers used as modified hairs for sensory purposes in mammals.

Antlers

Solid bone structures in deer and elk that are grown under "velvet" and shed periodically.

Heterodont teeth

Teeth that are not all the same shape and function, including incisors, canines, premolars, and molars.

Echolocation

A navigation system used by bats involving click signals and interpreting returned echoes.

Torpor

A state of reduced endothermy and body temperature used by mammals to survive periods of hardship.