Summary of Deuterostomes & Vertebrates Flashcards

This set of vocabulary flashcards covers the major clades and classes within Deuterostomia, specifically focusing on the phyla Echinodermata and Chordata as presented in the Kingdom Animalia lecture.

Echinodermata

A phylum of marine invertebrate deuterostomes named for their spiny skin; they possess calcareous dermal plates and show pentaradial symmetry in adults.

Water Vascular System

A key anatomical system in echinoderms used for locomotion and feeding; water flows through the madreporite $\rightarrow$ stone canal $\rightarrow$ ring canal $\rightarrow$ radial canals $\rightarrow$ tube feet.

Class Asteroidea

A class of echinoderms commonly known as sea stars, characterized by arms continuous with a central disc, tube feet with ampulli, and the ability to evert their stomach for external digestion.

Pedicillaria

Pincher-like external structures found in Class Asteroidea used primarily for defense.

Class Ophiuroidea

A class containing brittle and basket stars, featuring a distinct central disc and long, flexible arms used for serpentine motion.

Class Echinoidea

A class of echinoderms including urchins and sand dollars characterized by a fused dermal plate skeleton called a test and a complex scraping jaw known as Aristotle’s lantern.

Aristotle’s lantern

A complex jaw structure with $5$ teeth found in Class Echinoidea, used for scraping surfaces while feeding.

Class Holothuroidea

A class of echinoderms (sea cucumbers) with elongated bodies and reduced plates; they use Cuverian organs defensively by ejecting sticky structures.

Class Crinoidea

A class of stalked (sea lilies) or free-moving (feather stars) echinoderms that use a stalk called a serr to attach to substrate and are primarily suspension feeders.

Phylum Chordata

A group of animals defined by four diagnostic characters: a notochord, dorsal hollow nerve cord, post-anal muscular tail, and pharyngeal slits.

Cephalochordata

A subphylum of small ($\thickapprox 5-6 \text{ cm}$) chordates known as lancelets that retain all four chordate features throughout their lives and have V-shaped myomeres.

Urochordata

A subphylum of chordates known as tunicates or sea squirts; they have sessile filter-feeding adults, though the larval stage retains chordate characters briefly.

Class Myxini

A class of scavenging craniates known as hagfish that are unique for being true osmoconformers and producing massive volumes of defensive slime.

Class Petromyzontida

A class of jawless vertebrates known as lampreys, featuring a rasping sucker mouth and anticoagulant saliva; many lead a parasitic, blood-feeding lifestyle.

Class Chondrichthyes

A class of fishes with cartilaginous skeletons (sharks, rays, and skates) that possess placoid scales, liver oils for buoyancy, and electroreceptors.

Osteichthyes

The group of bony fishes characterized by a bony skeleton, an operculum covering the gills, and a swim bladder for maintaining buoyancy.

Actinopterygii

One of the modern classes of bony fishes known as ray-finned fishes; it is the most diverse group including goldfish, tuna, and seahorses.

Actinistia

A class of lobe-finned fishes known as coelacanths, which possess muscular lobed fins and were thought extinct until being rediscovered in $1938$.

Dipnoi

A class of bony fishes known as lungfishes that have both lungs and gills; they are capable of estivation during dry seasons.

Class Amphibia

A class of tetrapods with a $3$-chambered heart and poikilothermic metabolism that typically undergo metamorphosis; includes orders Anura, Urodela, and Apoda.

Reptilia

A class of animals with keratinized scaly skin and well-developed lungs; modern taxonomy includes birds (Aves) within this group as part of the archosaur lineage.

Aves

A lineage within Reptilia characterized by endothermy, feathers, lightweight honeycombed bones, air sacs, and a $4$-chambered heart.

Monotremes

A lineage of mammals consisting of the platypus and echidna which are oviparous (lay reptile-like eggs) and secrete milk.

Marsupials

A lineage of mammals where young are born alive but complete their development inside a pouch called a marsupium.

Eutherians

Placental mammals whose embryos develop in a uterus joined by a placenta; DNA evidence suggests an origin approximately $100$ million years ago.