Chapter 32: The Deuterostomes in Animal Kingdom

Adaptive radiation

Formation of many new species from an ancestral species, often occurs rapidly in geological time when a new niche opens up.

Arboreal

Living in the trees.

Cloaca

Common exit point shared by reproductive, excretory and digestive systems (literal translation is sewer).

Desiccate

Dry out from lack of water (dehydration).

Ectothermic

Animal whose body heat goes up and down with changes in the external environmental temperature, 'cold blooded'.

Endothermic

Animal whose body heat is maintained independent of the external temperature.

Eutheria

Animals that nourish the embryo via a placenta.

Metamorphosis

Undergo a change in body form from one developmental stage to another.

Metatheria

Animals that raise their young in a pouch (e.g. kangaroos).

Oviparous

Animals that lay eggs and embryo is nourished by the yolk.

Ovoviviparous

Animals that incubate an egg internally, embryo gets nourishment from the yolk, and have live births.

Protheria

Egg laying mammals (e.g. duckbilled platypus).

Viviparous

Animals where the young develop inside the uterus and nutrients are transferred from mother to embryo.

Deuterostomic development

Developmental pattern characterized by the formation of the anus from the blastopore.

ancestral features for deuterstomes

multicellularity - Organisms composed of multiple cells.

tisses - three layers

triploblastic

bilateral symmetry

true coelom

Segmentation

The division of the body into repetitive segments.

Endostyle

Ciliated groove in urochordates and cephalochordates involved in transporting food to the esophagus; in vertebrates, it is the thyroid gland.

Phylum Echinodermata

A group of marine animals including starfish.

phylum echinodermata: habitat

Marine environments.

phylum echinodermata: Water-vascular system

Derived defining characteristic used for feeding, gas exchange, and hydrostatic skeleton.

phylum echinodermata: Symmetry

Bilateral in larvae and pentaradial in adults.

phylum echinodermata: Body surfaces

Oral surface- on the bottom

aboral surface- outside or on top.

phylum echinodermata: Madreporite

Silk-like structure on the outside of echinoderms.

Asteroidea

Class of echinoderms that includes sea stars.

Crinoidea

Class of echinoderms that includes sea lilies and feather stars.

Echinoidea

Class of echinoderms that includes sea urchins and sand dollars, characterized by a round flat body with no arms.

Skeleton of Echinoidea

Interlocking calcium carbonate plates called a test.

Deuterostomes

A major group of animals that includes echinoderms and chordates.

Phylum Chordata

A phylum that includes all chordates.

Subphylum Urochordata

Invertebrate chordates, including tunicates.

Tunicates

Sea squirts and relatives with a carbohydrate tunic and openings for siphoning.

urochordate features in Larva

All chordate features present and swims.

urochordate features in Adult

Only gill slits present and is sessile.

Feeding in Urochordata

Suspension feeders.

Subphylum Cephalochordata

Invertebrate chordates with all four chordate features in adults.

Feeding in Cephalochordata

Filter feeders.

Genus Branchiostoma (subphylum cephalochordata)

gill plus mouth; originally Amphioxous: sharp on both sides.

example of cephalochordata: Fin ray

Blue lining along the outside of the body.

Distinguishing features of vertebrates

Includes vertebral column, pronounced cephalization, brain in cranium, neural crest cells, and Hox gene clusters.

Neural crest cells

Influence the development of many structures including melanocytes, smooth muscle, nerves, and craniofacial cartilage.

Hox gene clusters

Involved in the regulation of development and code for transcription factors.

Systems in vertebrates

circulatory system, digestive system, endocrine system, and endoskeleton.

Jawless Fish

Craniate jawless fish

hagfish- class myxini

Habitat of Hagfish

Marine only.

Cranium of hagfish

Brain enclosure.

Teeth of Hagfish

Keratin and on tongue (no jaws) can grasp prey.

Notochord

Flexible cartilage rod.

hagfish- no true vertebrae, partially enclosed nerve cord

Fins of Hagfish

No true fins, long dorsal fold.

Feeding of Hagfish

Either scavenger or predator - mostly scavenger.

Defense of Hagfish

Secretes slim- covers gills of attacking fish or prey.

Body tonicity of Hagfish

Only craniate isosmotic with salt water (ocean/marine environment).

Lampreys (Class Pteromyzontida)

oldest living vertebrate lineage, jawless vertebrae

Habitat of Lampreys

Marine, freshwater, estuaries.

Lifestyle of Lampreys

Parasites.

Cartilaginous Fish

(Class Chondrichthyes) Jawed fishes.

Habitat of Cartilaginous Fish

Mostly marine - some freshwater skates.

Skeleton and cranium of Cartilaginous Fish

Cartilage infused with calcium salts.

Teeth of Cartilaginous Fish

Replaceable modified scales.

Scales of Cartilaginous Fish

Placoid (tooth like), non overlapping.

Gill opening of Sharks

Lateral in sharks.

Cloaca

Common opening to outside for three systems: Reproductive, excretory, digestive (birds and amphibians too).

Sexual dimorphism in Cartilaginous Fish

Clasper (paired) - cartilaginous extensions of male pelvis fin.

examples of Oviparous animals

skates, some sharks, birds, reptiles, fish.

examples of ovoviviparous animals

many sharks, snakes, fish.

examples of Viviparous animals

some sharks, most mammals.

Chordates (Class Osteichthyes)

Bony fish, Jawed fish

Habitat of Class Osteichthyes

Freshwater and marine.

Skeleton and cranium of Class Osteichthyes

Calcified.

Teeth of Class Osteichthyes

Replicable.

Fins of Class Osteichthyes

Paired, supported by cartilage or bone.

Mouth of Class Osteichthyes

Anteriorly directed.

Gills of Class Osteichthyes

Internal, covered by operculum - lid.

Swim bladder in bony fish

Buoyancy - gas exchange in some.

Ray-finned bony fish

Most fish - rays of cartilage or bone run length of fin.

Lobe-finned bony fish

Some use lungs instead of gills - give rise to land dwelling tetrapods.

Class Amphibia

Having two lifestyles (one in water and one on land).

Metamorphosis in class amphibia

Many complete - some adults (salamanders) retain many larval characteristics (paedomorphosis).

Respiratory organ of Amphibians

Lungs, gills, skin.

Heart of Amphibians

Three chambers (two atria and one ventricle).

Amphibian orders

Urodela (or Caudata) - visible tail; Anura - no tail; Apoda - no feet.

Aminote egg

An egg that is adapted for life on land, allowing for the development of embryos in a protective environment.

Amnion

A fluid-filled sac that surrounds the embryo, providing cushioning and protection.

Class Reptilia

A class of animals characterized by their shelled eggs, hard scales, and ectothermic physiology.

Three-chambered heart in class reptilia

A heart structure in reptiles that separates oxygen-rich and oxygen-poor blood.

Ectotherms in class reptilia

Organisms whose body temperature changes with the surrounding environment.

Order Testudines

bony shell overlaid by horny scales

vertebrae and ribs are fused to shell, pelvic and pectoral girdles lie inside ribs

mouth covered by beak, no teeth

includes turtles, terrapins, and tortoises.

Carapace

The top, dorsal part of a turtle's shell.

Plastron

The bottom, ventral part of a turtle's shell.

Order Squamata

loosely articulated jaws, hinge construction

elastic skin

tongue used for touch and smell

pit organ used to detect heat from endothermic prey

ecdysis (molt)

includes lizards, snakes, and worm lizards.

Komodo dragon

A large lizard known for its infectious bite and scavenging behavior.

Order Crocodilia

live in swamps, rivers or along seacoasts

feed on various kinds of animals

includes crocodiles, alligators, caimans, and gavials.

Superorder Archosauria

A superorder that includes crocodiles and birds.

Class Aves

The class of animals that includes modern birds, characterized by feathers and beaks.

Palaeognaths

A clade of flightless birds including ostriches, kiwis, and emus.

Neognaths

A clade of birds that are mostly capable of flight.

Class Mammalia

The class of animals characterized by the presence of mammary glands and hair.

Middle-ear bones

Three bones in mammals (malleus, incus, stapes) that aid in hearing.

Clade Protheria

A clade of mammals that lay eggs, including the duck-billed platypus and echidnas.

Clade Theria

A clade of mammals that bear live young.