Kingdom Animalia II

Deuterstomes

anus develops before the mouth

Phylum Brachiopoda Characteristics

Body Plan: tube-in-tube

Symmetry: bilateral

Germ Layer: triploblastic

Body Cavity: coelomate

Segmentation: non-segmented

Dominated the Paleozoic sea

Lophophore: feeding tentacles around mouth

Molecular data suggests protostome, morphogenesis suggests deuterostome

Phylum Echinodermata Characteristics

Body Plan: tube-in-tube

Symmetry: bilateral

Germ Layer: triploblastic

Body Cavity: coelomate

Segmentation: non-segmented

No terrestrial examples; all marine

Water vascular system for movement, feeding, sensory, perception, and gas exchange

Tube feet

Nerve ring

Calcareous endoskeleton shows as ossicles (small, interlocking calcium carbonate plates)

Example of Class Asteroidea

starfishes

Example of Class Holothuroidea

sea cucumbers

Example of Class Crinoidea

feather stars

Example of Class Ophiuroidea

brittle stars

Examples of Class Echinoidea

sea urchins and sand dollars

Phylum Hemichordata Characteristics

Body Plan: tube-in-tube

Symmetry: bilateral

Germ Layer: triploblastic

Body Cavity: coelomate

Segmentation: non-segmented

Dorsal nerve cord & pharyngeal gill slits prove relation to vertebrates

Phylum Chordata Characteristics

Body Plan: tube-in-tube

Symmetry: bilateral

Germ Layer: triploblastic

Body Cavity: coelomate

Segmentation: segmented

Core Characteristics

Pharyngeal gill slits

Notochord

Dorsal hollow nerve cord

Muscular, post-anal tail

Subphylum Cephalochordata

Lancelets; All core chordate traits

Simplest chordate

Subphylum Urochordata

Tunicates; Adults are sessile

Filter feeders

Retains gill slits, but loses all other core chordate traits with age

Subphylum Craniata

Include vertebrates > backbone replaces notochord

Can remain cartilaginous or become calcified

Segmentation in muscles and vertebrae

Pharyngeal gill slits can remain open or close with development

Post-anal tail can be retained or be lost with development

Pisceans; Cyclostomes (Jawless Fish) Classes

Myxini, Petromyzontida

Class Myxini Characteristics

Jawless fish

Highly reduced vertebrae

Cartilaginous bones

Mouth has keratinous projections that resemble teeth

2 chambered heart

Detritivore

Defenses: Slime, Tying itself into knots

Class Petromyzontida Characteristics

Parasites: teeth and tongue penetrate host skin; feeds on tissues and fluids

Cartilaginous skeleton without collagen

Flexible sheath around notochord. That resembles vertebration

2 chambered heart

Pisceans: Gnathostomes Classes

Chondrichthyes, Osteichthyes

Class Chondrichthyes Characteristics

Cartilaginous skeletons

Must swim to stay afloat > no swimming = sinking

Urea retention for osmoregulation

Teeth are modified scales

2 chambered heart

Possess cloaca

Class Osteichthyes Characteristics

Calcium phosphate replaces cartilage during development

New features

Operculum: gill covering

Swim bladder: allows for vertical movement

2 chambered heart

2 subclasses: Sarcopterygii & Actinopterygii

Tetrapod Classes

Amphibia, Reptilia, Aves, Mammalia

Class Amphibia Charateristics

Have lungs but most gas exchange is through skin

2 nostrils

3 chambered heart

Undergo metamorphosis

Ectothermic

Amphibia Orders

Anura: frogs

Urodela: salamanders

Class Reptilia Characteristics

3 chambered hearts (except crocodilians)

Better limbs from amphibia

Scaled skin inhibits water loss

Better lungs

Ribcage

Internal fertilization

Amniotic egg

Reptilia Orders

Chelonia: turtles

Crocodilia: crocodiles

Squamata: lizards, snakes

Class Aves Characteristics

4 chambered heart

Hollow bones for lighter body

Feathers

Endodermic

Reptilian traits

Amniotic egg

Scaled legs

Class Mammalia Characteristics

Hair

Mammary glands

Sweat glands

Tooth differentiation

Well developed brain

Muscular diaphragm

Endothermic

Inner ear bones, malleus, incus, and stapes

Monotremes

egg laying

Marsupials

live bearer, no placenta

Placentals/Eutheria

live bearers, placenta