Vertebrates

people are fish

vertibrates

have a backbone

phylum chordata

bilaterians

All vertebrates and two inveribrates are chordates

Cordata three subphylums

cephalochordata

Urochordata

Vertibrata

5 derived characteristics

1. notochord

2. Dorsal, hollow nerve chord

3. Pharyngeal slits/clefts

4. Muscular, post anal tail

5. Endostyle

Notochord

long, flexible rod on dorsal side

Can develop into skeleton

dorsal, hollow nerve chord

develops from invaginated plate of the ectoderm

Develops into central nervous system (brain and spinal chord)

Pharyngeal slits/clefts

Develop from grooves in pharynx

Initially for filter feeding, are for gas exchange in verts

Develop into parts of the ear, head, and neck in tetrapods

muscular, post-anal tail

maybe greatly reduced as embryo

Contains skeletal elements and muscles

Provides propelling force in many aquatic species

endostyle

logitudinal, collimated tip on ventral side of pharynx

Metabolism regulation in verts

Thyroid gland

clade craniate

cordates with a head

Head enables coordinated movement and complex movements/feeding

craniate 3 adaptations

skull

Brain

Sensory organs

Most basal craniate

hag fish

Craniate derived characteristics

neural crest

Gill slits

Higher metabolism

More muscular

Heart with at least 2 chambers

Class myxini

most basal craniate

Cartilaginous skull

Lack jaw and vertebrae

Small brain, eyes, ears,

Marine-benthos scavengers

subphylum vertibrata

craniates with a backbone

Vertebrae enclosing spinal chord

Elaborate skill

Fin rays

most basal vertibrata

lampreys- skull with no jaw, cartilaginous and notochord

clade gnathostomes

Vertebrates with true jaws

Enlarged forebrain

Lateral lien system

Ex; chandrichthyans

Claude osterichthyes

bony fish

All vertebrates with a bony endoskeleton

Fins supported via bones/spines and swim blatter

clade tetrapod

earth-feet

Four limbs

Feet with digits

Neck- seperatemovement of head

A sense of gills (few exceptions)

Ears

Ex; amphibians

what does the evolution of a neck do?

Allow separated movement of the head ands body

clade amniota

reptiles (including birds) and mammals

terrestrially adapted eggs (membranes)

Relatively impermeable skin

Ability to use ribcage to vent lungs

smallest clade

amniotes

Super class chondrichtyes

cartinagenous fishes

Fatty liver for buoyancy

Subclass elasmobranchii

sharks, rays, skates, sawfish

4-7 pairs of gill clefs on each side of the head

Ridgid dorsal fin (may contain spines)

Skin covered in Dermal denticles

Swift swimmers

Acute senses: electric field detection

Subclass holocephali

compleate heads

Chimeras, rabbit-fish, elephant-fish

Close to seabed, benthic feeding

Single gill slit on each side of body

Long, slender tail with big head/eyes

Move by sweeping pectoral fins

superclass chonrichthyes reproduction

Internal

Cloacal

Three types of egg development

oviparous

Ovoviviparous

Viviparous

ovioparous

eggs hatch outside of mothers

ovoviviparous

embryo develops in in ueturus and is nourished by egg sack (hatched inside of mom)

viviparous

embryo develops in uterus and is nourished through yolk-sack/placenta from mother’s blood

clade osteichthyes

vast majority of vertebrates

Bony skeleton

Ray-finned/ lobe-finned fish or tetrapods

Operculum- bony protection over gills

Swim bladder

Most oviparous, some with internal fertilization

Superclass Actinopterygii

Ray-finned fish

Modified for defense/manuvering

class chondrostei

sturgons and paddlefish

Cartilaginous skeleton

Shark-like tail and rostrum

Claude cladistia

eel-shaped species

Dorsal fin with independent rays

Posteriorly elongated paraphenoid

class lepisosteriforms

gars

Elongated body w/ jaws, needle-like teeth

Ganoid scales

Dorsal fins sit more posteriorly and has few rays

ganoid scales

gars, diamond shaped interlocking armored scales

subclass Neopterygii

bowfins

Long body, mig mouth, small/sharp teeth, air blatter

Teleostei

teleostei

96% of ray finned fish

Protrusible jaws

Symmetric tail

superclass sarcopterygii

lobe-finned fish

Muscular pelvic and pectoral fins

3 liniages

3 liniages of sarcopterygii

coelacanths

Lungfish

Tetrapods

Class Coelanthitormes

2 species

Nocturnal

8 fins total

cosmoid armored scales

class dipnoi

Lungfish

Air blatter- oxygen absorbsion and removes waste

Hypernate and breathe air

Superclass tetrapoda

4 limbs, neck, feet, didgets

Ectothermic

Soft skin lacking scales

Both gill and lung breathers

3 chambered heart, 2 atria, 1 ventrical

classs Amphibia

”double-life”

All closely associated with water