vertebrates Flashcards
deuterostomes
first opening= anus
Chordates
-notochord(skeletal support)
-hallow nerve cord(cns)
pharyngeal slits or clefts
muscular, post-anal tail
craniates
chordates with head
vertebrates
craniates with backbone
have: vertabrae enclosing spinal cord, skull, fin rays
lampreys
oldest vertebrates
jawless
origin of bones and teeth
initially as unmeterialized cartilage
vertabrae endoskeleton became fully mineralized after
gnathostomes
vertebrates with jaw
evolved from skeletal support of pharyngeal slits
Chondrichthyes: (sharkes..)
cartilaginous skeleton
must swim or sink, sharp vision
Ray-finned and Lobe finned fishes
Oteichthyes (ray finned)-bony fish and tetrapods
have bony endoskeleton
operculum(protects gills) and swim bladder
Lobe finned: muscular pelvic and pectoral fins
tetrapods
gnathostomes that have limbs
fins or lobed fin fishes evolved into limbs and feet
Characteristics of Tetrapods
limbs with feet
ears for airborn sounds
Amphibians
“both ways of life”
moist skin gas exchange
external fertilization
Amniotes
tetrapods with adapted egg
living members are reptiles
Characteristics of Amniotes
amniotic egg that protects embryo
reptiles
scales with waterproof barrier
ectothermic vs endothermic
reptiles- ectothermic, absorb external heat as main source of energy
birds- endothermic, capable of warming themselves through metabolism
