Chapter 3 Flashcards
vertebral column
derived from notochord
series of bone/cartilage blocks
defines central axis of body
vertebrae
series of bone/cartilage blocks
neural spine and neural arch
covering the nerve cord (spinal cord)
centrum
body of vertebrae with a cushioning intervertebral disc
hemal spine and hemal arch
covers blood vessels
cranium
cartilage/bone plates protects the brain and sensory organs
neural crest cells (found only in vertebrates) are used to help build the cranium
neural crest cells
only vertebrates have these and the things that they give rise to
they are embryonic and build features that distinguish vertebrates from others
cephalochordate
peaceful protochordates
amphioxus-like, filter feeding, sinu venosus, hepatic cecum, myomeres… most resemble vertebrates
agnathan
first vertebrates. first fish. muscular pumping pharynx, cartilage replaces collagen in pharynx
-bigger appetite
gnathostome
powerful jaw for biting prey. body grows larger. predatory nature. powerful pharyngeal pump
agnathans
diverse jawless fish
conodonts
dentin (bone like) rasping mechanism in mouth. relationship to later species unclear
endoskeleton
cartilage, strengthens the notochord
exoskeleton
bony plates to protect soft bodies, head shields, first bone
ostracoderms
elaborate skeletons, ancestors to gnathostomes, ostracoderms extinct now
myxini (hagfish)
found today at bottom of oceans
feeding on dead fish
no vertebrae
but have cranium
eat dead stuff
burrow into carcasses of dead fish
pteraspidomorphi
extinct ostracoderms with head shields
cephalaspidomorpha (includes lamprey)
unusual single nasal opening