dinosaurs Flashcards
what did dinosaurs evolve from?
archosaurs
what type of eggs did dinos lay?
amniotic
what is amniotic egg
hard shell pourous for gas exchange
aquatic environment inside
yolk sac = food
what stage of growth did amniotic egg eliminate
larval stage - growth of small adult
what were the 2 types of dinousaur
ornithischia
saurischia
hip bones of ornithischian dinosuars
back pointing pubis (bird-hipped)
hip bones of saurischian dinosaurs
forward pointing pubish (reptile-hipped)
bird hipped
ornithischian
reptile hipped
saurischian
example of ornithischian dino
iguanadon
2 sub groups of saurischian
therapod
sauropod
example of therapod
tyrannosaurus
example of sauropod
diplodocus
which dino group did modern birds evolve from
therapod (saurischian)
what was special about walking igunadon dinos
bi-pedal and quad-pedal
characteristics of ornithischian dinos
bony armoured plates (DEFENCE, HEAT EXCHANGE)
duck billed
bird hips
characteristics of saurischian dino
reptile hips
3 digit hands with 1st finger longest (like thumb) for grasping
s shaped neck
diplodocus adaptions for chewing
gastroliths (stones) in stomach to grind leaves
what was diplodocus
sauropod herbivore
how did diplodocus defend itself
whip tail
how did diplodocus reach high trees
tall + long neck to reach high trees
what type of saurishian dino was tyrannasaurus
therapod (carnivore)
adaptions of tyrannosaurus
large teeth to tear meat
large legs
arguments for tyrannosaurs being a predator
large teeth- meat
many modern predators don’t use arms
arguments for tyrannosaurs being a svaveneger
large olfactory lobe - smell
useless forearms
small eyes
long legs to cover distance
adaptions of iguanadon
horny beak - crop veg
hinged upper jaw (back teeth chew) side to side chewing
3 digit fingers ending in hooves
conical thumb with spike as defence
how did birds evolve from dinos
thought to have evolved from coelurosaurs
similarities - coelurosaurs and birds
clawed hands
pubis bone shifting to posterior
elongated arms and forelimbs
light hollow bones
what is archaepteryx
1st known bird like fossil
bird qualities of archaepteryx
feathers
wings for flight
hollow bones
wishbone