BB10201
Archosauria
Chelonia (turtles and tortoises)
Primarly aquatic today
300 living species of turtles
14 different families, most of which are as old as the dinosaurs
Heavily armoured, carapace is primarily the ribcage topped by tusk scales, there
are belly ribs which are again covered in scales. They can pull in their whole
body in their shell
Turtles go back over 200 million years ago, emerge after Permian-triassic
extinction
Crocodilia
Closest living relatives to birds
23 living species
Smallest crocodilian 5 feet in length
Semiaqautic predators
Flattened tail, webbed feet, massive bones and increases sinking
Eyes and nose at top of head
Can survive in salt water
Feed on wide range of food items
Crocodilians have very few predators of their own, except other members of
their species (cannibalism) several reasons; source of protein, eliminates
competitors and works as an evolutionary strategy to increase own gene pool
Crocodilians have elaborate parental care, build nests and guard them, young
hatch and crocodile protects them in her jaws and protect them for first year of
life. Similar thing seen in birds, perhaps a behavioural homology. Maybe
behaviour is inherited from ancestors.
More diverse and larger in the past, could have taken down a T-rex, warm
climate may have driven this
There have been marine and terrestrial crocodiles in the past (Cretaceous)
In the Triassic crocodilian diversity is extremely large, some looking more like
traditional dinosaurs. Modern crocodilians are not representative of the
crocodilians at all. Dinosaurs competed with crocodilians for the same niches,
but mass extinction got rid of many of the lineages, leaving only one that gave
rise to the modern ones today
Birds (sauropsids)
Occupy many niches
Features; highly modified, warm blooded. Loss of teeth, sophisticated respiratory
system where air sacs fill the bones, walk on toes not heel, elaborate parental
care, and feathers
Flight most extraordinary adaptation, makes them very fast (60mph),
energetically efficient, can cover long distances especially migration flights,
access virtually any environment, safe (once airborne they are invulnerable to
predators).
Archosauria
Chelonia (turtles and tortoises)
Primarly aquatic today
300 living species of turtles
14 different families, most of which are as old as the dinosaurs
Heavily armoured, carapace is primarily the ribcage topped by tusk scales, there
are belly ribs which are again covered in scales. They can pull in their whole
body in their shell
Turtles go back over 200 million years ago, emerge after Permian-triassic
extinction
Crocodilia
Closest living relatives to birds
23 living species
Smallest crocodilian 5 feet in length
Semiaqautic predators
Flattened tail, webbed feet, massive bones and increases sinking
Eyes and nose at top of head
Can survive in salt water
Feed on wide range of food items
Crocodilians have very few predators of their own, except other members of
their species (cannibalism) several reasons; source of protein, eliminates
competitors and works as an evolutionary strategy to increase own gene pool
Crocodilians have elaborate parental care, build nests and guard them, young
hatch and crocodile protects them in her jaws and protect them for first year of
life. Similar thing seen in birds, perhaps a behavioural homology. Maybe
behaviour is inherited from ancestors.
More diverse and larger in the past, could have taken down a T-rex, warm
climate may have driven this
There have been marine and terrestrial crocodiles in the past (Cretaceous)
In the Triassic crocodilian diversity is extremely large, some looking more like
traditional dinosaurs. Modern crocodilians are not representative of the
crocodilians at all. Dinosaurs competed with crocodilians for the same niches,
but mass extinction got rid of many of the lineages, leaving only one that gave
rise to the modern ones today
Birds (sauropsids)
Occupy many niches
Features; highly modified, warm blooded. Loss of teeth, sophisticated respiratory
system where air sacs fill the bones, walk on toes not heel, elaborate parental
care, and feathers
Flight most extraordinary adaptation, makes them very fast (60mph),
energetically efficient, can cover long distances especially migration flights,
access virtually any environment, safe (once airborne they are invulnerable to
predators).
