Card Set Information
The Vertebrate Story
Dominant paleozoic freshwater predators.
Jointed braincases with strong bites.
Labyrinthodont teeth, which are also present in Labyrinthodonts.
Gave rise to tetrapods during Devonian.
Then went extinct in the Permian.
: Porolepiformes, Osteolepiformes and panderichthyids.
Rhipidistian from Devonian with a heterocercal tail.
Why did vertebrates move onto land?
They were probably trying to stay in the water!
Lungfishes, others and "walking catfishes" today, can survive out of water long enough to leave a drying pond in search of a better water source.
A present day example of a fish walking on land to get back to water.
Walking catfish were sold as pets - released accidentally, or intentionally, in Florida - survived and spread.
Generalist feeding species - adapt to many environs.
The success of these animals showed how it could have happened.
Now is used for modern groups only:
Temnospondyls (extinct in the Mesozoic)
Lepospondyls are antoher early extinct tetrapod group.
Had bony scales across abdomen.
Large, up to 5 meters long.
Had lateral lines in skull grooves.
Ex. Icthyostega - Devonian four-footed fish (really amphibious)
Amniotes and modern amphibians arise within this group.
This animal is Devonian in age, and a transitional form from fish to tetrapod.
Has eight fingers!
One meter long
Later anthracosaur from early Permian.
Lobe fin fish and amphibian movement
Dorsal views of body profiles of a lobe-finned fish and a tetrapod to show that both move by lateral unduation of body and use of tail.
The expanded cranial "horns" from tabular bones may be to allow an expanded lateral line system.
frogs, calamanders and caecilians
two major lineages:
Diverged by Carboniferous or earlier
Eggs which survive on land and nourish embryos with members.
Birds, dinosaurs, modern reptiles and Mesozoic reptiles.
Therapsids, modern mammals and extinct forms.
Amniote skull types
These used to be used in classification, but no longer. Now they are functional types only.
Related to Seymouriomorphs and amphibia
Perhaps belong with anthracosaurs and other late non-amniotes
Also called Cotylosauria
Specialized aquatic forms
Not closely related to other aquatic sauropsida
Skulls lack fenestrae
Long snouts and thin, sharp teeth indicate feeding habits
Testudines and extinct groups such as parieosaurs.
Ear drum supported by squamosal bone and retroarticular process.
Unique foot-ankle articulation.
Testudines already had carapaces and plastrons.
Appeared in the Triassic.
Two modern orders that differ in neck retraction mechanisms.
Cryptodire - vertical folding of neck.
Pleurodire - side-folding neck (South American forms)
Late Permian testudine
Lepidosauromorpha and Archosauromorpha
Palatine fenestrae in mouth roof
Marine sauropterygians and lepidosaurs.
Terrestrial snakes and lizzards
Lepidosaurs that gave rise to modern forms.
Many have reduced temporal bars and therefore have increased jaw mobility.
Dinosaurs and birds
Ichtyopterigia - icthyosaurs
Dinosaurs - often became bipedal
Convergent with other marine forms
Porpoise-like bodies but tail went side to side
Sleek shaped bodies
Mesozoic aquatic diapsids
Jurassic and Cretaceous Plesiosaurs
Contains Captorhinids that gave rise to later groups.
Similar to modern reptiles.
Small teeth probably ate insects.
No temporal openings appeared in Carboniferous
Extinct at end of Triassic
May have had a wingspan of up to 8 meters such as Pteranodon.
arose in mid-Carboniferous
Descended from cotylosaurs
Radiated through Permian
Gave rise to therapsids
Many theories have been advanced as uses for the sail, including sailing! It was probably a means of temperature regulation.
a three meter long herbivore
a Permian mammal-like reptile.
Specialized dentitions were present in these animals.