Skulls- Reptiles Birds And Fish Flashcards
What is the cladistic tree
Common ancestor -> jaws-> lungs-> amniotic egg -> hair-> no tail -> bipedal
What are the four orders of living reptiles
Squamata
Chelonia
Crocodylia
Rhynchocephalia
What animals belong to the Squamata order
Snakes and lizards (scaled reptiles)
What animals belong to the Chelonia order
Turtles (have shells)
What animals belong to the crocodylia order
Crocodilians
What animals belong to the rhynchocephalia order
An order of lizard- like reptiles that includes only 2 living species of tuatara
Reptilia are poikilothermic, what does this mean
Having a body temp. that varies with them temp of the surroundings
Do reptilia have internal or external fertilisation
Internal
How many heart chambers to reptilia have
3 or 4
What are the different environments reptilia live in
Aquatic, semi- aquatic, terrestrial, arboreal reptiles
Is there a huge range of morphologies in reptiles? If so how big
Yes, python up to 33 feet long
Dwarf gecko only about 1.3 inches long
How are snake skulls joined
Loosely joined = kinetic
How would you describe a crocodile skull
Robust solid skull
Do reptiles have a smaller or larger brain case compared to mammals
Smaller
What is the difference between the lower jaw of a reptile compared to a mammals
Reptiles have several bones mammals only have 1
Differences in the bony palate between reptile and mammals
Mammals - complete
Reptiles - incomplete
What is the only order involved with rhynchocephalia
Sphenodontida
What is the only surviving family in the rhynchocephalia
Sphenodontidae
What is the only surviving genus in the sphenodontidae family
Sphenodo or tuatara
What are the two species of tuatara
Punctatus and Guntheri
What are the differences between rhynchocephalia and lizards
Rhynchocephalia lack external ears, parietal eye more formed and lack of hemipenes or even a penis in general
What do rhynchocephalia and lizards have in common
1) Caudal autotomy
2) parietal eye
3) no hemipenis
What is the parietal eye used for
all lizards have it but it is much better in tuatara, not necessarily for vision. Used to let light in, believed to be useful in absorbing UV light and setting circadian and seasonal cycles. It does have a retina lens, cornea, nerves but not for vision.
Visible in hatchlings- covered in scales and pigments 4-6 months
Saltwater can produce ___psi of pressure
3700
Approximately how many socketed teeth do crocodilians have
72
What enables a crocodilian to snap its jaw shut without damaging teeth
Unlike other reptiles crocodiles dentition fits within jaw
What do the large neck muscles within crocodilians allow
Huge attachment area for muscle
The huge neck muscles in crocodilians help with what
The close the mouth not open
Muscles cannot ______ they ______. Therefore crocodilians sleep with their mouth ____
Push, pull, open
Describe the jaw and snout of a crocodilian
Long and narrow
What are the advantages of morphology within a crocodilian
Lends itself to a rapid closure
What muscles within the crocodilian are weak
Antagonistic masticatory muscles which open jaw
What is the type of environment crocodilians live in
Semiaquatic
What shaped palate do alligators have and what does this allow
U- shaped, easier to eat turtles.
Upper jaw wider so hides lower teeth
What shaped palate does a crocodile have and what does this allow
V- shaped, easier to catch fish. Jaw ear similar width so all teeth are exposed
What are Gharial/ gavial
Fish eating crocodiles (India), one of the longest crocs
What is a caiman
A smaller croc (south/central America), straight, wide jaws. Upper jaw covers lower jaw, so are technically alligators
Approx how many species of Squamata are there
5700