Crocodylians

Question 1

what is the most diverse era of crocodylians

Answer 1

early creataceous

Question 2

what are included in crocodylians

Answer 2

• crocodiles
• alliagtors
• gharials

Question 3

what is crocodylians habitat

Answer 3

tropics and sub tropics
- semi aquatic and hunt in the water

Question 4

how do crocodiles move on land?

Answer 4

belly crawl (slow)
- legs are to the side of body
high walk
- legs are under body
galloping (fast)
- like a dog, body is off the ground

Question 5

how do crocodiles move in water?

Answer 5

• they keep their limbs close to body unless they have to steer
• they can shuffle the lungs and liver to change their centre of gravity
• they jump by thrusting their tail

Question 6

how do crocodiles feed?

Answer 6

• they do the death roll to kill and takedown prey
• can hide on surface of water due to eyes and snut on dorsal surface head
• have a gizzard and consume rocks for mechanical digestion (gastroliths)
• they have very low metabolism so they can go awhile without food (fat pads)
• they have a gular valve to avoid getting water in lung while they eat

Question 7

how do crocodylians reproduce?

Answer 7

leathery eggs in nest (mound) or hole
- minimal parental care

Question 8

explain the heart of a crocodylian

Answer 8

4 chambered heart with right sinus venous and divided interventricular septum
- the foramen of panizza controls blood volume to lungs

Question 9

how crocodilian controls the flow of blood

Answer 9

during regular breathing, oxygenated blood goes through the left and right aortic arch due to the foramen of panizzan. During apnea (temporal stopping of breathing), the blood from the left ventricle go into the left aortic arch instead of going to the lungs and all he blood eventually gets mixed until breathing starts again

Question 10

why do crocodylians go through apnea after eating

Answer 10

to increase CO2 in blood to make stomach more acidic for digestion

Question 11

why do crocodilians have the most complex vertebrae heart?

Answer 11

they have 4 chambers like mammals and bird but can also shunt their blood when needed like turtles

Question 12

how do crocodliyans breathe?

Answer 12

they get air in the the body like humans which is the first of it being seen but it still goes in a unidirectional way so mixing does not occur

Question 13

what is the relation with bite force and body size?

Answer 13

bigger the body, harder the bite

Question 14

how do scales develop in crocodlyians?

Answer 14

they are no symmetrical like most reptiles
- head scales develop later and are random for them