Lepidosaurs

Question 1

what counts as lepidosaurs?

Answer 1

• snakes
• lizards
• mosasaurs (extinct)
• tuatara

Question 2

what are the shared lepidosaur characteristics

Answer 2

• keratinous overlapping scales
• 3 chambered heart similar to turtle
• detachable tail if danger (not snakes)
• paired hemipenis

Question 3

what is a rhychocephalian?

Answer 3

it is the only surviving species of tuatara
lives in New Zealand

Question 4

what are some shared lizard characteristics?

Answer 4

• paraphyletic group that excludes snakes
• they are diapsid
• most have cranial kinesis: additional joints in skull to make them flexible (open jaw wider)

Question 5

what are some says lizards breathe?

Answer 5

• by running bipedal
• glossal pumping (muscular throat pumping air)

Question 6

how intense is parental care in lepidosaurs?

Answer 6

varies within groups but no much

Question 7

what are some predatory adaptations in lepidosaurs

Answer 7

• sit and wait: usually camouflage into environment
• widely foraging: constantly on the move to find smt
• luring with tail to look like plant

Question 8

what are some snakes characteristics

Answer 8

monophyletic group
- absence of eyelids
- reduced colour vision
- highly modified skull
- lack of external ear
- even more cranial kinesis
(not all legless reptiles are snakes)

Question 9

what is special about snake heads

Answer 9

due to their extensive cranial kinesis they can increase their jaw flexibility A LOT because of their extra joints

Question 10

how do snakes feed?

Answer 10

• cranial kinesis allows them to eat things bigger than their mouth
• may immbolize or use venom to constrict prey
• have curved fangs

Question 11

how do snakes defend themselves?

Answer 11

• venom (most popular)
• taking the potions of others
• look more intimating with rattle

Question 12

what were mosasaur characteristics

Answer 12

they are extinct
- top predator
- breathed air
- vivparitous

Question 13

how are monosaurs related to lizards?

Answer 13

through varanid lizards (includes Komodo dragons)

Question 14

what are the evolution hypothesis of snakes?

Answer 14

swimming hypothesis
- they have the same skull as monosaurs and the earliest snake fossils came form the water so maybe they came from them
burrowing hypothesis
- many of their characteristics (like lack of eyelids) seems like they lived the fossorial lifestyle