Diapsids

Question 1

Give the 2 living lineages of diapsid.

Answer 1

Lepidosaurs

Archosaurs

Question 2

What is found within the Lepidosaurs lineage ?

Answer 2

Tuatara and Squamates

Question 3

Give some of the features of the Lepidosaurs lineage ?

Answer 3

Largest group of non avian reptiles
Primarily terrestrial tetrapods
Reduction or loss of limbs
Scale covered skin, shed at intervals

Question 4

When did the tuatara evolve ?

Answer 4

220 million years ago

Question 5

How many species of Tuatara remain ?

Answer 5

2 species, due to human colonisation

Question 6

Tuatara are lizard like, what is the defining difference between them ?

Answer 6

Tuatara have a heavier skull

Question 7

Why is temperature important to tuatara ?

Answer 7

Determines the sex of the offspring.

Can propagate extinction process, (i.e higher temp- more males)

Question 8

Describe key charecteristics of the tuatara life style.

Answer 8

Nocturnal (live in cool habitats)
Found in burrows- share with seabirds.
Dependant on seabirds for food
Sit and wait predators

Question 9

Tutatara have a slow reproduction, describe this ?

Answer 9

Reach maturity at 10-20 years
Breed once every 4 years
Embryos take 11-14 months to hatch

Question 10

What is the 3rd eye of the tuatara used for ?

Answer 10

Only present in young life

Absorbs UV light

Question 11

What species are contained within the Squamata ?

Answer 11

Lizards and snakes

Question 12

When did the squamates evolve ?

Answer 12

240 million years ago

Question 13

Give the key features of the squamates

Answer 13

Vary in size, 16mm- 3m
Highly kinetic skulls
Scaly skin 
Legged and legless forms 
Worldwide distribution

Question 14

What is the benefit of limb reduction to a diapsid ?

Answer 14

Advantages in habitats with narrowing openings

Beneficial on sand, tall grass and burrowing.

Question 15

List the 6 indigenous UK squamate species

Answer 15

Smooth snake 
Sand lizard
Common Lizard
Grass snake 
Adder
Slow worm

Question 16

What is the other lineage, besides the Lepidosaurs ?

Answer 16

The Archosaurs

Question 17

List the species, extant and extinct in the Archosaurs

Answer 17

Crocodillians
Pterosaurs
Dinasours, Birds

Question 18

What main groups are contained within the crocodilians ?

Answer 18

Alligators and Crocodiles

Question 19

How many species exist In the Crocodillians ?

Answer 19

23 living species

Question 20

What habitat are the crocodilians confined to ?

Answer 20

Tropical and subtropical waters

Question 21

Give an adaption of crocodiles and Gharials (fish eating croc) to marine environments

Answer 21

Modified salivary glands on their tongues for excreting excess salt

Question 22

What do Alligators and Caimans have that is also found in Gharials and crocodiles ?

Answer 22

The same modified salivary gland for secretion of salt.

However it is non functioning

Question 23

All crocodiles are Gastroliths, what does this mean ?

Answer 23

They have a stomach stone

Acts as a grinder to aid prey digestion

Question 24

How many stomach do crocodiles have ?

Answer 24

2 stomachs
1st is muscular to grind prey
2nd is acidic to digest bones, feathers and horns

Question 25

State the number of species in the Alligatoridea.

Answer 25

8 species

Question 26

State the number of species in the Crocodylidae.

Answer 26

13 species

Question 27

State the number of species in the Gavialidae

Answer 27

2 species

Gharial and the false gharial