#22 and #23 mammals

Question 1

what do all mammals have

Answer 1

all have hair, all lactate, all have distinct skeletal characteristics, all endothermic

Question 2

what groups of mammals does australia have

Answer 2

australia is the only continent with all 3 mammal groups - eutherians, monotremes and marsupials

Question 3

what are the 3 groups of mammals and what species do they contain

Answer 3

monotremes - echidna , platypus
marsupials - possum, koala, kangaroo
eutherians - bats, dingo, rodents, seals, whales, dolphins

Question 4

what are characteristics of monotremes

Answer 4

• mothers lay eggs - oviparous
• they have pectoral limb and girdle
• mothers lactate however they do not have teats
• use electroreception to locate prey in their bill

Question 5

what are the features of marsupials

Answer 5

• viviparous
• raise young in their pouch
• short gestation period
• long lactation period

Question 6

what are the two groups of marsupials and what are they based on?

Answer 6

based on their teeth

diprotodont: 1 pair of incisors (omnivores - possum koala kangaroo)
polyprotodont: more than one pair of incisors (carnovores or omnivores - tassie devil, antechinus)

Question 7

when did the australian marsupial megafauna go extinct?

Answer 7

in the pleistocene 1.6MYA-10,000 years ago

giant wombat, tassie tiger, giant snakes and birds

Question 8

what is the hypothesis on the key factor driving extinction

Answer 8

collapse in species following human arrival, not linked to fire increase, species that disappeared were susceptible to harvest - was due to overhunting by people

Question 9

what is the dingos role in conservation

Answer 9

dingos may control introduced feral foxes and cats
this benefits the small marsupials
called meso-predator suppression
dingos eat foxes and cats, therefore the marsupials can do better