Monotremata, Marsupiala and Eutherian --> major clades of mammals

Question 1

What species include Monotremes?

Answer 1

platypus and echidnas

Question 2

Where do monotremes mainly live?

Answer 2

australia or new guinea

Question 3

what type of eggs do monotremes lay? how do they feed their young?

Answer 3

oviparous (lays eggs) and they have skin patches (no nips) where milk comes out from and they feed their young

Question 4

what kind of reproductive site do monotremes have?

Answer 4

cloacas (no reproductive sites and pee and poop out same hole)

Question 5

What do monotremata feed on?

Answer 5

verebrates

Question 6

What are some similar features of marsupials and Eutherians? (how do they give birth, and what do they do after birth, what is the role of the placenta)?

Answer 6

they give viviparous birth –> birth to live young

• their placenta (extra embryonic membranes and lining of uterus) provides nourished to young initially
• after birth they are nursed on milk from nipples and they have conical outlets

Question 7

What structure is the placenta homologous to?

Answer 7

amniotic egg membrane

Question 8

What are some features about the birth of marsupials?

Answer 8

their young is briefly nourished by the placenta, and they are born as a partially developed embryo (really under developed)
- they continue the rest of their development usually in their mother’s mouth (their pouch has nipple glands) –> some don’t have a pouch and young hang on mother’s fur

Question 9

what species do marsupials consist of?

Answer 9

koalas, kangaroos, possums…etc..

Question 10

Why are MOST marsupials restricted to australia?

Answer 10

Earth used to be a big lump of land before, but when pangea and movement of tectonic plates started to occur,, there was more diversity in animals that outcompeted the marsupials in terms of survival and natural selection, the only place that didn’t have those competitions was the island of australia

Question 11

What structures are analogous and from convergent evolution?

Answer 11

• marsupials and placental mammals evolved to fill the same ecological niche in different parts of the world
  theres similarities in terms of mammals and marsupials in australia

Question 12

What kind of mammals are eutherians?

Answer 12

non-marsupial mammals

Question 13

how do eutherians nourish their young?

Answer 13

they nourish them in the womb via placenta until they are very DEVELOPED

Question 14

How do eutherians feed their young?

Answer 14

they have nipples that are not in pouches and number of nipples usually indicates number of offspring they can have at a time

Question 15

Do eutherians have a cloaca?

Answer 15

no they don’t. they have a separate anal and urinary opening

Question 16

Where did eutherians undergo diversification? what is this evidence based on ?

Answer 16

they went through diversification in africa and its based on dan evidence

Question 17

What species include the Xenarthra within the eutherian clade

Answer 17

anteaters, sloths, armadillos

- evolved in south america and many species lack teeth

Question 18

What continents do eutherian species live?

Answer 18

europe, asia and north america

Question 19

What are 6 phylum within the eutherian?

Answer 19

1. Carnivora –> dogs, wolves, bears, cats, weasels, otters, seals and walruses
2. cetariodactyla –> artiodactyls, sheep, pigs, cattle, deer giraffes (even toed- ungulates)
3. Cetaceans –> whales, dolphins, porpoises (marine mammals)
4. Perissodactyla –> horses, zebras, tapirs, rhinoceroses (odd toed ungulate)
5. Chiroptera –> bats
6. Eulipotyphla –> core insectivores, moles, shrews …. meer cats, hyenas, leopard seals…

Question 20

What are some facts about bats?

Answer 20

• they are the only mammals capable of flight
• they are nocturnal, and many use sonar argument sight
• they suffer from white nose syndrome due to being wiped out via fungi disease

Question 21

What other animals does the clade with rodents and humans have in?

Answer 21

Lagomorpha –> rabbits, hares and picas

• rodentia –> squirrels, beavers, rats porcupines and mice
• primates –> lemurs, monkeys, chimpanzees, gorillas and humans