Historical Geology - The Cenzoic

Question 1

What is the Cenzoic era?

Answer 1

After the Mesozoic era (end of the K/Pg event) continues into the present. Sometimes called the age of mammals

Question 2

How did the ocean recover from the K/Pg event?

Answer 2

• Planktonic foraminifera diversify at astounding rate
• marine megafauna Eocene evolution of whales
• Cetacean ancestors • Closest living relatives are hippopotamids
• Large sharks evolved during the Eocene

Question 3

What were the major shifts in cetaceans?

Answer 3

– Breathing mechanism
– Limb structure
– Vertebral column
– Echolocation

Question 4

How long did the megalodon shark survive?

Answer 4

until the pliocene

Question 5

How did the land recover from the K/Pg event during the Paleocene period?

Answer 5

• Slow recovery of biodiversity
• Flowering plants diversify and entrench themselves as the dominant plant life
• Birds and mammals start to occupy open niches

Question 6

Discuss the recovery of mammals after the K/Pg event.

Answer 6

• all modern mammalian orders were present at the beginning of the Eocene (~55mya)
• Rapid diversification of mammals into most available niches
• variation -Body size - Locomotory habits - Feeding habits

Question 7

When did grasslands start to become abundant after the K/Pg event?

Answer 7

~25mya during the Miocene

Question 8

Discuss the great American interchange.

Answer 8

peaked during the Pliocene ~3mya

North American taxa head south
racoons-rabbits-dogs-horses-deer-camels-bears-pumas-mastodonts

South American taxa head north
opossums-armadillos-porcupines-anteaters-glyptodonts-ground sloths

Question 9

What animal disappeared after the great American interchange?

Answer 9

The South American Megapredators • Phorusrhacidae (‘Terror Birds’)