Cenozoic-Diversification of animals

Question 1

What were the 3 main clades to emerge in the Palaeogene post extinction?

Answer 1

Birds, Mammals and Teleost fishes

Question 2

Define and describe birds

Answer 2

-Specialised archosaurs
-Therapods
-defined by feathers, endothermy, hollow bones, toothless beak and clasping claws
-Complex breathing through bidirectional air sacs
-Pectoral appendage modified for flight

Question 3

Name the 3 classifications of birds and their abundance of species.

Answer 3

-Neoaves (+9000)
-Fowl Galloanserae (400)
-Flightless palaeognathae (47)

Question 4

Describe the evolution of feathers

Answer 4

Hollow filaments, tufts, serial barbs, secondary barbs (filamentous barbs seen in pterosaurs/dinos)

Question 5

Define and describe mammals

Answer 5

-mammary glands+lactation
-Hair+sweat glands
-one jaw bone (dentary) and three middle ear bones
-originated from early synapsids (Dimetrodon) in the early Permian

Question 6

Name the 3 classifications of mammals and their abundance of species.

Answer 6

-Placentals (6000)
-Marsupials (300)
-Monotremes (5)

Question 7

Define and describe Ray-finned fishes

Answer 7

-Air-filled swim bladder controls buoyancy
-Fin rays
-large diversity in the Mesozoic
-mass radiation post Kt-P extinction (Acanthomorpha)

Question 8

Name the 2 classifications of Ray-finned fishes and their abundance of species.

Answer 8

-Teleost’s (26000)
-Non Teleost’s (100)

Question 9

What is adaptive radiation?

Answer 9

A rapid diversification of organisms from ancestral species into multiple new forms to fill new niches.

Question 10

What is an ecological niche?

Answer 10

The position of a species within an ecosystem in terms of the range of conditions it can persist in including both biotic an abiotic environments.

Question 11

How do mass extinctions cause adaptive radiations?

Answer 11

Mass extinctions cause niches availability which is filled in by new species once and as the ecosystem recovers.

Question 12

What happened to flora and fauna post Kt-P extinction?

Answer 12

-Plants recovered very quickly
-Mammals got bigger quickly
-Insects were relatively unaffected

Question 13

Describe the climatic conditions of the Palaeogene.

Answer 13

Very high temperatures (little polar ice) which was marked by the Palaeocene-Eocene thermal maximum (PETM)

Question 14

Describe the PETM.

Answer 14

5-8 degrees C higher temps (greenhouse conditions)
-Large injection of CO2 over a short period of time (1000s of years)
-Benthic foraminifera extinction due to pH spike

Question 15

What were some of the biotic responses to the PETM?

Answer 15

-Foraminifera got smaller
-Plants diversified
-Animal body size increased

Question 16

How does current climate change compare to the PETM?

Answer 16

Current rates of emissions and temperature rise is much higher the seen in the PETM :(

Question 17

What geologic and climatic events occurred during the Neogene?

Answer 17

-Continental arrangement finally resembles that of the modern planet
-Isthmus of Panama forms
-India and Eurasia collide
-Africa and Eurasia collide
-Ice covered poles

Question 18

What are browsers?

Answer 18

Herbivores that feed on leaves, shoots and fruits high up.

Question 19

What are grazers?

Answer 19

Herbivores that feed on low veggies (grasses/algae’s).

Question 20

What are Ungulates and what are their characteristics?

Answer 20

-Hoofed toes mammals (even and odd toed categories)
-Specialised guts and teeth to eat grass
-Whales are Ungulates but their hoofs adapted into fins (Ambulocetus: prehistoric walking whale)

Question 21

What feeding shift occurred in the Neogene?

Answer 21

There was a shift from browsing to grazing Ungulates.

Question 22

What are primates?

Answer 22

A diverse group of mammals with large brains, specialised vision and grasping appendages.

Question 23

What are the 3 main groups of primate?

Answer 23

Lemuriformes, Tarsiiformes and Simiiformes.

Question 24

What major characteristics to primates exhibit?

Answer 24

-Colour vision (tri/dichromatic)
-Grasping hands (flat keratin nails and opposable thumbs)
-Sexual dimorphism

Question 25

What feature impact brain size?

Answer 25

Body size, Sensory processing and social behaviour.