Paleogeography and Biodiversity in the Cenozoic

Species such as giant sloths and mastodons from the ice age have been found in southern states like South Carolina. What does this tell you about the climate in South Carolina during the last ice age? Was it COLDER or WARMER than the present day?

colder

What do you think is the advantage of having nostrils on top of the head if you live in water?

coming up for oxygen, it is easier to breath air without lifting the head out of the water

What has happened to the supercontinent Pangaea by the start of the Cenozoic?

completely separated and volcanic rifting

India has now collided with Eurasia, forming the Himalayan Mountains. What type of plate boundary is this?

continental-continental convergent

Analogous structures evolve independently; they are similar structures that appear in groups of organisms. Are these structures a result of BIOLOGICAL or CONVERGENT evolution?

convergent

Sometimes, two distinct lineages evolve similar characteristics, like wings, because of selective pressure. Would this be BIOLOGICAL or CONVERGENT evolution?

convergent

Antarctica separates from Australia during this epoch and a cold circumpolar ocean current forms (a current around Antarctica). This cold water current cuts off warmer water from circulating near Antarctica. Cold water cools the air above it. Will this WARM or COOL climate of Antarctica? Will the amount of glaciers on Antarctica INCREASE or DECREASE? Will this lead to a HIGHER or LOWER global sea level?

cool climate, increase glaciers, lower global sea level

Mammals evolved during the Mesozoic, but took over and diversified after the end-Cretaceous extinction event that wiped out what group of animals had dominated in the Mesozoic?

dinosaurs

What where teeth primarily used for in early reptiles

tearing & biting

What can the abundance of mammoth vs mastodon fossils tell us about climate in a particular region at that time?

tell us if it is cold/icy or warm/wet

biological evolution

the change over time in populations of related organisms

Describe the teeth of the bat. How many different kinds of teeth do modern mammals have?

they are not all the same size or shape, there are three different types of teeth

Describe the teeth of a Gorgonopsid. How are the teeth DIFFERENT from Dimetrodon?

they are not all the same size or shape. They are different because of the elongation of canine and incisors

How does having specialized teeth give mammals an advantage over their reptile ancestors?

they chew better, therefore breaking the food down more allowing an easier digestion process

What did mastodons eat?

trees & woody vegetation

After North and South America were connected, ocean currents were forced to flow north-south. Thewarm waters of the Gulf Stream now flow north along the east coast of North America and over toEurope. See slide 5. What affect did this have on climate in North America and Europe?

warmer and wetter climate

Based on what you learned about grasslands vs. forests in the Miocene section, question 2, what type of climate would mammoths have preferred based on what they ate? What type of climate would mastodons have preferred?

wooly mammoth (cold grasslands/ cold & dry climate), mastodons (warm forests/ warm & wet climates)

homologous structures

Structures in different species that are similar because of common ancestry.

What was the climate like during the Pleistocene? What was sea level like during this time?

less competition, isolated from other continents

The Cenozoic is known as The Age of __________________.

mammals

Is this an example of CONVERGENT or BIOLOGICAL evolution?

biological

When different species have a common ancestor, is this BIOLOGICAL or CONVERGENT evolution?

biological

How many millions of years long was the Mesozoic era?

251-65.5 mya

How many millions of years long was the Paleozoic era?

540-251 mya

How many millions of years ago did the Cenozoic era start?

65.5 mya

analogous structures

Body parts that share a common function, but not structure

Sedimentary Rock that would have formed in Egypt during the Eocene

Fossiliferous Limestone

Is Australia connected to any other continents? How might this explain why marsupials are so common in Australia compared to the rest of theworld?

No

convergent evolution

Process by which unrelated organisms independently evolve similarities when adapting to similar environments

What kind of geologic features and structures would you expect to find at convergent continental-continental collision? List all that apply from the following

Reverse faults, anticlines and synclines

Compare Xenosmilus, a Saber-toothed cat that lived in the Pleistocene (found along the backwindows), to Hoplophoneus, a smaller saber-toothed cat that lived during the Oligocene, 20 million years earlier(found in the case in the center of the museum on the side facing the entrance).a. What similarities do you see between these two predators?b. What is one BIG (hint) difference? 88d. Surprisingly, their large canines are an example of ANALOGOUS structures, which evolved independently(not from a common ancestor). Therefore, is this CONVERGENT or BIOLOGICAL evolution?

both have big canines, the Xenosmilus had bigger teeth and overall size, is an example of convergent evolution

What does the proliferation of grasslands indicate about the climate of the late Cenozoic compared to the late Cretaceous?

change in ocean currents create worldwide cooling & drying

Describe the teeth of the Dimetrodon

all are not the same size, but are the same conical shape

What do these animals all have in common when comparing them with their modern-day descendants, (Ice Age Megafauna), How does their size make them well-adapted to the cold climate during the Pleistocene?

bigger & more muscle warmth, larger bodies retain heat

Homologous structures are inherited from a common ancestor. Therefore, are these structures a result of BIOLOGICAL or CONVERGENT evolution?

biological

what is the general trend of sea level so far in the Cenozoic? Is it RISING or FALLING?

falling

Rocks and fossils that once existed in the Tethys Sea can now be found high in the Himalayas. Describe how the formation of the Himalayas caused this to occur

formed by the collision of the Indian and Asian plates. One plate cannot subduct the other, the convergent boundary's compression pushes up the crust and sediments

Biodiversity increases when there are multiple small landmasses compared to one large landmass. Based on this, is biodiversity HIGH or LOW in the Cenozoic?

high

Megalodon teeth can be found in Charleston. What does that tell you about sea level during the Miocene?

high

What is sea level like during the Eocene, HIGH or LOW?

high

Are the teeth of cynodont and the bat are ANALOGOUS or HOMOLOGOUS?

homologous

Compare the bones in the front foot of Maiacetus to flipper of Tursiop truncates. Do they have the sametypes of bones (think back to the bones of tetrapods like Acanthostega from the Paleozoic lab) like thehumerus, radius & ulna, and distal elements? Or do they have different types of bones, like the rayfinned fish compared to the lobe-finned fish? Is this an example of ANALOGOUS or HOMOLOGOUS structures? Is this an example of CONVERGENT or BIOLOGICAL evolution?

no they have different types of bones, example of homologous structures, example of biological evolution

What did mammoths eat?

plants (grass & sedge)

What kind of food did Megalodon eat?

seals, sea turtles, dolphins, whales, other sharks, & large fish

Describe the teeth of cynodont.

small and sharp, contain molars. They are not all the same size or shape. There are three different types of teeth.

What type of skull does Dimetrodon have? DIAPSID or SYNAPSID

synapsid

What type of skull does Gorgonopsid have? DIAPSID or SYNAPSID

synapsid

What type of skull does cynodont have? DIAPSID or SYNAPSID

synapsid

What type of skull does the modern mammal (bat) have? DIAPSID or SYNAPSID

synapsid