Paleogeography and Biodiversity in the Cenozoic: GEOL 105 Lab
What type of skull does Dimetrodon have?
Synapsid
What type of skull does the Cynodont have?
Synapsid
What were teeth primarily used for in early reptiles?
Tearing, not chewing
Process by which unrelated organisms independently evolve similarities when adapting to similar environments. Sometimes, two distinct lineages evolve similar characteristics, like wings, because of selective pressure. What type of evolution would this be?
Convergent evolution
A transitional fossil that lived in the Permian (299-251 my)
Cynodont
How many different kinds of teeth do modern mammals have?
3
How many different kinds of teeth does Cynodont have?
3
Sudden expansion of species diversity into new ways of life. One way it occurs is in response to events that free up previously occupied environmental zones and roles, making way for many new species that adapt to these vacant living spaces. e.g. extinction of the dinosaurs
Adaptive Radiation
When species have a common ancestor. Homologous structures are inherited from a common ancestor, therefore, these are a result of ______ evolution?
biological evolution
How are the teeth of the Gorgonopsid different from Dimetrodon?
Canine is longer/larger
How does having specialized teeth give mammals an advantage over their reptile ancestors?
Chewing breaks down food more effectively for metabolism by the body.
What happened to the supercontinent Pangaea by the start of the Cenozoic?
Completely separated.
India has now collided with Eurasia, forming the himalayan mountains. what type of plate boundary is this?
Continental-continental convergent
Describe the teeth of Cynodont
Differ in shape and size.
Describe the teeth of the modern mammal (bat)
Differ in size and shape
A mammal-like retile that lived in the Devonian (416-359 mya)
Dimetrodon
Same shape, differ in size
Dimetrodon teeth
Mainly small insect-eating creatures adapted to nighttime activity. Descended from more archaic synapsid relatives.
Early True Mammals
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 collision of the Indian and Asian plates.
What is the sedimentary rock that would have formed in Egypt during the Eocene?
Fossilferous limestone
A transitional fossil that lived in the mid-late permian (265-252 my)
Gorgonopsid
During the Eocene Epoch, methane was released from frozen tundra in Siberia, making this one of the warmest periods of Earth's history. There is no ice on earth. What is sea level like at this time, HIGH or LOW?
High
Are the teeth of cynodont and the bat A
Homologous
Biodiversity increases where there are multiple small landmasses compared to one large landmass. Based on this, is biodiversity HIGH or LOW in the Cenozoic?
Low
What was sea level like during the Pleistocene?
Lower
The Cenozoic is known as the Age of________?
Mammals
What was the climate like during the Pleistocene?
Much colder
Megalodon teeth can be found in Charleston. What does that tell you about sea level during the Miocene?
Much higher than today
Carry their young in a pouch (e.g. kangaroos, opossums)
Marsupials
Lay eggs externally (e.g. platypus and spiny anteater)
Monotremes
Retain the fetus internally during long gestation period (e.g. humans, cows, horses)
Placental mammals
What kind of geologic features and structures would you expect to find at the continental-continental plate boundary?
Reverse faults, anticlines and synclines
What kind of food did the Megalodon eat?
Seals, sea turtle, dolphins, whales
Describe the teeth of Gorgonopsid?
same shape, differ in size
What type of skull does Gorgonopsid have?
synapsid
What type of skull does the modern mammal have?
synapsid
