Geology 105 Final (College of Charleston) || with
Authenticated Answers.
By the end of the cretaceous were there many types of mammals? correct answers No, because
dinosaurs dominated the previous period and when they went extinct, only few types of
mammals were left.
Describe a typical mesozoic mammal. correct answers - Synapsid skull
- Different tooth pattern
- Improved thermal regulation
- Hair
What were the possible functions of the "sail/fin" on the backs of some pelycosaurs, such as
Dimetrodon? correct answers
Describe the earliest known mammal, Morganucodon. When did it live? What was the size,
morphology, and ecology of Morganucodont? correct answers - very small (4 in long)
- large brain / great senes
- Late triassic
- laid eggs
- hair
- teeth like mammals
- jaw of a reptile
Is Dimetrodon a dinosaur? why/why not? correct answers No, because dimetrodons have a
synapsid skull where dinosaurs have a diapsid skill.
Discuss the steps in the transition from therapsid reptiles to mammals.
What were the major innovations during the transitions?
Be sure to include changes to the jaws/ears from reptiles to mammals. correct answers - more
upright stance, where the belly would be under the body. Canines, molars, and incisors showed
different tooth pattern. Improved thermal regulation. Hair in small therapsids.
From what reptile group did mammals evolve? What are the differences between reptile and
mammals? correct answers - Cynodont is the transitional animal between mammal and reptiles.
- Reptiles lower jaw has 4 bones and jaw hinges, mammals have 1 bone.
- Mammals nurse there young, warm blooded, and have hair versus scales.
How are monotremes, marsupials, and placentals different with respect to the birth of their
offsprings? correct answers -Monotremes are mammals that lay eggs; babies grow inside egg
until fully developed; the only living form is the platypus
-Marsupials give birth to live young; young are carried in a pouch on the front of the mothers
body; stay inside pouch until fully developed
, -Placentals give birth to live young; fetus is nourished during gestation; carried in mother until
fully developed
What is the relationship between Cynodonts and early mammals? Explain and cite evidence.
correct answers - Cynodonts have the same teeth as mammals-- humans got their tooth pattern
from mammals.
What characteristics do you share with Theriodonts? correct answers - Mammal- like reptiles
that lived from Mid Permian to late cretaceous.
- Theriodont jaws that made chewing a lot easier, back teeth were larger to chew meat;
- Synapsid skull
What is a mammal? correct answers - Warm blooded animals have body hair, 3 middle ear
bones, special teeth structure and nourish young with milk.
What is special about the duck-billed platypus? By examining the duck-billed platypus what can
we learn about early mammals? correct answers - Australia is the only continent with living
Platypus
- The platypus swims in muddy water with its eyes, ears, and nostrils slightly shut searching for
crustacean prey w/ electoral sensors in its beak.
Summarize the evidence for a meteorite impact causing the mass extinction at the ned of the
mesozoic era? correct answers - iridium found in sediment.
- There was a crater from a meteorite.
- Ash layer from fires
- shocked quartz and tektites
Why are extinctions important? correct answers - resets evolutionary clock
- many open niches
- opportunity for diversity
- new species
Describe the effects of the meteorite impact on Earth's systems and how these effects would have
led to the mass extinction. correct answers - Smoke from meteorite caused a nuclear winter
- months of global refrigeration, the sunlight was blocked.
- delayed greenhouse warming
- acid rain and wild fires.
- no photosynthesis, so plants die = ecosystems die.
What are shocked quartz and tektites and how were they formed? correct answers - shocked
quartz form when a microscopic structure becomes deformed along plane inside crystal de to
intense pressure and temperature of meteorite impact.
- Tektites are small, pebble like glassy objects of earths material that have been melted by
meteorite impact.
Authenticated Answers.
By the end of the cretaceous were there many types of mammals? correct answers No, because
dinosaurs dominated the previous period and when they went extinct, only few types of
mammals were left.
Describe a typical mesozoic mammal. correct answers - Synapsid skull
- Different tooth pattern
- Improved thermal regulation
- Hair
What were the possible functions of the "sail/fin" on the backs of some pelycosaurs, such as
Dimetrodon? correct answers
Describe the earliest known mammal, Morganucodon. When did it live? What was the size,
morphology, and ecology of Morganucodont? correct answers - very small (4 in long)
- large brain / great senes
- Late triassic
- laid eggs
- hair
- teeth like mammals
- jaw of a reptile
Is Dimetrodon a dinosaur? why/why not? correct answers No, because dimetrodons have a
synapsid skull where dinosaurs have a diapsid skill.
Discuss the steps in the transition from therapsid reptiles to mammals.
What were the major innovations during the transitions?
Be sure to include changes to the jaws/ears from reptiles to mammals. correct answers - more
upright stance, where the belly would be under the body. Canines, molars, and incisors showed
different tooth pattern. Improved thermal regulation. Hair in small therapsids.
From what reptile group did mammals evolve? What are the differences between reptile and
mammals? correct answers - Cynodont is the transitional animal between mammal and reptiles.
- Reptiles lower jaw has 4 bones and jaw hinges, mammals have 1 bone.
- Mammals nurse there young, warm blooded, and have hair versus scales.
How are monotremes, marsupials, and placentals different with respect to the birth of their
offsprings? correct answers -Monotremes are mammals that lay eggs; babies grow inside egg
until fully developed; the only living form is the platypus
-Marsupials give birth to live young; young are carried in a pouch on the front of the mothers
body; stay inside pouch until fully developed
, -Placentals give birth to live young; fetus is nourished during gestation; carried in mother until
fully developed
What is the relationship between Cynodonts and early mammals? Explain and cite evidence.
correct answers - Cynodonts have the same teeth as mammals-- humans got their tooth pattern
from mammals.
What characteristics do you share with Theriodonts? correct answers - Mammal- like reptiles
that lived from Mid Permian to late cretaceous.
- Theriodont jaws that made chewing a lot easier, back teeth were larger to chew meat;
- Synapsid skull
What is a mammal? correct answers - Warm blooded animals have body hair, 3 middle ear
bones, special teeth structure and nourish young with milk.
What is special about the duck-billed platypus? By examining the duck-billed platypus what can
we learn about early mammals? correct answers - Australia is the only continent with living
Platypus
- The platypus swims in muddy water with its eyes, ears, and nostrils slightly shut searching for
crustacean prey w/ electoral sensors in its beak.
Summarize the evidence for a meteorite impact causing the mass extinction at the ned of the
mesozoic era? correct answers - iridium found in sediment.
- There was a crater from a meteorite.
- Ash layer from fires
- shocked quartz and tektites
Why are extinctions important? correct answers - resets evolutionary clock
- many open niches
- opportunity for diversity
- new species
Describe the effects of the meteorite impact on Earth's systems and how these effects would have
led to the mass extinction. correct answers - Smoke from meteorite caused a nuclear winter
- months of global refrigeration, the sunlight was blocked.
- delayed greenhouse warming
- acid rain and wild fires.
- no photosynthesis, so plants die = ecosystems die.
What are shocked quartz and tektites and how were they formed? correct answers - shocked
quartz form when a microscopic structure becomes deformed along plane inside crystal de to
intense pressure and temperature of meteorite impact.
- Tektites are small, pebble like glassy objects of earths material that have been melted by
meteorite impact.
