GEOLOGY 105 FINAL (COLLEGE OF CHARLESTON) 75
ACTUAL QUESTIONS & CORRECT DETAILED ANSWERS
|| GRADED A+ 2025 UPDATE
1. By the end of the cretaceous were there many types of mammals? ANS >>
No, because dinosaurs dominated the previous period and when they went extinct,
only few types of mammals were left.
2. Describe a typical mesozoic mammal. ANS >> - Synapsid skull
- Different tooth pattern
- Improved thermal regulation
- Hair
3. What were the possible functions of the "sail/fin" on the backs of some
pelycosaurs, such as Dimetrodon? ANS >>
1 B/ B
17
,4. Describe the earliest known mammal, Morganucodon. When did it live?
What was the size, morphology, and ecology of Morganucodont? ANS >> -
very small (4 in long)
- large brain / great senes
- Late triassic
- laid eggs
- hair
- teeth like mammals
- jaw of a reptile
5. Is Dimetrodon a dinosaur? why/why not? ANS >> No, because
dimetrodons have a synapsid skull where dinosaurs have a diapsid skill.
6. 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. ANS >>
- 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.
7. From what reptile group did mammals evolve? What are the differences
between reptile and mammals? ANS >> - 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.
2 B/ B
17
, 8. How are monotremes, marsupials, and placentals different with respect to
the birth of their offsprings? ANS >> -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
3 B/ B
17
ACTUAL QUESTIONS & CORRECT DETAILED ANSWERS
|| GRADED A+ 2025 UPDATE
1. By the end of the cretaceous were there many types of mammals? ANS >>
No, because dinosaurs dominated the previous period and when they went extinct,
only few types of mammals were left.
2. Describe a typical mesozoic mammal. ANS >> - Synapsid skull
- Different tooth pattern
- Improved thermal regulation
- Hair
3. What were the possible functions of the "sail/fin" on the backs of some
pelycosaurs, such as Dimetrodon? ANS >>
1 B/ B
17
,4. Describe the earliest known mammal, Morganucodon. When did it live?
What was the size, morphology, and ecology of Morganucodont? ANS >> -
very small (4 in long)
- large brain / great senes
- Late triassic
- laid eggs
- hair
- teeth like mammals
- jaw of a reptile
5. Is Dimetrodon a dinosaur? why/why not? ANS >> No, because
dimetrodons have a synapsid skull where dinosaurs have a diapsid skill.
6. 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. ANS >>
- 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.
7. From what reptile group did mammals evolve? What are the differences
between reptile and mammals? ANS >> - 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.
2 B/ B
17
, 8. How are monotremes, marsupials, and placentals different with respect to
the birth of their offsprings? ANS >> -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
3 B/ B
17
