Mammalogy Midterm Review Questions

Origins

1. What characteristics define the mammals? Include both physiological and morphological characters. 2. Explain why the evolution of endothermy is so problematic. Recall, ectotherms require only about 5% as much energy as endotherms. What happens if fur evolves first? What happens if the high metabolic rate evolves first? 3. What is the significance of the synapsid skull? 4. Explain the evolution and significance of the dentary/squamosal jaw articulation. 5. Explain the significance of the sail found on some pelycosaurs. 6. How does the evolution of mammals correspond to the 2 major mass extinctions (end Permian mass extinction, and end Cretaceous mass extinction)? 7. Explain the significance of the secondary palate, jaw musculature, complex cheek teeth, and dentary to the adaptive radiation of the mammals. 8. Explain how regionalization of the vertebral column influenced mammalian life styles. 9. Are mammals monophyletic or polyphyletic? Why? 10. What is the significance of the triconodont tooth? 11. Be able to diagram and label a tribosphenic tooth. 12. What is the significance of the multituberculata? 13. What factors contributed to the adaptive radiation of the mammals after the end Cretaceous mass extinction? Was this radiation due solely to the extinction of the dinosaurs? Did other factors contribute? What?

Monotremes

1. List and explain the morphological and physiological characteristics of monotremes that are similar to those of the reptiles. 2. Why, do you think, male monotremes have permanently abdominal testes? 3. Characterize the placentas of Monotremes, Marsupials (except numbats), Reptiles, and Eutherians.

Marsupials

1. Explain the worldwide distribution of marsupials in light of continental drift. 2. Why are young marsupials born while still so poorly developed? This is a solution to what problem? 3. What is wrong with the argument that marsupial diversity is so low because of competition with eutherians? 4. What does Thylacosmilus tell us about the evolution of marsupials? 5. How do new world marsupials differ from Australian marsupials? 6. Think about teeth and feet. What are the major morphological themes of the marsupials? 7. How does the morphological diversity of marsupials mirror other mammals? Are their ecological equivalents? Give some examples.

Insectivores

1. Why are the insectivores considered a garbage basket of groups? 2. What morphological features are associated with the insectivores? 3. What is zalambdodont dentition? What is dilambdodont dentition? 4. When we say the dental formula is plesiomorphic, what do we mean? 5. What is ‘self annointing’ in hedge hogs? 6. Why are all insect eating insectivores so small? 7. Describe the morphological adaptations associated with fossoriality in the Talpidae. 8. What’s the big deal about Tenrecs? 9. What is the significance of Solenodon? 10. What is meant by ‘red-toothed’ and ‘white-toothed’ shrews? 11. What is the consequence of small size in insectivores? 12. Why were the Tupaiid long considered primates?

Dermoptera

1. Why do I care about Colugos? 2. What’s up with the patagia of the Dermoptera? 3. What is the function of the pectinate incisors in Colugo?

Chiroptera

1. Be able to discuss the 2 major hypotheses for the origin of flight. 2. Why are bats nocturnal and birds diurnal? 3. Why do we have no intermediate forms for the evolution of bats? 4. Be able to discuss the morphological adaptations of bats to flight. 5. What are the basic physical requirements of flight 6. How does wing morphology relate to flight style? 7. Be able to diagram and label the components of the bat flight structures. 8. Be able to discuss echolocation. 9. Be able to differentiate between FM and CF bats. How do these modes differ? 10. What foraging mode fits with each? 11. Why use high frequency sound waves? 12. Are the bats diphyletic or monophyletic? Why do you think that?

Primates

1. Why is it difficult to define the primates? 2. How do haplorhines and strepsirhines differ? 3. Why might rotation of the hindlimb be important for primates? 4. What is the significance of the postorbital bar? 5. Ther is some speculation in the literature that paramomyids were gliders. What morphological features of primates might also be associated with gliding locomotion? 6. Did primates evolve from a terrestrial form, or an arboreal form? 7. Describe the unique morphology of the Aye-aye. 8. We made a big deal about the role of communication in primates. Explain how this is manifested in the external appearance and behavior of various primate groups. 9. Why is there such diversity in the morphology of primate hands and feet? 10. How would you expect the morphology of brachiators and vertical clingers/leapers to differ? 11. How does sexual dimorphism relate to reproductive system in primates?