What are distinguishing characteristics of metatherian mammals?
Follow the directions for each activity. Answer the essay questions completely using thoughtful ideas, the course text, and outside reference sources, where applicable. Proofread answers for potential writing errors.
Part A. Metatherian Mammals
Part A Question1) What are metatherian mammals? What are distinguishing characteristics of metatherian mammals?
Extinct mammals, they are very few living. Metatherians, which comprise marsupials and their closest fossil relatives, were one of the most dominant clades of mammals during the Cretaceous and are the most diverse clade of living mammals after Placentalia. The only living metatherian mammals are the marsupials. There were some extinct metatherians that were not marsupials, such as the Sparassodonts, but as these have gone extinct, a metatherian is now just a synonym for a marsupial Metatherians belong to a subgroup of the northern tribosphenic mammal clade or Boreosphenida. They differ from all other mammals in certain morphologies like their dental formula, which includes about five upper and four lower incisors, a canine, three premolars, and four molar. In metatherians, marsupium is present which is required for carrying the infants
Part A Question2) Describe the biogeography of metatherian mammals.
Part A Question3) Using the following websites choose one extant (currently living) metatherian (marsupial) mammal species. Conduct research about the species. Discuss and analyze the species’ anatomy, ecology, and life history. Write a species account of at least 300 words correctly citing the reference source(s) you used. Scientific names are comprised of the genus (capitalized) followed by the species name (not capitalized) and they are italicized. For example, Ornithorhynchus anatinus.
Site Name
Web Site URL/Address
Mammalogy on the Internet
http://www.mammalsociety.org/mammalogy-internet
Tree of Life Web Project
http://www.tolweb.org/Mammalia
Animal Diversity Web
http://animaldiversity.ummz.umich.edu/site/accounts/information/Mammalia.html
Wilson & Reeder’s Mammal Species of the World
http://www.vertebrates.si.edu/msw/mswcfapp/msw/index.cfm
American Society of Mammalogists: Mammalian Species
http://www.mammalsociety.org/publications/mammalian-species
Mammalian Species pdf Site
http://www.science.smith.edu/departments/Biology/VHAYSSEN/msi/
National Geographic Mammals
http://animals.nationalgeographic.com/animals/mammals/
Species Scientific Name:
Species Common Name:
Species Account:
Part B. Comparison of Metatherian and Eutherian Mammal Ecology
Complete the table using the websites listed in Part B. Match the eutherian (placental) mammal with a similar ecological equivalent metatherian.
Scientific Name of Metatherian Mammal
Common Name
Ecological Description
Eutherian Mammal Match
Petaurus breviceps
Vombatus ursinus
Myrmecobius fasciatus
Notoryctes typhlops
Dasycercus cristicauda
Sarcophilus harrisii
Thylacinus cynocephalus
List of Eutherian Mammals to Match
Peromyscus polionotus
Talpa europaea
Glaucomys volans
Taxidea taxus
Myrmecophaga tridactyla
Canis latrans
Marmota flaviventris
Part B Essay Question: What are potential hypotheses (explanations) regarding why there are ecological equivalents between many metatherians and eutherians? Discuss your hypothesis in terms of the processes that could lead to the current ecologies and distributions of metatherians and eutherians.
