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
Metatherian mammals, also known as marsupials, are a group of mammals that are characterized by their distinctive mode of reproduction. Unlike placental mammals, which give birth to relatively mature young that are nourished by a placenta, metatherian mammals give birth to relatively undeveloped young that are carried and nourished in a pouch on the mother’s abdomen.
Some of the distinguishing characteristics of metatherians include:
• Pouch: Most metatherians have a pouch, also known as a marsupium, in which their young are carried and nourished. The pouch is located on the mother’s abdomen and typically opens towards the hind legs.
• Birth: Metatherian mammals give birth to relatively undeveloped young, which are called joeys. The young are born after a relatively short gestation period, and continue their development in the pouch.
• Teats: Metatherian mammals have teats that are located outside of the pouch. The young are able to access the teats and nurse while they are inside the pouch.
• Dentition: Most metatherians have a different dental formula than placental mammals. They typically have fewer incisors and molars, and more premolars.
Some examples of metatherian mammals include kangaroos, opossums, and wallabies. These animals are found primarily in the Americas and Australia