Biology Homework Help

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.