Taxonomic Classification:

• Monotremes belong to the Subclass Prototheria, meaning egg laying mammals.

• The order is Monotremata• They are split into two families,

Ornithorhynchidae meaning platypus, and Tachyglossidae meaning echidnas.

• There are also two genus forms of the Tachyglossidae family, Tachyglossus aculeatus meaning short-beaked echidnas and Zaglossus referring to the long-beaked echidnas.

How Monotremes are different from other mammals:

• a complex pectoral girdle• laying of eggs rather than giving birth to live young• limbs oriented with humerus and femur held lateral to

their body• and a cloaca

How Monotremes are similar to other mammals:

• they have fur• four chambered heart• single dentary bone• three middle ear bones• and the ability to lactate

Duck-billed PlatypusOrnithorhynchus anatinus

• The bill of the platypus is ultra sensitive for finding prey when digging underwater.

• The young platypuses have molar teeth, when they are adults they form horny plates on each side of their jaws for crushing and chopping their prey.

• Male platypuses have a sharp spur attached to each ankle, which are used for fighting.

The Order Didelphimorphia

• These are the opossums • They are marsupials • They are in one family, however there are

over 60 species• Most live in Central and South America• The opossum that we know belongs to the

species Didelphis virginiana (Virginia Opossum), which covers most of the U.S.

Common Characteristics of Opossums:

• Well developed teeth with large canines• They have a partially opposable toe on their

hind feet.• They have a prehensile tail that is usually long

and scaly.

Sources:

• http://animaldiversity.ummz.umich.edu/site/index.html