Cladotheria

Cladotheria is a taxonomic group. It includes two of the three living groups of mammals. These are the placental mamnals and the marsupials. The monotremes are not in this group, but all other living mammals are in the group.^[1]

Cladotheria Temporal range: Middle Jurassic – Holocene, 165–0 mya
Kangaroo with her joey
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Clade:	Trechnotheria
Clade:	Cladotheria McKenna, 1975
Subgroups
†Amphitheriida †Dryolestida Zatheria

The Cladotheria also includes some groups which have become extinct.^[2]

Common traits

Members of the group have a number of common traits:

• They give birth to live young (as opposed to the egg-laying monotremes)
• They have two separate openings, one for the anus, and the other one for the urethra (the monotremes have just one opening)
• The shoulder area only has two bones, the scapula (shoulder blade), and the clavicula
• The mammary glands are connected to teats
• Their skull has a common layout
• On their face they have hairs called whiskers which are sensitive to touch.
• Their molars have a common pattern.