Amphitheriida

Amphitheriida Temporal range: Middle Jurassic, 176–161 Ma PreЄ Є O S D C P T J K Pg N
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Subclass:	Theriiformes
(unranked):	Cladotheria
Superorder:	Dryolestoidea
Order:	Amphitheriida Prothero, 1981
Family:	Amphitheriidae Owen, 1846

Amphitheriida is an order of mesozoic mammals restricted to the Middle Jurassic of Britain. They were closely related to the Dryolestids but possessed five molars instead of the usual four in Dryolestida, (with the exception of the family Dryolestidae whose members possessed between 8 and 9 molars). The Amphitheriida contains one family, the Amphitheriidae.

Classification

• Mammalia
  • Theriiformes
    • Holotheria
      • Trechnotheria
        • Cladotheria
          • Dryolestoidea
            • Dryolestida
            • Amphitheriida
              • Palaeoxonodon

Further reading

• Zofia Kielan-Jaworowska, Richard L. Cifelli, and Zhe-Xi Luo, Mammals from the Age of Dinosaurs: Origins, Evolution, and Structure (New York: Columbia University Press, 2004), 14,395.
• A lower jaw of Palaeoxonodon from the Middle Jurassic of the Isle of Skye, Scotland, sheds new light on the diversity of British stem therians