Tethytheria

Tethytheria is a clade of mammals that includes the sirenians, proboscideans, and the extinct order Embrithopoda.^[1]

Tethytheria Temporal range: Paleocene-Holocene
Top: African elephant, Caribbean manatee; middle: Moeritherium, woolly mammoth; bottom: Paleoparadoxia, Arsinoitherium
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Grandorder:	Paenungulata
Mirorder:	Tethytheria McKenna 1975
Subclades and orders
†Embrithopoda †Desmostylia (?) Proboscidea Sirenia

Though there is strong anatomical and molecular support for the monophyly of Tethytheria, the interrelationships between the included taxa remain disputed. The tethytheres are united by several characters, including anteriorly facing orbits and more or less bilophodont cheek teeth (double transverse ridges on the crowns of the teeth). Proboscidea and Sirenia are linked together based on auditory characters in their petrosal bones, but this link may be a homoplasy. Desmostylians, traditionally considered tethytheres, have been tentatively assigned to Perissodactyla, along with the Early Eocene family Anthracobunidae, which was considered a sister group to Tethytheria.^[2][3]

Systematics

Cladogram modified from Rose 2006 and Cooper et al. 2014.^[4]

Afrotheria	Paenungulata Hyracoidea Tethytheria †Embrithopoda Sirenia Proboscidea Afroinsectiphilia

Classification

Classification modified from Rose 2006.^[2]

• Clade Tethytheria
  • order †Embrithopoda
    • †Phenacolophidae
    • †Arsinoitheriidae
  • order Sirenia
    • †Prorastomidae
    • †Protosirenidae (Dugongidae?)
    • Dugongidae
    • Trichechidae
  • order Proboscidea
    • †Phosphatheriidae (Numidotheriidae?)
    • †Numidotheriidae
    • †Moeritheriidae
    • †Barytheriidae
    • †Deinotheriidae
    • †Palaeomastodontidae
    • †Phiomiidae
    • †Hemimastodontidae
    • †Mammutidae
    • †Gomphotheriidae
    • Elephantidae