Tethytheria

Caribbean Manatee ( Trichechus manatus )

• Proboscidea ( Proboscidea )
• Manatees ( Sirenia)

The Tethytheria provide a taxon within the mammals, are in the orders of the Proboscidea ( Proboscidea ) and manatees ( Sirenia) summarized. Next to them are assigned the extinct Embrithopoda († ) in this taxon.

Features

Although distinguish the manatees and the mammoths greatly in their anatomy visible, they have a number of anatomical features that constitute a sister group relationship ( apomorphies ). Of particular note are the lack of sweat glands, the very specific and occurs only when you build the metacarpal skeleton, the enamel structure of the molars, the structure of the inner ear as well as the very high accreting zygomatic arches and external auditory canals.

Phylogeny

The Tethytheria probably originated in the late Cretaceous period, from the last phase, the upper Paleocene fossils of possible stem group representatives are detectable. The heyday of both orders, especially the mammoths, took place in the subsequent Eocene.

As a representative of the earliest Tethytheria semi -aquatic forms living in the border area of the Tethys be accepted, as both the earliest Seekuhverwandten as well as the ancestors of today's elephants, especially Moeritherium, have a corresponding habit. Moreover, the absence of sweat glands speaks for all representatives for this origin.

System

As a next of kin of Tethyteria the hyrax be discussed, where this discussion is not yet complete. The common taxon from Tethytheria and hyraxes is called Paenungulata. Within the mammals are correspondingly the following relationships:

Hyrax ( Hyracoidea )

Embrithopoda †

? Desmostylia †

Proboscidea ( Proboscidea )

Manatees ( Sirenia)