what are tethytheria?

Tethytheria is a clade of mammals that includes the sirenians and proboscideans, as well as the extinct order Embrithopoda

Tethys ocean to north of Africa in the Mesozoic

Considered to have evolved on the southern margins of the Tethys ocean and spread from there

Hyraxes, proboscideans, manatees

How are tethythers defined?

United by several characteristics, including anteriorly facing orbits, or more or less bilophodont cheek teeth

Proboscidea and serenia are linked together based on auditory characters in there petrosal bones, but this link may be homoplasy

Tethytheria is thought to have evolved from hoofed mammals ‘condylarths’ along the shores of the Tethys ocean.

1 of 10


Hyraxes are small, thickset, herbivorous mammals in the order Hyracoidea. Hyraxes are well-furred, rotund animals with short tails. Typically, they measure between 30 and 70 centimetres long and weigh between 2 and 5 kilograms.

Five extant species

Their distribution is limited to Africa, except for Procavia capensis, which is also found in the Middle East.

Pachyhyrax championi, a large fossil hyrax from the Miocene of Rusinga, Kenya

Around 11 genera of fossil hyrax are reported from the Eocene to Oligocene.

Male hyraxes lack a scrotum and their testicles remain tucked up in their abdominal cavity next to the kidneys, as do those of elephants, manatees, and dugongs

The tusks of hyraxes develop from the incisor teeth as do the tusks of elephants; most mammalian tusks develop from the canines. Hyraxes, like elephants, have flattened nails on the tips of their digits, rather than curved, elongated claws which are usually seen on mammals.

2 of 10

Sirenians- dugongs and manatees

Sirenians- dugongs and manatees

Dugong, tail fluke fish like, smooth skin restricted to indo pacific region

Manatee, broad paddle like fluke, rough skin, west African manatee, florida manatee, Amazonian manatee and antillean manatee.  Herbivores, eat eel grass, dense bones in the rib cage pachyostosis

3 of 10


encompasses the elephants and their close relatives. Most proboscideans are now extinct, including all species endemic to the Americas, Europe, and northern Asia. Many of these extinctions occurred during or shortly after the last glacial

The largest extant proboscidean is the african bush elephant, with a record of size of 4 m (13.1 ft) at the shoulder.

Largest of terrestrial vertibrates

First elephant- phosphatotherium paleocene- Eocene, Morocco, characteristed lophodont detention

4 of 10


One species phosphatatherium escuilliei

Early mammoth form, moeritherium, enlarges incisors

Amebelodon, enlarged eincisors

Gomphotherium, enlarged incisors on upper and lower jaw, reduced to two pairs, lophodont teeth, reduced dentition three molars

Deinotherium giganteum , down turned incisers

Stegodon florensis

Dwarf mammoth

Mammoth gave rise to modern elephants,

5 of 10


 extinct genus of early Proboscidea found in the Ouled Abdoun basin (early Thanetian age), Morocco. It lived about 60 million years ago. Eritherium is the oldest, smallest and most primitive known elephant relative.

The molars were generally bunodont (i.e. with small enamel cusps on the occlusal surface-bearing structure). Between these bumps were approaches for forming transverse strips on the first two molars and on the rearmost molar, which is typical in lophodont teeth

6 of 10


37-35 million years ago 

they were heavily built and about 3 feet tall, the shape of the skull suggests that while Moerithium did not have a trunk, it may have had a broad flexible upper lip, like a tapirs for grasping aquatic vegetation.

7 of 10


small tusks on its upper and lower jaw, used for cropping plants.

8 of 10


Closest relative to modern elephants is the mammoth which were around 1.6 million years ago. The last mammoth species became extinct about 10,000 years ago, at the end of the last ice age.

9 of 10

elephant populations

As of 2013 there has been an estimated 90 percent decline in the Asian elephant population.

And a 75 percent decline in the African elephant population over the last 100 years.

Asian elephantnumbers have dropped by at least 50% over the last three generations, and they’re still in decline today. With only 40,000-50,000 left in the wild, the species is classified as endangered.

some populations of African elephant are secure and expanding, primarily in southern Africa, numbers are continuing to fall in other areas

10 of 10


No comments have yet been made

Similar Geology resources:

See all Geology resources »See all Dinosaurs and Mammals exam resources »