Page 115 - Prehistoric Animals

Rynocer-Oji Die

Rhinoceratoidea

Rhinoceratoidea is a superfamily consisting of five fami-
lies of odd-toed ungulates, four of which, are extinct.

Extinct Families

(All members of the order Perissodactyla)

1. Amynodontidae (Named by Scott and Osborn in 1883: de-
fensive tooth): is an extinct family related to
true rhinoceroses. Amynodontids roamed the planet in the
Late Eocene about 56 to 33 million years ago to the Early Mi-
ocene, 23 million years ago to around 15 million years ago.
They are sometime referred to as "swamp rhinos" because
they were believed to be semi-aquatic, wallowing in marshy
pools like the modern day Rhino.

2. Hyracodontidae: (Named by, Edward Drinker Cope in
1879) is an extinct family of rhinoceroses. Hyracodons
(Named by, Joseph Leidy in 1856: Hyrax tooth) were lightly
built, pony-like mammals - sometime referred to as “the run-
ning rhinoceroses” - with long limbs and no horns and were
about 1.5 metres in length. They roamed North America, Eu-
rope, and Asia from the Late Eocene about 56 to 33 million
years ago to the Early Oligocene about 40 million to 25 mil-
lion years ago. They are thought, by some, to be the ancestors
of Indricotheriinae or Paraceratheriinae

3. Eggysodontidae: (Named by, Breuning in 1923) is a family
of perissodactyls closely related to rhinoceroses. Eggysodonts
(Named by, Roman in 1910) were dog-size ground-dwelling
browsers. Fossils have been found across Europe the Cauca-
sus, Central Asia, China, and Mongolia, in Oligocene deposits
dating from 40 million to 25 million years ago. Analysis of
the fossilised teeth revealed, tusk-like canines and smaller,
and fewer, incisors, suggesting Eggysodont may have been
related to Preaceratherium who has this teeth arrangement.

4. Paraceratheriidae: See page 68

Extant Family

5. Rhinocerotidae (true rhinoceroses)