Paraceratheriidae is an extinct family of long-limbed, hornless rhinocerotoids, commonly known as paraceratheres or indricotheres, that originated in the

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

epoch and lived until the early

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" ...

. The first paraceratheres were only about the size of large dogs, growing progressively larger in the late Eocene and

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but ...

. They were most common in the

rainforest Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainfo ...

floodplain region which is now

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia Russia (, , ), or the Russian Federation, is a transcontinental coun ...

India India, officially the Republic of India ( Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the ...

, and southwest China, and lived further inland throughout northern and central Asia as well. The paraceratheres reached the peak of their evolution from the middle Oligocene to the early Miocene, where they became very large, herbivorous mammals. Most genera were about the size of modern draft horses and the extinct giant horse ''

Equus giganteus The giant horse (''Equus giganteus'') is an extinct species of horse which lived in North America. It was classified as a species based on the finding of a single tooth larger than the teeth of even the largest modern draft horse A draft h ...

'', with some growing significantly larger. The largest genus was ''

Paraceratherium ''Paraceratherium'' is an extinct genus of hornless rhinoceros. It is one of the largest terrestrial mammals that has existed and lived from the early to late Oligocene epoch (34–23 million years ago). The first fossils were discovere ...

'', which was more than twice as heavy as a bull African elephant, and was one of the largest land mammals that ever lived. However, they remained confined to Asia, which at the time was mostly lush lowland floodplains. No fossil remains of paraceratheres have been found in Europe or North America, even though the paraceratheres had millions of years of opportunities to reach those regions. The collision with the

n subcontinent and the

Himalaya The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 10 ...

n uplift led to

global cooling Global cooling was a conjecture, especially during the 1970s, of imminent cooling of the Earth culminating in a period of extensive glaciation, due to the cooling effects of aerosols or orbital forcing. Some press reports in the 1970s specul ...

desertification Desertification is a type of land degradation in drylands in which biological productivity is lost due to natural processes or induced by human activities whereby fertile areas become increasingly arid. It is the spread of arid areas caused b ...

, and the disappearance of forest habitats, which resulted in the extinction of these giant ungulates. Although considered a subfamily of the family

Hyracodontidae The Hyracodontidae are an extinct family of rhinoceroses endemic to North America, Europe, and Asia during the Eocene through early Oligocene, living from 48.6 to 26.3 million years ago (Mya), existing about . The Hyracodontidae thrived in the ...

by some authors, recent authors treat the paraceratheres as a distinct family, Paraceratheriidae (Wang et al. 2016 recover hyracodonts as more basal than paraceratheres).

References

{{Taxonbar, from=Q1094909 Eocene rhinoceroses Aquitanian extinctions Eocene first appearances Oligocene rhinoceroses Miocene rhinoceroses Fossil taxa described in 1923