Skull of Hipparion found from the early Pleistocene of Longdan, Northwestern China

Feb 16, 2012
Skull of Hipparion found from the early Pleistocene of Longdan, Northwestern China
Fig.1 Lateral view of the skull of Hipparion (Proboscidipparion) sinense from Longdan (HMV 1872). Credit: DENG Tao

In a study published in the latest issue of of Vertebrata PalAsiatic 2012(1), Dr. DENG Tao, Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), Chinese Academy of Sciences in Beijing, reported a skull of Hipparion (Proboscidipparion) sinense from the Longdan locality in Dongxiang, Gansu Province, northwestern China. The previously known material of this species in the Early Pleistocene Longdan fauna was only a Metacarpal III. This find not only confirms the specific identification of Hipparion in this fauna, but also increases the understanding of the cranial and dental characters of this species.

Proboscidipparion is a derived, large- to giant-sized form of the three-toed horse with a special muzzle structure, and its nasal notch reaches deeply above the middle part of the cheek tooth row. Their distribution was limited to northern China, but recent studies expanded its distribution as far as to England.

The new specimen was unearthed from the lower part of the Early Pleistocene Wucheng Loess at Shitougu of Nalesi Town, Dongxiang County, Gansu Province. It is a juvenile male individual with an erupted large-sized canine. Its age is approximately 2.5 years determined by the eruption of its cheek teeth.

Skull of Hipparion found from the early Pleistocene of Longdan, Northwestern China
Fig.3 Skull and cheek teeth of Hipparion (Proboscidipparion) sinense from Longdan (HMV 1872); A. skull in ventral view; B. cheek teeth in occlusal view; C. skull in occipital view; scale bars = 5 cm. Credit: DENG Tao

The holotype specimen of Hipparion sinense belongs to a senile individual, and no other complete of this species has been found. Therefore, the new material from Longdan provides some key information for the diagnoses of Hipparion sinense, and reveals the structure of the nasal notch of this species. The lower part of the nasal bone is a tenuous strip that extends far forward, comprises the posterior part of the lower margin of the nasal notch, and has a sharp anterior end reaching the level of the P2/P3 boundary, at a 30 mm distance from the posterior end of the nasal process of the premaxillary bone. “The recognition of these characters is greatly important in determining the phylogenetic relationship of Proboscidipparion”, said Deng Tao.

Proboscidipparion might prefer living in an area with abundant water, same as tapirs which have a similar nasal structure. The discovery of Proboscidipparion at Longdan further supports the environmental implications of fossil beavers and other members of the Longdan , indicating streams and small lakes for the Linxia Basin during the Early Pleistocene.

Explore further: T. rex gets new home in Smithsonian dinosaur hall

Provided by Institute of Vertebrae Paleontology and Paleoanthropology

4.5 /5 (6 votes)
add to favorites email to friend print save as pdf

Related Stories

Recommended for you

Clippers and coiners in 16th-century England

Apr 14, 2014

In 2017 a new £1 coin will appear in our pockets with a design extremely difficult to forge. In the mid-16th century, Elizabeth I's government came up with a series of measures to deter "divers evil persons" ...

Serbia experts use heavy machinery to move mammoth

Apr 11, 2014

Serbian archaeologists on Friday used heavy machinery to move a female mammoth skeleton—believed to be one million years old—from an open mine pit where it was unearthed nearly five years ago.

User comments : 0

More news stories

Online reviews: When do negative opinions boost sales?

When purchasing items online, reading customer reviews is a convenient way to get a real-world account of other people's opinions of the product. According to a new study in the Journal of Consumer Research, negative review ...

Low Vitamin D may not be a culprit in menopause symptoms

A new study from the Women's Health Initiative (WHI) shows no significant connection between vitamin D levels and menopause symptoms. The study was published online today in Menopause, the journal of The North American Menopa ...

Astronomers: 'Tilt-a-worlds' could harbor life

A fluctuating tilt in a planet's orbit does not preclude the possibility of life, according to new research by astronomers at the University of Washington, Utah's Weber State University and NASA. In fact, ...