The Bahe Formation is a Late Miocene

Miocene

The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...

 (Tortonian/Vallesian

Vallesian

The Vallesian age is a period of geologic time within the Miocene used more specifically with European Land Mammal Ages. It precedes the Turolian age and follows the Astaracian age. The Turolian overlaps the Tortonian and Messinian ages....

/Bahean, about 11.6-9.0 mya) formation in Shaanxi

Shaanxi

' is a province in the central part of Mainland China, and it includes portions of the Loess Plateau on the middle reaches of the Yellow River in addition to the Qinling Mountains across the southern part of this province...

, China

China

Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

. Its coordinates are 33.5N and 109.5E. It has "a complex lithology of predominantly orange-yellow conglomerate

Conglomerate (geology)

A conglomerate is a rock consisting of individual clasts within a finer-grained matrix that have become cemented together. Conglomerates are sedimentary rocks consisting of rounded fragments and are thus differentiated from breccias, which consist of angular clasts...

s, sandstone

Sandstone

Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

s, tan-yellow sandy mudstone

Mudstone

Mudstone is a fine grained sedimentary rock whose original constituents were clays or muds. Grain size is up to 0.0625 mm with individual grains too small to be distinguished without a microscope. With increased pressure over time the platey clay minerals may become aligned, with the...

s, and tan-red mudstones.". The main fossil locality is in the Jiulaopo region on the left bank of the Bahe River in Lantian.

Mammals

Genus	Species	Abundance	Notes
Acerorhinus Acerorhinus Acerorhinus was a genus of rhinoceros of the tribe Aceratheriini endemic to Asia from the Miocene, living from 13.6—7.0 mya existing for approximately .-Taxonomy:...	A. sp.		A rhinocerid Rhinoceros Rhinoceros , also known as rhino, is a group of five extant species of odd-toed ungulates in the family Rhinocerotidae. Two of these species are native to Africa and three to southern Asia....
Chleuastochoerus	C. stehlini
Dicerorhinus	D. ringstromi		A rhinocerid. One member of this genus is still alive today: Dicerorhinus sumatrensis, the Asiatic One-Horned Rhinoceros
Erinaceus Erinaceus Erinaceus is a genus of European hedgehog from the family of Erinaceidae. There are four main species of Erinaceus. The range is all across Europe, throughout the Middle East, parts of Russia, and extending to northern China...	E. sp.		Of order Erinaceomorpha, the hedgehogs, four species from this genus are alive today.
Hipparion Hipparion Hipparion is an extinct genus of horse living in North America, Asia, Europe, and Africa during the Miocene through Pleistocene ~23 Mya—781,000 years ago, existing for...	H. (Hippotherium Hippotherium Hippotherium is an extinct genus of horse endemic to North America, to Asia, Europe, and Africa during the Miocene through Pliocene ~13.65—3.3 Mya, existing for .- Taxonomy :... ) weihoense	Relatively common in this region	An early equid. Appeared very horse-like, roughly the size of a pony, but still had three toes: one large, central toe that carried most of its weight, and two vestigial toes, one on each side. The skull bears a diastema Diastema Diastema may refer to:*Diastema , from the family Gesneriaceae*Diastema , a gap between the front teeth... .
	H. chiai	Relatively common in this region
Miomachairodus Miomachairodus Miomachairodus was an extinct genus of large saber-toothed cats of the subfamily Machairodontinae, that lived in Europe, Asia, Africa, and North America during most of the Miocene...	M. pseudaeluroides	rare	an early machairodont, member of tribe homotheriini, ancestral to Homotherium Homotherium Homotherium is an extinct genus of machairodontine saber-toothed cats, often termed scimitar cats, endemic to North America, South America, Europe, Asia, and Africa during the Pliocene and Pleistocene epochs , existing for approximately .It first became extinct in Africa some 1.5 million years ago... and Machairodus Machairodus Machairodus was a genus of large machairodontine saber-toothed cats that lived in Europe, Asia, Africa and North America during the Miocene through Pleistocene living from 11.6mya—126,000 years ago, existing for approximately .-Species:... .
Palaeotragus Palaeotragus Palaeotragus was a genus of very large, primitive okapi from the Miocene of Africa, Asia, and Europe.Palaeotragus primaevus is the older species, being found in early to mid-Miocene strata, while Palaeotragus germaini is found in Late Miocene strata.P. primaevus is distinguished from P. germaini...	P. decepiens		An early giraffid
	P. microdon		An early giraffid
Samotherium Samotherium Samotherium is an extinct genus of giraffe from the Miocene and Pliocene of Eurasia and Africa. Samotherium had two ossicones on its head, and long legs. The ossicones usually pointed upward, and were curved backwards, with males having larger, more curved ossicones, though, in the Chinese...	S. decipiens		An early giraffid
Tetralophodon Tetralophodon Tetralophodon is an extinct gomphothere genus . Like typical gomphotheres, Tetralophodon had four tusks and a trunk. This genus of animals stood about ten feet tall and was a very widespread and successful proboscidean. Tetralophodon lived through the Miocene and Pliocene epoches...	T. exoletus		A ten-foot tall proboscid who is known generally from fossilized teeth, known for its four ridges.
Dinocrocuta Dinocrocuta Dinocrocuta is an extinct genus of hyena-like feliform carnivores. It lived in Asia, and Africa, during the Miocene epoch. It had very strong jaws that were able to crush bones. It's estimated to weight roughly 400 kg...			A large carnivore with in the family Percrocutidae Percrocutidae The Percrocutidae form an extinct family of hyena-like feliform carnivores endemic to Asia, Africa, and Southern Europe from the Miocene through Pliocene living 20—2.59 Ma existing for approximately .... , closely related to family Hyaenidae, containing today's hyenas. They appeared slope-backed and had powerful jaws.
Chleuastochoerus
Gazella	G. gaudryi		Still a common genus in Africa, central and southeast Asia. Usually light and swift, adapted to open areas and sprints. Six species are still alive today, including Gazella thomsoni, the Thomson's gazelle, and Gazella dorcas, Dorca's gazelle.
Shaanxispira
Nannocricetus	N. primituvus	well documented, but not wildly abundant in any formation, unlike closely related species Sinocrietus	Holotype Holotype A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...  for Nannocricetus primituvus discovered in the Bahe Formation
Percrocuta Percrocuta Percrocuta is an extinct genus of hyena-like feliform carnivores. It lived in Europe, Asia, and Africa, during the Miocene epoch.With a maximum length of 1.50 m , Percrocuta was much bigger than its modern relatives, but smaller than a female lion. Like the Spotted Hyena, Percrocuta had a robust...	P. macrodonta

Turtles

Genus	Species	Abundance	Notes
Testudo Testudo Testudo may refer to:* Testudo , a genus of tortoises* The Latin variant of the Greek chelys harp made from a tortoise shell* The testudo formation, a Roman military tactic...	T. sphaerica
Indeterminate emydid Emydidae Emydidae, commonly called the pond turtles or marsh turtles, is a family of turtles. Previously, several species of Asian box turtle were classified in the family. However, revised taxonomy has separated them to a different family. Now, Emydidae, with the exception of two species of pond turtle,...  remains

Geology and Environment

Six general facies

Facies

In geology, facies are a body of rock with specified characteristics. Ideally, a facies is a distinctive rock unit that forms under certain conditions of sedimentation, reflecting a particular process or environment....

 have been identified in the region: (1) massive or crudely bedded conglomerates

Conglomerate (geology)

A conglomerate is a rock consisting of individual clasts within a finer-grained matrix that have become cemented together. Conglomerates are sedimentary rocks consisting of rounded fragments and are thus differentiated from breccias, which consist of angular clasts...

, (2) cross-stratified conglomerate and sandstone

Sandstone

Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

 deposits, (3) minor sandstone deposits, (4) fine-grained deposits, (5) gritty mudstone and sandstone deposits and (6) marl

Marl

Marl or marlstone is a calcium carbonate or lime-rich mud or mudstone which contains variable amounts of clays and aragonite. Marl was originally an old term loosely applied to a variety of materials, most of which occur as loose, earthy deposits consisting chiefly of an intimate mixture of clay...

 deposits.

The presence of these types of facies suggest active channels, crevasse splays, sheet floods, and floodplains with paleosols and lakes.Thick and laterally pervasive units of fine-grained sediments, formed as suspension fall-out on the floodplain

Floodplain

A floodplain, or flood plain, is a flat or nearly flat land adjacent a stream or river that stretches from the banks of its channel to the base of the enclosing valley walls and experiences flooding during periods of high discharge...

, indicating low-energy conditions and a relatively gentle surface gradient

Surface gradient

In vector calculus, the surface gradient is a vector differential operator that is similar to the conventional gradient. The distinction is that the surface gradient takes effect along a surface....

 in the area, are by far the most common sedimentary component. Channel-related sandstones and conglomerates indicate that the rivers had a low-sinuosity and were braided, to anastomosing types.