Early Eocene
In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by the Eocene Lutetian Age. The Ypresian i ...
(
Ypresian
In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...
, or
Bumbanian The Bumbanian is an Asian Land Mammal Age (ALMA), a large biozone which corresponds to ages between 55.8–46.8 Ma for finds of fossil mammals in Asia. This zone lies within the Ypresian stage of the Eocene
The Eocene ( ) Epoch is a geological ...
geologic formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...
in the
Osh Region
Osh Region ( ky, Ош облусу, translit=Osh oblusu; russian: Ошская область, Oshskaya oblast) is a region (''oblast'') of Kyrgyzstan. Its capital is Osh, which is not part of the region. It is bounded by (clockwise) Jalal-Abad Re ...
of southwestern
Kyrgyzstan
Kyrgyzstan,, pronounced or the Kyrgyz Republic, is a landlocked country in Central Asia. Kyrgyzstan is bordered by Kazakhstan to the north, Uzbekistan to the west, Tajikistan to the south, and the People's Republic of China to the east. ...
. The formation has provided many
fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
s of
mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...
s,
lizard
Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...
s,
turtle
Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked tu ...
s and
snake
Snakes are elongated, Limbless vertebrate, limbless, carnivore, carnivorous reptiles of the suborder Serpentes . Like all other Squamata, squamates, snakes are ectothermic, amniote vertebrates covered in overlapping Scale (zoology), scales. Ma ...
s.Alai Beds at
Fossilworks
Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database
The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...
.org
Description
The Paleogene Alai Beds have a limited distribution, and are restricted to the northern slope of Aktash Range, formed by
Paleozoic
The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon.
The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838
by combining the Greek words ''palaiós'' (, "old") and ' ...
rocks, which is one of the foothills of the
Turkestan Range
One of the northern extensions of the Pamir-Alay system, the Turkestan Range (russian: Туркестанский хребет; ky, Түркстан кырка тоосу; uz, Туркистон тизмаси, Turkiston tizmasi; tg, Қатор ...
. The Paleogene deposits on the Aktash Range are badly exposed, they can be observed only in three
outcrop
An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth.
Features
Outcrops do not cover the majority of the Earth's land surface because in most places the bedrock or superficial ...
s, separated by short distances about . Despite their close position, the Paleogene deposits in these outcrops are varied greatly in composition and thickness of layers.Averianov, 1994a, p.399
The lower Alai Beds contain of silts and siltstones, and the upper part comprises
oyster
Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but not al ...
-bearing
limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...
s of which are exposed. At the base of the Upper Alai Beds there is a layer of conglomerate which produces a number of marine vertebrates, but a few terrestrial vertebrates including mammals. The section I1 is more complete and has a greater thickness, but produces a few shark teeth only. The third Paleogene section, where the mammal bearing locality Andarak 2 is located, has a much greater thickness of sands of the lower Alai Beds (more than of visible thickness) with some horizons of oyster-bearing conglomerates.Averianov, 1994a, p.400
Ieper Group
The Ieper Group ( nl, Ieper Groep; french: Groupe d'Ypres) is a group of rock strata in the subsurface of northwest Belgium. The group is subdivided into three marine formations, all formed during the Ypresian, a single age of the geologic timesc ...
of Belgium
**
Fur Formation
The Fur Formation is a marine geological formation of Ypresian (Lower Eocene Epoch, c. 56.0-54.5 Ma) age which crops out in the Limfjord region of Denmark from Silstrup via Mors and Fur to Ertebølle, and can be seen in many cliffs and quarries in ...
of Denmark
**
London Clay Formation
The London Clay Formation is a marine geological formation of Ypresian (early Eocene Epoch, c. 56–49 million years ago) age which crops out in the southeast of England. The London Clay is well known for its fossil content. The fossils from th ...
Nanjemoy Formation
The Nanjemoy Formation is a geologic formation pertaining to both the Wilcox Group and the Pamunkey Group of the eastern United States, stretching across the states of Virginia, Maryland, and District of Columbia. The formation crops out east of ...
of the eastern United States
**
Wasatch Formation
The Wasatch Formation (Tw)Shroba & Scott, 2001, p.3 is an extensive highly fossiliferous geologic formation stretching across several basins in Idaho, Montana Wyoming, Utah and western Colorado.Itaboraian formations
**
Itaboraí Formation
The Itaboraí Formation ( pt, Formação Itaboraí) is a highly list of fossiliferous stratigraphic units in Brazil, fossiliferous geologic Formation (geology), formation and LagerstätteKellner & Campos, 1999, p.399 of the Itaboraí Basin in Rio ...
of Brazil
**
Laguna del Hunco Formation
The Laguna del Hunco Formation or Laguna del Hunco Tuff ( es, Formación Laguna del Hunco, Tufolitas Laguna del Hunco) is a localized Early Eocene (Itaboraian in the SALMA classification) fossiliferous geological formation of the Cañadón Asfalto ...
of Argentina
References
Bibliography
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* {{cite journal , last=Averianov , first=A. O , year=1994b , title=A new species of ''Sarcodon'' (Mammalia, Palaeoryctoidea) from the Lower Eocene of Kirgizia , journal=
Geobios
Geobios is an academic journal published bimonthly by the publishing house Elsevier. Geobios is an international journal of paleontology, focusing on the areas of palaeobiology, palaeoecology, palaeobiogeography, stratigraphy and biogeochemistry ...