Alai Beds

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The Alai Beds is an Early Eocene (Ypresian, or Bumbanian in the ALMA classification) geologic formation in the Osh Region of southwestern Kyrgyzstan. The formation has provided many fossils of mammals, lizards, turtles and snakes.^[1]

TypeGeological formation

OverliesPaleozoic rocks

ThicknessMore than 25 m (82 ft)

PrimarySiltstone, conglomerate

Quick facts Type, Overlies ...

Alai Beds
Stratigraphic range: Ypresian (Bumbanian) ~55.8–48.6 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Overlies	Paleozoic rocks
Thickness	More than 25 m (82 ft)
Lithology
Primary	Siltstone, conglomerate
Other	Limestone
Location
Coordinates	39.9°N 69.5°E / 39.9; 69.5
Approximate paleocoordinates	40.7°N 69.7°E / 40.7; 69.7
Region	Osh
Country	Kyrgyzstan
Extent	Aktash Range
Alai Beds (Kyrgyzstan)

Description

The Paleogene Alai Beds have a limited distribution, and are restricted to the northern slope of Aktash Range, formed by Paleozoic rocks, which is one of the foothills of the Turkestan Range. The Paleogene deposits on the Aktash Range are badly exposed, they can be observed only in three outcrops, separated by short distances about 1 to 2 kilometres (0.62 to 1.24 mi). Despite their close position, the Paleogene deposits in these outcrops are varied greatly in composition and thickness of layers.^[2]

The lower Alai Beds contain 5 metres (16 ft) of silts and siltstones, and the upper part comprises oyster-bearing limestones of which 2 to 3 metres (6 ft 7 in to 9 ft 10 in) 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 25 metres (82 ft) of visible thickness) with some horizons of oyster-bearing conglomerates.^[3]

Fossil content

The formation has provided the following fossils:^[1]

Mammals

Artiodactyls

Eolantianius russelli^[4]
Diacodexis sp.^[4]
Diacodexeidae indet.^[4]

Cimolesta

Metasarcodon udovichenkoi^[5]
Nuryctes alayensis^[6]
Palaeoryctidae indet.^[7]

Hyaenodonta

Isphanatherium ferganensis^[8]
Neoparapterodon sp.^[8]

Lipotyphla

Protogalericius averianovi^[7]

Perissodactyls

Eoletes tianshanicus^[9]
Pataecops minutissimus^[5]
Sharamynodon kirghisensis^[9]
Teleolophus medius^[9]

Rodents

Aktashmys montealbus^[10]^[11]
Alaymys ctenodactylus^[12]
Anatolimys rozhdestvenskii^[13]
Gobiolagus hekkeri^[14]
Khodzhentia vinogradovi^[15]
Advenimus cf. burkei^[15]
Petrokozlovia cf. notos^[15]
Saykanomys cf. bohlini^[15]
?Adolomys sp.^[15]
Ctenodactyloidea indet.^[15]

Reptiles

Lizards

Snakes

Calamagras turkestanicus^[17]
Palaeophis ferganicus^[18]
Boidae indet.^[18]

Turtles

References

[1]
Alai Beds at Fossilworks.org
[2]
Averianov, 1994a, p.399
[3]
Averianov, 1994a, p.400
[4]
Averianov & Danilov, 1996b
[5]
Averianov, 1994b
[6]
Lopatin & Averianov, 2004
[7]
Lopatin, 2006
[8]
Lavrov & Averianov, 1998
[9]
Averianov & Godinot, 2005
[10]
Averianov, 1994a, p.406
[11]
Averianov & Lopatin, 2005
[12]
Averianov, 1994a, p.401
[13]
Averianov, 1994a, p.402
[14]
Lopatin & Averianov, 2006
[15]
Averianov & Danilov, 1996a
[16]
Averianov & Danilov, 1997
[17]
Danilov & Averianov, 1999
[18]
Danilov & Averianov, 1999
[19]
Averianov, 2002

Bibliography

Lopatin, A. V (2006). "Early Paleogene insectivore mammals of Asia and establishment of the major groups of Insectivora". Paleontological Journal. 40 (S3): S205–S405. Bibcode:2006PalJ...40S.205L. doi:10.1134/S0031030106090012.
Lopatin, A. V.; Averianov, A. O. (2006). "Eocene Lagomorpha (Mammalia) of Asia: 2. Strenulagus and Gobiolagus (Strenulagidae)". Paleontological Journal. 40 (2): 198–206. Bibcode:2006PalJ...40..198L. doi:10.1134/S0031030106020110.
Averianov, A. O.; Godinot, M. (2005). "Ceratomorphs (Mammalia, Perissodactyla) from the early Eocene Andarak 2 locality in Kyrgyzstan". Geodiversitas. 27: 221–237.
Averianov, A. O.; Lopatin, A. V. (2005). "Eocene Lagomorphs (Mammalia) of Asia: 1. Aktashmys (Strenulagidae fam. nov.)". Paleontological Journal. 39: 308–317.
Lopatin, A. V.; Averianov, A. O. (2004). "New Palaeoryctidae (Mammalia) from the Eocene of Kyrgyzstan and Mongolia". Paleontological Journal. 38: 556–562.
Averianov, A. O (2002). "Review of Mesozoic and Cenozoic sea turtles from the former USSR". Russian Journal of Herpetology. 9: 137–154.
Danilov, I. G.; Averianov, A. O. (1999). "A new species of Calamagras Cope 1873 (Serpentes, Boidae, Erycinae) from the early Eocene of Kirghizia". Geodiversitas. 21: 85–91.
Lavrov, A. V.; Averianov, A. O. (1998). "The Oldest Asiatic Hyaenodontidae (Mammalia, Creodonta) from the Early Eocene of the Southern Fergana Basin (Andarak-2 Locality)". Paleontological Journal. 32: 200–205.
Averianov, A. O.; Danilov, I. G. (1997). "A varanid lizard (Squamata: Varanidae) from the early Eocene of Kirghizia". Russian Journal of Herpetology. 4 (2): 143–147. doi:10.30906/1026-2296-1997-4-2-143-147.
Danilov, I. G.; Averianov, A. O. (1997). "New data on the turtles from the Early Eocene of Kirghizia". Russian Journal of Herpetology. 4: 40–45. doi:10.30906/1026-2296-1997-4-1-40-45.
Averianov, A. O (1996a). "Early Eocene Rodentia of Kyrgyzstan". Bulletin du Museum national d'Histoire naturelle, Paris, 4e serie. 18: 629–662.
Averianov, A. O (1996b). "Artiodactyla from the early Eocene of Kyrgyzstan". Palaeovertebrata. 25: 359–369.
Averianov, A. O.; Danilov, I. G. (1996). "Agamid lizards (Reptilia, Sauria, Agamidae) from the early Eocene of Kyrgyzstan". Neues Jahrbuch für Geologie und Paläontologie - Monatshefte. 1996 (12): 739–750. doi:10.1127/njgpm/1996/1996/739.
Averianov, A. O (1994a). "Early Eocene mimotonids of Kyrgyzstan and the problem of Mixodontia". Acta Palaeontologica Polonica. 39: 393–411. Retrieved 2020-09-10.
Averianov, A. O (1994b). "A new species of Sarcodon (Mammalia, Palaeoryctoidea) from the Lower Eocene of Kirgizia". Geobios. 27 (2): 255–258. Bibcode:1994Geobi..27..255A. doi:10.1016/S0016-6995(94)80012-X.