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]
| Alai Beds | |
|---|---|
| Stratigraphic range: Ypresian (Bumbanian) ~ | |
| Type | Geological formation |
| Overlies | Paleozoic rocks |
| Thickness | More than 25 m (82 ft) |
| Lithology | |
| Primary | Siltstone, conglomerate |
| Other | Limestone |
| Location | |
| Coordinates | 39°54′N 69°30′E / 39.9°N 69.5°E |
| Approximate paleocoordinates | 40°42′N 69°42′E / 40.7°N 69.7°E |
| Region | Osh |
| Country |  Kyrgyzstan |
| Extent | Aktash Range |
  Alai Beds (Kyrgyzstan) | |
Description
editThe 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
editThe formation has provided the following fossils:[1]
Mammals
edit- Artiodactyls
- Cimolesta
- Hyaenodonta
- Lipotyphla
- Perissodactyls
- Rodents
Reptiles
edit- Lizards
- Snakes
- Turtles
See also
edit- Ypresian formations
- Ieper Group of Belgium
- Fur Formation of Denmark
- London Clay Formation of England
- Silveirinha Formation of Portugal
- Wasatchian formations
- Nanjemoy Formation of the eastern United States
- Wasatch Formation of the western United States
- Itaboraian formations
- Itaboraí Formation of Brazil
- Laguna del Hunco Formation of Argentina
References
edit- ^ a b Alai Beds at Fossilworks.org
- ^ Averianov, 1994a, p.399
- ^ Averianov, 1994a, p.400
- ^ a b c d e Averianov & Danilov, 1996b
- ^ a b Averianov, 1994b
- ^ Lopatin & Averianov, 2004
- ^ a b Lopatin, 2006
- ^ a b Lavrov & Averianov, 1998
- ^ a b c d Averianov & Godinot, 2005
- ^ Averianov, 1994a, p.406
- ^ Averianov & Lopatin, 2005
- ^ Averianov, 1994a, p.401
- ^ Averianov, 1994a, p.402
- ^ Lopatin & Averianov, 2006
- ^ a b c d e f Averianov & Danilov, 1996a
- ^ Averianov & Danilov, 1997
- ^ Danilov & Averianov, 1999
- ^ a b c Danilov & Averianov, 1999
- ^ Averianov, 2002
Bibliography
edit- 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.