Alai Beds

Alai Beds
Stratigraphic range: Ypresian
(Bumbanian)
~55.8–48.6 Ma
TypeGeological formation
OverliesPaleozoic rocks
ThicknessMore than 25 m (82 ft)
Lithology
PrimarySiltstone, conglomerate
OtherLimestone
Location
Coordinates39°54′N 69°30′E / 39.9°N 69.5°E / 39.9; 69.5
Approximate paleocoordinates40°42′N 69°42′E / 40.7°N 69.7°E / 40.7; 69.7
RegionOsh
Country Kyrgyzstan
ExtentAktash Range
Alai Beds is located in Kyrgyzstan
Alai Beds
Alai Beds (Kyrgyzstan)

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]

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
Cimolesta
Hyaenodonta
Lipotyphla
Perissodactyls
Rodents

Reptiles

Lizards
Snakes
Turtles

See also

References

  1. ^ a b Alai Beds at Fossilworks.org
  2. ^ Averianov, 1994a, p.399
  3. ^ Averianov, 1994a, p.400
  4. ^ a b c d e Averianov & Danilov, 1996b
  5. ^ a b Averianov, 1994b
  6. ^ Lopatin & Averianov, 2004
  7. ^ a b Lopatin, 2006
  8. ^ a b Lavrov & Averianov, 1998
  9. ^ a b c d 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. ^ a b c d e f Averianov & Danilov, 1996a
  16. ^ Averianov & Danilov, 1997
  17. ^ Danilov & Averianov, 1999
  18. ^ a b c 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.