Jaisalmer Formation
The Jaisalmer Formation is a Middle to Late Jurassic-aged geologic formation located in India near the city of Jaisalmer that consists mainly of marine deposits.
The formation was first identified and defined by geologist Richard Dixon Oldham in 1886.
| Jaisalmer Formation | |
|---|---|
| Stratigraphic range: Middle-Late Jurassic, | |
 An outcrop of the Jaisalmer Formation which is the type locality for Tharosaurus indicus. Photographed between 2019-21. | |
| Type | Geological formation |
| Sub-units | Badabag Member, Fort Member, Hamira Member, Jajiya Member, Joyan Member, Kuldhar Member |
| Underlies | Baisakhi Formation |
| Overlies | Lathi Formation |
| Thickness | Variable, typically 120–170 km (75–106 mi) |
| Lithology | |
| Primary | Siltstone, sandstone |
| Other | Limestone |
| Location | |
| Coordinates | 26°54′42″N 70°55′23″E / 26.911661°N 70.922928°E |
| Country |  India |
| Extent | Jaisalmer |
| Type section | |
| Named for | Jaisalmer, India |
| Named by | Richard Dixon Oldham |
| Year defined | 1886 |
Dinosaur remains are among the known fossils recovered from this formation.
Strophodus jaisalmerensis, a hybodont, was named after this formation and the Jaisalmer District where its holotype was found.
Sub-units
The Badabag, Fort, Joyan and Hamira members represent the Middle Jurassic Bajocian and Bathonian stages, while the Jajiya and Kuldhar members represent the Middle Jurassic Callovian and the Late Jurassic Oxfordian stages.
The Fort Member is the most extensively studied and consists of fine to medium grain sandstones and oolitic limestones. The Badabag Member consists of intraformational conglomerate and is fossil bearing.
Paleoenvironment
The Jaisalmer district of India is a landlocked district in the state of Rajasthan. However, during the Middle Jurassic, the Jaisalmer Formation was located on the Tethyan coast of Gondwanan India. A marine paleoenvironment is supported by the presence of Hybodont sharks. The Kuldhar Member Limestone contained carbonate microfacies that also indicate a depositional environment comprised mainly of lagoons, shoals and open marine environments.
Paleofauna
This section needs expansion. You can help by adding to it. (August 2022) |
Dinosaurs
| Dinosaurs of the Jaisalmer Formation | ||||
|---|---|---|---|---|
| Genus | Species | Material | Notes | Photos |
| Turiasauria indet. | Fragmentary tooth | Possibly the oldest Turiasaur | ||
| Averostra indet. | isolated tooth | A possible Ceratosaur or a Non Spinosaurid Megalosauroid | ||
| Spinosauridae Indet. | Pedal ungual phalanx | Possibly the oldest Spinosaurid |  | |
| Tharosaurus | T. indicus | Partial cervical, dorsal, and caudal vertebrae and a dorsal rib | Oldest Dicraeosaurid and oldest Diplodocoid |
|
Other Reptiles
| Reptiles of the Jaisalmer Formation | ||||
|---|---|---|---|---|
| Genus | Species | Material | Notes | Photos |
| Crocodylomorpha | Indeterminate | Scutes | ||
| Reptilia | Indeterminate | Teeth | A possible Marine reptiles | |
Ichnofossils
- (?)Bichordites sp. – "Ichnofossils"
- Cytherella indica
- Micropneumatocythere joyanensis
- Planolites .sp – "Ichnofossils"
- Progonocythere khoslai
- Rhizocorallium irregulare – "Ichnofossils"
- Rhizocorallium jenense – "Ichnofossils"
- Taenidium serpentinum – "Ichnofossils"
- Thalassinoides .sp – "Ichnofossils"
- Trichordis minuta
Sharks
- Strophodus jaisalmerensis
- Strophodus indicus
- Strophodus magnus
- Strophodus medius
- Planohybodus sp.
References
This article uses material from the Wikipedia English article Jaisalmer Formation, which is released under the Creative Commons Attribution-ShareAlike 3.0 license ("CC BY-SA 3.0"); additional terms may apply (view authors). Content is available under CC BY-SA 4.0 unless otherwise noted. Images, videos and audio are available under their respective licenses.
®Wikipedia is a registered trademark of the Wiki Foundation, Inc. Wiki English (DUHOCTRUNGQUOC.VN) is an independent company and has no affiliation with Wiki Foundation.