# 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.
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 composed mainly of lagoons, shoals and open marine environments.

## Paleofauna

| Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon | Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited. |

### Dinosaurs
#### Sauropods

Sauropods of the Jaisalmer Formation :
| Genus | Species | Locality | Material | Notes | Photos |
| Turiasauria | indeterminate | Chandoo Village quarry | Fragmentary tooth. | The oldest turiasaur. | |
| Tharosaurus | T. indicus | Jethwai Village | Partial cervical, dorsal, and caudal vertebrae and a dorsal rib. | Oldest dicraeosaurid and oldest diplodocoid. | |

#### Theropods

Theropods of the Jaisalmer Formation :
| Genus | Species | Locality | Material | Notes | Photos |
| Spinosauridae | Indeterminate | Chandoo Village quarry | Pedal ungual phalanx. | Possibly the oldest spinosaurid. Had affinities with spinosaurinae. | Specimen RAJ/JAIS/CVQS002 |
| Averostra | indeterminate | Chandoo Village quarry | Isolated tooth. | A possible Ceratosaur or a Non Spinosaurid Megalosauroid or a Allosauroid. | |

### Other Reptiles

Reptiles of the Jaisalmer Formation :
| Genus | Species | Locality | Material | Notes | Photos |
| Crocodylomorpha | Indeterminate | Chandoo Village quarry | Scutes. | | |
| Neodiapsida | Indeterminate | Chandoo Village quarry | Teeth. | Either a sauropterygian, thalattosaurian, choristodere or an ichthyosauromorph. | |

### Fish

Fishes of the Jaisalmer Formation :
| Genus | Species | Locality | Material | Notes |
| Hybodontiformes Indet. | Indeterminate | | | |
| Strophodus | S. jaisalmerensis | Jethwai village | Teeth. | A hybodont shark. |
| Strophodus | S. indicus | Chandoo Village quarry | Teeth. | A hybodont shark. |
| Strophodus | S. magnus | Chandoo Village quarry | Teeth. | A hybodont shark. |
| Strophodus | S. medius | Chandoo Village quarry | Teeth. | A hybodont shark. |
| Planohybodus | P. aff. grossiconus | Chandoo Village quarry | Teeth. | A hybodont shark. |
| Osteichthyes | Indeterminate. | Chandoo Village quarry | Teeth and scales. | Found along with an averostran tooth. |
| cf. Eomesodon | cf. Eomesodon sp. | Jethwai Village | Prearticular dental plate and isolated teeth. | Oldest East Gondwanan Pycnodont. |

### Crustaceans

Crustaceans of the Jaisalmer Formation :
| Genus | Species |
| Cytherella | C. indica |
| Micropneumatocythere | M. joyanensis |
| Progonocythere | P. khoslai |
| Trichordis | T. minuta |

### Ichnofossils

* (?)Bichordites sp. – "Ichnofossils"
* Planolites .sp – "Ichnofossils"
* Rhizocorallium irregulare – "Ichnofossils"
* Rhizocorallium jenense – "Ichnofossils"
* Taenidium serpentinum – "Ichnofossils"
* Thalassinoides .sp – "Ichnofossils"