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

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Dinosaurs

Sauropods of the Jaisalmer Formation
Genus	Species	Locality	Material	Notes	Photos
Turiasauria	indeterminate		Fragmentary tooth.	The oldest Turiasaur.
Tharosaurus	T. indicus		Partial cervical, dorsal, and caudal vertebrae and a dorsal rib.	Oldest Dicraeosaurid and oldest Diplodocoid.

Theropods of the Jaisalmer Formation
Genus	Species	Locality	Material	Notes	Photos
Spinosauridae	Indeterminate		Pedal ungual phalanx.	Possibly the oldest spinosaurid. Had affinities with spinosaurinae.
Averostra	indeterminate		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		Scutes.
Neodiapsida	Indeterminate		Teeth.	Either a sauropterygian, thalattosaurian, choristodere or an ichthyosauromorph.

Fish

Sharks of the Jaisalmer Formation
Genus	Species	Locality	Material	Notes	Photos
Strophodus	S. jaisalmerensis		Teeth.	Hybodont shark.
	S. indicus		Teeth.	Hybodont shark.
	S. magnus		Teeth.	Hybodont shark.
	S. medius		Teeth.	Hybodont shark.
Planohybodus	P. sp.		Teeth.	Hybodont shark.
Osteichthyes	Indeterminate.		Teeth and scales.	Found along with an averostran tooth.
cf. Eomesodon	cf. Eomesodon sp.		Prearticular dental plate and isolated teeth.	Oldest East Gondwanan Pycnodont.

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