115 Million Year Old Shark Fossil Discovered In Jaisalmer, Rajasthan

A team of researchers has discovered India's first Early Cretaceous shark fossils, which are approximately "115 million years old", in the Jaisalmer region of Rajasthan. This research paper was published in ‘Historical Biology, An International Journal of Paleobiology’ on 18 November 2023 with the title ‘First Early Cretaceous Shark from India’.

Shark fossil discovered by these researchers:

• The team of researchers includes Triparna Ghosh from Geological Survey of India (GSI), Jaipur; Professor Sunil Bajpai from the Department of Earth Sciences at the Indian Institute of Technology (IIT) Roorkee; Krishna Kumar from GSI, Kolkata; Abhyanand Singh Maurya from IIT and Debashish Bhattacharya from GSI, Kolkata.

Sharks underwent significant transformations during the Early Cretaceous period

• According to researchers, the Early Cretaceous was a period of great change for sharks, as new species evolved and many older species disappeared.

Fossils discovered from Habur Formation of Jaisalmer Basin:

• According to the researchers, the Habur Formation of the Jaisalmer Basin consists of several layers, including brown, hard, sandy coquinoidal limestone and orange to brown calcareous sandstone in the lower part and yellowish arenaceous limestone, calcareous in the upper part. Consists of sandstone and sandy marl bands.
• The Habur Formation represents a near-shore environment with occasional storm events, as evidenced by ammonite beds associated with arenaceous limestone and calcareous sandstone.

Five shark species were discovered from the Habur Formation:

• Based on isolated teeth found from the Habur Formation near Kanoi village in Jaisalmer, the presence of five lamniform genera - Cretalamna, Dwardius, Leptostyrax, Squalicorax, and Eostriatolamia - makes it clear that these are all species of large, predatory sharks with serrated teeth that lived during the Cretaceous period.
• The fossils excavated from the Habur Formation near Kanoi village in Jaisalmer include isolated Neoselachian teeth.

Oldest records from Dvardius and Eostriatolamia:

• According to Professor Bajpai, records from Dwardius and Eostriatolamia may possibly be among the oldest globally.
• Their fossils are surprisingly 115 million years old. Researchers have very little knowledge about Early Cretaceous vertebrates in India.

Mesozoic lamniform shark species formerly found in India:

• Mesozoic lamniform sharks, such as Cretalamna appendiculata, Dwardius sudindicus, Squalicorax aff. Baharijensis, Eostriatolamia sp., and Cretodus longiplicatus, were previously documented in the Cenomanian Karai Formation of the Cauvery Basin in southern India.

Fossils recovered from Habur Formation kept in ASI Jaipur:

• This collection is now housed in the Palaeontology Division of the Geological Survey of India (GSI), Western Region, Jaipur. According to the researchers, the Aptian age and 115 million year old specimens represent one of the oldest records of the genus Cratalamna globally, underscoring the reliability and significance of the findings.
• According to the research paper, the team of researchers not only documented the presence of five lamniform genera, but also underlined the lack of prior knowledge about Early Cretaceous sharks in India.

Fossils of many marine creatures were also discovered east of Jaisalmer:

• Even before this, the Geological Survey of India has found whale fossils and shark teeth in Jaisalmer. These fossils have been dated to the Middle Eocene (Lutecian) era, which is believed to be around 41.2 to 47.2 million years old.
• Expert scientists finding fossils and remains of marine creatures in Bandha village, 80 km from Jaisalmer, proves that there must have been an ocean here at that time.

Akal Wood Fossil:

• Fossils of 180 million years old oak (Akal) wood have been found in Jaisalmer. These are kept in the fossil museum located at a distance of 20 kilometers from Jaisalmer city.

Eocene era:

• The Eocene era is considered to be the middle period of the Paleogene era (6.5 to 23 million years ago). The Eocene era is divided into three periods (Low, Middle and Upper).
• This was the period in which many types of birds, reptiles and mammals were found in water and land. Among the creatures living on land, horses, deer and pigs were prominent, and among marine creatures, sharks and primitive whales were prominent.
• Sea whales are believed to have originated in the Eocene era. Many changes related to sea and land took place during this period.