Ichthyosaur points to evolutionary links

A near-complete Jurassic-era fossil of an intriguing animal that looks like a mashup of a dolphin and lizard, and lived during the twilight of the dinosaurs, has been unearthed in Kutch, Gujarat.

Ichthyosaurs, or ‘fish- lizards’ in Greek, were large reptiles that lived at the same time as dinosaurs. While many ichthyosaur fossils have been found in North America and Europe, the fossil record in the Southern Hemisphere has mostly been limited to South America and Australia.

Guntupalli Prasad, a geologist at the University of Delhi, said when a fossil bone from the animal’s skeleton was first found by an Indo-German research team in Kutch in 2016, they suspected it to be a dinosaur. “But the bone was too long and later the whole skeleton was unearthed. It’s the first Jurassic ichthyosaur found in India,” he told The Hindu .

The 5.5 metre-long skeleton is thought to belong to the Ophthalmosauridae family, which likely lived between 165 and 90 million years ago, when the arid Kutch was a sea. The remains were found among fossils of ammonites and squid-like belemnites, and the way the creature’s teeth were worn out suggest it ate animals with thick, bony coverings, the team of scientists report in the October 25 edition of PLOS ONE .

Dr. Prasad, one of the authors of the report, notes: “This also throws light on the evolution and diversity of ichthyosaurs in the Indo-Madagascan region of the former Gondwanaland and India’s biological connectivity with other continents in the Jurassic.”

Sparse evidence

Earlier too, researchers have discovered evidence of ichthyosaurs in prehistoric India. Remnants were reported from Ariyalur, Tamil Nadu in 2016 but these were only fossils of teeth and part of the vertebra. In Kutch, the team reported the finding of vertebral column, ribs, neural spines and a part of the snout. Some isolated teeth, vertebrae, jaw fragments, and other bone fragments were found scattered around the excavation site.