Meghalaya: Archeologists unearth rare 100 million-year-old fossil of sauropod dinosaur

In a breakthrough, archaeologists in India have unearthed 100 million-year-old fossil bone fragments of a sauropod dinosaur in West Khasi Hills district, Meghalaya. Researchers from the Geological Survey of India's Palaeontology division, who are yet to publish the findings, carried out the excavations in the Northeast and discovered the rare fossils which they speculate have its origin in the Titanosaurian period. The recent findings make Meghalaya the first northeast state and the fifth in India after Gujarat, Madhya Pradesh, Maharashtra, and Tamil Nadu to have discovered the prehistoric fossils, according to a PTI report. 

Natural History Museum describes the Sauropod as a giant herbivore that walked mostly on four legs. In the late Cretaceous period, there were at least 20 species of dinosaurs recognised to have been found in India in 1933, including the Sauropods, theropods and ornithopods. In 1982 the maiden discovery of dinosaur nesting sites and eggs in the Lameta sediments and associated skeletons of titanosaurian and abelisaurid dinosaurs revived interest in dinosaur research, said D.M. Mohabey of the Palaeontology Division, Geological Survey of India, in his palaeontological and sedimentological observations. 

"Dinosaur bones from Meghalaya were reported by GSI in 2001 but they were too fragmentary and ill-preserved to understand its taxonomic identification," Arindam Roy, Senior Geologist, Palaeontology Division, GSI was quoted saying by PTI. He continued, “the present find of bones is during fieldwork in 2019-2020 and 2020-21. The last visit of the team was in February 2021. The fossils are presumably of Late Cretaceous, about 100 million years ago.” 

[Sauropod specimen. Image Credit: Twitter/@matthew_rhodes_]

A diverse group of sauropod dinosaurs, known as the Titanosaurs were found in India that lived from the Late Jurassic Epoch (163.5 million to 145 million years ago) to the end of the Cretaceous Period (145 million to 66 million years ago). The species ranged across Africa, Asia, South America, North America, Europe, Australia and Antarctica. These dinosaurs’ fossils have been excavated across all continents except for Antarctica and they are the largest terrestrial species of an animal ever known to mankind. Researchers describe these dinosaurs as herbivorous quadrupeds with long tails, long necks, and small heads, growing at a length of 7 metres (about 23 feet) and a weight of approximately 10,000 kg (11 tons).

25 disarticulated, fragmentary bone specimens dug

The preserved fossils, excavated by India’s archaeologists include the limb bones, with a separate type of curvature, lateral and proximal margins of the partially preserved bone, which are also indicative of it being a humerus bone. The study on the details of the fossil fragments is still ongoing. Scientists described the bones as purplish to greenish, having a “coarse-grained arkosic sandstone interlaid with pebbly beds.” At the site, as many as twenty-five disarticulated, mostly fragmentary bone specimens were collected, which the archaeologists said, were found in close proximity with each other.

The largest specimen was a preserved limb bone of 55 centimetres (cm), and a separate incomplete limb bone measuring 45cm in length matched the limb bones of the titanosauriform clade. In India, Late Cretaceous sauropod dinosaur generally belongs to the titanosaurian clade and mostly existed in the Lameta Formation of Gujarat, Madhya Pradesh and Maharashtra and Kallamedu Formation of Tamil Nadu, the researchers said.

“The abundance of bones recovered during the present work and especially the finding of few limb bones and vertebrae having taxonomic characters of titanosauriform clade are unique,” Roy told PTI. “The record of the sauropod assemblage of probable titanosaurian affinity from Meghalaya extends the distribution and diversity of vertebrates in the Late Cretaceous of India,” he added.