Episode 119 – India

commondescentpc

Listen to Episode 119 on PodBean, YouTube, Spotify, or maybe somewhere else!

The Indian subcontinent has a dramatic and storied past, having traveled from one continent to another, hosting a diversity of ancient life along the way before coming to rest between a vast ocean and a monumental mountain range. This episode is all about India.

In the news
Biomechanical evidence for baby pterosaur flight
“Giant” vampire bat found in a possible sloth burrow
Tiny structures, 890 million years old, might be the oldest evidence of animals
New species of microsaur shows the earliest reptiles were pretty diverse

The Subcontinent of India

India is a sizeable landmass in southeast Asia with a fascinating modern and ancient natural history. Not only is it among the largest countries in the world today (with the second-largest human population), it also features a diversity of natural landscapes. India’s southern borders are coastlines adjacent to the Indian Ocean, and much of its northern border is marked by the Himalayan Mountains. In between lie some of the richest biomes in the world, including tropical rainforests, high-altitude coniferous forests, a variety of wetlands, and more.

Diversity of Indian landscapes.
Images by Mehrajmir13, CC BY-SA 4.0 (top left), Yathin S Krishnappa, CC BY-SA 3.0 (top right), Buddhapedia, CC BY-SA 4.0 (bottom left), and Joginder Pathak, CC BY-SA 2.0 (bottom right).

With that in mind, it’s not surprising that India’s animal life is also very diverse, including many endemic species. Of particular interest to us, of course, are India’s very impressive snakes (including massive species like king cobras and reticulated pythons) and crocodilians (including mugger crocs, saltwater crocs, and gharials).

An Incredible Tectonic Journey

India’s geologic history, at least during the Phanerozoic Eon, can be thought of in three major parts: first, when it was attached to the southern continents as part of Gondwana; second, as it split off on its own and traveled across the ancient Tethys Ocean; and finally, as it collided with Asia and became part of the northern continents.

Pre-insular India (that is, before it became an island) was joined in the supercontinent of Gondwana along with Madagascar, Australia, Antarctica, and other southern landmasses. Toward the end of the Paleozoic, all of the world’s continental land came together into Pangaea, and in the middle of the Mesozoic Era, Pangaea broke up again, and throughout all of this, India remained part of Gondwana. During this time period, India was home to a number of fascinating fossil creatures, including the bizarre Triassic reptile Shringasaurus, a number of early sauropod dinosaurs, and a multituberculate named Indobaatar which represents one of the earliest southern members of this successful group of mammals.

By the Late Cretaceous, tectonic motion had dragged India away from its adjacent landmasses, and it was off on a journey northward across the Tethys Ocean. Insular India wasn’t totally isolated; during this time, it shared ecological features with Africa, Europe, and Asia. In the early part of its island days, India was home to a variety of Cretaceous dinosaurs, including some famous titanosaurs and abelisaurs, as well as Sanajeh, a snake discovered in a dinosaur nest. Moving into the Cenozoic Era, India hosted a variety of ancient mammals, including some of the oldest known whale and rabbit ancestors.

Some famous Indian fossils.
Top: The bizarre Triassic reptile, Shringasaurus. Image from Sengupta et al. 2017, CC BY-SA 4.0
Bottom left: Diagram of Sanajeh, the Cretaceous snake found in a sauropod nest. Image from Wilson et al, 2010, CC BY 2.5
Bottom right: Sivatherium, a Late Miocene giraffe-cousin. Image by Basu et al, CC BY-SA 4.0

Starting around 40-50 million years ago, India collided with Asia. This tectonic event not only set the stage for the formation of India’s modern Asian fauna, but the deformation of the crust also formed the Himalayan mountain range, which today includes many of the world’s highest mountain peaks. The fossil record of India over the last several million years includes the famous giraffe-cousin Sivatherium as well as ancestors of India’s modern gharials, mugger crocs, and sloth bears.

Learn More
More about the Himalayas:
The Himalayas: Two continents collide
Rewriting India’s Geologic History
Why Mount Everest keeps changing its height

Some famous fossils finds from India:
Shringasaurus, the horned lizard
Jurassic “Sea Monster” – the first Jurassic ichthyosaur from India
Sanajeh, the snake found in a dinosaur nest
The origin and early evolution of whales: macroevolution documented on the Indian Subcontinent (technical)

India’s paleontologists fight destruction of its fossil riches

—

If you enjoyed this topic and want more like it, check out these related episodes:

We also invite you to follow us on Twitter, Facebook, or Instagram, buy merch at our Zazzle store, join our Discord server, or consider supporting us with a one-time PayPal donation or on Patreon to get bonus recordings and other goodies!

Please feel free to contact us with comments, questions, or topic suggestions, and to rate and review us on iTunes

Leave a comment