These creatures represent a snapshot of a key moment in the evolution of primates. Not only had the all-important split between these two aforementioned groups only recently occurred – on geological timescales at least – but back then, India was an isolated landmass drifting northwards. It would be another 15.5 million years before it smashed into Asia.
This means that, like Madagascar today, India was a (sizeable) island, an evolutionarily isolated experimental laboratory, and out of this laboratory emerged some of the earliest primates. So did primates originate in India before spreading around the world once it joined up with Asia?
A study from 2010 dramatically revealed that a 65-million-year-old primate-like animal was found in southern India, representing a lineage that survived the dinosaur-killing asteroid impact just a million years earlier. This fossil definitely seemed to suggest that primates began first evolving in India.
However, in 2013, the fossilized remains of a tiny monkey-like creature was unearthed in China. Dating back to 55 million years ago, it shows omomyid-like characteristics, and likely would have been part of a group that evolved into modern tarsiers. This shows that primate-like creatures were already evolving in Asia before India collided with it.
If this is true, then how were the Vastan animals, another group of extremely primitive primate ancestors, evolving on an adrift India at the same time? Tantalizingly, right now, this is a question without a definitive answer.
Simplified diagram illustrating evolutionary relationships between primates and primate ancestors. The Vastan animals belong pretty much where the blue circle is. Kenneth Rose, JHM