LONDON.- About 50 million years ago, Asia's climate was transformed by landmasses colliding, the birth of the Himalaya mountain range and the planet cooling.

Over time, these large geological changes caused the heavy seasonal rainfall, known as monsoons, to develop in India. But as the monsoons stabilised, the region also experienced periods of dryness.

Deepak Veerappan, Marie Curie Post-Doctoral Fellow at the Natural History Museum, has been investigating the effect the development of this dynamic weather system might have had on the diversity of animals evolving at the time.

Deepak was at the Centre for Ecological Science in Bangalore, India, until 2016 investigating a group of reptiles known as fan-throated lizards, which appeared around 18 million years ago in the midst of this climatic upheaval. There he realised that not only were there more species in this group of lizards than anyone had previously noticed, there was also an entirely new genus.

He says, 'I was surprised about the underestimated diversity of this group, and how researchers in the past had decided to classify the lizards as just a few species.'

The latest finds
A few years on from this startling discovery and Deepak has just published another paper in Zootaxa describing his seventh and eighth new species of fan-throated lizard from India, Sitana gokakensis and Sitana thondalu.

Both of the new species come from dry environments and - despite looking almost identical - are separated by over 500 kilometres. By testing their DNA, Deepak could confirm that they are separate species and are endemic (found nowhere else in the world).

What is most surprising is that the fan-throated lizards were found not in the biodiversity hotspot of the Western Ghats, which is well known for its wealth of species and diversity, but on the Deccan Plateau, an area often regarded as parched and desolate.

'This landscape has been long underrated in terms of biodiversity and it's about time that it gets the due credit,' says Deepak. 'It is not just a barren and unproductive land.'

Key players
These small, ground-living lizards might not look like much as they scamper across rocks and among vegetation, but they are vital to the challenging environments in which they live.

'They play a key role in the ecosystem as a potential predator. They are known to feed on insects and in certain seasons molluscs,' explains Deepak. 'On the other hand they are prey for several predatory birds, snakes and other large lizards, as well as small mammals such as foxes and jungle cats.'

As if describing a new genus and eight new species of lizard were not enough, Deepak plans on describing even more in the future, highlighting the impressive diversity in regions of India that often get overlooked.