Discovery of new lizard species sheds light on Western Ghats’ rich biodiversity

Adding to the list of approximately 12,000 species of reptiles in the world, a new species has been discovered from Kerala. The study about the new species was published in the scientific journal, Vertebrate Zoology,’ of the Senckenberg Museum, based in Germany, on January 25. The research team includes Malayali researchers Dr Sandeep Das, Dr Rajkumar KP, Dr Muhammad Jafer Palot, Dr Subin K, along with Dr Deepak V from Tamil Nadu, Surya Narayanan, and Sounak Pal from Maharashtra.

The new species was discovered in the Kulamavu area of Idukki and is known as the Northern Kangaroo lizard (Vadakkan Kangaroo Onthu). It is relatively smaller and measures between 5.5 and 8 cm in length. Unlike other lizards, these do not climb trees; instead, they inhabit the ground, often hiding among fallen leaves. They feed on small animals and are known to quickly flee on their hind legs into the leaves when threatened by predators, which is likely why they were originally named ‘kangaroo lizard’ in English.

The new species has been named Agasthyagama edge as a tribute to the Zoological Society of London’s EDGE of Existence program. This program supports young researchers in countries like India who study and protect Evolutionarily Distinct and Globally Endangered (EDGE) species. These are species with unique evolutionary traits that are also facing a global threat of extinction. The naming of the new species as Agasthyagama edge acknowledges the importance of conservation efforts for such unique and endangered species around the world.

During a field trip in 2014-15, aimed at studying the tadpoles of the ‘Mahabali frog,’ the research team first spotted the species by a roadside near a forest stream in Idukki. However, at first glance, they did not pay much attention, assuming it might be the ‘Agasthyagama beddomii,’ a species previously discovered from the Agasthyamala region.

It was after discussions with Dr Deepak Veerappan, a global expert in lizard taxonomy, that the research team began to consider the possibility that the species they observed might be distinct from those found in the Agasthyamala ranges. Meanwhile, Dr Subin noted several areas during his travels where he frequently encountered these lizards, and he documented these locations. This information prompted the team to initiate a study and analyze available museum specimens in India, furthering their research into understanding and classifying this unique species.

Genetic studies revealed differences between these lizards, but morphological differences are crucial in taxonomy. The comparison with specimens collected in the late 1800s and 1935, which are deposited in the London Natural History Museum and the Chicago Field Museum, was a significant challenge. Completing this comparison was essential for the study to be comprehensive. Dr Deepak V from the University of Wolverhampton pointed out that this comparative study took years to complete due to its complexity and the importance of thorough analysis to accurately classify the species.

In this study, information about other species in the Agasthyagama genus, such as Agasthyagama beddomii, and their distribution was shared, along with data from museum specimens. The naming of the new species also serves to bring attention to EDGE species – those with unique evolutionary features but facing a global extinction threat. Despite numerous studies, researchers are still discovering new species in the Western Ghats, highlighting the region's rich biodiversity and the potential for further discoveries and research. Dr Sandeep Das, a National Post Doctoral Fellow in the Zoology Department at the University of Calicut, emphasized that these ongoing discoveries are evidence of the vast amount of biodiversity yet to be explored and understood in the area.

The study involved collaboration with several institutions, including the Zoology Department of Calicut University, the Zoological Survey of India, the Kerala Forest Research Institute, the Bombay Natural History Society, ATREE Bangalore, the Senckenberg Museum in Germany, the London Natural History Society, and the Aranyakam Nature Foundation.