A new species of vine snake, belonging to an ancient lineage dating back to between 20 and 30 million years, has been discovered in the Agasthyamalai hills in the Western Ghats of India1. The vine snake Proahaetulla antiqua , which lives in trees, is a member of the Ahaetuliinae family.
Proahaetulla antiqua © Saunak P. Pal
Lead author Ashok Kumar Mallik of the Center for Ecological Sciences, Indian Institute of Science, Bangalore reckons other researchers might have come across this snake but may not have identified it as a new species because of its taxonomic similarities with other vine snakes, such as Ahaetulla dispar.
The Ahaetuliinae family comprises 62 non-venomous species of snakes belonging to four genera: Ahaetulla (vine snakes), Chrysopelea (flying snakes), Dendrelaphis (bronzebacks) and Dryophiops (whip snakes). They are distributed mostly in south and south-east Asia, and parts of East Asia. Dendrelaphis is the largest genus, with 45 species.
The researchers found that the genus Proahaetulla is nested within the family Ahaetuliinae, is a close relative of all the other vine snakes belonging to the genus Ahaetulla and is visually similar.
Integrative taxonomy — an amalgamation of different lines of evidence, from teeth, genetics and molecular phylogenetics, structure and bone analysis to traditional taxonomy — helped the researchers identify a new genus.
The discovery partially sheds light on the ancient colonisation of members of the family Ahaetuliinae in various parts of Asia, such as Peninsular India and Sri Lanka, Malik says.
While finding a deeply divergent snake lineage is rare, it indicates that “many more new lineages (genus or species) are waiting for their turn to be known to science”.
References
1. Mallik, A. K. et al. Discovery of a deeply divergent new lineage of vine snake (Colubridae: Ahaetuliinae: Proahaetulla gen. nov.) from the southern Western Ghats of Peninsular India with a revised key for Ahaetuliinae. PLoS (2019) doi: 10.1371/journal.pone.0218851
