After an extensive fieldwork for over five years, a team of biologists discovered a new type of limbless amphibians in the rain-soaked habitats in the less explored states in northeast India.

According to the researchers, the newly found species is the 10th caecilian family to be identified and is called chikilidae, derived from the name used in the local Garo language.

While
While living in forest soil, adult chikilidaes remain with their eggs until they hatch. During the period, they use to forgo food. Credit: SD Biju

The new species looks like worms at first glance. While living in forest soil, adult chikilidaes remain with their eggs until they hatch. During the period, they use to forgo food.

According to the discovery, published Wednesday in the Royal Society journal Proceedings B, the species may come under threat of population growth and slash-and-burn agriculture.

Based on further analysis and nuclear DNA sequences, researchers have claimed that the family has an unexpected sister-group relationship with the exclusively African family Herpelidae.

DNA evidence also suggested that the family diverged from its African relatives about 140 million years ago, a time when the ancient super-continent of Gondwana split, separating existing India and Africa.

Caecilians are the most cryptic group of animals, and it's not possible to identify whether it's a new species or genus or family just after collecting it, SD Biju from the University of Delhi, who led the project, told BBC News.

We studied the molecules (DNA) and the morphology, both internal and external, to identify the species, he added.

Caecilians are not like other amphibians such as frogs and salamanders. They are limbless and smooth. They have very limited eyesight while their skulls are adapted for burrowing.

Unlike the mistaken belief that caecilians are poisonous snakes, they are, in fact, harmless. They may even be helpful for farmers by feeding on worms and insects that might damage crops, and churning the soil as it moves underground.

Chikilidaes grow to about 4 inches (10 centimeters) and are very fast. If you miss it the first try, you'll never catch it again, said Biju, who has been dubbed FrogMan.

Researchers said the discovery adds a major branch to the amphibian tree of life, shedding light on both evolution and biogeography of caecilians as well as the biotic history of northeast India.