They aren't worms or even snakes. They're soil-burrowing, limbless amphibians, and they're completely new to science, a new study suggests.
Pictured guarding a brood of eggs in its native northeastern India, the animal above is one of about six potentially new species belonging to a mysterious group of animals called caecilians. What's more, the newfound critters represent an entirely new family of amphibians—family being the next major level up from genus and species in scientific naming conventions—according to findings announced today by the journal Proceedings of the Royal Society B.
Christened Chikilidae ("Chikila" being a local tribal name for caecilians), the family's closest relatives live more than 7,000 miles (11,265 kilometers) away in tropical Africa, the study team reported.
A 3-D skull reconstruction based on CT scans reveals telltale features to scientists who have now assigned up to half a dozen newfound caecilian species from India their own separate family.
Tiny distinctions in the jaw, nose, and eye structures of the snakelike amphibians show the new family belongs to an ancient lineage whose nearest relatives live in Africa, the study team said.
DNA evidence indicates that the Indian group split off from other caecilians more than 140 million years ago.
Image courtesy S.D. Biju
Bundles of Joy?
A clutch of eggs in a muddy nest is buried treasure to a research team that spent five years digging for caecilians in over 250 spots across northern India.
Hunting the elusive animals involves lots of shovel work, explained S. D. Biju, whose team included scientists from the University of Delhi, the U.K. Natural History Museum, and Belgium's Vrije University.
"Because of their burrowing nature and cryptic appearance, they are very difficult to see above the soil," he said.
A total of more than 2,000 hours spent digging beneath tropical undergrowth produced about six suspected new species, three of which have now been confirmed, Biju added.
The embryo of a newly discovered caecilian species, Chikila fulleri, is revealed in microscopic detail inside its translucent egg.
Also visible is the embryo's white yolk supply, which provides the legless amphibian enough nourishment to emerge from its egg as a miniature adult (most amphibians go through a tadpole-like, swimming stage in their early development).
Some young caecilians are known to feast on their mother's skin after hatching. Such behavior has yet to be observed in the newfound Indian species, however.
Indian caecilians, such as these emerging hatchlings, face an uncertain future, according to the team that discovered the new tropical species.
The newly described family is confined to a populated region of northeastern India where its habitats are becoming increasingly fragmented due to slash-and-burn agriculture and development, Biju said. (See a deforestation guide.)
"We are destroying the habitat ruthlessly, without any mercy," he said. "I hope that, in future, this family may be a flagship animal for conservation in the region."