As we reported recently, a team of researchers from the New Jersey Institute of Technology has made a fascinating discovery about a weird little blind fish that dwells in the caves of Thailand. Scientists found that the tiny fish’s method of walking actually closely mimics that of a vertebrate with a pelvis, not unlike a salamander.

While it is certainly interesting to watch a blind fish wiggle its way up a rushing waterfall, the discovery actually offers a rich new insight into how the first animals emerged from the seas and began roaming around on dry land. The fish bore striking similarities to tetrapods, or four-footed mammals and amphibians.

The fish, known as Cryptotora thamicola, is unlike any other walking fish – certain species like the snakehead have the ability to survive on damp ground, slithering their way from pond to pond. The blind cave fish, however, has certain morphological features that have only been observed in mammals and amphibians – namely a “hip” bone that allows them to walk on four separate pressure points and not just their bellies.

The arrival of the pelvis in the fossil record marks the first time animals left the oceans and began walking on dry land. The transition from finned to limbed organism was a major turning point for life on Earth, which occurred during the Devonian period some 420 million years ago.

The study was published in the journal Nature Scientific Reports. The development of a pelvis-like bone in this tiny species of cave fish offers unique insights into what was going on during the Devonian period. The bone is a “convergent morphological feature,” which means that while it may not have descended from a mammal or amphibian directly, it likely developed at the same time and for similar reasons as the pelvic bone of tetrapods. The tiny blind cave fish offers yet another clue into how life came to be the way it is today.

A press release from the New Jersey Institute of Technology describing the details of the study can be found here.