A Kilkenny woman, Tara Shine, has discovered a type of crocodile previously unknown outside a small region of eastern Mauritania, in the south of the Sahara desert.

These crocs, living in a very dry region, are only about five feet long. They hike to seasonal water, and "estivate" within caves during the dry season. (that's like "hibernating," but in the Summer.) Unlike full-sized, river-dwelling varieties, they are non-aggressive.

This variety of crocodiles (it is unclear whether they are a separate species) has evolved only over the last 5- to 8-thousand years, from a full-size crocodile. Even during Roman times, 2000 years ago, the Sahara was wetter than it is now.

Ms. Shine, 29, had been studying the water conditions on the land, treking to random sites of the hundreds of seasonal water pools, or "gueltas." During this time, she was volunteering with a nonprofit development organization. She is currently studying at the University of Ulster.

At first, Ms. Shine, who was working among the locals and speaking their dialect, had been skeptical. "I kept hearing stories from the local people that there were crocodiles, but it was hard to believe. They'd never been seen this far north." But she looked.

She found populations of the crocodiles in small groups of eight to 20 at eight sites; she estimates that about 20 such groups exist.

The locals have a reverence for the crocodiles, and sense a mythical connection between the animals and the water. Water is rare, sporadically available, and of course essential. The well-being of the crocodile populations portends the life-supporting supply of water, in the mythology of the people. In other words, the people believe that if the crocs are doing well, the water will continue to be in good supply.

The two species, human and reptile, co-inhabit the land and the water; the crocodiles are pacific about the peoples' visits to the water, and the people guard the crocodiles against poaching.

"The Sahara desert is definitely a surprising location to find a crocodile" — Adam Britton, a zoologist and crocodile expert at Australia's Wildlife Management International.