Scientists have discovered six bizarre new species of land snails that have “scaly” shells and hope that studying them will help them find out exactly how this unusual feature forms.

The snails are absolutely tiny, measuring just a couple of millimeters in length. They belong to the genus Georissa, and were found in Borneo by a team led by Mohd Zacaery Khalik from the Naturalis Biodiversity Center in the Netherlands. Their findings are published in the journal ZooKeys.

“The published article is the first part of our study on this group of snails,” Khalik told IFLScience. “Before we do a detailed investigation on these unique snails, we wanted to find out how the species within this genus are related to one another.”

Scaly snails were first discovered all the way back in 1889, but their spiral shells remain a bit of a mystery. Other species in the genus do not have this characteristic, which gives these mollusks a very unique appearance.

The team in this paper studied microsnails in the region from 2015 to 2017 to try to work out how these shells evolved, using DNA data and 3D modeling, with the help of X-ray scanning. This allowed them to peek inside the shells and study them in better detail.

^{Here's a video showing 3D models of the snails, and the scientists out in the field collecting them.}

“This article is the first step towards our study on the evolutionary history of this minutely-formed group of gastropods,” said Khalik. “As most of the works are in progress, we haven't come to any conclusion just yet.”

Of the six species, the researchers found a number of interesting differences between them. They had different patterns and orientations of scales, while the number of scales in total also varied. Shell shape and size also differed between the species.

Khalik noted that they haven’t encountered any species of Georissa with this scale-like feature anywhere in Southeast Asia except Borneo. Thus, they suggest these creatures may be endemic to the region.

So the story of how exactly these microsnails got their scales remains a bit of a mystery. But it’s pretty awesome these unique, tiny creatures are hanging out in Borneo.