Researchers examining soil from China have discovered the empty, light gray shells of seven new species of land snails. One of them is so miniscule, 10 of them could fit into the eye of a large sewing needle at the same time. The new microsnails are described in ZooKeys this week.
Shinshu University’s Barna Páll-Gergely and colleagues found the shells in samples collected from the base of limestone rocks in Guangxi Province. The smallest of the new microsnails has been named Angustopila dominikae – after Páll-Gergely's wife, Dominika – and its shell measures just 0.86 millimeters in height. Even though only one specimen was found, the team determined it was a previously unknown species based on the shape of its shell, aperture (the opening), and umbilicus (the hole between the whorls when viewed from the underside), as well as the little “teeth” in the aperture.
It’s perhaps the world's smallest land snail species. It probably feeds on microorganisms and may be hermaphroditic. However, because the team didn’t recover any DNA, a lot of uncertainly remains.
Perhaps the world's smallest land snail species, Angustopila dominikae, in the eye of a sewing needle. Barna Páll-Gergely and Nikolett Szpisjak
Another one of the new species, called Angustopila subelevata, measured 0.87 millimeters in height on average (eight of these were found). Until now, the smallest known land snail was a thai species measuring about 0.9 millimeters long. The smallest snails on the planet, however, are marine species. The Caribbean-living Ammonicera minortalis, for example, ranges in size from 0.32 to 0.46 millimeters.
All seven new snails belong to the family Hypselostomatidae of Indochina, Indonesia, Australia, and the Philippines. Their round shell shape may allow them to wedge into tiny cracks in limestone and help them trap air bubbles to float with if they ever become dislodged by rain, according to study coauthor Adrienne Jochum from the University of Bern. It also makes it possible for them to survive being swallowed by a bird. And being so small is a huge evolutionary advantage: It allows the sails "to survive anything," Jochum told Newsweek.
"Extremes in body size of organisms not only attract attention from the public, but also incite interest regarding their adaptation to their environment," the team writes. "Investigating tiny-shelled land snails is important for assessing biodiversity and natural history as well as for establishing the foundation for studying the evolution of dwarfism in invertebrate animals."
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