Tiny, record-breaking Chinese land snails fit almost ten times into the eye of a needle

Minuscule snails defy current knowledge and scientific terminology about terrestrial "microsnails". While examining soil samples collected from the base of limestone rocks in Guangxi Province, Southern China, scientists Barna Páll-Gergely and Takahiro Asami from Shinshu University, Adrienne Jochum, University and Natural History Museum of Bern, and András Hunyadi, found several minute empty light grey shells, which measured an astounding height of less than 1 mm.

The single known shell of Angustopila dominikae, named after the wife of the first author, was measured a mere 0.86 mm in shell height. Thus, it is considered to be perhaps the World's smallest land snail species when focusing on the largest diameter of the shell. With very few reported instances of species demonstrating this degree of tininess, the team have described a total of seven new land snail species in their paper, published in the open access journal ZooKeys.

Another of the herein described new species, called Angustopila subelevata, measured 0.83-0.91 mm (mean = 0.87 mm) in height.

Two of the authors have previously described other species of tiny land snails from China and Korea in the same journal.

In their present paper, Dr. Pall-Gergely and his team also discuss the challenges faced by scientists surveying small molluscs, since finding living specimens is still very difficult. Thus, the evolutionary relationships between these species, as well as the number of existing species are yet little known.

"Extremes in body size of organisms not only attract attention from the public, but also incite interest regarding their adaptation to their environment," remind the researchers. "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."

"We hope that these results provide the taxonomic groundwork for future studies concerning the evolution of dwarfism in invertebrates," they finished up.