Research News 

Snail is a Main Character in New Book Wildsnailcover 

Curator Tim Pearce worked closely with author Elisabeth Tova Bailey as she wrote The Sound of a Wild Snail Eating, a charming book about the relationship she developed with a snail during the eight months she was bedridden from a mystery virus. The story brings to the popular consciousness intriguing details in splendid (and accessible) prose about the lives of these traditionally overlooked creatures with whom we share the planet. The author is very inquisitive and an insatiable reader, so it was a joy to work with her in getting the science right. Her book is helping snails to get some of the attention they deserve. For more information, visit

Land Snails of Pennsylvania 2015: Updated Distribution Maps & Imperilment Ranks 

Utilizing 17,472 records of Pennsylvania land snails from modern field work and museum specimens, this report updates county occurrences for the 129 species of land snails in Pennsylvania. Sampling leaf litter was necessary to find the minute species that make up more than half the fauna, with at least one sample of leaf litter from every county reporting at least 14 species. Using these maps along with historical museum records in the NatureServe rank calculator to determine imperilment ranks for these species, it was discovered that 46 species are of conservation concern (S1-S3 ranks). Finally, using elevation information, it was determined that at least five species might be susceptible to climate warming if their populations are forced upward into smaller spaces and 19 important snail areas in the state were recognized. Click here to see the report (Acrobat PDF, 5.6 Mb)

Slugs on the Radio 

The leopard slug, Limax maximus, is native to Europe but was introduced (inadvertently) to North America more than 150 years ago. Noticed for their large size and spotted pattern, they are remarkable for their aerial mating. Leopard slugs are agricultural pests and are known to be quite aggressive (for a slug). However, they tend to occur in human-modified areas and evidence is equivocal about whether they harm native species. Is 150 years sufficient time that we should consider them native? Listen to the program: Experts Debate Leopard Slugs’ Place in Urban Areas.

Land Snails of Limestone Communities and Update of Land Snail Distributions in Pennsylvania (2008) 

Pennsylvania has 120 reported land snail species, but information about their distribution within Pennsylvania has been poor. Prior to this study, six well-surveyed counties were known to have 35 or more species, but 34 (50%) counties reported fewer than 15 species. To improve knowledge about distributions and habitat associations of land snails, curator Tim Pearce compiled museum records, inventoried land snails through fieldwork at 11 limestone areas in western Pennsylvania (limestone has diverse snail faunas), and documented plant communities, habitat parameters, and soil chemistry at fieldwork sites. He documented 1,022 new county records since the 1985 distribution maps. Now only 15 counties report fewer than 15 snail species. Habitat analysis confirms that limestone areas harbor greater diversity of snails. Updated distribution maps of 120 species of Pennsylvania land snails are presented. Click here to see the report (Acrobat PDF, 2.8 Mb)

bookcoverCarnegie Museum researchers contribute to a new publication from the American Malacological Society 

Have you ever wondered about collecting snails with a leaf blower? How about the ins and outs of preserving a giant squid? If questions like these arise from time to time, you want a copy of The Mollusks: A Guide to Their Study, Collection, and Preservation. This book would not exist without major contributors from Carnegie Museum of Natural History Section of Mollusks personnel. Click here to learn more about the book and find out how to order! (Microsoft Word, 26Kb)

American Malacological Society meets in Pittsburgh 

The American Malacological Society, founded in 1931, held its annual meeting in Pittsburgh during the summer of 2011. This was the third time Carnegie Museum of Natural History played a significant role in this meeting.

In 1965–1966, then-curator Juan Jose Parodiz (1911–2007), as president of the American Malacological Society, hosted the annual meeting. In 1999, the annual meeting was again held in Pittsburgh, and Carnegie staff provided access to the collections and helped lead field trips.

In 2011, researchers presented talks on snails, clams, octopus, and much more. Among the many events were a behind-the-scenes tour of Carnegie Museum of Natural History's Mollusks collection and field trips led by museum personnel. In addition, museum staff and volunteers were involved in all aspects of planning for the yearly event.

he_occuSnails on the Radio  

A rare snail, Hendersonia occulta (cherrystone drop), was known from only 2 of Pennsylvania's 67 counties before 2005. Fieldwork by Tim Pearce in 2005 increased the number of known counties for this snail from 2 to 5, and noted finding the snail near rare larkspur plants. A 5-minute radio expedition produced in 2006 by Cynthia Berger from WPSU-FM in University Park, Pennsylvania, featured Pearce successfully following a 10-year old report of the larkspur to find Hendersonia occulta in yet another county: 

Eastern Land snails website, including Pennsylvania and Virginia 

This informative website presents species descriptions and images of the land snail species found in Pennsylvania and Virginia. The site also provides detailed discussions of Land Snail Ecology as well as a helpful identification key. The site can be accessed at: 

Powdermill Nature Reserve: Type Locality for a Flagellate Protozoan  


Triodopsis tridentata
Illustration: Emily Ullo

Cryptobia innominata
Photo: Acta Protozoologica

Powdermill Nature Reserve, the environmental research center of Carnegie Museum of Natural History, is now the type locality for a flagellate protozoan that is a parasite in a land snail. The new species of flagellate, Cryptobia innominata, is microscopic with two whip-like flagellae and occurs in the northern threetooth land snail, Triodopsis tridentata. Powdermill is the type locality for the new flagellate because the “host” snail was collected there by Curator Tim Pearce during the June 2002 BioForay, a two-day biodiversity identification event.

The flagellate was described in the journal Acta Protozoologica (2004, vol. 43, pp. 123-132) by protozoologist Eugene N. Kozloff of Friday Harbor Labs in Washington State. Dr. Kozloff was skeptical about J. Leidy’s 1846 description of a related flagellate as occurring in three different species of snails, because the parasitic flagellate is passed among host individuals when they mate. Since snails mate with their own species, different species of snails could have different species of flagellates. When he examined the flagellates in the Powdermill snail, his suspicion was confirmed, and he named the new species of flagellate from the Powdermill snail.

A type locality is where a particular type specimen was found. The type specimens (individuals he examined when he wrote the description of the new species) of the flagellate are deposited in the collection at the Smithsonian. Type localities are important because if someone needs to examine additional specimens, the best place to look is the type locality.


Corbicula, an annotated bibliography
By Clement L. Counts, III. 2006. 436 pages.

2.3 Mb Adobe PDF version
2.4 Mb Microsoft Word version 

Identification Guide to Land Snails and Slugs of Western Washington  

By Timothy A. Pearce, Casey H. Richart, William P. Leonard, and Paul A. Hohenlohe

High-quality photographic images facilitate identification of the 78 species of native and introduced Pacific Northwest land snails. This key is intended for use by scientists, amateurs, and conservation workers. We would appreciate knowing your suggestions, corrections, and additions. The guide may be reached at this link: