09 July 2008

Field trip to LaRue Pine Hills

Last Thursday about 25 attendees of the American Malacological Society annual meeting had a field trip to an area called LaRue Pine Hills within Shawnee National Forest in Illinois. The majority of the group, including myself, were interested in collecting land snails and the attraction of the location to us was a long limestone cliff that was known, from previous surveys, to harbor a rich diversity of land snail species.


The road going due north along the cliff had been flooded for some time.


Luckily the southbound road was clear and provided easy access to the cliff. We spent several hours searching for and collecting snails. The picture below shows 2 of the most common species, Xolotrema fosteri (left) and Anguispira alternata. The 2 separate pictures below are not to scale; X. fosteri grows about as wide as a penny, while A. alternata can grow as wide as a nickel.


There were many other species, including Pomatiopsis lapidaria, which is often treated as an aquatic snail and Euchemotrema hubrichti, a land snail endemic to this location. I will write about them in separate posts.

The Zen of snail collecting: Tim Pearce becomes one with leaf litter (also a good way to get ticks and chiggers).


Deniz Bevan said...

but what if you sit on some by accident? :-)

Kevin Bonham said...

How high is the species tally for this site? And do you often get very restricted limestone-area endemic species in the USA?


The pre-field trip species list had 31 land snails + 1 slug. I don't yet know if we added any new records.

All of those species, except E. hubrichti, also live elsewhere. There are some, but not many, species with restricted ranges in the U.S. Polygyriscus virginianus is another calciphile species that is endemic to a small area (in Virginia) and may, in fact, be extinct.