SCIENTIFIC ART AND ILLUSTRATION AS AN INTERPRETATIVE TOOL FOR THE BEAR GULCH LIMESTONE (MISSISSIPPIAN, MONTANA)

In central Montana lies the Bear Gulch Limestone, a sequence of thin plattenkalk limestone about 30 m thick and located in Fergus County, central Montana. This unit belongs to the Heath Formation of the Big Snowy Group. It is dated in the Mississippian as late Chesterian (=Namurian A). The Bear Gulch is a lagerstatten that contains about 150 species of fish, 60 of which are sharks, rays and related taxa. It also is celebrated for its soft-part preservation in both fish and invertebrates. The deposit existed as a tropical bay along the western coast of the ancient continent at 10 degrees north of the equator. Fish diversity was high there whereas the invertebrate diversity was only moderate.

Art illustration is used to bring the collective information from both field and the laboratory to not only show the general environment and the organisms but also to better illustrate the intricacies of their paleoecologic relationships. For example, sponges of the genus Arborispongia always are found in association with conularids and byssate bivalves. These associations occurred in shallow northeastern margins of an east-west trending bay. The artist/ illustrator must take diverse information from the field and information extracted from the collections. Finding from publications are integrated with those derived from laboratory studies to produce airbrushed acrylic imagery on canvas. Computer imagery can also be used to accurately reflect the paleoecological associations. Thus art illustration turns into valuable paleoecological tools, providing a window into the Mississippian Bear Gulch world that can be understood by laymen and academics alike.