The Pipe Creek Sinkhole biota, a diverse late Tertiary continental fossil assemblage from Grant County, Indiana

Quarrying in east-central Indiana has uncovered richly fossiliferous uncons olidated sediment buried beneath Pleistocene glacial till. The fossiliferou s layer is part of a sedimentary deposit that accumulated in a sinkhole dev eloped in the limestone flank beds of a Paleozoic reef Plant and animal (mo stly vertebrate) remains are abundant in the fossil assemblage. Plants are represented by a diversity of terrestrial and wetlands forms, all of extant species. The vertebrate assemblage (here designated the Pipe Creek Sinkhol e local fauna) is dominated by frogs and pond turtles, but fishes, birds. s nakes and small and large mammals are also present; both extinct and extant taxa are represented. The mammalian assemblage indicates an early Pliocene age (latest Hemphillian or earliest Blancan North American Land Mammal Age ). This is the first Tertiary continental biota discovered in the interior of the eastern half of North America.