Redescription of Early Pennsylvanian trace-fossil holotypes from the nonmarine Hindostan Whetstone beds of Indiana

Abstract
The late Namurian Hindostan Whetstone beds are among the oldest Pennsylvanian strata recognized in the Illinois Basin. Trace-fossil holotypes of Haplotichnus indianensis, Plangtichnus erraticus, and Treptichnus bifurcus were first described and illustrated from these nonmarine strata with line drawings without reference to scale in a relatively obscure work by S. A. Miller (1889). These holotypes are refigured and redescribed in this paper. Based on examination of holotype collections, the Ordovician “Feather-stitch Trail” of Wilson (1948) is judged not to be congeneric with Treptichnus. The ichnogenus Ancorichnus, which is present in the Hindostan Whetstone beds, superficially resembles Haplotichnus; however, Haplotichnus lacks the internal meniscae characteristic of Ancorichnus.