THE MYSTERIES OF WESTERN EXPLORATION–SO MANY NAMES AND SO FEW TYPES: THE WHITE RIVER GROUP DISCOVERIES AND DECISIONS OF EVANS, SHUMARD, MEEK, AND HAYDEN

In 1853, seemingly important paleontological decisions were being made about who would be allowed to study what fossils in the Mauvaises Terres of South Dakota, with the beginnings of careers in the balance. As it turned out, White River Group pulmonate gastropods would be described over the next 25 years and remain enigmatic in most ways until now. Current studies resolve the primary collecting areas and stratigraphy.

In 1849, John Evans was sent by D.D. Owen (1852) to the upper Missouri River region “to trace out the boundaries of the cretaceous and tertiary formations west of that river, with special reference to their connexion with the formations of Iowa.” Evans's explorations resulted in the discovery of magnificent vertebrate fossils. During the summer of 1853, Evans returned to the Big Badlands with B.F. Shumard and collected gastropods from “the vicinity of Peno Creek.” This collection resulted in their 1854 description of four new snail species. Our work shows Poeno Creek exposures are of the Chadron Formation, or of Chadron lithologies, and fossil pulmonates are located in T. 2 N., R. 17 E. (sec. 9; Locality L3033, Horse Tooth 7.5' Quad.), Pennington Co. Also in 1853, James Hall of New York sent F.B. Meek and F.V. Hayden to the “Bad Lands” to make the best fossil collection to date. Their confrontation with Evans and Shumard in St. Louis almost resulted in the collapse of Hall's expedition. In letters to Hall, Meek clearly implies that Evans and Shumard had a prior claim on the paleontologic study of the then almost entirely unexplored West. They apparently parted amicably, however, after their last meeting in the badlands. The only nonmarine mollusk described immediately following the return of Meek and Hayden was Helix leidyi Hall and Meek 1855, which was reported as from “Near the head of Bear Creek, Mauvaises Terres, turtle and bone bed. Eocene Tertiary” (L4277). The taxon was probably collected from the Brule Formation in about the E½ of T. 3 S., R. 13 E., Pennington Co. (Scenic 7.5' Quad.). Although Meek and Hayden published two new species from “Pinots' Creek in 1860, Meek refrained from publishing additional Poeno Creek new species until 1876 and did so with Shumard's permission. To date, the majority of the nine types described by the above authors are lost, and only until Meek's 1876 paper were any of the specimens figured.