THE 19TH-CENTURY DISCOVERY OF JURASSIC CYCADS IN THE FREEZEOUT HILLS, CARBON COUNTY, WYOMING

During the late 19th century, Wyoming became famous for fossil vertebrate and plant discoveries. Among these finds was the first Jurassic cycad locality in North America, in the Morrison Formation of the Freezeout Hills of Wyoming. This unique discovery sparked interactions, both collaborative and contentious, among four of paleontology’s most notable and eccentric historic figures: Othniel C. Marsh and George R. Wieland (Yale University), Lester F. Ward (U.S. National Museum), and William H. Reed (Wyoming University).

During that time, debate raged among the scientific community on the best method to determine the geologic age of strata. Ward and Marsh debated on the utility of fossil plants versus fossil vertebrates for Atlantic Coast strata. Their dispute continued for a decade with Ward arguing for an Early Cretaceous age and Marsh, mistakenly, for a Jurassic age. To bolster his position, Marsh asked Reed to search for Jurassic cycads in Wyoming. Reed had previously discovered and collected some of Marsh’s most important dinosaur fossils before resigning in frustration. Reed remained embittered by his former employer’s treatment, but when he discovered a new cycad locality in the Freezeout Hills in 1898, he immediately contacted Marsh. Marsh purchased two cycads from the Wyoming University and invited Ward to study these fossils.

In 1899, Ward visited the Freezeout Hills to inspect the geology of the Jurassic site and collect additional cycad specimens. The following year, he described the new genus, Cycadella, and twenty new species based on these specimens. An illustrated monograph followed in 1905. Inspired by Ward’s work, Wieland shifted his focus from fossil vertebrates to fossil cycads. He reviewed and rejected Ward’s earlier classifications, concluding that the specimens belonged to two or three species of the genus Cycadeoidea. Reevaluation by Theodore Delevoryas in 1960, synonymized the Freezeout Hills cycads into the taxon: Cycadeoidea wyomingensis (Ward, 1900). The interactions among Marsh, Ward, Reed, and Wieland over the Freezeout Hills cycads, highlight a complex interplay of scientific competition and collaboration as well as the evolving interpretations of fossil cycad taxonomy. Recently, this historic cycad quarry was rediscovered on land managed by the Bureau of Land Management.