Serving the Big Horn Basin for over 100 years
Serving the Big Horn Basin for over 100 years
Artist Wyatt Andrew's depiction of the environment at Oregon Basin south of Powell 78 million years ago: an estuary ecosystem at a time when the Western Interior Seaway separated North America into two island continents. This site has uncovered fossilized remains of small mammals, softshell turtles, sharks, guitarfish, gar, hadrosaurs, tyrannosaurs and toothed birds (all depicted) and more, all dated to this time period.
The Washakie Museum held a Paleontology Symposium on Saturday, July 6 that hosted presenters from across the country, and one from Belgium.
Each presenter is a respected member of the scientific community, having published work relating to the paleontological phenomena found in the Big Horn Basin.
Many of them have made their entire careers studying the ancient history of the Big Horn Basin, which is unique among fossil sites for having well-preserved specimens of both flora and fauna - not just from a single time period - but encompassing a time frame from the Cambrian period 520 million years ago, to the most recent fossils produced during the Ice Age 18,000 years ago. What is even more incredible, is that the fossil record present here is nearly continuous; for paleontologists operating at time scales of geological periods, the basin might as well be an atomic clock for the resolution it offers while studying the ancient past.
Of its caliber, there is only one other site on the planet that compares: the Chengjiang Fossil Site in the Yunnan province of China. When it comes to paleontology, the Big Horn Basin is the best place in the Western Hemisphere.
Today, the Big Horn Basin can be mostly described as a desert ecosystem sparsely populated by any living thing; with inhabitants including sagebrush,cacti and grasses, insects, small rodents, reptiles and birds, dotted herds of ungulates and the occasional deviation from this formula when interrupted by rivers, mountains or human settlements.
To put it simply, it's not very exciting to the average nature enthusiast; those in the area will typically get their fix by travelling to recreate in the oasis of natural diversity found in the mountains. These scientists, however, offer a glimpse into the Big Horn Basin of the ancient past, before the polar ice caps formed 33 million years ago, when the water level was significantly higher; during a time when much of Wyoming was a seafloor beneath the Western Interior Seaway that split the United States into two island continents, separated by a body of saltwater 600 miles wide.
The Big Horn Basin was on the eastern shore of the Larimidia continent, and has a fossil record indicating a nearly unimaginable amount of diversity that persisted until its aridification to the desert recognized today, beginning at the Paleocene-Eocene Thermal Expansion (PETM) about 75 million years ago.
Presenter Andrew Farke of the Raymond M. Alf Museum of Paleontology in Claremont, California, gave a presentation in which he focused on a snapshot of the basin around 78 million years ago in the Mesozoic period. He and his students have dedicated much of their time scouring fossil sites outside of Worland and Powell in search of animals that called the basin their home during this period.
Farke gave a presentation on the rich animal diversity present in the varied ecosystems that used to be here: coastal wetlands, estuaries and inland forests. He and his team have found countless fossils representing saltwater, freshwater and land-dwelling animals, all living here at around the same time; if you have the patience for it, it's not out of the question that you could wander the desert and find a gar scale, a frog bone or the horn of a triceratops.
Scott Wing, Ph.D., of the Smithsonian Museum of Natural History in Washington, D.C., gave a presentation on his findings related to plant fossils found between Worland and Ten Sleep. Wing has spent 40 years coming to the area, and discussed his search for supplementary evidence of the PETM, which was still a contested theory in 2005, when he famously discovered fossilized specimens of legumes at the Castle Gardens dig site.
These bean plants represented the culmination of decades of Wing's work, because they did not occur in the continuous fossil record in the basin before – nor after – the supposed thermal event; but for this brief time in Earth's history they did. The knowledge that legumes thrive in high temperatures suggested a period of rapid heating of Earth's climate, supporting the theory of the PETM.
This is just a taste of what was offered at the Symposium; if you want to learn more about what the Big Horn Basin can teach about the ancient past, visit the Washakie Museum at 2200 Bighorn Avenue in Worland.
