The Friends of the Florissant Fossil Beds, Inc.

Paleontology intern Eva Lyon takes a GPS reading, while Dr. Herb Meyer and paleo intern Kathy Salas collect fossils.
I’m Melissa Barton, and in addition to maintaining the Friends website, I am currently the Museum Technician at Florissant Fossil Beds National Monument. This fall I will begin graduate school in Museum & Field Studies at the University of Colorado. I’m currently getting a head start on my master’s thesis, which will focus on the plant paleoecology of the Antero Formation of South Park and its relationship to regional and global climate. I plan to post updates here about my research, primarily about the process of paleontology, from fieldwork to lab to (hopefully) publication.

The Antero Formation is a lake shale deposit like Florissant, and it has been dated from sanidine crystals to 33.76 million years old, whereas Florissant has been dated to about 34.07 million years old. Geologically speaking, this is very close, and would place the Antero Formation just before or just after the Eocene-Oligocene transition, depending on the time scale used. This is important because the Earth’s climate cooled fairly rapidly during this time, resulting in major changes to plant and animal communities. Comparing fossils from the two formations will provide more information about the effects of Eocene-Oligocene cooling in North America, as well as the local paleoecology of the region.

Lake Antero was an interior freshwater lake similar to Lake Florissant…

Lake Antero was an interior freshwater lake similar to Lake Florissant, but much larger, covering about 172 square kilometers. Little work has been done previously on the Antero Formation, most of it on the insects.

A list of known plant species includes redwood (Sequoia), cypress (Chamaecyparis), fir or Douglas-fir (Abies or Pseudotsuga), spruce (Picea), and several species of pine (Pinus), one of which may resemble today’s bristlecone pine, which grows in cold climates. The fossil plants also include mountain mahogany (Cercocarpus), which is extremely common, a small-leaved oak similar to living subalpine oaks (Quercus), blueberry (Vaccinium), Eleopoldia, elm (Ulmus), and mahonia or holly grape. Unfortunately, we haven’t yet tracked down all previous collections to confirm identifications, many of which were tentative.

After a great deal of planning and obtaining permits to work and collect in county road easements, Dr. Herb Meyer (our paleontologist), Kathy Salas and Eva Lyon (paleontology interns), and I finally made it out to South Park to collect some fossils! The shale of the Antero Formation weathers quickly, so it was a slow and sometimes frustrating effort. We collected primarily mountain mahogany leaves, but also a few pine needles and small unidentified leaves that will merit future examination. I also found one tiny insect, possibly a member of the fly or wasp families.

We also collected some rocks for pollen samples. Since it is difficult to gain a concept of the true diversity of the Lake Antero flora from mountain mahogany alone, pollen will play an important role in reconstructing the ancient ecosystem. In addition, since all types of fossil records are biased in some way, collecting different types of plant fossils gives a more complete picture. For example, plants that grew further from the lake probably wouldn’t have fossilized well as leaves, but their wind-borne pollen may be present.

We’re very excited about this project. If you have any questions, you can comment below and I’ll try to answer (your email address will not be posted publically or shared; it is only for verification purposes).

-Melissa Barton

Photo Credits: Melissa Barton

This project is funded by a Cooperative Ecosystems Study Unit agreement with the University of Colorado, and permission to work and collect in South Park road easements was granted by Park County and the State of Colorado. The fossils will remain the property of the State, to be reposited for future study and exhibit at Florissant Fossil Beds National Monument or the University of Colorado Museum of Natural History.

Trackback URI | Comments RSS