National Fossil Day   Explore Nature
National Park Service
US Department of the Interior

Paleozoic Partner Highlight

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Paleogeographic maps showing two hemispheres of earth approximately 280 million years ago, as well as an enlargement of western North America. Base maps by Ron Blakey (Colorado Plateau Geosystems).

Prehistoric Trackways National Monument
(New Mexico)

Rewriting Scientific Understanding
of Permian Footprints

Track your way to the Permian Period, 280 million years ago—a time when Las Cruces, New Mexico was located near the equator. It was a tropical coastal environment next to the inland Hueco Sea. The vegetation was thick with ancient conifer trees. Fern-like plants grew densely from the ground. Large amphibians and reptiles were on the top of the food chain. Smaller amphibians and reptiles fought for survival. Various insects made their homes amongst the swampy landscape. This was tens of millions of years before the dinosaurs and hundreds of millions of years before humans.

At Prehistoric Trackways National Monument, this ancient world has been preserved as tracks, traces, and various sedimentary features in the red mudstones of the Hueco Group. Hundreds of fossil sites in and around the approximately 5,280 acre Monument preserve different parts of this ancient ecosystem. In particular, the Monument includes a major deposit of Permian-aged fossilized footprint megatrackways.

The trackways at the Prehistoric Trackways National Monument rewrote scientific understanding of Permian footprints. They represent an instant in time almost 300 million years ago, and you can look at it and understand how animals were behaving.
—Dr. Spencer Lucas, Curator of Paleontology,
New Mexico Museum of Natural History and Science

Prehistoric Trackways National Monument (PTNM) was the 100th national monument established in the United States. It was established in 2009 to conserve, protect, and enhance the unique and nationally important paleontological, scientific, educational, scenic, and recreational resources and values of the Robledo Mountains in southern New Mexico. Managed by the Bureau of Land Management (BLM), Prehistoric Trackways National Monument is part of the National Landscape Conservation System (NLCS), which is managed for preservation, public enjoyment, and scientific study.

The Story of Prehistoric Trackways National Monument

Jerry MacDonald at PTNM
In the mid-1980s, amateur paleontologist Jerry MacDonald discovered the trackways that would become Prehistoric Trackways National Monument. Photograph courtesy McKinney Briske (Prehistoric Trackways National Monument).

In the mid-1980s Jerry MacDonald, an amateur paleontologist, brought national recognition to the Robledo Mountains when he found intact, Permian-aged fossilized trackways in the Las Cruces area. Under the supervision of the Smithsonian Institution National Museum of Natural History and the Carnegie Museum of Natural History, MacDonald excavated thousands of specimens from these trackways from what is now known as the Discovery Site. The majority of the over 2500 slabs removed in the excavation comprises "The Jerry MacDonald Paleozoic Trackways Collection" at the New Mexico Museum of Natural History and Science in Albuquerque, New Mexico.

Further research conducted by scientists from all over the world confirms that the Robledo trackways represent one of the most important Late Paleozoic fossil records in the world. A 2010 scientific survey, headed by the New Mexico Museum of Natural History and Science, located over 150 fossil sites in and around the Monument. All of these sites date to the same time period—280 million years ago during the Permian. These sites consist of tracks and imprints made by reptiles such as Dimetrodon, amphibians, fish, arachnids, and insects, along with marine fossils, plant fossils, and petrified wood, as well as rare eurypterid traces shown below.

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Eurypterids swimming in freshwater pools were likely responsible for these interesting traces, indentified as Palmichnium. A reconstruction of a eurypterid making the traces is illustrated below the slab. Eurypterids are featured on the 2013 National Fossil Day Artwork. New Mexico Museum of Natural History and Science photograph and diagram, courtesy McKinney Briske (Prehistoric Trackways National Monument).

The trace fossils preserved in Prehistoric Trackways National Monument provide a window into a single instant in time, hundreds of millions of years in the past. Now under the management and protection of the BLM, scientists and the public will be able to study, enjoy, and learn about these fossils for generations to come.

Ranger hike at PTNM
Ranger-led hikes are one way to experience Prehistoric Trackways National Monument. Photograph courtesy McKinney Briske (Prehistoric Trackways National Monument).

Educational Initiatives

The BLM promotes the excellent educational opportunities of Prehistoric Trackways National Monument. Park rangers lead guided hikes for the public approximately twice a month on Saturdays (weather permitting), regularly give programs for local community groups and partnering agencies, host an annual K-5 paleontology day camp, visit classrooms, and host field trips. BLM has partnered with the New Mexico Museum of Natural History and Science and New Mexico State University STEM and Creative Media Institute to create roving school-kits in which students work with paleontologists, through a media component, to solve some of the mysteries of this ancient fossil environment. In 2011, videos were created to document the research of various scientists working together and with BLM staff. Filming was a partnership with faculty and students from the Creative Media Institute at New Mexico State University, Illinois State Geological Survey–Prairie Research Institute, and Royal Holloway, part of the University of London. View the videos here. This project was made possible in part with funds provided through a BLM NLCS grant.

BLM has partnered with the City of Las Cruces Museum of Nature and Science to feature the Monument's fossils in their Permian Trackways Exhibit, including display of a 30-foot-long trackway.

To celebrate National Fossil Day 2013, Monument staff, along with the National Park Service, U.S. Forest Service, Las Cruces Museum of Nature and Science, Asombro Institute for Science Education, and Mesilla Valley Bosque State Park, will host hands-on, interactive programs at a local school where students rotate through stations and learn about different fossils from various time periods and locations that record the natural history of southern New Mexico.

More information about Prehistoric Trackways National Monument, including location and upcoming events can be found at the Bureau of Land Management's Prehistoric Trackways National Monument website.

Article and photographs provided by McKinney Briske (PTNM Park Ranger).

2013 Paleozoic Partner feature articles:

| January: Fossils of the 2013 National Fossil Day Artwork | February: Paleontological Research Institution, Museum of the Earth | March: Falls of the Ohio State Park | April: Field Museum of Natural History, Mazon Creek Collection | May: Prehistoric Trackways National Monument | June: Cincinnati Museum Center | July: Glacier Bay National Park & Preserve | August: University of Michican Museum of Paleontology, Silica Formation Fossils | September: Yale Peabody Museum of Natural History, Beecher's Trilobite Bed | October: Guadalupe Mountains National Park | November: Utah Geological Survey, Millard County Cambrian Fossils | December: Denver Museum of Nature and Science, High-Altitude Mass Extinction |

Last updated: May 1, 2013