Monument in the Robledo Mountains, near Las Cruces, includes a major deposit of Paleozoic Era fossilized footprints in fossil mega-trackways of land animals, sea creatures, and insects

How to Get There

Overview

Prehistoric Trackways National Monument is a national monument in the Robledo Mountains of Doña Ana County, New Mexico, near the city of Las Cruces. The monument's Paleozoic Era fossils are on 5,255 acres (2,127 ha) of land administered by the Bureau of Land Management. It became the 100th active U.S. national monument when it was designated on March 30, 2009.

Bureau of Land Management, Public domain, via Wikimedia Commons ; Image Size Adjusted

Fossils

The Prehistoric Trackways National Monument site includes a major deposit of Paleozoic Era fossilized footprints in fossil mega-trackways of land animals, sea creatures, and insects. These are known as trace fossils or ichnofossils. There are also fossilized plants and petrified wood present, as well as plenty of marine invertebrate fossils including brachiopods, gastropods, cephalopods, bivalves, and echinoderms. Much of the fossilized material originated during the Permian Period and is around 280 million years old.

Some of the animals who may have left tracks in the Robledo Mountains include Dimetrodon, Eryops, Edaphosaurus, and multiple other pelycosaurs. There are at least 13 major trace fossils found at the monument.

The trackways can be difficult for the general public to find, as the monument is largely undeveloped with few facilities yet existing to aid fossil hunters. Guided hikes are periodically offered by BLM interpretive staff.

Bureau of Land Management, Public domain, via Wikimedia Commons ; Image Size Adjusted

Geology

The monument lies along the western portion of the Rio Grande rift and is within part of the Robledo Mountains. It is made up of Cenozoic and Paleozoic (Hueco Group) sediments. The Hueco Group is Early Permian strata. Most of the monument is Permian and would have been underwater or along the coast of what was once the Hueco Seaway. The tracks can be found in the red rock which is called the abo red beds.

Flora and fauna

The monument is situated at the northern tip of the Chihuahuan Desert. Some examples of plants within the monument are ocotillo, mesquite, creosote bush, prickly-pear cactus, Torrey yucca, barrel cactus, sotol, agave and snakeweed. A few examples of animals are mule deer, rattlesnakes, desert cottontail, many species of lizards, and several species of birds.

This article uses material from the Wikipedia article "Prehistoric Trackways National Monument", which is released under the Creative Commons Attribution-Share-Alike License 3.0