During the week of May 24 – 28, 2010, in Albuquerque, New Mexico, researchers presented findings from nearly two decades of work at the Prehistoric Trackways National Monument during A Decade of Discovery, a science symposium celebrating the 10th anniversary of the National Landscape Conservation System sponsored by the Bureau of Land Management and the New Mexico Museum of Natural History and Science.
Dr. Spencer Lucas, paleontology curator at the New Mexico Museum of Natural History and Science, tells us, "The tracks 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 back then were behaving. Acre for acre, this is one of the best fossil records on the planet." He adds, "The number, the quality, the diversity is amazing, and we're still finding new things. Scientists have come from all over the world to study them." Lucas and his colleagues made several presentations at the symposium on the significance of these findings.
The fossils at this site are called trace fossils (ichnofossils) and can be used to develop a picture of what life was like on the tidal flat many millions of years ago, before the age of dinosaurs. Leaf impressions and petrified wood tell us what was growing on the landscape; some specimens are new to science. When the sea level rose, the tidal flats were inundated by marine waters, and the limestones were deposited. These marine limestones contain a variety of invertebrate body fossils such as shells of brachiopods, clams, and gastropods.
Many of the tracks and traces were made by small animals the size of a salamander or small lizard. The largest animal during the time period was Dimetrodon, a mammal-like reptile that grew to a maximum of 11 feet and produced tracks about the size of a hand. Eryops was a large amphibian whose swimming traces are seen in some places.
The Monument was established in 2009 to protect the unique and nationally important paleontological, scientific and other resources found there. The area was discovered and brought to the attention of paleontologists in the 1980s by a local Las Cruces citizen, Jerry MacDonald. He was at the symposium to talk about its history and about the fossil collection he initiated that is housed at the New Mexico Museum of Natural History and Science.