National Geographic Society awards grant to continue exploration and preservation of 100-million-year-old, fossil-rich Arlington Archosaur Site

A research team that includes paleontologists from the Perot Museum will continue the exploration of an ancient fossil site in Arlington, thanks to a $25,000 grant from the National Geographic Society.

Chris Noto


Research team, that includes paleontologists from the Perot Museum, will use funds to excavate and preserve 100-million-year-old Arlington Archosaur Site as residential development closes in

DALLAS (June 30, 2016) – In the heart of the Dallas-Fort Worth region exists a treasure trove of fossils from the age of dinosaurs. Discovered in 2003 by amateur fossil hunters Art Sahlstein, Bill Walker and Phil Kirchoff in Arlington, Texas, the area is undergoing rapid residential development. The fossil site, now known as the Arlington Archosaur Site (AAS), preserves a nearly complete ancient ecosystem estimated to be 95-100 million years old, which will be further explored thanks to a recent grant from the National Geographic Society. While most of the state was covered by a shallow sea at this time, the area around the AAS formed a large peninsula that jutted out into this sea, creating a lush environment of river deltas and swamps that teemed with wildlife, including dinosaurs, crocodiles, turtles, mammals, amphibians, fish, invertebrates and plants. Many of the fossils found here represent new species unknown to the world and unique to this part of Texas.

Perot Museum of Nature and Science adjunct research affiliate Chris Noto, who is also assistant professor of biology at the University of Wisconsin–Parkside, is heading the paleontology team working to excavate and research the AAS. Joining Noto are Stephanie Drumheller-Horton, assistant adjunct professor in Earth and Planetary Sciences at the University of Tennessee; Thomas Adams, curator of paleontology and geology at the Witte Museum in San Antonio; and Anthony Fiorillo, vice president of research and collections and chief curator at the Perot Museum of Nature and Science in Dallas.

The team was recently awarded a $25,000 grant from the National Geographic Society to continue the excavation and study of this unique fossil site through summer 2017. Teams of scientists and trained volunteers will work to recover as many fossils as possible before completion of a nearby residential development. Excavated and collected fossils were initially taken to UTA for curation and scientific study, and have since been donated to the Perot Museum, where they’re being catalogued and preserved for future academic study in the public domain.

“These conservation efforts are important for supporting the ongoing work at the Arlington Archosaur Site, but the rapid pace of development in the area means the long-term future of the site and its fossil resources is less certain,” said Noto. “Therefore it is critical we collect as many fossils and other data as possible now while continuing to demonstrate the scientific, educational, and cultural value of this site to the community.”

“Research has traditionally been focused on either the Early or Late Cretaceous, which have proven to be incredibly fossil-rich,” said Adams, “but the diversity of fossils and the number of species being discovered at the AAS is providing a true picture of an ancient coastal ecosystem that existed 95-100 million years ago.”

The sponsored research will expand the group’s scientific study of the site, allowing new analyses of the rocks enclosing the fossils to reveal important details about the ancient climate and environment that existed at this time during the Cretaceous.  Techniques such as palynology (the study of fossil pollen and spores), stable isotope, X-ray diffraction (XRD), and X-ray fluorescence (XRF) will help the team understand how Texas fits into the larger picture of faunal change that was happening through the middle of the Cretaceous Period, around 90-115 million years ago. Very little is known about this turnover in North America, and the excellent fossil records at the Arlington Site provide a critical window into this important transitional period. “Not only is this site important because it tells us something about the history of the area we live in, but it is also important because the site helps us frame the discoveries we are making in far northern Alaska in rocks of comparable age,” said Fiorillo.  “By being able to study these extinct animals across such a wide range of latitude we can better understand the role of ancient climate in structuring ancient ecosystems.”

As the name suggests, the most commonly found fossils at the AAS are archosaurs, or the group that includes dinosaurs (including birds) and crocodylians. Bite marks and skeletal material from a large crocodile fossil indicate crocs were actually the top predators in the rivers and swamps of this part of Cretaceous Texas.

“We call the Mesozoic the age of dinosaurs for a reason,” said Drumheller-Horton. “But people sometimes forget that other kinds of animals lived in these environments, too. Fossils from the Arlington Archosaur Site preserve evidence that the crocs were major predators in this ecosystem, even eating the dinosaurs that lived there.”

Plans are underway to perform detailed x-ray computed tomography (CT) scans on a selection of turtle and dinosaur fossils that may have had injuries or infections that might help scientists better understand how these structures were formed, providing insights into how they affected the life and death of the animals.

From its first discovery, the AAS has been an important tool for science education and outreach. Trained volunteers from the community, who are passionate about preserving this important resource, perform the majority of the fossil excavation. This is an unprecedented opportunity for the public to be involved in a scientific excavation, sharing their experiences directly with the community. Research stemming from the National Geographic Society grant, and bolstered by public donations through crowdfunding site, will help extend the educational reach of the site beyond the Dallas-Fort Worth area through the creation of teaching materials such as 3D models,  public lectures and website articles.


About the Arlington Archosaur Site.  The AAS is an important fossil locality found in the heart of the Dallas-Ft Worth metroplex. The site is found in the Woodbine Formation, a rock unit formed during the Late Cretaceous period, approximately 95-100 million years ago. The AAS contains an extraordinary diversity, abundance, and quality of fossil material, preserving one of the most complete terrestrial ecosystems known for this time period and area. Thousands of specimens have been found belonging to numerous groups including carnivorous dinosaurs, duck-billed dinosaurs, crocodilians, turtles, mammals, amphibians, sharks, bony fish, invertebrates, and plants. The AAS has a lot to tell us about Late Cretaceous life in North America by filling a significant gap in the fossil record for this time. Studying these fossils will help to establish the geographic and environmental forces that shaped Cretaceous ecosystems in North America. The urban location of the AAS allows members of the public to volunteer at a fossil excavation, providing a unique opportunity to learn about and contribute to the science of paleontology through hands-on experience.

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