Petrified Forest National Park Unearthed

National Park Service

U.S. Department of the Interior

Petrified Forest National Park

P.O. Box 2217

1 Park Road

Petrified Forest, AZ 86028

(928)524-6228 phone

(928)524-3567 fax

Petrified Forest N.P.

News Release March 18, 2002

For Immediate Release Michele Hellickson, Superintendent ext 225 Michael Stuckey, Park Ranger ext 233 225


The National Park Service with the assistance of scientists who volunteered their time and expertise recently unearthed the remains of the armored reptile (aetosaur) Stagonolepis wellesi, in Petrified Forest National Park in northeastern Arizona. Preliminary investigation of the specimen suggests that over 100 individual bones are present, mostly armor plates. Numerous non-armor elements are present as well, including a portion of the pelvis, portions of the backbone, and a few ribs. The skeleton is about 2.5 meters in length and was recovered from mudstone layers just below the ground surface in the park. Using the dates of the rock layers in which the excavation site is located, researchers estimate that the reptile may date to about 220 million years ago. Common in late Triassic terrestrial sediments, aetosaurs comprise a major portion of the animal life from this ancient time. This new specimen is of great significance because associated skeletons, including those of aetosaurs, are very rare.

Only one other relatively complete (more than 50% of elements present) aetosaur skeleton, Desmatosuchus haplocerus , has been recovered to date from Arizona. While a large amount of associated aetosaur material has been recovered from other sites in the southwestern United States, few are as complete as this one. As a result of the lack of whole specimens, reconstruction of these animals has mainly been based upon isolated elements. The recently excavated specimen from Petrified Forest National Park should allow for analytical comparisons with other aetosaur remains to improve these reconstructions and ensuring their accuracy. Preparation of the bones will take place at the park through the end of 2002 with a scientific description being released sometime the following year. In addition, park staff hope to create a public display featuring more on this unique animal sometime in the future. The discovery and excavation of this large, herbivorous, heavily armored reptile resulted from recent fieldwork conducted in conjunction with an inventory of paleontological resources in Petrified Forest National Park. Funding for the inventory effort has come from the fees paid by visitors to the park, under the authority of the Recreation Fee Demonstration Program. The park's strategic plan and annual performance plan for FY2002 established goals for inventorying and monitoring the park's resources. Inventory and regular monitoring of Petrified Forest's fossil resources are critical activities.

Ongoing erosion continually uncovers buried fossil deposits. Newly exposed fossils deteriorate very rapidly, breaking down and disappearing over a relatively short period of time. Monitoring of known fossil sites is essential to recovery of significant fossil materials and the scientific information associated with them. Petrified Forest National Park is one of a very limited number of places in which scientists have the opportunity to study a Late Triassic period terrestrial environment. The park's badlands exposures offer a three-dimensional opportunity for such study and scientists consider the park's resources to be globally significant. In the park's 1992 General Management Plan the National Park Service recommended a major boundary expansion for the park for the express purpose of protecting globally significant paleontological resources found in the exposures on lands adjacent to the park. The National Parks Conservation Association listed Petrified Forest National Park as one of America's ten most endangered parks in 2000 and again in 2001, due to the fact that the proposed boundary expansion had yet not been authorized by Congress. In September 2000 Senator Jon Kyl announced that $2 million was being made available for the acquisition of lands adjacent to Petrified Forest National Park. Since the National Park Service currently lacks the legislated authority to acquire these lands, the funding is currently being administered by the Bureau of Land Management and pre-acquisition work is underway.

Scientific research is ongoing in Petrified Forest National Park under permits from the National Park Service. The research effort is supported by grant assistance from the Petrified Forest Museum Association, a non-profit association that aids the educational and scientific programs of the park, and by partnerships with educational institutions. Ongoing research includes studies in many scientific fields such as geology (the study of the Earth), archeology (the study of human cultures), paleontology (the study of fossils), and biology (the study of lifeforms). These investigations can furnish new insights into the history and ecology of our earth. Petrified Forest National Park was set aside as a National Monument in 1906 to protect the remains of the Mesozoic forests. Over time it has become an outdoor laboratory in which scientists can conduct investigations that may help us to better understand our Earth and how it has developed and changed, said Michele Hellickson, park superintendent. In recent years, researchers have made several exciting discoveries in the park, and we look forward to more research and data from these scientists and to the debates that may surround some of these discoveries. Petrified Forest is a wonderful place that affords visitors of all ages both the chance to experience spectacular scenery and wildness and the opportunity to discover, wonder, question and learn.

Aetosaur pronunciations: Aetosaur (AY-e-to-SAWR) Greek for eagle lizard in regards to the birdlike skull

Desmatosuchus (DES-ma-to-SOOK-us) Greek for banded crocodile

Stagonolepis (sta-GON-o-LEEP-is) Greek for drop scale.

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