The U.S. Forest Service has recently discovered “new” dinosaur trackways along the Purgatoire River, Picket Wire Canyonlands, south of La Junta on the Comanche National Grassland.
About 65 volunteers of all ages assisted Forest Service paleontologists in uncovering more than 45 dinosaur tracks and three trackways. Volunteers included Boy Scout Troops 30 and 232 and Cub Scout Packs 5, 237 and 412 from Pueblo and La Junta, as well as others from Colorado, Kansas, Oklahoma and Arizona.
The newly discovered dinosaur tracks were once exposed by the action of the Purgatoire River but became covered by modern river sediments in the past century.
Paleontologists said the re-exposed tracks are especially important because they contain parallel trackways of three sub-adult sauropod dinosaurs. The similar size, gait and trend of these sauropod trackways strongly suggest the animals were traveling together in a group.
The Purgatoire tracksite is one of the first places where gregarious behavior in dinosaurs was first postulated based upon the behavior recorded in the tracks, and the newly re-exposed tracks provide further support for this theory.
The trackways parallel ripple marks, indicating that sauropod dinosaurs walked along the shore of a shallow freshwater lake. There is also high potential for continuation of the sauropod trackways because the limestone dips downward, indicating a prehistoric swale with more muddy conditions.
Dinosaurs walking through muddier areas sank deeper into the mud, thus increasing the likelihood that their tracks would be preserved.
The Purgatoire dinosaur tracksite dates to the Jurassic Period and records compelling evidence that plant-eating sauropod dinosaurs (brontosaurs) lived in herds while meat-eating theropods like Allosaurus were solitary.
More than 1,300 prints in 100 separate trackways extend across a quarter-mile expanse of bedrock where they were preserved for 150 million years.
Visitors can take the Picket Wire Canyonlands guided auto tour to learn about the new discovery. During the tour, guides also show visitors difficult-to-find dinosaur tracks and point out prehistoric, historic and natural features of the canyons.
All-day tours (8 a.m.-4 p.m.) are offered on Saturdays and some Sundays in June, September and October for a small fee. Due to rough roads, visitors will need their own four-wheel drive vehicle.
To make reservations, visit recreation.gov or call 877-444-6777. For additional information call the Comanche National Grassland in La Junta at 719-384-2181.