Skeptics try to shoot holes in dinosaur-track theory

A grouping of sandstone pockmarks in northern Arizona heralded last month as dinosaur footprints by geologists and reported in the news worldwide is actually just another example of erosion's unique handiwork in the area, according to a group of skeptical paleontologists who recently visited the site.

Although the University of Utah research announcing the find was published in the October issue of the international paleontology journal Palaios, paleontologists in Arizona, St. George and Wyoming were publicly skeptical and privately incredulous that the collection of potholes was being touted as dinosaur tracks.

While there is plenty of evidence that the creatures roamed that section of the Colorado Plateau 190 million years ago, a visit to the site identified in the U. study two weeks ago has all but convinced the paleontologists that the holes are indentations left by wind and water, two elements that are particularly effective in carving the relatively soft stone into shapes that capture human imagination.

Buttes and bluffs are named after temples,erect stones are called goblins, and holes in the sandstone, which are as evident on sheer cliff faces as they are on flat ground, can be called a "dinosaur dance floor."

"But that doesn't mean that's what they are," said Andrew Milner, a paleontologist in St. George. "What they're showing here looks nothing like substantiated tracks elsewhere in the area."

Lurking unseen in the footprint controversy is the irony of geologists seeing dinosaur tracks where paleontologist see potholes. Geologists study the dynamics and physical history of the earth and rocks; paleontologists study the life forms existing in former geologic periods represented in fossil remains.

Research boundaries exist but aren't absolute, the scientists said last week.

"Science is an evolving process where we seek the truth," said Marjorie Chan, professor and chairwoman of geology and geophysics and co-author of the recent study that concluded the pockmarked, three-quarter-acre site in Vermilion Cliffs National Monument was a 190-million-year-old dinosaur "trample surface."

"We went through the proper scientific process of careful study, comparisons with other published works and peer review" of the study by independent scientists, Chan said in a Friday news release from the U. "We gave the project considerable critical thought and came up with a different interpretation than the paleontologists, but we are open to dialogue and look forward to collaborating to resolve the controversy."

Brent Breithaupt, a paleontologist and curator of the University of Wyoming's Geological Museum, agreed that "science works best when scientists work together."