Geologists discover 'dinosaur dancefloor' in remote American wilderness



An amazing array of footprints made by more than 1,000 dinosaurs have been uncovered on the Arizona-Utah border in the U.S.



Scientists have likened the wealth of tracks and tail-drag marks on the three-quarter acre site to a crowded 'dinosaur dance floor.'

Geologist Winston Seiler with some of the dinosaur tracks he identified for his thesis as a University of Utah master's degree student. The tracks were made some 190 million years ago

They believe the remote dry wilderness was once a sandy desert oasis 190 million years ago. It was then in the tropics as part of the supercontinent Pangaea.

'We're looking at an area much like the Sahara Desert with blowing sand dunes,' geologist Winston Seiler reported in the international paleontology journal Palaios.

'Areas between these sand dunes could have had ponds - oases.'

This would explain the sheer number of tracks as the exhausted thirsty giants traveled to the watering hole.



'Unlike other trackways that may have several to dozens of footprint impressions, this particular surface has more than 1,000,' lead researcher Professor Marjorie Chan from Utah University said.

'It was a place that attracted a crowd, kind of like a dance floor.'

Tracks from sauropodomorphs - dinosaurs who walk on four legs - were found at the site

The range of tracks suggest at least four dinosaur species ranging from youngsters to adults visited the site.

'The different size tracks (from one to 20 inches long) may tell us that we are seeing mothers walking around with babies,' Seiler said.

He marked off 10 random plots of two square yards and counted 473 tracks - an average of 12 per square yard. His conservatively estimates the site has more than 1,000 tracks, but he and Chan believe there could be thousands.



They also discovered 2.4inch-wide tail-drag marks up to 24 feet long, which are particularly rare. There are fewer than a dozen such sites worldwide.





Geologists believe these markings show dinosaur footprints and tail-drag marks. Dinosaur footprints are named by their shape because the species and genus of animal that made them isn't known

When the site was first visited in 2005, Professor Chan originally thought they were strange potholes caused by erosion. However, on closer examination she discovered dinosaur features such as obvious claw, toe and heel marks. After the dinosaurs left their prints the trample surface was covered by shifting dunes, which eventually became Navajo Sandstone. Then the rock slowly eroded away exposing the tracks. 'The tracks will eventually erode too,' Seiler said.

(L) A 14-inch-long Sauropodomorph dinosaur track is two footprints in one. It was left by the front and back foot of a dinosaur that walked on four legs

(R) Scientists believe this 4-inch long Grallator dinosaur track was made by a tiny dinosaur only 3ft tall