A squatting dinosaur left a butt-print in the mud. A pack of dinosaurs swam in water deep enough that their toes just scratched the bottom. Another was momentarily swept off its feet by the current.

These are among discoveries at the St. George dinosaur track site. Some are mentioned briefly in a new scientific publication, while others there are described in detail. The book is "The Triassic-Jurassic Terrestrial Transition," just printed by the New Mexico Museum of Natural History and Science, Albuquerque.

The book's 650 pages concern other fossil finds as well, but a great deal of information was dug out of the St. George site, which dates to around 199 million years ago. The dinosaur footprints, bones, teeth and other animal and plant fossils fill a gap in the record between earlier and older sites in the Southwest.

Sheldon Johnson made the initial discovery in February 2000, while clearing land at the farm he owns with his wife, LaVerna. Since then other nearby sites have turned up specimens.

Jim Kirkland, Utah's state paleontologist and one of the book's editors, estimated that about 250 pages derived from the St. George discoveries. That so much scientific work has been carried out in the relatively few years since the first discovery is a major accomplishment, he said.

One of the most amazing records of dino behavior is preserved in-situ within the museum itself. "It's a pretty impressive trace" fossil, said Andrew R.C. Milner, paleontologist for the city of St. George, another of the editors, who mentioned the find in the book.

"At the time when it was discovered it was the fourth known specimen in the world of a sitting meat-eating dinosaur trace." Since then, another has been discovered.

At the end of a trackway, a three-toed dinosaur sat down. The three-toed variety are theropods, meat-eaters that walked on hind legs. This one may have been searching for fish to snap in what has been dubbed ancient Lake Dixie.

"What makes it really unique is that it actually places its hands down in the sediment, so it rested its hands down on the muddy surface," said Milner.

The fossilized mud preserves the impression of part of the dinosaur's lower leg, from when it leaned back.

"There's a circular mark ... basically it's a butt print," he said. After the dinosaur touched down on the mud, "it shuffled itself forward. It didn't put its hands down on its second squat. Then it stood up and it stepped forward with its left foot first."