Hundreds of dinosaur footprints and bones have been found in Poland.
The prints are in such good condition that even the scaly skin can be seen.
The finding gives important information about the complex environment that existed about 200 million years ago, researchers said.
The Polish Geological Institute-National Research Institute described the find as a treasure trove, meaning a collection of valuable things.
The footprints and bones were found in a clay mine in Borkowice, 130 kilometers south of Warsaw.
Scientists Grzegorz Pienkowski from the National Geological Institute in Warsaw and Grzegorz Niedzwiedzki from Uppsala University in Sweden found the remains.
Niedzwiedzki said the find offers much information.
"In the traces left by dinosaurs, you can read their behavior and habits...we have traces left by dinosaurs running, swimming, resting and sitting," he said.
The largest footprints measure 40 centimeters.
The researchers said those were left by meat eaters, or carnivores.
In many prints, the skin left a very clear image.
"In order for such a state of preservation to be possible, a very special sequence of events had to take place in a short time," Pienkowski said in a statement.
Several hundred dinosaur tracks, representing at least seven kinds of dinosaurs, have been found and geologists say they are likely to find more.
They have also discovered small pieces of bone from animals and fish.
I'm John Russell.