KEY POINTS:
Seventy-two million years ago, a dinosaur with a sail-shaped crest on the top of its head lived at a Mexican seashore, munching plants and trying to avoid a cousin of Tyrannosaurus rex.
US, Mexican and Canadian scientists have announced the discovery of Velafrons coahuilensis, a duck-billed dinosaur that
lived about 7 million years before a big rock from space wiped out the dinosaurs.
"Velafrons was probably a beach bum," said palaeontologist Terry Gates of the Utah Museum of Natural History and University of Utah.
Its shoreline home was lush, with rivers flowing into a warm, shallow sea, the scientists said.
"It would have been a beautiful time to have been there - very warm, very Mediterranean-like," Utah Museum of Natural History palaeontologist Scott Sampson said. "But you've got to worry about the tyrannosaurs out there." Gates said it was the most complete dinosaur ever discovered in Mexico. The fossilised remains of Velafrons were found in rugged, dry terrain in north-central Mexico in the state of Coahuila.
Sampson said the discovery is helping open a window into life in the late Cretaceous Period on the southern tip of western North America.
The continent at the time was sliced in two by a big inland sea stretching from the Arctic Ocean to the Gulf of Mexico.
The creature's head is its most remarkable feature. Sitting on the top of its skull is a hollow crest shaped a bit like the sail of a boat. Velafrons coahuilensis means "sailed forehead from Coahuila".
Velafrons and other similar duck-billed dinosaurs had nose bones at the top of the head, with their nasal passages greatly lengthened and running through large crests. "By lengthening its nasal passage, it allowed it to do all sorts of crazy things," Gates said. "It's totally odd and freakish."
Scientists think the crest may have helped attract mates. Air blown through the crest passages made a distinctive trumpeting noise.
The adolescent Velafrons was 7.6m-9m long, and a full-grown adult would have been 10.7m long.
Duck-billed dinosaurs were very common at the time. Sampson said Velafrons closely resembled another duck-billed dinosaur called Corythosaurus that lived roughly 3 million years earlier in Canada.
The Velafrons fossils were found in 1995, but it was not until 2002 that scientists using a jackhammer to get through the hard rock managed to free the skull from the ground. Velafrons lived alongside small mammals, lizards, turtles and other dinosaurs.
Sampson said the remains of a horned dinosaur related to Triceratops were also found, as was evidence that a big meat-eater related to Tyrannosaurus was on the prowl. Many of the bones are covered with fossilised snails and clams, indicating these animals lived near the shore.
'FREAKISH' BIG BOY
* The most complete dinosaur ever found has been discovered in Mexico
* A fully grown adult would have been 10.7m long
* It had a sail-shaped crest on its head
* Air blown through the crest passages could make a distinctive trumpeting noise
* The duck-billed dinosaur lived about 72 million years ago
- REUTERS