'Dinosaur heaven' reveals wonders
Paralititan's shoulder blade
By BBC News Online science editor Dr David Whitehouse
The partial skeleton of a massive dinosaur, one of the largest creatures ever to walk the Earth, has been unearthed at an Egyptian site.
The 70-tonne beast, 24 - 30 metres (80 -100 ft) long, lived during the Cretaceous period (about 146 to 65 million years ago).
Called Paralititan stromeri, which means "tidal giant," it also marks the revival of Egypt's Bahariya Oasis as a paleontological treasure trove.
"We may have stumbled on dinosaur heaven at Bahariya," says Josh Smith of the University of Pennsylvania.
Long-necked, long-tailed
In the early 20th century, teams led by German geologist Ernst Stromer uncovered a wealth of Late Cretaceous fossils at the site, including four entirely new dinosaur species, but the fossils were destroyed during an Allied attack on Munich during World War II.
Paralititan is the first dinosaur discovery reported from the site since 1935.
The scientists who found it, led by Josh Smith of the University of Pennsylvania, hope that Paralititan and other discoveries at Bahariya will help answer some questions about a relatively mysterious time and place in their history.
Paralititan's skeletal features have convinced researchers that it was a new species of titanosaurid - a group of long-necked, long-tailed, plant-eating dinosaurs - that includes some of the largest land animals ever.
Paralititan's humerus, or upper arm bone, measures 1.69 metres (5.5 ft) in length. It is about 14 percent longer than the next largest Cretaceous dinosaur humerus.
Estimates of Paralititan's overall body size suggest that it may have been one of the heaviest terrestrial vertebrates yet discovered.
"The discovery of a huge sauropod, especially in a near-shore environment, is of great interest," said Hans-Dieter Sues of the University of Toronto.
Where it fell
Smith and colleagues discovered the partial skeleton preserved in fine-grained sediments full of plant remains and root casts. The overall geology of the site suggests that Bahariya may have once consisted of a shallow water area of tidal flats and tidal channels.
Paralititan's skeleton appears to lie where it first fell, since the parts of the skeleton are associated, and the bones of the carcass couldn't have been carried away by the currents or floated to their final resting place in the shallow waters.
There is also evidence that the skeleton was scavenged by another dinosaur.
"The skeleton was spread around in sort of an odd way, and the bones weren't separated at the bone sutures. In fact, the pelvis was ripped apart, just torn to bits," says Smith.
Along with Paralititan, researchers uncovered other fossils that they believe may belong to some of Stromer's lost dinosaur species, as well as fossils from fish, crab, coelacanth, and crocodile-like species. Many of these fossils are giants in their own right, causing Smith and colleagues to speculate on the special nature of the Egyptian site.
"It's really weird, because along with Paralititan and other big sauropods, we also have three carnivores in this system that are the size of T rex" says Smith.
The research team plans to return to the site at the end of this year, continuing work that they hope will give them a better picture of Paralititan's place within the entire ancient ecosystem.
"The rediscovery of the original Bahariya Oasis paleontological site has allowed a new glimpse into the age of dinosaurs in northern Africa," says Thomas Holtz of the University of Maryland.
The research is published in the journal
Science.
-- Anonymous, June 01, 2001