On the road
After breakfast, we check our supplies, pack the vehicles, and then drive to our field destinations. The road that we most often use is graded gravel, marked by an occasional sand dune or run-off trough. This road is the lifeline to the western regions of China, as it curves to the west near the Mongolian border and on into Xingjiang. It follows the ancient Silk Routes, which were used by camel caravans that connected China's oldest cites in the east to central Asia.

Paul and Jeff map the bones
they have just uncovered.

A day at the site
Work at the theropod site has reached a fever pitch, as we work on the bone horizon that until recently was buried deep within a rocky hill. The bone layer, to our relief and excitement, continues. Each bone is mapped before it is removed, preserving valuable information to sort out how these dinosaurs died and were buried.

Lunchtime at the site means noodles eaten
in the narrow shadow of a car.

Lunch break
At midday, we sit in the narrow zone of shade provided by our vehicles. There are no trees in most of the Gobi, and therefore little shade. On most days we eat noodle packets. Sandwiches are nowhere to be found in China. Hot water from a thermos added to these packets makes for a delicious lunch at the site.

JAWS!
It happened suddenly. The rock looked like any other of a million piled nearby. But when Paul turned it in his hand, he saw the roots of savage, meat-cutting teeth set deep in fossil bone.

"Jaws!" he yelled, and quickly was surrounded by team members. The blade of the bulldozer was cutting closer to the final level but not yet there. Encountering bone, especially something like a jaw with teeth, was unexpected. We swarmed the furrows just pushed aside, and quickly retrieved another piece that fit neatly on the first.

Two pieces of the jaw that fit together
and encase several sockets and teeth
of a new, large-bodied predator.

"I think this might be it," announced Fabrice, who's intense pursuit of the smallest traces of bone led him to the rest of the jaw, still embedded in the base of the hill. "You bet it is!", exclaimed Paul, well aware of the significance of the find. There in the rock also lay the opposite upper jaw, nearly a foot long, and other bones of the cranium composing the main part of the skull. A meat-eater was born.

A tyrannosaur?
Now the first kind of large predator that comes to mind when digging in rock of Late Cretaceous age in Asia is a tyrannosaur. Not Tyrannosaurus rex itself, but one of its cousins. Sometimes this comes as a surprise. North America's Tyrannosaurus is so well known that it's easy to think that it was so distinct and fearsome there were no other predators like it. However, its closest cousin, Tarbosaurus bataar, is so similar to Tyrannosaurus that some specialists want to call it by the same (generic) name--Tyrannosaurus bataar.

Be that as it may, Tarbosaurus, lived in Mongolia at about the same time as Tyrannosaurus was roaming the western United States and western Canada. That is sort of peculiar-closest cousins lived on opposite sides of the Pacific? Geologists have discovered rocks in Alaska and nearby on the Pacific coast of Asia that indicate that the Bering region, with its 60-mile-wide waterway separating Asia and North America, then was bridged by a continuous mountain range. This land bridge must have allowed occasional intercontinental exchange, so that closest cousins would evolve on each continent in many dinosaur groups that lived on both.

Although Tyrannosaurus is terribly famous, I bet most dinosaur paleontologists would trade one of the dozen skulls we have found of T. rex for a skull of its more distant cousin Aublysodon, that lived in western North America before T. rex evolved. Aublysodon, still known only from teeth and fragments, was a smaller than T. rex. Like T. rex, it has an unusual set of small "incisors" at the front of the upper jaws and, toward the rear, has inflated, almost cylindrical teeth. Also like T. rex, its closest cousin, Alectrosaurus, lived in Mongolia.

Now Alectrosaurus is particularly interesting to us because it lived about 90 million years ago, 20 million years before Tarbosaurus and Tyrannosaurus. And that is the estimated age of the beds we are digging. So what did we look at before gluing anything together? The teeth. Did our jaws belong to a tyrannosaur? Was it Alectrosaurus? Did it have incisors and cylindrical cheek teeth? The answer--nope. We chattered in excitement about the discovery of . . . well, of something new!

What could it be?
This blade-toothed predator, very likely a new species, will remain mysterious until its skull bones, jaws, and teeth are fully exposed later in the lab. Not knowing exactly what one has just dug up is a fact of life for the paleontologist and part of the excitement of labwork. We can't know everything in the field. Quite frequently our identifications are slightly off or sometimes just plain wrong. In the field, often we see only a part of a bone, or only a few bones of a skull or skeleton. The rest we need to guess at for the time being. Cleaning this skull in the months to come will be like unwrapping a great Christmas present.

B-BALL REMATCH

Mike Hettwer sinks a shot.
(photo by Gabe Lyon)