You may have seen a fossil hunt on television, or you may have visited a fossil site. Perhaps you have been lucky enough to find your own fossil. What happens on an organized fossil dig?
IT WAS FOUND THERE!
Every dinosaur dig is different. Some fossils are found embedded in solid rock that needs to be chipped away bit by bit. Others fall out of soft, crumbly cliffs and can be very fragile, falling apart easily. The dinosaur above was found buried in the desert sand and was easy to dig out by hand.
A fossil hunter’s toolbox
Scientists who study fossils are called paleontologists. Paleontologists use basic digging tools to remove fossils from the ground, such as hammers, chisels, and trowels. Brushes help sweep away dust.
Paleontologists classify the dinosaur fossils they uncover in one of four ways.
■ Articulated skeleton. This is a skeleton that is still joined together. It may be complete, but pieces are usually missing.
■ Associated skeleton. This means the bones have broken up and spread out, but they can be identified as belonging to the same dinosaur.
■ Isolated bone. This is a bone that has been separated from its skeleton, and fossilized alone. It may be a leg bone such as a femur (thigh bone), which is a large fossil.
■ Float. These are scraps of fossilized bone—the fossil has shattered, and the scraps are usually too small to be useful.
A SLOW JOB
Once the paleontologists have carefully removed all dirt from around each of the fossilized bones, the position of each bone is carefully mapped on graph paper, with the help of a square grid called a quadrat.
EXCAVATING A DINOSAUR
The excavation of two dinosaur fossils, Afrovenator (a theropod) and Jobaria (a sauropod) has started in Africa. The bones were first discovered by local tribesmen, who found them jutting out of desert rock. It can take many months to excavate a complete dinosaur find, and this dig was no exception.
MAKING A START. Painstaking work over a number of weeks to remove rock finally revealed each fossil. A large team of people worked on this dig.
ON SHOW. As more soil is removed, the fossils become clear. The team was dealing with a theropod that could reach 30 ft (9 m) and a sauropod that could reach 60 ft (18 m) in length, so the bones were large.
SITE MAP. One paleontologist made a final, detailed drawing of the bones in position. This showed clearly how some bones had separated from the animal over the millions of years it had lain encased in rock.
WRAP IT UP! Once the bones were ready to be removed, they were covered with bandages soaked in a plaster solution. When the plaster sets hard, this protects the fossil, ready for its removal to a museum laboratory for further study.
So many bones…
One quarry has yielded far more dinosaur bones than any other. From 1909 to 1924, 385 tons (350 metric tons) of dinosaur fossils were removed from the Dinosaur National Monument on the Utah-Colorado border.
That’s a lot of bones!