A Michigan farmer Bristle was digging with a backhoe (反铲挖土机) in one of his wheat fields when — bang — it struck a large bone.
Bristle contacted Fisher, a paleontology (古生物学家) professor at the University of Michigan. Fisher rushed to the farm and identified the bone as a fossil of an Ice Age mammoth (猛犸象). Since it was harvest season, Bristle gave Fisher and his students only one day to remove the rest of the fossils from the ground. The team found 20 percent of the animal’s bones, including its skull, tusks, pelvis, and shoulder blades as well as some teeth, ribs, and other bones.
The age of a mammoth can be determined by counting the rings in one of its tusks. Like the rings in a tree trunk, each ring stands for one year of a mammoth’s life. Fisher thinks that the bones are supposed to belong to male mammoth around forty years old. It was probably a rare hybrid of a woolly mammoth and a Colombian mammoth that lived between 11,700 and 15,000 years ago during the Pleistocene lee Age, when ice sheets covered much of Earth’s land.
The bones appeared to have been cut up and some of them were missing, leading Fisher to conclude that early humans must have killed the animal and stored its meat so they could return to it at a later time. Some other indications of human activity include a stone flake (薄片) that might have been from a cutting tool and the arrangement of the neck bones in order. If the mammoth had died naturally, its bones would have scattered randomly.
In the US, fossils found on private property belong to the owner of the land. However, Bristle donated the fossils to the University of Michigan for further study. Fisher hopes to display the bones at the University of Michigan Museum of Natural History, possibly combined with fiberglass models of bones from other Michigan mammoths to form a complete Mammoth skeleton (骨架).
【小题1】Why was Fisher’s time limited to one day?| A．Because the mammoth was a small one. | B．Because it was easy to remove the bones. |
| C．Because it was the time of gathering crops. | D．Because Bristle was busy planting in the field. |
| A．By counting the bones. | B．By judging the living age. |
| C．By measuring the ice sheets. | D．By numbering the tusk rings. |
| A．How the mammoth died. | B．Where the missing meat was. |
| C．How the stone flake was made. | D．Whether the neck bones scattered. |
| A．To own the fossils. | B．To study the mammoth. |
| C．To complete the skeleton. | D．To promote the university. |
