When very small dinosaur bones were found in a Germany mine people thought they were from baby dinosaurs.__31__ scientist Martin Sander's work shows that they were probably fully __32__ (grow) and belong to the smallest giant dinosaur species ever found.
Growth marks on dinosaur bones are similar __33__ growth rings on trees.The rings are far apart while the animal is young and growing quickly.__34__ get closer as growth slows."It is __35__ (exact) these tight ring marks that we found in the fossil (化石) bones," says Sander.So the fossils must have been from adult animals.
__36__ was this German dinosaur so much smaller than other giant dinosaurs,which grew up to 45 metres long and weighed as much as a thousand humans?
150 million years ago,most of Germany was underwater.Scientists think that __37__ water levels rose,there was less and less land and food available.The dinosaur __38__ (force) to adapt and evolved into a smaller animal __39__ (need) less space and food.
Since 1998,scientists have dug up more than 1,000 dinosaur fossils in the mine.It is one of the few places in the world __40__ the bones and footprints of dinosaurs have been found together.