Only about 100 Dinosaur Rex Fossils The species was discovered in 1902 by American archaeologist Henry Fairfield Osborne. Carnivorous dinosaur species D. Rex Lived in the Cretaceous about 66-68 million years ago in western America including Montana and Wyoming.
But how many live D. Rex Did individuals roam the land during this period?
Polyontologists led by Charles Marshall at the University of California, Berkeley, used a method used by ecologists studying contemporary organisms to estimate the population density of endangered species. The team found, Published in Science Magazine this week, About 20,000 years old D. Rex Individuals can live at any time, give or take 10 factor.
The population density of living animals is related to their body size (mass) and the geographical range they occupy (and available resources) – this is called the law of Tamu. Tamut’s law states that the average population density of a species decreases predictably as body weight increases; For example, some elephants in the same area can be supported, but a greater number of rats.
“The project started as a lark in a way,” Marshall said. “When I have a fossil in my hand, I can not help wondering if this animal was alive millions of years ago. Here I have a part of its skeleton – it seems so impossible. One in a thousand, one in a million, one in a billion? ‘ We can really estimate how many people were alive, and thus, I began to realize that I could answer that question.
The team used an estimate of the total range D. Rex Across modern North America, along with their estimates of dinosaur body mass, to calculate the absolute abundance and protection rate D. Rex population. The authors point out that the uncertainties in the estimates are large. At any given time when the population is 20,000 adults, 95% of the confidence limit – 95% of the population range is likely to be the false number 1,300 to 328,000 persons. The total number of individuals in the lifespan of the creatures may range from 140 million to 42 billion.
Number D. Rex The list of 100 people, including 32 adults, includes individuals mentioned in museums and in the hands of private collectors. It is recovering a fossil sample for every 80 million animals that have ever lived. These numbers confirm an old rule in archeology – fossils in general are very rare, indicating that many species that once lived on earth were never preserved.