Two Superlatives

On opposite sides of the world last week two veteran paleontologists reported two remarkable fossil finds that could literally be described as superlative. One discovery may well qualify as the "largest," the other as the "oldest."

> The largest was found by Brigham Young University's James A. Jensen,* a tall (6 ft. 3 in.), lanky scientist known as "Dinosaur Jim," who worked as a taxidermist, welder, carpenter and longshoreman before turning to paleontology. Last year, on a tip from two amateur rock collectors, Jensen began exploring what was once a prehistoric riverbed near the little farming and lumber town of Delta in western Colorado. By spring he had unearthed a trove of bones that included the remnants of a large carnivorous dinosaur, three prehistoric turtles, parts of ancient crocodiles and small, chicken-sized flying reptiles. But his really big find came only a few weeks ago, when he discovered the matching shoulder blades, pelvis and five vertebrae of what appeared to be a huge, four-legged plant-eating reptile that was more than 50 ft. tall, weighed more than 80 tons and measured as much as 100 ft. from the tip of its nose to the end of its tail. Says Jensen: "I believe we are uncovering the largest dinosaur ever found on the face of the earth."

The giant beast resembles the Brachiosaurus, a huge herbivorous dinosaur that prowled the earth from some 165 million to 100 million years ago. But Jensen thinks that the bones are sufficiently different to indicate that they belong to an entirely new species. As yet, Jensen's discovery has not been confirmed by other specialists, but he thinks that he can provide even more persuasive evidence. By probing further in the Colorado quarry--"a paleontologist's paradise," he says--Jensen hopes eventually to recover enough bones to reconstruct the entire skeleton of the prehistoric monster.

> The oldest find was made by Norman Wakefield, 53, who, like Jensen, is also a tall (6 ft. 2 in.), rangy digger. On holidays from his post as head of the biology department at the teachers' college of Melbourne's Monash University, he likes nothing better than to clamber over the rocks of Australia's bush country. Last September, while exploring a rock-rimmed stream in eastern Victoria, he discovered, preserved in the rock, several small imprints of an ancient four-legged creature with webbed five-toed hind feet and possibly three-toed front feet. Geological dating showed that the sediment in which the markings were made was some 355 million years old, which means that they may be the oldest footprints ever found on earth.

Wakefield's colleagues at first showed disbelief, since the earliest fossil evidence of limbed vertebrates in the Southern Hemisphere dates back only 230 million years. But the skeptics were convinced when Wakefield later found in the same area plant fossils that clearly dated back to the same period, often called the Age of Fishes, during which the first primitive amphibians edged their way toward land.

One significance of Wakefield's discovery is that it may help solve a major evolutionary riddle: How did the webbed feet of the amphibians evolve from the paddle-shaped fins of their fish ancestors? Possibly his creature may be kin to a little (3-ft.-long) lizard-like amphibian called Ichthyostega, whose remains have been found in Greenland. The outward-pointing feet of Wakefield's find "demonstrate," he says, "a stage intermediate between the backward paddle of the ancestral fish and the forward-pointing foot of a four-limbed animal." To help settle that old scientific question, Wakefield is hopeful of locating an even bigger prize: a complete fossil skeleton of the missing amphibian.

*In 1969. Jensen found the tooth of a long-extinct, snub-nosed little reptile called Lystrosaurus, which lived in Asia and Africa 200 million years ago. Its discovery in Antarctica provided convincing evidence that the continents were once linked together.

This file is automatically generated by a robot program, so reader's discretion is required.