October 28, 2008
In the summer of 1908, the freelance fossil hunter Charles H. Sternberg and his three sons, George, Levi, and Charles, were on the hunt for dinosaur fossils in Wyoming. George and Levi found a skeleton in sandstone. When the duo made the discovery, however, the family had only potatoes left to eat, so their father and younger brother left to stock up on supplies.
When they returned, they saw George and Levi had found something absolutely stunning. In his autobiography, The Life of a Fossil Hunter, their father would wrote of the discovery, “Shall I ever experience such joy as when I stood in the quarry for the first time, and beheld lying in state the most complete skeleton of an extinct animal I have ever seen.”
It was an exceptionally preserved hadrosaur which Sternberg identified as belonging to the genus Trachodon, “with front limbs stretched out as if imploring aid, while the hind limbs in a convulsive effort were drawn up and folded against the walls of the abdomen.”
Yet this was not just an articulated skeleton. The skin of the animal had been preserved in sandstone, too, giving a distinct impression of the animal “as he breathed his last some five million of years ago.”
C.H. Sternberg was not an academic. He was a bone sharp, a title for those who knew where to find fossils and how to get them out of the ground, and the welfare of his family depended on the specimens he collected. He had already bagged a good Triceratops skull that season, and by a prior arrangement, the British Museum of Natural History would get first dibs on that one. But the unexpected discovery of the hadrosaur mummy had the promise of a little extra income.
For reasons unknown to us now, however, C.H. Sternberg wrote to Henry Fairfield Osborn, the curator of vertebrate paleontology at the American Museum of Natural History in New York City, about the find in September, 1908. Osborn was excited by the news, but cautious, and he quickly sent paleontologist Albert Thomson out to appraise the find. When Thomson arrived he found that the fossil had already been encased in flour paste-soaked burlap and shellac. There was no way to know what was under to gooey layers, and Thomson would have to go by Sternberg’s word. The asking price was $2,000, “a stiff price to pay for a pig in a bag,” according to Thomson.
By a coincidence, paleontologist W.J. Holland from the Carnegie Museum in Pittsburgh arrived at the same train station in Wyoming on the same day as Thomson. Osborne heard about this and feared competition for the Trachodon, so he purchased the specimen for the AMNH for an undisclosed sum. As Osborn later found out when the fossil arrived in New York, it was a priceless find.
Osborn published his research on the Trachodon “mummy” in the Memoirs of the American Museum of Natural History in 1912. Although it was not the first example of skin impressions of a dinosaur being found (Osborn listed at least seven other examples, going back to a discovery of another hadrosaur in 1884), the Sternberg mummy was the most extensive and spectacular.
The skin was covered in tiny bumps and nodes, which Osborn called tubercles, and the hand of the dinosaur seemed to be enclosed in skin so that it looked almost like a mitten. Osborn interpreted this as meaning that the dinosaur had webbed forefeet useful for swimming, making the hadrosaur at least semi-aquatic.
Research conducted in the years since Osborn published his description has changed our image of hadrosaurs. The name Trachodon, for starters, is no longer valid; the hadrosaur is now called Edmontosaurus. A more substantial revision, however, involves the supposed webbed feet of the dinosaur. Osborn had interpreted the skin-enclosed hand of the mummy as a kind of webbing; other animals have skin between their toes to increase the surface area (and therefore propulsive force) while paddling. The hadrosaur mummy, by contrast, had its forelimbs enclosed within skin, making them rather small and inefficient organs for paddling. Hadrosaurs were land animals, we now know, not swamp-bound creatures.
During the past year announcements about two new dinosaur mummies have thrilled researchers with the expectations of specimens as rare and stupendous as the Sternberg mummy. An Edmontosaurus mummy named “Dakota” was the subject of newspaper articles, two books, and a television special last year. It has yet to be fully described in the scientific literature, and rumor has it that it is not as well-preserved as was hoped, but it still is an exciting discovery.
Even more amazing is a hadrosaur mummy that is due to be unveiled this month at the Houston Museum of Natural Science. Named “Leonardo,” this Brachylophosaurus has the distinction of being the world’s best-preserved dinosaur, at least according to Guinness, the company famous for compiling world records (as well as brewing beer). Particularly exciting is the possibility that this mummy appears to have preserved not only skin and muscle, but also the shape and arrangement of some internal organs. If this is true, it is one of the most important paleontological discoveries ever made.
Both mummies will require years of careful study, but they offer paleontologists an unprecedented look into the lives of animals that lived while our ancestors scurried beneath their feet. I can’t wait to hear more about these fantastic discoveries.
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