March 22, 2012
Out of all the parts of a dinosaur’s skeleton, nothing is as prized as the skull. While an entire Tyrannosaurus is a frightening visage, the jaws are what we fear the most. Triceratops is a stout herbivore, but the highly decorated skull is what makes the dinosaur a fan favorite. And the entire character of Apatosaurus, née “Brontosaurus,” changed when paleontologists recognized that they had mounted the wrong head on the dinosaur’s body. No surprise, then, that many paleontologists have been dinosaur head-hunters.
Royal Tyrrell Museum paleontologists Darren Tanke and Rhian Russell recently solved one case of a decapitated dinosaur, they explained at the 16th annual symposium of the Alberta Palaeontological Society. In 1992, paleontologists prospecting in Alberta’s Dinosaur Provincial Park came across an abandoned dinosaur quarry. The site was one of many unrecorded quarries scattered throughout the park—remnants of early 20th century expeditions that did not necessary excavate or record data to modern scientific standards. But the early fossil hunters hadn’t collected everything in the rock. The 75-million-year-old site still contained the parts of the hips legs, and tail of a large hadrosaur, while the front half of the skeleton seemed to have eroded away. For whatever reason, the fossil collectors decided to abandon the quarry without collecting the whole dinosaur.
Paleontologist Phil Currie found a hadrosaur lower jaw at the site in 1992, but this did not seem remarkable since the site was part of a bonebed with many fossils. The site was recorded and sometimes visited, but who dug the quarry and when remained a mystery. Then, last year, someone found a hadrosaur toe bone and a scrap of newspaper at the quarry. The newspaper carried a 1920 date, and there was only one person working in the area at that time: George F. Sternberg.
With a little historical detective work, Tanke and Russell found that Sternberg, accompanied by his wife and young son, collected a single hadrosaur specimen in 1920. The fossil was a skull of Corythosaurus, although the specimen was missing the lower jaws. The skull is on display at the University of Alberta in Edmonton, while the jaw and toe bone are at the Royal Tyrrell Museum and the remainder of the skeleton is in the field.
But why did Sternberg leave so much of the fossil in the ground? Maybe, Tanke and Russell propose, he thought that the skull was the only part worth collecting. The dinosaur’s body between the skull and the hips—including the neck, chest and arms—was disarticulated, and lacking a trained field crew to excavate what remained, maybe Sternberg decided to pick up the skull and leave the body. We may never know for sure.
Still, the fact remains that a single dinosaur is now split among several places—two museums and a field site. This is not an isolated case. Other headless dinosaur bodies undoubtedly exist in the field, and these fossils might be collected and stored in different museums. And even sites that have been carefully excavated may yield additional bones as erosion scrapes away at the rock, and different paleontologists may eventually find parts of skeletons that have already been mostly collected. This is why detailed records are so important in paleontology. Even if a skeleton is scattered hither and yon, there is at least the hope that the parts can be reunited someday.
Tanke, D., Russell, R. 2012. Headless wonder: Possible evidence of a head-hunted dinosaur skeleton in Dinosaur Provincial Park, Alberta. Alberta Palaeontological Society Sixteenth Annual Symposium Abstracts. 14-17
January 10, 2012
Of all the crested hadrosaurs, Parasaurolophus is one of my favorites. The long, slightly-curved tube that projects from the back of the dinosaur’s head is a wonderful ornament. But why did this peculiar dinosaur decoration evolve?
Parasaurolophus was initially described by paleontologist William Parks in 1922 on the basis of a skeleton found in the vicinity of Alberta’s Red Deer River. This dinosaur was clearly different from other ornamented hadrosaurs–such as Corythosaurus and Saurolophus–that had been found before, and especially perplexing was the makeup of the dinosaur’s crest. The structure was not solid–a break in this part of the skull revealed a series of internal tubes separated by thin walls of bone.
No one was exactly sure why Parasaurolophus had a hollow crest, but the supposed hadrosaur lifestyle generated a number of speculative answers. Hadrosaurs were supposed to be amphibious dinosaurs who acted like giant, dabbling ducks. After all, their broadened snouts gave them the popular moniker “duckbill dinosaurs.” Paleontologists therefore considered the dinosaur’s crest in reference to a life spent foraging for soft plants in Cretaceous swamps.
Paleontologist James Hopson reviewed these ideas in a 1975 Paleobiology paper about the role hadrosaur crests may have played in display. In 1933 Alfred Sherwood Romer speculated that the crest might have been used as a snorkel or an air storage chamber. While there was no hole in the crest to allow air to come in–the snorkel idea was scuttled–the air tank hypothesis was popular. As a young dinosaur fan, I remember encountering an image of a submerged Parasaurolophus in Edwin Colbert’s The Dinosaur Book with a solid black line running through the crest to indicate the amount of stored air. Another book, Rudolph Zallinger’s Dinosaurs and Other Prehistoric Reptiles, featured an even more detailed vision of Corythosaurus and Parasaurolophus paddling around beneath the surface of a prehistoric lake. But this notion didn’t last either. The anatomy of hadrosaurs has undeniably cast them as terrestrial animals, not expert swimmers, and the amount of air these dinosaurs were able to store in their crests would have been miniscule compared to their lung volume–the supposed air tanks would not have done them much good.
Charles Mortram Sternberg, son of the celebrated dinosaur collector Charles H. Sternberg, proposed a different variation of the aquatic feeding theme. In 1935 Sternberg wrote a paper on the “hooded” hadrosaurs from the Late Cretaceous of Canada and proposed that a U-shaped bend in the tubular crest passage prevented water from entering the respiratory system while the dinosaur was feeding underwater. Again, this idea is based on the notion that hadrosaurs frequently dipped their heads underwater to feed, and paleontologist John Ostrom later pointed out that, in such a scenario, the water pressure would have overcome the air pressure inside the crest and flooded the passage. Whatever the function of the Parasaurolophus crest, the structure was certainly ill-suited to underwater feeding.
Paleontologists kicked around a few other ideas. In a series of papers published in the late 30s and 40s, Martin Wilfarth suggested that elaborate hadrosaur crests were attachment areas for long, fleshy snouts. No evidence was found to support this. Likewise, Ostrom’s later suggestion that the nasal passages were extended to give the dinosaurs a better sense of smell was refuted–there was no indication that the convoluted passageways had anything to do with a better sense of smell.
Hopson himself considered the crests to primarily be visual display structures, and hadrosaurs with hollow crests, such as Parasaurolophus, may have also used their crests as resonating chambers to send low-frequency sounds over long distances. This is the view generally taken now, but settling on particular functions for the crests does not necessarily illustrate how those structures evolved. Perhaps the origin of the various hadrosaur crest shapes was driven by pressures associated with species recognition–the need to identify members of one’s own kind, be they parents, rivals, mates, etc. Then again, perhaps some aspect of sexual selection was at play. Exactly what evolutionary factors led to the origin of such strange skull shapes is difficult to ascertain. Much remains unknown about the evolution and social significance of fantastic ornaments in dinosaurs.
Hopson, J. 1975. The Evolution of Cranial Display Structures in Hadrosaurian Dinosaurs. Paleobiology, 1 (1). pp. 21-43
Naish, D. 2009. The Great Dinosaur Discoveries. Berkeley: University of California Press. pp. 72-73
January 9, 2012
Last month, paleontologist Andrew Farke and colleagues described the previously-unknown, multi-horned dinosaur Spinops sternbergorum. The centrosaurine was a gnarly-looking creature and worthy of headlines by itself, but the real hook of the story was that this dinosaur had been hiding in the collections of London’s Natural History Museum for nearly a century. The fossils–collected by veteran dinosaur hunter Charles H. Sternberg and his sons from the Cretaceous badlands of Alberta, Canada in 1916–had been regarded as “rubbish” by the museum’s staff, and it wasn’t until Farke took a second look at the specimen that the unique nature of this dinosaur was realized. But Spinops wasn’t the only creature found by the Sternbergs and ultimately lost. The same year that the bones of Spinops were first uncovered, an entire shipment of dinosaurs vanished into the cold waters of the Atlantic ocean.
Charles H. Sternberg began working for the Natural History Museum–then still part of the British Museum–in the field season of 1916. This was a lucky break. The Geological Survey of Canada–which employed Sternberg and his sons to collect Late Cretaceous dinosaurs in Alberta in a bit of friendly competition with the American Museum of Natural History’s own excavator Barnum Brown–decided to stop field work and focus on the preparation of dinosaurs already stored at the National Museum of Canada in Ottawa. But Sternberg was a field man, through and through. While his sons George and Charles Mortram stayed with the survey, his other son Levi joined Charles the elder in looking for other fieldwork opportunities.
Finding funding seemed to be a daunting task. World War I limited the amount of money available for paleontology–armored dinosaurs could not compete with armored tanks for attention–but the Natural History Museum was able to wrangle enough to underwrite Sternberg’s expenses through the Percy Sladen Memorial Fund. According to a proposal letter written by a member of the museum staff, and reprinted via a paper about the expedition by David Spalding in Mesozoic Vertebrate Life, Sternberg was to receive $2,000 for two months of initial work, with an opportunity to earn another $2,000 during the following two months if the museum was pleased with what was collected. The museum would also undertake the expense of shipping the specimens across the Atlantic so that they could be examined, prepared and stored. With any luck, the investment would yield a collection that would rival the collections the American Museum of Natural History had built up. “The Cretaceous Dinosaurs of Alberta comprise a great variety of the strangest armoured forms related to Triceratops besides other most astonishing developments of the Iguanodont and Megalosaurian groups,” the proposal promised, and it noted that the new specimens would complement an earlier collection made for the museum by William Cutler.
The challenge for Sternberg and his crew wasn’t finding dinosaurs. That part was easy. The trick was obtaining the high-quality, mountable skeletons the Natural History Museum was after. Since the area had already been explored so intensely, only the best dinosaurs available would do. Early finds–including what we now call Spinops–were scrappy and not especially wonderful, but Charles and his son Levi had better luck as the summer wore on.
In a letter sent to the museum’s paleontology curator Arthur Smith Woodward near the very end of the field season, Sternberg promised that “We have had the most wonderful success[;] three skeletons that can be mounted.” Even better, the last skeleton found that season was a nearly-complete hadrosaur, including numerous skin impressions. Sternberg regarded it as the second best specimen of its kind found in the strata–if only the dinosaur had a neck and skull! Still, the haul was good and additional specimens could certainly be obtained. While Sternberg felt that no one could ever exceed the collection Barnum Brown had built, he believed that the Natural History Museum “can however be equal or even superior to [the museum at] Ottawa if you please.”
But we’ll never know how good these specimens actually were. While an earlier shipment of fossils reached the British museum without incident about the SS Milwaukee, the second shipment was sunk along with the SS Mount Temple on December 6, 1916. The German military vessel the SMS Möwe stopped the ship, took the passengers prisoner, and then blew the Mount Temple to bits. (Coincidentally, the 95th anniversary of this event was the day when Spinops sternbergorum made its public debut.)
What had seemed like an excellent opportunity for the British museum became a frustrating tangle of paperwork. Half the dinosaurs were lost, those which had been received were not as impressive as hoped, and Sternberg sent multiple letters stressing his dire need for adequate compensation. And even the two crested hadrosaurs might not have been exactly as spectacular as the museum expected–each of the three hadrosaur skeletons was incomplete, and the dinosaur had already been named Corythosaurus by Barnum Brown. At least the fossil shipment had been insured, although this significantly complicated and delayed the payment to Sternberg.
Sternberg did not find out about what happened to the second shipment until a month after the event. “This is bitter news for me as well as for you,” he wrote to Woodward in a letter dated January 22, 1917, “As I considered the two skeletons in that shipment worth two or three times what the first shipment was, because it contained two skeletons that could be mounted.” All that work for nothing, and Sternberg urged Woodward to hurry up and send the insurance money to cover the field expenses of the previous year. In a way of mending wounds–and also securing employment–Sternberg also suggested that the museum sponsor him at the rate of $500 a month for a full year. This would allow Sternberg to make a new collection and fully prepare the specimens during the winter (while also meaning that he would have steady employment).
The museum does not seem to have shown any interest in supporting Sternberg, and the fossil hunter’s letters became more desperate as months went by. Confusion over shipping documents delayed the process of the insurance claim, and the Percy Sladen Memorial Fund was so unimpressed with the material that had been sent that they did not want to shell out additional funds for specimens sitting on the ocean bottom.
The letters sent from Sternberg to Woodward vacillated between sweet and sour–Sternberg was more polite and seemed hopeful each time he removed an additional bureaucratic obstacle to getting paid, but he would then write a cranky follow-up letter when the money still failed to arrive. In a letter to Woodward dated April 3, 1917, Sternberg wrote “Day after day I am waiting for the money I earned, and you promised to pay me, in your letter of June 3rd, 1916.” Sternberg felt betrayed. He had mortgaged his home and used all the credit available to him to excavate and ship the dinosaurs and was left to his own devices to pay down his debts while waiting for the monetary reward that had been promised. Worst of all, Sternberg lamented, there was virtually no money to launch an expedition for the summer of 1917. What had seemed to be an excellent opportunity to supply one of the world’s greatest museums with dinosaurs had turned into a financial mire that threatened to keep Sternberg out of the field. “It was awful enough to have a German Raider sink the two best specimens of Corythosaurus my party have found in 5 years … It will be still worse to completely ruin me, so I cannot keep at work.”
Just in time, the money came through. The various complications regarding paperwork were resolved and the full $2,500 estimate for the value of the fossils was awarded. Sternberg would have a 1917 season after all. He thanked Woodward for settling the matter, and in a May 5th letter advertised various fossil finds–and finds he hoped to make–that were for sale to museums. But the Natural History Museum seemingly did not want anything more to do with Sternberg. In a note Spalding turned up in the museum’s files from 1931, W.D. Lang wrote “Mr Charles Sternberg is constantly approaching the museum with offers of specimens for purchase. There is no need to take any notice of this appeal.”
Despite all the hurt feelings and frustration, however, very little was actually lost in this episode. Presuming that Sternberg had collected skeletons of Corythosaurus, the dinosaurs were not exactly rare specimens. Other, more complete individuals had been found and have been found since. As Spalding noted, their disappearance beneath the waves was primarily a loss to the British museum-going public. Beyond that, the damage was mostly restricted to Sternberg’s pride. The episode had ruined his relationship with the Natural History Museum and limited his pool of clients for the fossils he wanted to sell. Nevertheless, he kept on collecting for at least another two decades. For all the headaches the sinking of the Mount Temple created, the event is a strange wrinkle in the history of paleontology rather than a true tragedy.
Spalding, D. 2001. Bones of Contention: Charles H. Sternberg’s Lost Dinosaurs. In: Mesozioc Vertebrate Life. Ed.s Tanke, D. H., Carpenter, K., Skrepnick, M. W. Indiana University Press. pp. 481-503