Dinosaur Feathers or What?
It’s not hard to imagine the scene. A lush forest crowds the shores of a glittering lake. Chicken-sized birds perch on tree branches or fly ponderously over the lake. Smaller birds also perch or flit joyously hither and thither through the sky. A frisky bipedal (runs on two feet) dinosaur pursues its own agenda in the adjacent woods. One consumes a small sharp-toothed little mammal, perhaps a type of rodent. Insects buzz lazily over the lake while fish and various tiny crustaceans lurk in the watery depths. It all seems so placid. What could mar this moment?
Something terrible befell this community in northeastern China. These creatures now lie entombed in fine grained sedimentary rock. How did the birds, the terrestrial animals and the creatures of the lake all become trapped together? This is a very good question since the quality of preservation here is like no other that we know about. Scientists believe that the entire community was suddenly wiped out by a brief but lethal event. The community was buried so suddenly that some of the internal organs of a bipedal dinosaur were actually preserved. The dinosaur was female with an oviduct inside in which there was an egg almost ready to lay. Hundreds of the larger bird were also preserved, some with impressions of the plumage.
Normally fine sediments settle very slowly out of a lake. But these organisms were entombed suddenly, before the carcasses and delicate bones could decay. Obviously the sediments had to come down like a ton of bricks – not over years, decades, centuries or millennia. And how did tree perching birds and terrestrial dinosaurs, not to mention insects, all become entombed together? There is some volcanic ash in the sediments, so toxic gases might have asphyxiated the community. But the birds and terrestrial organisms would not be in the lake. They would be dead, but not entombed by sediment. They would decay at leisure and we would never know about them. The instantaneous nature of the catastrophe and the fine quality of the preservation seem intertwined. All these creatures died at the same time and they were quickly buried together. One cannot help thinking a monstrous tidal wave would be required to sweep the birds, the plants and terrestrial creatures into the same grave as the aquatic animals. Fine grained sediments normally sink slowly, but recent studies have shown that such sediments sometimes abruptly settle out from storm-induced turbidity currents. Could these diverse creatures have been the victims of a terrible flood?
We fast forward this scene several thousand years to August 1996. Near the remote village of Beipiao in Liaoning Province, a farmer discovered a fine large fossil. The man knew exactly what it was since geologists had recently been conducting studies in the vicinity. He resolved to obtain maximum profit from this artifact. The rock had split to reveal the complete metre-long skeleton of a dinosaur splayed out on a mudstone slab. Normally such an artifact is sold as one unit. But the farmer in this case sold one half to the Nanjing Paleontology Institute and the other half to the Chinese Geology Museum in Beijing.
A few weeks later, Canadian palaeontologist Dr. Philip Currie of the Royal Tyrrell Museum in Alberta, found himself in China conducting tourists on a venture called Dinotour. No doubt this was a money raising venture in support of Canadian palaeontological research. Scientists really should not be forced to conduct tours to raise money. At any rate after the tourists had left, Dr. Chen Pei-Ji, a Chinese colleague, invited Dr. Currie to the Nanjing Institute to view the new dinosaur fossil. This particular specimen had a dark line running parallel outside the backbone. It occurred to these two scientists that this might be a highly significant discovery. What did that line represent? What if, they speculated, it was the down from developing feathers? What if similar dinosaurs had developed into birds? Was this the confirmation of a dinosaur-bird relationship that palaeontologists had been seeking? The two men took photographs of the specimen to show at the up-coming Annual Meeting of the Society of Vertebrate Paleontologists at the American Museum of Natural History in New York City.
At the scientific meetings held October 16-19, these two men were the centres of attention. Scientists clustered around to view the photographs, but no paper or written information of any kind was presented. Dr. Ji Qiang from the rival institution in Beijing had named the organism Sinosauropteryx (which means first Chinese dinosaur with feathers) – but he has not published anything or formally presented any information either. What is more, the Chinese authorities insist that no photographs be published although some are posted on the Internet. It is certainly a rare event in world class scientific circles that findings of such potential significance are treated so casually. The scientists involved would have acted much more responsibly if they had researched their material thoroughly and then published a scholarly analysis in a scientific journal. The upshot of the October meeting was the organizing of a group of specialists to visit China in the spring of 1997.
The party of palaeontologists who went to China included Dr. John Ostrom, Professor Emeritus from Yale. For twenty five years he had been prominently connected to the idea that dinosaurs gave rise to birds. Also there was Dr. Peter Wellnhofen from the University of Munich. He is an expert on the fossil bird Archaeopteryx (means ancient feather). Dr. Larry Martin from the University of Kansas, led the opposition to Dr. Ostrom’s position. Dr. Martin and Dr. Alan Feduccia are the most famous supporters of the idea that non-dinosaur reptiles developed into birds. Also there was another scientists Dr. Alan Brush from University of Connecticut. It is obvious that all these specialists support evolutionary interpretations of the fossil record although they disagree on details.
The party of scientists returned to North America and within two weeks, on April 24, they presented a report of their expedition to a meeting of the Academy of Natural Sciences in Philadelphia. They mentioned 200 fossils of the chicken sized bird, called Confuciusornis sanctus (holy wise bird), the sparrow sized Liaoningornis (bird from Liaoning Province), the metre-long dinosaur now called Sinosauropteryx (of the famous dark line indicating ???), and many other species of dinosaurs as well as many other organisms from the community.
Dr. Ostrom in October had been quoted as remarking that the dark mark associated with the one specimen of Sinosauropteryx was “compelling evidence that birds derived from dinosaurs” (Science 1 November 1996 v. 274 p. 720). Having returned from China he still believed that the mark was a fossil remnant of fur or possibly feathers (New York Times April 25, 1997 p. A17). Dr. Martin and supporters argued alternatively that the black mark might be the residue of tissues that lay under the skin in life. The smudge might even be bacteria left over from the decay process. Some other cases of such smudges left over from decay are indeed known. A specimen of the arthropod Marella for example from the Burgess Shale, illustrated in Geological Survey of Canada Miscellaneous Report # 43 (p. 7) includes a large irregular stain probably caused by decay products leaking out of the body into the surrounding sediment.
The last act in this comedy of evolutionary claim and counter-claim concerns age estimates of the sedimentary rock of the Yixian Formation in which these fossils lie. In Mongolia’s Gobi Desert, where many spectacular dinosaur fossils have been found, there are no traces of volcanic rock or volcanic ash. Thus radiometric dating is not possible and scientists are left to make “guesstimates” based on supposed rate of evolution or comparisons with rocks in other regions. In northeast China however there is some volcanic ash and radiometric dating has been carried out. Age estimates vary from 142 million years to 137 million years, but the most recent study puts it at 121 million years. The trouble is that these estimated ages are too low to suit the evolutionary interpretations of the palaeontologists involved. It is impossible to have ancestors that lived more recently than the descendants. Thus they are unhappy with the results of the radiometric dating. So they are in effect ignoring the currently avail able numbers. A paper published November 15, 1996 says concerning the rocks of the Yixian Formation “we think that these deposits essentially bridge the Jurassic-Cretaceous transition. Any more precise dating will require further field work in China.” (Science v. 274 #5290 pp. 1164-1167 see last sentence of text). In addition an article by Malcolm Browne (April 25, 1997 New York Times p. 16) repeats the current attitude to the age of the rocks “the dates of the fossils are somewhat uncertain because geologists are not sure a bout when the sediments in which the fossils are embedded were laid down.”
It is evident that machine derived dates are only accepted when they fit with evolutionary expectations. Otherwise they are ignored or rejected. There is no such thing as an absolute date. As with all the other aspects of this intriguing study in attitudes, professional intrigue and remarkable artifacts, these fossils from China will be in the news a long time. The personalities and the hyperbole surrounding the interpretations, make for interesting reporting – but a skeptical attitude is always a strong defense against evolutionary wishful thinking, especially when scientists, without due reflection, try to shoehorn evidence into their pet theories.
This article first appeared in Christian Renewal in September 1996.
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