Posted on 02/28/2003 8:46:57 PM PST by CalConservative
Chinese Fossil Bed Astounds Paleontologists 02/21/2003
The Feb. 20 issue of Nature has a review article on the rich and well-preserved Cretaceous fossils in Liaoning province, China, dubbed the Jehol Biota. The beds of volcanic tuff were so ideal for fossil preservation, they contain soft tissue impressions of feathers, fur, and stomach contents. An abundance of dinosaurs, birds, mammals, fish, insects, amphibians, conifers and flowering plants are well represented, sometimes with 3D impressions and some with hundreds of specimens of certain species in one spot. Famous dinosaurs found in the area include tyrannosaurids, titanosaurian sauropods, velociraptors, ankylosaurs and ceratopians. Also found are pterodactyls, pterosaurs, and the most significant discoveries are undoubtedly the non-avian coelurosaurian theropods, the diverse avifauna and a variety of mammals, all of which have impacted on wide-ranging evolutionary debates.
From this region have come the recent claims of feathered dinosaurs and early birds, possible ancestors of flowering plants and early representatives of placental mammals. The authors Zhou, Barrett and Hilton describe dinosaur and bird specimens which provide additional, indisputable support for the dinosaurian ancestry of birds, and much new evidence on the evolution of feathers and flight. They conclude, The spectacular fossils of the Jehol Group have already provided many important insights into the evolution of birds, angiosperms and mammals. Nevertheless, the rate of fossil discovery presently outstrips the rate of description, and detailed monographic treatments of all species from the biota are needed if the full potential of these deposits is to be realized. The Jehol Biota currently represents our best chance of viewing the composition and dynamics of an intact Early Cretaceous terrestrial ecosystem: continuing study of the fauna, flora, taphonomy and palaeoenvironment is likely to yield exciting new results for years to come.
China has become one of the worlds hottest fossil collecting spots. These fossils surely deserve careful examination and study. The article here, however, is so impregnated with evolutionary assumptions that trying to get at the actual raw data without the assumptions is like trying to unsalt an egg. The authors are totally convinced that the data support evolution, but some interesting aspects come to light when you read closely (emphasis added in quotes):Clearly these beds are exciting and amazing, and much work remains to be done. But so far, does a clear picture of evolution emerge? The evidence indicates rapid burial by catastrophic events covering vast regions, burying hundreds specimens of a single species in one locale. There is abrupt appearance of diverse plants and animals. The dating is contentious. Even with the cases they make for evolution, they need to make it happen fast, and fail to explain how or why a dinosaur would develop advanced flying technology. The context of the fossils is unclear. If true birds are found below the so-called feathered dinosaurs, for instance, they cannot use the latter as precursors of the former. From this article, it is also not clear if anyone can distinguish which fossils are genuine; it could be that some of the alleged transitional forms are fakes or composites. Its always wise to wait for the rest of the story, as we saw with the Archaeoraptor debacle. A reader writes, What would these folks do if they saw a flying squirrel, flying fish, or flying snake? Ive seen all of those, but I havent seen any of them grow feathers, or change into birds. They are kind of like the jumping dinosaurs. Why arent they evolving?
- The dating of the Yixian and Jiufotang Formations [the primary geological strata housing the beds] has proved to be contentious. The authors make a case for early Cretaceous (110-125 million years), but other indications are late Jurassic (137-147 million years). If late Jurassic, it pushes the origin of birds and mammals uncomfortably early in the fossil record. One reason they doubt the Jurassic date is that the evidence suggests that the samples used were either altered diagenetically or contained trapped argon, either of which could adversely affect the results of the analyses. How can we be sure their preferred dates are not similarly contaminated, considering their zeal to put the fossils into a certain time period that fits with their evolutionary assumptions?
- The fossils were buried in mass-kill catastrophic events. The excellent preservation state of the fossils is due largely to volcanic tuff, which kept oxygen and burrowing creatures from decaying or disrupting the trapped remains. Moreover, the deposits are intruded by basalt dikes and sills. The authors describe the Yixian outcrop at Lujiatun near Beipiao, western Liaoning Province: The fossil-bearing tuffs at this locality lack obvious bedding planes, suggesting that this deposit resulted from a single, catastrophic mass mortality event.
In addition, from their map, the catastrophe apparently occurred over a vast area. The Yixiang and Jiufotang formations cover half of China, southern Japan, all of Korea, and most of Mongolia. If such a large area contains similar fossil deposits, this represents a cataclysm too large to fit within uniformitarian assumptions.- Although the authors present arguments for birds evolving from dinosaurs, it had to occur rapidly: Body size and locomotory differences between sympatric Jehol taxa indicate that a rapid ecological diversification of avian taxa occurred during the early Cretaceous. Confuciusornis, a bird, is represented by hundreds of specimens from the same locality, suggesting a mass mortality event. Another bird, Yanornis, possessed an advanced flight apparatus, including an elongated, deeply keeled sternum and a coracoid of modern appearance, both of which indicate strong flight capability. The stratigraphic scale provided as an illustration shows Confuciusornis at the bottom layers, indicating that numerous flight adaptations would have had to evolve simultaneously and rapidly.
Interestingly, the authors make a case for the cursorial theory of the evolution of flight, but then in a late-news footnote, mention the new Microraptor gui fossil that provides additional support for the hypothesis that this taxon was an arboreal glider. Thus the debate over dinosaurs learning to fly by running along the ground or jumping out of the trees continues unresolved.- The authors claim early on that the beds provide clues to the origin of flowering plants, but further down say: putative early angiosperms ... although rare, have been proposed as the oldest flowering plants, and have received disproportionate attention owing to their possible relevance to the origin and early radiation of angiosperms. Most of these angiosperms have now been discredited, and only Archaefrucus is currently thought to represent a stem-group flowering plant. In our view, however, the affinities of this taxon remain controversial. This plant lacks petals, but contains stamens, anthers, pollen sacs and pinnately compound leaves, and disputably, carpels. Other important features that might resolve the controversy remain unknown. Therefore, they conclude, we cannot unquestioningly accept Archaefructus as an angiosperm.
- The authors cannot decide if the beds represent a refugium or a cradle; i.e., was it a lost world of Cretaceous ecology insulated from the rest of the world, or a nursery of new species that evolved only in this locale? Why did east Asia host a combination of relicts, cosmopolitan taxa and endemics at this time? they ask. The Jehol Group can be viewed as a window on succession in an Early Cretaceous terrestrial biome, in which an established biota merged with and was partially replaced by a novel biota composed of immigrants and new taxa that were evolving in situ. But this is a story imposed on the evidence.
- Illegal collecting is confusing the picture; the authors cannot distinguish the genuine from the fake. Advances in our understanding of the Jehol Biota have been hampered by illegal collecting, manufacture of faked and composite specimens (as in the Archaeoraptor debacle), illegal sale and export of fossils, and difficulties in the acquisition of specimens by international scientific institutions bound by ethical collecting standards. Private collectors have not been accurately recording the context of their finds: the stratigraphy, locality, and sedimentology.
- Evidence for rapid burial is abundant. Freshwater and terrestrial organisms from the biota usually occur together within the same sedimentary horizon. Preservation of complete articulated shells, arthropod exoskeletons, vertebrate skeletons and terrestrial plant stems with associated leaves, rootlets and other structures, indicates that all of these specimens originated in close proximity to low-energy lacustrine [lake] depositional sites and were not transported over extensive distances. Individual elements are generally unbroken and display little or no abrasion.
The Nature authors are like evolutionary salt shakers, flavoring the data to their taste in every paragraph. Yet the sample problems we have listed above cast doubt on their story and allow for different interpretations of the same evidence. A few of the gaps (which are systematic in the fossil record) they claim to fill, but theres another deposit in the region that throws the whole evolutionary story into disrepute: the Chengyiang bed in southern China. Here, the Cambrian Explosion has been documented in fine detail; all the major animal phyla appear in the early Cambrian without precursors. Even though conditions for the preservation of ancestral forms, whether soft-bodied or microscopic, are ideal (even sponge embryos are found in similar strata), the precursors are nowhere to be found. Paleontologist J. Y. Chen said in the film Icons of Evolution, Darwinism is maybe only telling part of the story for evolution. Darwins tree is a reverse cone shape. Very unexpectedly, our research is convincing us that major phyla is starting down below at the beginning of the Cambrian. The base is wide and gradually narrows. This is almost turned a different way. His colleague Zhou Qui Gin, a senior research fellow at the site, says (translated), I do not believe that animals developed gradually from the bottom up. I think the animals suddenly appeared. Among the Chengyiang animals we have found 136 different kinds of animals. And they represent diversity in the level of phyla and classes. So they sudden appearance makes them very special.
If all the animal and plant types appeared abruptly at the Cambrian, then evolution is debunked right there. Zhou, Barrett and Hilton cannot therefore make a case for Darwinism in the Cretaceous. Perhaps with different glasses on, paleontologists will find the same reverse cone in the Jehol strata. Earlier epochs were much richer in species diversity. By comparison, our world is impoverished. This is devolution, not evolution. Consider this in a creation context; if the antediluvian world were much richer in species than the present, and were buried in catastrophes, would we not expect to find apparent transitional forms? I.e., some extinct species might be force-fitted by todays evolutionists into the gaps, even when the original creatures had no phylogenetic relationship. The observed species are the tips of branches; the tree is only inferred. It follows that the more tips you have, the more trees you can draw. We expect the Jehol specimens, when sifted of fakes and correlated, will preserve the world-wide reverse cone picture, and confirm the general pattern that gave rise to the punctuated equilibria model: abrupt appearance of animals and plants, stasis, and extinction.
The spectacularly preserved fossils in the Jehol Biota need to be interpreted in their own context, without evolutionary presuppositions adding a preferred seasoning.
In addition, from their map, the catastrophe apparently occurred over a vast area. The Yixiang and Jiufotang formations cover half of China, southern Japan, all of Korea, and most of Mongolia.
What a remarkable opportunity to see a snapshot of life as it existed at one short period of time over 100 mya.
The size of the formation is quite large for an single explosive volcanic event there should be evidence in other parts of the world of such an event.
Pompeii comes to mind.
Half the size of Asia? -- Yellowstone x 5 comes to my mind.
These types of deposits are best dated by the material immediately above and below the deposit in question - so you get a range.
The Bishop Tuff and around Mono Lake is less than 50 miles from the Long Valley Caldera so that smaller ash vents could have contributed to the deposits over time ie Inyo and Mono Craters. It would take a pretty large blast to expel tuff thousands of miles and those don't happen too often from one caldera.
I would be interested in knowing if and where they have found any welding in these deposits (Asia).
I have been going to the area around Crowley Lake, Mammoth Lakes and Bishop for over 45 years. I am not a Geologist but even as a kid I wondered why the area around Crowley Lake and the Owens River Gorge looked so weird.
Yes, we should be seeing species coming into existence by some unbalanced ratio of 4:1 or 10:1 or 100:1. Instead we are hearing that species are dying out at that rate.
If we can document species dying out at 100:1, where is the documented 1 coming into existence?
Indeed, a paleo-pompeii...
Good logic. The evos found their links-- many times:
Nebraska man
Piltdown man
Orce man
Java man
Lucy
Homo habilis
etc. etc. etc.
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