Artist's impression of dinosaur Lingwulong shenqi Credit: Zhang Zongda |
From this week's research papers we have a very nice example of how science is an ever developing picture of reality and a very nice example of a new species of dinosaur.
Despite the sensational headlines, this one doesn't really mean we have to forget everything we ever thought we knew; nor does it mean all the textbooks are going to need to be re-written. It means that what we thought we knew turns out to be not quite right and maybe a paragraph or two will need to be added or altered in the next edition of a book on the evolution of the sauropod dinosaurs.
It was previously believe that the massive sauropods dinosaurs evolved after the breakup of the super-continent, Pangea, so that the various groups evolved in geographical isolation. The absence of fossil remains of these sauropods from South-East Asia was considered evidence of this geographical distribution. This view now needs to be revised because an Anglo-Chinese team of paleontologists from the Chinese Academy of Science and University College, London have discovered fossil remains of massive sauropods in Ningxia Autonomous Region in northwest China, and date them from about 174 million years ago - 15 million years older than the previous earliest known members of this family. This places them chronologically before the breakup of Pangea.
They have named this new species Lingwulong shenqi, or 'amazing dragon of Lingwu, the twon near where it was found.
Abstract
The fragmentation of the supercontinent Pangaea has been suggested to have had a profound impact on Mesozoic terrestrial vertebrate distributions. One current paradigm is that geographic isolation produced an endemic biota in East Asia during the Jurassic, while simultaneously preventing diplodocoid sauropod dinosaurs and several other tetrapod groups from reaching this region. Here we report the discovery of the earliest diplodocoid, and the first from East Asia, to our knowledge, based on fossil material comprising multiple individuals and most parts of the skeleton of an early Middle Jurassic dicraeosaurid. The new discovery challenges conventional biogeographical ideas, and suggests that dispersal into East Asia occurred much earlier than expected. Moreover, the age of this new taxon indicates that many advanced sauropod lineages originated at least 15 million years earlier than previously realised, achieving a global distribution while Pangaea was still a coherent landmass.
Introduction
Sauropods were gigantic long-necked herbivorous dinosaurs that dominated many Jurassic and Cretaceous terrestrial faunas1,2. Although sauropods were globally distributed2, several subgroups displayed restricted geographic ranges that potentially reflect endemism caused by the fragmentation of Pangaea3. The absence of Diplodocoidea from the otherwise rich sauropod faunas of East Asia has thus been interpreted as a genuine biogeographic pattern4,5,6.
From 2005 onward, we organised four excavations at a new dinosaur site in the lower Middle Jurassic Yanan Formation at Ciyaopu, Lingwu, Ningxia Hui Autonomous Region, northwest China (Supplementary Notes 1 and 2, Supplementary Fig. 1), which resulted in the discovery of fossil material comprising 7–10 partial skeletons (including portions of two skulls), ranging from juveniles to adults. Here, we name a new sauropod based on this material, and demonstrate that it is, to our knowledge, the earliest diplodocoid (and therefore also the earliest neosauropod) sauropod, and the first from East Asia (Supplementary Notes 3–7). This discovery has major implications for calibrating the timing of neosauropod diversification, provides the first insight into a previously hidden aspect of their evolutionary history, and questions East Asia’s hypothesized status as an isolated island continent during the Jurassic (Supplementary Notes 4–7).
Xu, X., Upchurch, P., Mannion, P. D., Barrett, P. M., Regalado-Fernandez, O. R., Mo, J., … Liu, H. (2018).
A new Middle Jurassic diplodocoid suggests an earlier dispersal and diversification of sauropod dinosaurs.
Nature Communications, 9(1). https://doi.org/10.1038/s41467-018-05128-1
Copyright: © 2018 The Authors
Published Open Access
Reprinted under the terms of a Creative Commons Attribution 4.0 International Licence (CC BY 4.0)
Quite bizarrely, for some unfathomable reason, the creationist frauds at the ridiculously and misleadingly named Institute for Creation Research (sic) have presented these 174 million year-old fossils as evidence that Earth is just a few thousand years old - on the grounds that the they were found in strata below those the previous oldest had been found in!
Seriously! Read it!
Presumably, their reasoning goes something like, "Wow! Look these scientists have discovered they were a bit wrong! This means we are right and don't need any evidence!
But anyway, what this shows is that science, unlike religion, doesn't sit back and declare it knows all the answers, complete in every detail, but constantly revises and researches. When science finds something that requires our understanding to be revised it is accepted and incorporated, happy that our knowledge and understanding is a little better today than it was yesterday.
Contrast that to this typical creationists response to information that falsifies their beliefs - it is dismissed and any excuse to claim it actually supports them will be produced without the slightest logic or reason and no matter how bizarre or how much it insults the intelligence of their dupes. No evidence is ever permitted to modify what creationists pretend they know by faith and this insult to their willing dupes intelligence will go unnoticed because it seems to tell them what they want.
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