Retrato do autor

Gregory S. Paul

Autor(a) de The Princeton Field Guide to Dinosaurs

8 Works 459 Membros 3 Críticas

About the Author

Gregory S. Paul is one of America's leading dinosaur paleontologists and also a gifted paleo-artist, renowned for his anatomical accuracy. He has served as a consultant on Jurassic Park and the Disney film Dinosaurs. His scientific papers have been printed in numerous magazines and journals, and he mostrar mais is the author of several books mostrar menos

Obras por Gregory S. Paul

Etiquetado

Conhecimento Comum

Nome legal
Paul, Gregory Scott
Data de nascimento
1954-12-24
Sexo
male
Nacionalidade
USA
País (no mapa)
USA

Membros

Críticas

Gregory S. Paul, author of Predatory Dinosaurs of the World, seems like an interesting sort. The dust jacket blurb describes him as a “free-lance dinosaurologist” and his Amazon author page calls him a “free-lance researcher”. He doesn’t seem to have an advanced degree; in fact there’s no evidence he ever graduated from college – or even high school (his CV has him attending Northern Virginia Community College from 1973 to 1978, but doesn’t list a degree or course of study). OTOH, he has a long list of scientific papers published in peer-reviewed journals, plus several books, plus credit for dinosaur design on Jurassic Park and other films. It thus seems that he is the rare professional that can prosper in a scientific field without the cachet that PhD provides.


It’s not clear who’s the expected audience for Predatory Dinosaurs of the World. It’s sort of a coffee table book, with lots of illustrations – yet the illustrations are all pencil drawings done by Mr. Paul; there are none of the full-color double pages you would expect in a traditional coffee table book. (I’m not criticizing the quality of the drawings; they are all outstanding, although a few don’t reflect discoveries made after the 1988 publication date).Further, the level of technical detail is way beyond a “popular” book; there are a lot of discussions of ankle morphology and the shapes of pubic bones and skull elements; the reader is expected to know what premaxilla and dentaries and quadratojugals are. The reader is also expected to know, or at least pick up, geological time down to the stage level, continental positions in the Mesozoic, and the vagaries of taxonomic name assignment. The book badly needs an introduction explaining these things for the casual reader – perhaps with a note that you can skip it if you already understand Mesozoic time divisions, Linnean binomial nomenclature, and basic reptilian cranial anatomy.


The first half of the book is background – but, again, fairly detailed background, discussing basic dinosaur anatomy and autecology. It’s quite idiosyncratic; Mr. Paul has strong opinions about a lot of things and is not afraid to state them; this is both refreshing and disturbing. It’s refreshing in that you don’t often see this in scientific publications; perhaps Paul’s lack of academic affiliation helps him out here, in that he doesn’t have to worry about angering a colleague who might turn up on his tenure committee someday. The flip side is that some of Paul’s opinions are definitely not in the mainstream of paleontology; in particular his treatment of Protoavis, which he accepts without reservation as a real animal rather than a chimera assembled from the bones of different species. It’s perhaps telling that while there’s not the slightest doubt that Paul is an outstanding anatomist and probably understands dinosaur bones as well as anyone in the world, he doesn’t seem to have any field experience and thus may not be as expert on how these things look when they come out of the rock. (To be fair, he does provide an illustration of a compressed and distorted Velociraptor mongoliensis skull as it was discovered; even here, though, it’s still an entire skull rather than the assortment of disconnected bones that were apparently put together to make Protoavis). There’s no hint in Paul’s discussion that there’s any controversy regarding Protoavis; in fact, he goes on at considerable length about its importance in understanding dinosaur evolution.


Similarly, Paul is not enthusiastic about an end-Cretaceous impact to explain dinosaur extinction. He concedes that earlier Mesozoic impacts seem linked major extinction events (for example, that the thecodonts went extinct after the end Triassic Manicouagan; the catch here being that thecodonts are no longer considered a monophyletic group and the Manicouagan impact has since been more accurately dated to about 15 million years before the end of the Triassic). Paul’s argument against impact-related extinction for dinosaurs is simplistic; there are other craters larger than Chicxulub that didn’t cause similar extinctions (for example, the already mentioned Manicouagan); hence Chicxulub couldn’t have caused dinosaur extinction. More research has caught up to Paul; since the 1988 publication of Predatory Dinosaurs of the World the size of the Chicxulub crater has been upgraded (Paul has it at 100 km, about the same size as Manicouagan; it’s now measured at 180 km; the only larger known impact craters date to the Proterozoic) and the difference in the impact site (Manicouagon was a hit on a continental shield while Chicxulub hit limestone and gypsum sedimentary deposits, dumping a lot of carbon dioxide and sulfur dioxide into the atmosphere). It’s true that there are still details to be ironed out about the KT extinction, but Paul’s view was in the minority even in 1988.


At the same time, though, many of Paul’s 1988 thoughts have been borne out. Birds are now generally acknowledged to be derived from theropods, the view that Paul advocates (ironically, Protoavis was often cited as evidence that birds originated from thecodonts). Paul is in the “hot blooded” (endothermic) dinosaur camp and provides evidence from bone structure and refutes counterarguments. Paul's suggestion that dinosaurs had avian-style air sacs, based on details of rib morphology, is now generally believed to be correct (once again he doesn’t mention the competing theory: that they had a hepatic piston pump like crocodiles; the old idea that they had an entirely reptilian respiratory system has been dismissed based on lung volume calculations; without air sacs a dinosaur couldn’t have moved enough air out of its lungs on an exhale breath to avoid inhaling it all back again).


Paul does allow for some continuing “dinosaur mysteries” in the first section; for example, where were the middle sized Cretaceous animals? All known terrestrial vertebrates in the Cretaceous were either multi-ton giants (dinosaurs) or rabbit-sized or smaller things (mammals, reptiles, amphibians). Why isn’t there anything that’s a horse-sized herbivore or a wolf-sized predator? (There are perfectly good small predators and herbivores earlier; the first dinosaurs, from the Triassic, are about the size of a weasel; it’s just in the Cretaceous that the size distribution splits). Why didn’t dinosaurs occupy the ocean like later mammals did? (Maybe because mosasaurs, plesiosaurs, ichthyosaurs, and large sharks were already there?) How did polar dinosaurs make do? There are dinosaur fossils from paleolatitudes of ±70°; even if the climate was a lot warmer they still would have had to deal with month-long nights. Why are there bone beds with so many predatory dinosaurs? The most famous are the Cleveland-Lloyd quarry in Utah (44 allosaurs, three times as many as herbivorous species); the Ghost Ranch quarry in New Mexico (in 1988 when Paul was writing there were at least 500 specimens of Coelophysis bauri; it’s up to around 1000 now, and the only ones with gut contents contained smaller C. bauri); and a similar site in Zimbabwe with Coelophysis rhodesiensis instead. The La Brea tar pits is an example of a more recent “predator trap” but even there the ratio of predators to herbivores was nowhere near as distorted. It’s now accepted that these things hunted in packs, but a pack of 40 odd allosaurs or over 1000 coelophysids is enough to give even hardened Jurassic Park viewers the heebie-jeebies. Did these things wander around the Mesozoic countryside like army ants, eating anything that got in their way (including, apparently, smaller individuals that didn’t get out of the way in time)?


The second half of the book is a catalog of individual species; all that were known at the 1988 publication date. Paul’s famous for his ability as an illustrator and he doesn’t disappoint, with every specimen that has enough bones to reasonably reconstruct a skeleton. Paul draws all the specimens in the same pose and at the same size by scaling the upper jaw length; while this allows for interspecies comparison of things like arm and leg bone morphology, he doesn’t provide a scale bar to allow quick size comparisons (the femur size and overall length of each species are listed in the text, if known). While Paul’s refusal to reconstruct animals if there isn’t enough data to depict an entire individual is laudable as far as it goes, but it also means we don’t get to see his interpretations of some of the poorly known but interesting forms like Spinosaurus. Paul devotes a lot of space to Tyrannosaurus rex and Velociraptor sp., understandable given his work on Jurassic Park and the iconic status of these animals. Most impressive is Paul’s calculation of bite volume for T. rex based on jaw anatomy; each bite took out a chunk of flesh three feet long, one foot wide, and one foot deep. Paul again exercises his opinions by providing lists of prey animals for all these species without noting that there’s rarely any evidence for what they ate. A few Triceratops sp. bones are known with gouges probably referable to T. rex teeth based on the reasonable assumption that it was the only thing around big enough to make cuts like that, but that’s not the same as finding Triceratops sp. bones inside a T. rex skeleton.


There are an annoying number of proofreading errors in the work; the Mesozoic North Pole is listed in text as being in Prince Edward Island rather than Prince Albert Island (the location is correctly shown on an accompanying map); in one case the Chinle Formation is listed as the Chinlo Formation, and Elaphrosaurus bambergi is once abbreviated as Z. bambergi. The illustrations, as mentioned, are all outstanding, with the caveat that Paul makes most theropod necks and tails somewhat more flexible than more recent reconstructions; Paul didn’t have the advantage of recently developed computer software that allows skeletal model manipulation to see how far joints could bend. The reference list is outstanding, but it’s almost all primary sources; the original paper describing the species Paul is illustrating or a hypothesis Paul is suggesting or refuting. There are no “Suggestions for further general reading”.


As already mentioned, I’m not sure who this book is for. Most of the world’s dinosaur enthusiasts seem to be preteen boys; I expect this is too technical even for the most enthusiastic of them. It’s also rather out of date; it’s ironic that paleontology becomes obsolete much more rapidly than the study of modern animals, as a single new fossil can change ideas dramatically. I suppose it would best serve as a reference text if you wanted to look up the original reports on a species and and see excellent state-of-the-art illustration for 1988. I see that Paul has a number of more recent books out; I suspect they would be more valuable than this one but I would still recommend Predatory Dinosaurs of the World if you can handle the anatomical details, take Paul’s opinions with a grain of salt, and find it used somewhere (which is how I got mine).
… (mais)
½
 
Assinalado
setnahkt | Dec 16, 2017 |
 
Assinalado
JNSelko | Jun 13, 2008 |
There being so few books on the dazzling prospect of transhumanism (others: those by Moravec, Hughes, Young, Kurzweil), I'm sorry my getting hold of this 500-page effort was delayed by more than a decade. Paul and Cox concur, more or less, with the other authors that mind uploading may be possible by the middle twenty-hundreds. (And by uploading they mean mind *transference*, not just mind *copying* with its troubling personal-identity implications; for them, unlike Moravec and Young, these processes do *not* entail a belief in dualism.) Eventually, they say, the resulting cyberintelligences will be humanity's successor species, free of religion and short lifespans, and will spread out to the stars.… (mais)
 
Assinalado
fpagan | May 17, 2007 |

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Estatísticas

Obras
8
Membros
459
Popularidade
#53,510
Avaliação
4.1
Críticas
3
ISBN
17

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