by velocibadgergirl

Friday, April 27, 2007

Gorgon:  Paleontology, Obsession, and the Greatest Catastrophe in Earth's History by Peter D. Ward

Many people (maybe even most people) have heard of the K-T Boundary, the line of iridium-rich deposits marking the division between the Cretaceous Period and the Tertiary Period. In less sciencey-speak terms, most people have heard of the Cretaceous-Tertiary extinction, because it's the one that killed the dinosaurs. Fewer people have heard of the Permian-Triassic extinction, but it was the Big One. After this so-called "Great Dying," almost 90 percent of the species on land and in the sea had been wiped out. 90 percent.

Even as a geology major, I knew only vaguely of the P-T extinction. I knew it was the biggest mass extinction in Earth's history, but I didn't realize that, as Peter Ward puts it in Gorgon, it basically reset the evolutionary clock. Large species of "mammal-like reptiles", the reptilian ancestors of modern mammals, were at the top of the food chain by the end of the Permian, but few survived the extinctions. I had forgotten that critters like Dimetrodon were Permian, even though I knew they were pre-mammals.

Sidebar: Dimetrodon was not a dinosaur. Dinosaurs' legs were directly under their bodies, like elephants. If it's got a sprawling, lizard-esque walk, it's not a dinosaur.

It's sort of amusing and maddening that the cover photo of a Gorgonopsian is credited as "dinosaur image," since Gorgons weren't dinosaurs, either.

Also, while grabbing the link for Dimetrodon, I found this hilarious note: "Dimetrodon appeared in the film Journey to the Centre of the Earth, live acted by iguanas." This, of course, begs one question--how'd they attach the sails? /sidebar

The Gorgonopsians for which the book was named were pretty fearsome characters:

However, they're only part of what Gorgon is about. Ward is a paleontologist, but he writes with an accessible journalistic style. The book tells the story of his quest to uncover the truth about the P-T extinction, documenting both the science behind the hunt and the specifics of spending more than ten years searching for bones and answers in the Karoo of South Africa, beginning in the late days of apartheid.

As a geologist (even a non-practicing one), I find his geology-related sections especially cool, but I suspect that even someone without a geology degree will find them interesting and easy to understand:

No other field of science has found it necessary to codify the timescale applicable to, and usually known only to, geologists. There is no formalized biological or chemical timescale, although, of course, all processes described by these two great fields have temporal components. All other fields of study simply use the intervals of time known to us all: seconds, minutes, hours, days, and so on. Geologists, on the other hand, talk about periods and epochs, eras and zones, stages and series, the arcane subdivisions of what is known as the geological timescale. All are defined by death. The bigger the division, the greater the body count. For geologists, death becomes the ticking of the geological clock.

The divisions of time used in geology come from a study of the fossil record. Major time units are recognized and defined by mass-extinction events, sudden global catastrophes causing major biotic turnovers and extinctions. Two of these were especially dramatic. At the top of strata named the 250-million-year-old Permian System--and at the top of a much younger, 65-million-year-old Cretaceous System--the vast majority of animal and plant fossils were replaced by radically different assemblages of fossils. Nowhere else in time were such abrupt and all-encompassing changes in the faunas and floras to be found.

These two wholesale turnovers in the makeup of animal life on earth were of such magnitude that they were used to subdivide the geological timescale into three large-scale blocks of time: the Paleozoic Era, or "time of old life" (extending from the first appearance of skeletonized life 530 million years ago until it was ended by the gigantic extinction of 250 million years ago); the Mesozoic Era, or "time of middle life" (beginning immediately following the great Paleozoic extinction and ending 65 million years ago); and the Cenozoic Era, or "time of new life" (extending from the last great mass extinction to the present day.

Here's another supercool version of the time scale, and a link to another one.

There were so many times when I'd think, "That is exactly right!" while reading one of his descriptions.

For instance, after the field team couldn't afford to rent a Land Rover and got a little Korean car instead of the large sedan they asked for:

"We made our way through the valley once more, again slowly crawling over the large field, trying to avoid the holes and termite mounds. Time and time again, we scraped the bottom of the stolid car so unsuited for this type of fieldwork. This ridiculous Korean car was trying to kill us. Or, more accurately, I guess we were trying to kill it. I wondered then, as I do know, why there isn't some large box printed in red on every car rental form: "I swear on all that is holy that I am not a geologist and will not be using this rental car for geological fieldwork." How many rental cars must the fraternity of geologists have trashed?"

When I was in college, our professors always borrowed 15-passenger vans from the school to take us on field trips. When we brought them back, they were always full of dirt and mud and tiny pieces of all the rocks we'd hauled back from the field. Once, on a 10-day trip to Canada, the guys' van had the rankest smell imaginable, and no one could figure out why, until one day they opened the cooler and realized that the bottom was full of half-rancid juice that had leaked out of a package of ground beef. Lovely, yeah? We always wondered why the school still let us have vans, or why they didn't at least give us the same trashed vans every time.

And this sounded pretty familiar, based on my 6 1/2 weeks of geologic field camp in the desert valleys of Montana:

"Life in the field seems to accentuate everything. Food tastes better, smells are sweeter, and all things physical seem more pronounced. You get a sense that you are a center of consciousness being carried on a physical body and that the two are allied but separate things. And while the brain may not seem any better--quite the opposite if it is hot--the body is in its element. You--the brain, the Command Center in this situation--really take account of how your Mobile Unit is doing."

Ward can be funny, as he demonstrates with the caption accompanying a photograph of his alarmed-looking toddler son standing next to a Gorgon skull: "Patrick Ward, age two, being menaced by a large mammal-like reptile skull in the South African Museum--an example of paleontological child abuse."

He's also insightful, and I really like his style: "We had no outhouse at this camp. A shovel stood in the corner with a roll of toilet paper wound around its handle. Everyone found some remote spot behind some tree or other. It was awkward business on those cold mornings. We pretend we are not animals, with our antiseptic and comfortable bathrooms. The Karoo lays bare the lie."

I'm not sure I completely buy his conclusion about the cause(s) of the P-T extinction, but the book itself was fantastic and enveloping. Even though there's a lot of science, I feel like the book will be enjoyable for non-scientists, and I'd definitely recommend it as a good, non-dry nonfiction book about paleontology.

To conclude, I found this earlier this month and posted it on my other blog:

Brak = love, everybody! I predict you'll find Gorgon twice as amusing if you picture Brak every time Ward mentions the gorgonopsians.



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