All Yesterdays: Unique and Speculative Views of Dinosaurs and Other Prehistoric Animals
by John Coseway, C. M. Kosemen, and Darren Naish.
Since before this book came out in print this was an Internet sensation, and now I finally get to read it I understand why. The book is not long, only 104 pages, but it doesn't need to be to convey its simple, powerful idea: how little we actually know about dinosaurs and other fossil beasts like plesiosaurs and pterosaurs. When reconstructing the living appearance of these animals, we are usually guilty of pretending knowledge we don't really have, particularly about living appearance, diet, habits, ecology, etc. Furthermore, reconstructions tend to bow both to conservatism--rarely do reconstructors speculate beyond what is patently shown by fossil evidence--and to fad and fashion, as in Paul's "shrink-wrapped" dinsosaur reconstrctuons. (they certainly had more "meat" on their bones than Paul shows!)
The book is in two major sections: There's a brief introduction, followed by "All Yesterdays," where featured artists Conway, Kosen and Naish (featuring skeletal illustrations by Scott Hartman) put forth their most liberally imaginative and speculative reconstructions of ancient life, often using attibutes of living, even common organisms, their imaginations bounded only by the "hard" evidence(that is, what we know from their fossils they could NOT have done, had, etc.) Then there's an "All Todays" section, where these artists imagine how paleontologists of the distant future might try to reconstruct familiar animals of today with no more to go on than what we have of creatures of the past.
My personal favorite is their reconstruction of the Australian dinosaur Leallynasaura amicagraphica. We know from fossil and geological evidence that Australia lay close to the South Pole during the time Leallynasaura lived; It was a plant eater and forager in an environment with no real parallels in our modern world: a polar forest that lay in 24/7 sunlight for half the year and total darkness the other half. And despite the Cretaceous climate being much warmer than today's, even at the poles, we also have reason to believe it did get cold enough during those six-month nights for snow to accumulate.
Traditionally, Leallynasaura was reconstructed with scaly skin; "feathers" or "dinofuzz" were believed beind restricted only to those dinosaurs closely related to birds (the "raptors"). I always had problems with that, because Leallynasaura was not a large animal, smaller than a person in fact. And since dinosaurs have for a while now been believed warm-blooded, I just couldn't see how Leallynasaura could have survived those cold winters with a lizard's hide. Fortuately, new fossils out of Asia: Psittacosaurus and Tianyulong, suggest "dinofuzz" (the technical term is pycnofibers) was more widespread than previously believed.
Thus: Leallynasaura the fuzzball, most of its features hidden under dense "fluff" and fat, with an incredibly long tail, which they tipped with a fluff flag out of Dr. Seuss. While I'm conviced of the fuzz, the tail I'm certain is a mistake in the original "scientific" reconstruction--too many vertebrae added.
My second favorite is a NSFW reconstrction of a sexually frustrated Stegosaurus forcing its attentions on a hapless Haplocanthosaurus. Not only does it graphically illustrate how the prickly creatures may have managed to mate, it shows just how </em>huge Stegosaurus</em> really got!
An interesting epilogue reminds us that ultimately, what we know--or think we know--about the world constrains our understanding of the past. A Swiss scholar from 1726, Johan Jakob Scheuchzer interpreted a fossil salamander as a human drowned in Noah's flood, because that was the reality he understood.
It's certain many of these speculative reconstractuons will be ruled out by future findings--my bet is on Leallynasaura's tail--and others will be seen as prescient. Even if that happens, we'll still have gained, because we'll at least know more about these creatures that we need to heep reminding ourselves: we do not know as much as we think we do.