Princeton University Press
What color were the dinosaurs? Looking at the Jurassic Park movies, the answer seems obvious: gray, brown or, at best, dull green.
in a new book, British paleontologist David Hone drily asks, “Has there ever been a more annoyingly colored array of animals than seen in those movies?”
In How fast did T. rex run?Hone sets the record straight. Some dinosaurs wore red, white or iridescent black colors and showed patterns of colorful spots, spots or stripes. A small dinosaur called Sinosauropteryx from China, for example, is described as “‘ginger’ with white stripes.”
How do scientists reconstruct colors of animals that have been extinct for 65 million years (except birds, and more on that in a moment)? The key, Hone explains, are “packets of pigments,” called melanosomes, which are found in cells. Many living animals, including humans, have melanosomes, and they are also found in rock formations that contain preserved dinosaur skins or feathers. It is extremely fortunate that the shape of a melanosome exactly reflects its color type: “So although the fossil melanosomes now have no color, we know what they should have contained and from that we can determine the colors.”
Hone wanted to write a book that emphasizes what is not yet known about dinosaurs, but what is known. (As for the title, how fast T. rex ran is one of the unknowns.) He achieves this balance beautifully. Packed with gripping accounts of advances in dinosaur science, the book also serves as a handbook for anyone looking to identify central gaps in our knowledge. With regard to color information, for example, he laments the “frustratingly incomplete” nature of the data: Whether colors were muted or bright is unclear — and only about six dinosaurs have been studied so far. We have no idea of the range of color variation between species, genera, or individuals over time.
While I’m thrilled to observe or learn about almost any animal, dinosaur fever, whether in childhood or adulthood, has somehow eluded me—until now. I was fascinated by the inviting way Hone explained everything from the basics to the more advanced aspects of dinosaur science.
During their reign on Earth, dinosaurs — about 1,500 species — lived in nearly every ecosystem on the planet. Although the stereotype of tropical swamp creatures is firmly entrenched in popular culture, dinosaurs actually lived “on mountains, in deserts, lakes and seashores, temperate and coniferous forests, and in all kinds of temperatures, rainfall, snow, wind and other variations in both climate and again.”
Dinosaurs are divided into three types or clades. Theropods are bipedal, often carnivorous dinosaurs, including Tyrannosaurus and Velociraptor. Sauropodomorphs such as Brontosaurus and Brachiosaurus walked on all fours and had huge bodies and long necks. Ornithischians are herbivorous, often displaying bony plates and crests, and include Stegosaurus and Triceratops.
How long did the reign of the dinosaurs last? I hereby submit a complaint. Hone says at various points that dinosaurs have been around for “some 130 million years,” 150 million years, or “180 million years.” An inexplicable 50 million year discrepancy is not trivial even in a book about what is not fully known in dinosaur science, and is confusing to readers.
But when he gets into the details, Hone is fantastic. In addition to dinosaur appearances, he covers extinction, origin, conservation, diversity, evolutionary patterns, habitats, anatomy, mechanics, physiology, coverings, reproduction, behavior, ecology, dinosaur descendants, and changing aspects of research and communication. It’s hard to pick favorites here, but the reproduction section was one of the most stunning.
Hone includes in that chapter a picture, taken by himself in China, of a nest of eggs laid and assembled by a giant Oviraptorosaurus. The caption underlines what we can see in the photo: “The eggs were laid in several layers in a ring and the animal was probably in the middle.” There is an irony in the fact that this dinosaur shows parental care for the eggs: “Oviraptorosaur” means “egg thief”. When researchers first discovered skeletons of this dinosaur in combination with eggs, the assumption was that they ate the eggs of other dinosaurs and did not incubate. Dinosaurs called titanosaurs apparently didn’t breed, but instead heated the eggs, judging by the location of their egg beds and the composition of the egg shells, from volcanic heat. That behavior is “completely unexpected,” Hone notes.
There’s a lot we still don’t understand about dinosaur reproductive biology. Did the female or male sit on the eggs, or did they trade with each other? A little coy with the mating moments, Hone once again shows some dry humor: “How on earth are you supposed to get together two clumsy and very spiny ankylosaurs, or some of the gigantic multi-ton bipedal theropods, or the largest of the sauropods? “
Today there are ten thousand dinosaur species: the birds, of course. Hone has a lot to say about the origins of bird lineage, again balancing strong evidence with open questions. Birds and dinosaurs coexisted for about 100 million years, so we know that birds didn’t come into existence until after the famous extinction of 65 million years ago. Flying reptiles called pterosaurs and the non-avian dinosaurs all disappeared at that time, as did “very large numbers” of bird lines. The bird survivors were the species that were largely confined to the ground but were still able to fly, apparently indicating that trees in trees experienced more severe habitat loss.
And what about that extinction event? Yes, the asteroid that hit Mexico’s Yucatan Peninsula remains the top contender for explaining the loss of dinosaurs. But Hone complicates that story in an intriguing way. He raises the possibility that if the asteroid had “passed Earth without a scratch,” the dinosaurs would have gone extinct anyway because they were already struggling to survive in a world severely altered by previous volcanic eruptions.
At the back of the book, beyond the references section, is a request from Hone for readers to complete a short online survey to discover who may have been inspired to learn more about dinosaurs. “Keeping track of the impact my work has on the general public helps me keep doing it,” notes Hone. I predict he will hear a lot of good news soon.
Barbara J. King is an emeritus biological anthropologist at William & Mary. Animals’ Best Friends: Using Compassion for Captive Animals is her seventh book. Find her on Twitter @bjkingape