Princeton University Press
What color were the dinosaurs? Watching the Jurassic Park movies, the answer seems clear: gray, brown, or at best, dull green.
in a new book, British paleontologist David Hone asks dryly, “Has there ever been a set of more tediously colored animals than in these movies?”
In How fast did the T. rex run?, Hone sets the record straight. Some dinosaurs sported iridescent red, white, or black colors and showed patterns of colored spots, spots, or stripes. A small dinosaur called Sinosauropteryx from China, for example, is described as “‘ginger’ with white stripes.”
How do scientists reconstruct the colors of animals that have been extinct (except birds, and more on them in a moment) for 65 million years? The key, Hone explains, are “packages of pigments” called melanosomes 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 extraordinarily fortunate that the shape of a melanosome exactly reflects its color type: “So while fossil melanosomes have no color now, we know what they should have contained and from there we can determine the colors.”
Hone set out to write a book that emphasizes what is not yet known about dinosaurs as much as what is known. (As for the title, how fast T. rex ran is one of the unknowns.) It strikes that balance beautifully. The volume is packed with captivating descriptions of advances in dinosaur science, while also serving as a handbook for anyone wishing to identify key gaps in our knowledge. Regarding color information, for example, he laments the “frustrating and incomplete” nature of the data: it’s unclear whether the colors were muted or bright – and only about six dinosaurs have been studied so far. here. We have no idea of the range of color variation between species, sexes or individuals over time.
Although I enjoy observing or learning about almost any animal, dinosaur fever, whether in childhood or adulthood, has kind of eluded me – until now. I was captivated by Hone’s inviting way of presenting everything from the basics to the more advanced aspects of dinosaur science.
During their reign on Earth, dinosaurs – about 1,500 species of them – lived in almost every ecosystem on the planet. Although the stereotype of creatures living in tropical swamps is firmly rooted in popular culture, in fact dinosaurs lived “on mountains, in deserts, lakes and seashores, temperate and coniferous forests, and at through all kinds of temperature, precipitation, snow, winds and other variations in climate and weather.”
Dinosaurs are divided into three types or clades. Theropods are bipedal, often carnivorous dinosaurs, including Tyrannosaurus and Velociraptor. Sauropodomorphs like Brontosaurus and Brachiosaurus walked on all fours and had huge bodies and long necks. Ornithischians are plant eaters, often display bony plates and ridges, and include Stegosaurus and Triceratops.
How long did the reign of the dinosaurs last? Here I propose a complaint. Hone says at various times that dinosaurs have been around for “some 130” million years, 150 million years, or “about 180 million years”. An unexplained gap of 50 million years is not trivial, even in a book about what is not fully known in dinosaur science, and is confusing to readers.
But when he dives into the details, Hone is superb. In addition to dinosaur appearance, it covers extinction, origins, preservation, diversity, evolutionary patterns, habitats, anatomy, mechanics, physiology, coatings, reproduction, behavior, ecology, dinosaur descendants and changing aspects of research and communication. It’s hard to pick favorites here, but the breeding chapter was among the most mind-blowing.
Hone includes in this chapter an image, taken by himself in China, of a nest of eggs laid and preserved by a giant oviraptorosaur. The caption highlights what we can see in the photograph: “The eggs are laid in several layers in a ring and the animal was probably sitting in the middle.” There is an irony to be found in the fact that this dinosaur shows parental protection towards eggs: “Oviraptorosaur” means “egg thief”. When researchers first discovered skeletons of this dinosaur in association with eggs, the assumption was that they were eating the eggs of other dinosaurs, not hatching. The dinosaurs called titanosaurs apparently did not incubate but, judging from the location of their egg beds and the composition of the eggshells, warmed the eggs with volcanic heat. This behavior is “quite unexpected,” Hone notes.
There’s still a lot we don’t understand about the reproductive biology of dinosaurs. Did the female or the male sit on the eggs, or did they compromise? Going back a bit to the mating moments, Hone again shows a bit of dry humor: “How the hell are you supposed to get two unsightly, very spiny ankylosaurs together, or some of the giant, multi-ton bipedal theropods, or the most great of sauropods?”
Ten thousand species of dinosaurs are alive today: birds, of course. Hone has a lot to say about the origin of the bird line, again balancing strong evidence with open questions. Birds and dinosaurs coexisted for about 100 million years, so we know that birds didn’t appear only after the famous extinction event 65 million years ago. Flying reptiles called pterosaurs and non-avian dinosaurs all died out by this time, along with “a huge number” of bird lineages. The surviving birds were the species largely confined to the ground but still capable of flight, apparently indicating that arboreal birds suffered more severe habitat loss.
And what about this extinction event? Yes, the asteroid that hit Mexico’s Yucatan Peninsula remains the main contender for explaining the loss of dinosaurs. But Hone oddly complicates this story. He raises the possibility that if the asteroid “had passed Earth without a scratch,” the dinosaurs might well have disappeared anyway, as they were already struggling to survive in a world badly weathered by earlier volcanic eruptions.
Hidden at the end of the book, after the references section, is a request by Hone for readers to complete a brief online survey aimed at finding out who may have been inspired to learn more about dinosaurs. “Following the impact of my work on the general public helps me keep doing it,” notes Hone. I predict he will hear a lot of good news very soon.
Barbara J. King is Distinguished Biological Anthropologist at William & Mary. Animals’ Best Friends: Bringing Compassion to Animals in Captivity is his seventh book. Find her on Twitter @bjkingape