Princeton University Press
What color were the dinosaurs? If you look at the Jurassic Park films, the answer seems clear: grey, brown or, at best, dull green.
In a new book, British paleontologist David Hone asks wryly, “Has there ever been a line of animals with duller colors than in those movies?”
in the How fast did T. rex run?, Hone sets the record straight. Some dinosaurs wore red, white, or iridescent black colors and displayed patterns of brightly colored spots, spots, or stripes. For example, a small dinosaur named Sinosauropteryx from China is described as “ginger with white stripes.”
How do scientists reconstruct colors of animals that died out 65 million years ago (excluding birds, and more on that in a moment)? The key, Hone explains, are “packages of pigment,” 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 extremely fortunate that the shape of a melanosome accurately reflects its color type: “Although the fossil melanosomes now have no color, we know what they should have and from that we can calculate the colors.”
Hone set out to write a book that would emphasize what is not yet known about dinosaurs as much as what is known. (Regarding the title, how fast T. rex ran is one of the unknowns.) He achieves that balance beautifully. Packed with gripping descriptions of the advances in dinosaur science, the volume also serves as a handbook for anyone wishing to identify key gaps in our knowledge. Regarding 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, sexes, or individuals over time.
While I’m thrilled to observe or learn about almost any animal, dinosaur fever somehow eluded me as a child or adult—until now. I was fascinated by Hone’s welcoming way of explaining 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 earth. Although the stereotype of tropical swamp creatures is firmly entrenched in popular culture, dinosaurs actually “lived on mountains, in deserts, lakes, and coasts, in temperate and coniferous forests, and in all sorts of temperatures, rainfall, snow, winds, and other variations in both 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 herbivores that often feature bony plates and crests, including Stegosaurus and Triceratops.
How long was the reign of the dinosaurs? Here I offer a complaint. Hone says at various points that dinosaurs existed “about 130 million years,” 150 million years, or “about 180 million years.” An unexplained discrepancy of 50 million years, not even in a book about something not fully known in dinosaur science, is trivial and confusing for readers.
But when he dives into the details, Hone is great. In addition to the appearance of dinosaurs, it covers extinction, origins, conservation, diversity, evolutionary patterns, habitats, anatomy, mechanics, physiology, coverage, reproduction, behavior, ecology, descendants of dinosaurs, and changing aspects of research and communication. It’s difficult to pick favorites here, but the procreation chapter was one of the most underwhelming.
Hone includes in this chapter an image he took himself in China, showing a nest of eggs laid and tended by a giant oviraptorosaur. The caption underlines what we can see in the photo: “The eggs are laid in several layers in a ring and the animal probably sat in the middle.” There is an irony in the fact that this dinosaur had parental care for the eggs shows: “Oviraptorosaur” means “egg thief”. When researchers first discovered skeletons of this dinosaur associated with eggs, it was assumed that they ate the eggs of other dinosaurs and did not breed. Dinosaurs called titanosaurs apparently did not breed, but rather heated the eggs by volcanic heat, judging by the location of their egg beds and the composition of the egg shells. This behavior is “completely unexpected,” notes Hone.
There’s a lot we don’t yet understand about dinosaur reproductive biology. Did the female or the male sit on the eggs, or did they switch places? Hone goes back a bit to the mating moments, again showing some wry humor: “How on earth do you put together two clumsy and very spiny ankylosaurs, or some of the huge, multi-ton, bipedal theropods, or the largest of them, sauropods? “
Ten thousand species of dinosaurs are alive today: the birds, of course. Hone has much to say about the origin of the bird lineage, again balancing strong evidence with open questions. Birds and dinosaurs coexisted for about 100 million years, so we know birds didn’t appear after the famous extinction event of 65 million years ago. Flying reptiles called pterosaurs and the non-avian dinosaurs all disappeared by this time, as did a “very large number” of bird lineages. The surviving birds were the species that were mostly ground restricted but still capable of flight, apparently suggesting that arboreal birds suffered more habitat loss.
And what about this extinction event? Yes, the asteroid that struck Mexico’s Yucatan Peninsula remains the leading contender for explaining dinosaur loss. But Hone complicates this story in an intriguing way. He raises the possibility that if the asteroid “had sailed past Earth without a single scratch,” the dinosaurs would have been extinct anyway, already struggling to survive in a world profoundly changed by previous volcanic eruptions.
Hidden at the end of the book, behind the reference section, is Hone’s request for readers to fill out a short online survey to find out who might have been inspired to learn more about dinosaurs. “Tracking the impact my work is having on the general public keeps me going,” notes Hone. I predict he will hear a lot of good news very soon.
Barbara J. King is Biological Anthropologist Emeritus at William & Mary. Animals’ Best Friends: Using compassion for animals in captivity is her seventh book. Find her on Twitter @bjkingape