HEADLINE: Knuckle Walkers and the Discovery of Color in Cretaceous Dinosaurs BOOK TITLE: Other Lands, a journey through Earth's extinct worlds GUEST AUTHOR NAME: Thomas Halliday 200-WORD SUMMARY: This section focuses on the Cretaceous period, 125 million

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HEADLINE: Knuckle Walkers and the Discovery of Color in Cretaceous Dinosaurs
BOOK TITLE: Other Lands, a journey through Earth's extinct worlds

GUEST AUTHOR NAME: Thomas Halliday
200-WORD SUMMARY: This section focuses on the Cretaceous period, 125 million years ago, exploring the heyday of non-avian dinosaurs. Herbivores, such as the 17-meter-long titanosaurs, are described as "knuckle walkers" because they lost their finger bones and supported their immense weight on modified hand bones. The forests at this time were primarily composed of conifers, ginkos, and ferns, as flowering plants were only just beginning to emerge. The site of Liaoning, China, provides extraordinary preservation, allowing scientists to determine dinosaur coloration. By examining melanosomes (pigment packets) preserved at a subcellular level, researchers identified patterns, such as the black bandit stripe on Sinosauropteryx. Furthermore, the counter shading found on Psittacosaurus suggests it lived in a forested ecosystem. Defense mechanisms, similar to those seen in modern ecology, were also present. For instance, lace wings (Grammalysa) possessed eye spots on their wings, likely intended to mimic the eyes of a predator, most plausibly a small theropod dinosaur, thus providing a glimpse into Cretaceous signaling and ecology.