A recent analysis of theropod dinosaur bones challenges the traditional theories of dinosaur development. Previously, it was believed that theropods evolved into giants and smaller sizes by adjusting the pace of their growth. However, a study published in Science in 2023 examined bones from 42 different species of theropods and found that they used a variety of developmental mechanisms to change their size. The researchers used microscopic analysis of cross sections of fossilized bones to determine the age and rate of growth of the dinosaurs. They discovered that theropods had different growth patterns depending on their lineage and environment. Some species increased their growth rate, while others prolonged the duration of their growth. Additionally, some theropods that became smaller over time displayed decreased growth rates and durations. The study suggests that ecological factors played a role in the diverse growth strategies of theropods. The research also sheds light on the broader understanding of animal development throughout history. The study of theropods and their bones provides valuable insights into the puzzle of animal size. Another study by the same researcher analyzed how sauropods, the long-necked herbivores, evolved to such large sizes. The study found that at least 36 different lineages of sauropods surpassed the maximum size achieved by the largest land mammals over the course of 100 million years. The findings suggest that the body plan of sauropods, with their long necks, tails, and small heads, was advantageous for achieving large sizes. [Extracted from the article]