Su suggerimento di @GiMa
Un articolo di Ed Yong su The Atlantic racconta le cause che portarono le tartarughe ad evolvere il loro caratteristico carapace.
For almost a century, biologists argued about how turtles got their shells—a debate almost as slow and plodding as the creatures themselves. Paleontologists mostly argued that the shells evolved from bony scales called osteoderms, which are also responsible for the armor of crocodiles, armadillos, and many dinosaurs. These scales simply expanded to fuse with the ribs and backbone, creating a solid covering. But developmental biologists disagreed. By studying modern turtle embryos, they deduced that the shell evolved from ribs, which broadened out and eventually united.
Immagine da Wikimedia Commons