In an article about the complexity of animal skulls, Jack Tseng, PhD
, provides expertise on the skulls of animal fetuses. They have approximately 43 bones that are developmentally distinct, “but some of them fuse as mammals grow,” and the number of fused bones may differ among mammal groups notes Tseng, assistant professor of pathology and anatomical sciences
. “I would say that you could probably find marsupial species with close to that number of skull bones,” Tseng adds.