A new biomechanical modeling study suggests that some of the earliest land vertebrates—early tetrapods—had surprisingly limited ability to move their necks, even though their evolution produced a separation between the skull and the shoulders. The findings are reported in Nature and are based on a model that uses sturgeon as a physical analog for relevant anatomy and material properties.
The study argues that a long-standing hypothesis is incorrect: it had proposed that anatomical changes accompanying the move onto land improved neck mobility. Instead, the model indicates that the early tetrapod neck was relatively rigid. Nature’s accompanying coverage explains that the emergence of a neck occurred during the fish-to-tetrapod transition, but that mobility did not follow expectations.
Overall, outlets align on the core result: early tetrapods possess limited neck mobility according to biomechanical modeling. The main difference is emphasis—Phys.org focuses on how the modeling overturns the mobility-improvement hypothesis, while Nature emphasizes the evolutionary context of how the neck forms and what the new evidence implies.
