Australia: The Land Where Time Began

A biography of the Australian continent 

Acanthostega – Feeding biomechanics Across the Fish-Tetrapod Transition

A primary aquatic lifestyle is indicated by many fish-like features in Acanthostega, among the earliest and most primitive of the tetrapods, though the morphology of the cranial suture suggests the skull is more similar to the skulls of terrestrial taxa. In this study Neenan et al. have applied geometric morphometrics and 2-D finite element analysis to the lower jaw of Acanthostega, as well as 22 other taxa of tetrapodomorphs to quantify morphological and functional changes that took place across the fish-tetrapod transition. The Acanthostega jaw is morphologically similar to the jaw of certain tetrapodomorph fish and taxa from the Devonian that are transitional, as its proximity to those taxa in morphospace, and functionally, as indicated by the stress value distribution and the relative magnitude of the bite force. A slow rate of morphological and biomechanical change for the transition from tetrapod jaws in the Devonian to tetrapod jaws that were aquatic/semiaquatic in the Carboniferous, is suggested by the results of the study. It has been concluded by Neenan et al.  that Acanthostega has retained a lifestyle that was primitively aquatic and lacked cranial adaptations that would indicate it fed on land.

Sources & Further reading

1. Neenan, J. M., et al. (2014). "Feeding biomechanics in Acanthostega and across the fish–tetrapod transition." Proceedings of the Royal Society B: Biological Sciences 281(1781).