Bristol University sheds new light on early terrestrial vertebrate
The first 3D reconstruction of the skull of a 360 million-year-old near-ancestor of land vertebrates has been created by scientists from the Universities of Bristol and Cambridge.
The 3D skull, which differs from earlier 2D reconstructions, suggests such creatures, which lived their lives primarily in shallow water environments, were more like modern crocodiles than previously thought.
The researchers applied high-resolution X-ray computed tomography (CT) scanning to several specimens of Acanthostega gunnari, one of the ‘four-footed’ vertebrates known as tetrapods which invaded the land during one of the great evolutionary transitions in Earth’s history, 380-360 million years ago. Tetrapods evolved from lobe-finned fishes and display a number of adaptations to help them survive on land.
An iconic fossil species, Acanthostega gunnari is crucial for understanding the anatomy and ecology of the earliest tetrapods. However, after hundreds of millions of years in the ground fossils are often damaged and deformed. No single specimen of Acanthostega preserves a skull that is complete and three-dimensional which has limited scientists’ understanding of how this key animal fed and breathed – until now.
Using special software, the Bristol and Cambridge researchers ‘digitally prepared’ a number of Acanthostega specimens from East Greenland, stripping away layers of rock to reveal the underlying bones.
They uncovered a number of bones deep within the skull, including some that had never before been seen or described, resulting in a detailed anatomical description of the Acanthostegaskull.
The 3D model showing the complete skull on top with ‘exploded’ views of the upper and lower jaws below. Credit: Dr Laura Porro, University of Bristol.
Read more at University of Bristol.