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New Ichthyostega reconstruction (Nature)





Ahlberg, P.E., Clack, J.A. and Blom, H. (2005). The axial skeleton of the Devonian tetrapod _Ichthyostega_. Nature 437: 137-140.

Abstract. "_Ichthyostega_ was the first Devonian tetrapod to be subject to a whole-body reconstruction1, 2, 3. It remains, together with _Acanthostega_4, one of only two Devonian tetrapods for which near-complete postcranial material is available. It is thus crucially important for our understanding of the earliest stages of tetrapod evolution and terrestrialization. Here we show a new reconstruction of _Ichthyostega_ based on extensive re-examination of original material and augmented by recently collected specimens. Our reconstruction differs substantially from those previously published and reveals hitherto unrecognized regionalization in the vertebral column. _Ichthyostega_ is the earliest vertebrate to show obvious adaptations for non-swimming locomotion. Uniquely among early tetrapods, the presacral vertebral column shows pronounced regionalization of neural arch morphology, suggesting that it was adapted for dorsoventral rather than lateral flexion."