Tungsenia, earliest stem-tetrapod from Lower Devonian of China

[Ben Creisler <bcreisler@gmail.com>]

From: Ben Creisler
bcreisler@gmail.com

Non-dino but of interest:


Jing Lu, Min Zhu, John A. Long, Wenjin Zhao, Tim J. Senden, Liantao
Jia & Tuo Qiao (2012)
The earliest known stem-tetrapod from the Lower Devonian of China.
Nature Communications 3, Article number: 1160
doi:10.1038/ncomms2170
http://www.nature.com/ncomms/journal/v3/n10/full/ncomms2170.html



Recent discoveries of advanced fish-like stem-tetrapods (for example,
Panderichthys and Tiktaalik) have greatly improved our knowledge of
the fin-to-limb transition. However, a paucity of fossil data from
primitive finned tetrapods prevents profound understanding of the
acquisition sequence of tetrapod characters. Here we report a new
stem-tetrapod (Tungsenia paradoxa gen. et sp. nov.) from the Lower
Devonian (Pragian, ~409 million years ago) of China, which extends the
earliest record of tetrapods by some 10 million years. Sharing many
primitive features with stem-lungfishes, the new taxon further fills
in the morphological gap between tetrapods and lungfishes. The X-ray
tomography study of the skull depicts the plesiomorphic condition of
the brain in the tetrapods. The enlargement of the cerebral
hemispheres and the possible presence of the pars tuberalis in this
stem-tetrapod indicate that some important brain modifications related
to terrestrial life had occurred at the beginning of the tetrapod
evolution, much earlier than previously thought.