Talks, field trips and events organised by west country geological organisations are publicised on this blog. Discussion about geological topics is encouraged. Anything of general geological interest is included.
Sunday, 28 October 2012
Friday, 26 October 2012
Limbed Fish
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. However, a new stem-tetrapod (Tungsenia paradoxa gen. et sp. nov.) from the Lower Devonian (Pragian, ~409 million years ago) of China, 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 (photo) 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.
Labels:
General Interest
Wednesday, 24 October 2012
Tuesday, 23 October 2012
Thursday, 18 October 2012
West Country Geology field programme 2013
A meeting was held at Box during August where it was agreed by representatives of BNS Geology Section, Bath Geological Society and West of England Geologists’ Association that, as a one-year trial, the three societies will organise a joint programme of field meetings for 2013. This should be of benefit to members of all the societies, as we can all draw on a wider base of expertise, avoid clashes and repetitions, and ensure good attendance. I am sure that this will be a positive improvement for all involved.
Please add any comments, thoughts and suggestions to this post.
Please add any comments, thoughts and suggestions to this post.
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