Monday, 21 October 2013

Thoughts on a head crest

 The skull of Tapejara wellnhoferi has bony extensions to the upper and lower mandible and a long spinous bone extending back over the top of the skull.  There is no evidence of soft tissue crests in this species, but since the other tapejarids; Tupandactylus navigens and  Tupandactylus imperator have soft tissue crests it is probable that T. wellnhoferi also had a soft tissue crest.
We can speculate that without the bony spine above the mandible, the crest would need to be small, or flexible.  Perhaps it was inflatable using blood or air sacs.  This would be an interesting notion!
As soft tissue is seldom preserved and in the case of pterosaurs, occasionally seen as just a residue with no structural detail preserved, any speculation could be valid.
Many illustrators see colour preserved in these crests.  I am not sure of this and it seems more likely that the difference in colour seen in some fossils may actually be an artifact of the preservation.  The impression of colour is more likely to be due to differences in tissue density, tissue type or the chemistry of fossilisation.  Give a thought to the scientists who have to interpret this evidence.  It is easy to see things that are not there, just to make sense of the evidence that is there.  Anyway, I like the thought of pterosaurs being able to fold and display soft tissue crests, even if the evidence is not present in the fossil record - or is it?

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