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Do we really know what colour ichthyosaurs were? Dan Bensen
> In the book Dinosaurs and
> Prehistoric Animals (primarily by Dougal Dixon) it says, "The remains
> of pigment cells have also been preserved and the analysis of these
> suggests that the smooth, thick skin of Ichthyosaurus was a dark
> reddish-brown color in life." What ever became of that theory? Is it
> still valid?
Whitear (1956) is the one reference everyone alludes to when
discussing fossil pigment in ichthyosaurs (it is paper from _Ann. Mag.
Nat. Hist._). Whitear reported microscopic structures in
_Ichthyosaurus_ soft tissues that she interpreted as skin cells, and cells
with dark brown melanocytes. Obviously I have discussed this quite a
bit with David Martill, my supervisor and an authority on soft tissue
preservation in marine reptiles - judging by his published abstracts he
has formerly accepted this interpretation ('Some ichthyosaurs were
brown (Whitear 1956)' (Martill 1997)) but I can't recall what his take
is on it now. Many structures previously identified as 'skin cells' have
recently been reinterpreted as non-organic, so Whitear's identifications
need to be scrutinised.. also, if a fossil cell is brown, is that really an
accurate representation of pigmentation during life? Also, I am reliably
informed that Whitear's specimens are not of high quality (though this
might be due to recent degradation (L. Steel pers. comm.)).
I think this has been covered on the list before (check the archives).
On a related matter, it is probable that preserved ichthyosaur soft tissue
outlines are not ALL autolithified bacterial mats: Keller (1992 I think,
a _Kaupia_ paper) presented an alternative model. Those who work on
this area seem to agree that neither model explains ALL of the cases.
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