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On the trail of post-KT non-avian dinosaurs etc, Pieter Depuydt wrote..
> So perhaps one day we will
> hear of the find of a non-avian dinosaur in Paleocene or Eocene
> strata (it seems unplausible they made it into the late Paleogene
> (with G), which was already a very different world as the Mesozoic).
Before I talk about fossil tetrapods, a warning...
I think that, as people really interested in the truths of palaeontology and the
history of life in general, we have to be careful not to make speculations that
can be misinterpreted. Creationists, for example, make a good job of taking
observations such as these and misrepresenting them for their twisted cause. One
of the things they are often big on is the idea that Mesozoic fauna was
contemporaneous with humanity and/or still around in the present day (cf. recent
email sent to Jeff Poling on the Zuiyu Maru 'plesiosaur'). Inevitably,
therefore, any mention of post-Cretaceous dinosaurs or whatever is employed by
them as proof of their claims. I don't doubt that there is some 'scientific
creationist' somewhere citing Dr. Karl Shuker's book _In Search of Prehistoric
Survivors_ as scientific endorsement of Creationist views, for example.
Speculators everywhere: please be careful.
(Note that this does not necessarily attach itself to Pieter's comments above -
they are concerned only with the geologic record.)
Onto the views of New Global Zoology...
A number of organisms have surprised scientists by turning up as an extant form
when thought long extinct, or by being discovered in unexpectedly young
deposits. The famed 1938 discovery (first published in 1939 though) of living
coelacanths, in particular, has resulted in many a claim that other Mesozoic
animals may also be awaiting discovery.
Well, OK, nothing is impossible, I'll grant you that. But... of all of the
'Lazarus' organisms thus far known, all are very unusual exceptions and none of
them compare with other archaic taxa (including non-avian dinosaurs, pterosaurs,
all manner of marine reptiles and 'archaeocete' whales: all of which have been
theorised to life at various times) as regards survivability stakes.
Coelacanths, even if they had not been discovered alive in modern times, already
had the longest fossil record of any vertebrate group. They are clearly a
remarkable and very very tough lineage. Chirostoderes have an unusual fossil
record: they seem to pop in and out without warning and provide a conspicuous
number of ghost taxa. They are real hard to kill. Likewise for sphenodonts, some
gymnosperms, horseshoe crabs and so on.
The same does **NOT** go for any of the tetrapod clades that so often have been
theorised back to life. They are typically large animals with good fossil
records that undergo fairly regular extinctions and don't do a Lazarus.
Dinosaurs, marine reptiles etc etc etc are simply _not_ comparable with
coelacanths or tuataras or Woolemi pines or horseshoe crabs or etc etc etc. Or,
to put it another way '_Latimeria_ is a red herring' (I've already copyrighted
that so don't use it;-)).
To put it another way: if _Latimeria_ was a surprise, I dread to think what will
happen if someone digs up an early Tertiary non-avian dinosaur....
"Your hate has made you powerful"