[Taxacom] Mesozoic origins of many insect families (was: ISE...)

[Vladimir Blagoderov]

Hi Kenneth,

"It seems to me" is not an argument in scientific discussion. By the
end of Cretaceous percentage of extinct families of insects fell to
13% (J/K - 50%, T/J - 70%). Data suggest that there is no significant
change in insect diversity at family level at K/P boundary. It's all
been published, no doubt you can find these papers easily. If you do
not agree, I suggest you re-analize the data and publish your results.

Cheers,

Vlad

On 26 July 2011 03:51, Kenneth Kinman <kennethkinman at webtv.net> wrote:
> Hi Vladimir,
>       Thanks for the statistics.  The presently known Dipteran families
>
> (modern) that are pre-Cretaceous are therefore 26, and add to that those
>
> which are only known from the Cenozoic (post-Cretaceous) would yield a
> total close to (or even exceeding) the 36 families originating in the
> Cretaceous.  That is certainly what I would have expected.  Definitely
> no "vast majority" originating in the Cretaceous.
>      As for 25 families going extinct in the Jurassic (which seems too
> high), I suspect that this is due to two factors: (1) some of them made
> it into the Cretaceous, but haven't yet been documented in the
> Cretaceous; and (2) some of those Jurassic families are actually
> paraphyletic with respect to extant families that are presently viewed
> as first appearing in the Cretaceous (thus being pseudoextinctions
> vis-a-vis the Jurassic-Cretaceous boundary).
>     Therefore (thirdly), I would be suspicious that these numbers
> actually indicate the faunal turnover of insect families during the
> Jurassic-Cretaceous transition to be quite that significant, compared to
>
> the Permian-Triassic extinction, the Cretaceous-Cenozoic (K-T)
> extinction, or even the Triassic-Jurassic extinction.  My experience is
> that the Jurassic-Cretaceous transition was probably milder than any of
> those other three, and that a lot of taxa crossed that boundary even
> though pseudoextinction and a poor Jurassic fossil record has made that
> transition appear more abrupt than it actually was.  It certainly cannot
>
> rival the devastation of either the Permo-Triassic or end-Cretaceous
> extinctions.
>            -----Cheers,
>                        Ken Kinman
> ----------------------------------------------------

-- 
Dr Vladimir Blagoderov, FLS
Department of Entomology
The Natural History Museum
Cromwell Road, London
SW7 5BD, UK
Tel: +44 (0) 207 942 6629 (office)
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e-mail:
vlab at nhm.ac.uk
vblago at gmail.com

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