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RE: On the subject of mysterious absences...The Answer



David Marjanovic wrote:

>>  wonder if Pterodaustro is the first known filter feeder to have evolved?
> 
> Among reasonably big vertebrates, you mean? Leedsichthys is older (Middle 
> Jurassic and later). 


_Pseudocetorhinus_ is even older (Triassic).  It was an elasmobranch (maybe a 
synechodontiform).



Dan Varner wrote:

> << Briefly: if you want to filter feed without gills, you need to take in a
> large amount of water and then somehow stop it going down your gullet before
> you spit it out past filtering surfaces such as baleen . Only mammals can do
> this, as only they have seals that shut off the back of the throat (such as
> you use when you gargle) -- probably evolved in association with suckling.">>
>
> See: http://dml.cmnh.org/2008Feb/msg00330.html


Also:

http://dml.cmnh.org/2008Feb/msg00331.html

(The filter-feeding croc _Stomatosuchus_ has already been mentioned.)

Cheers

Tim

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