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Re: CORRECTION Re: CORRECTION...



On Fri, 25 May 2001 14:51:12  
 David Marjanovic wrote:
>> Well, all I can say is that it obviously did survive, somehow :-)  As Ken
>mentioned, some bats can reach really small sizes, and the same is true for
>some rodents, particularly shrews.
>
>Well, shrews are Real True Insectivores (now called Eulipotyphla) like
>hedgehogs, moles and *Solenodon*, phylogenetically far from rodents (mice,
>rats, squirrels, porcupines, guinea pigs...). According to the geneticists
>rodents are even closer to us than to shrews, and shrews are closer to
>horses (both belong to the ill-named Laurasiatheria) than to rodents.

What was I thinking??  Maybe it was because I was looking at two guinea pigs 
when I wrote this.  Anyway, yes, shrews are insectivores, and not rodents.  
There are some really small rodents, though...

>> So, either this little new guy was an ectotherm, or it was an early
>endotherm mammal with a very fast heartrate and very high metabolism.  I
>wouldn't at all be surprised if it turned out to be ectothermic, which may
>say a lot about the origins of endothermy in mammals (which may have
>re-evolved).
>
>Was it actually adult? (Newborn shrews, and lots of other newborns, are
>indeed ectothermic, so that they don't need to boost their terribly high
>metabolism even further.) However, _Suncus etruscus_ is well endothermic,
>and (even more) so are hummingbirds (which reach even smaller sizes).

I assume it was an adult.  If not, then it makes determining metabolism that 
much more difficult.  Suncus is endothermic, but this new mammal is smaller 
than Suncus.  What does that mean?  I have no idea.  I think that it would be 
easier to study the metabolism of this new critter if we could indeed find out 
where on the mammalian family tree it belongs.  

>Can't wait for the paper...

Yeah, I'll have to get my hands on it somehow, too.  

Steve

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