Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!uunet!tdatirv!sarima
From: sarima@tdatirv.UUCP (Stanley Friesen)
Newsgroups: sci.bio
Subject: Re: On the classification of Platypus
Keywords: monotremes
Message-ID: <227@tdatirv.UUCP>
Date: 30 Apr 91 00:54:12 GMT
References: <1991Apr22.111159.29888@kuhub.cc.ukans.edu> <4896@kitty.UUCP> <421@smds.UUCP> <2350@cluster.cs.su.oz.au>
Reply-To: sarima@tdatirv.UUCP (Stanley Friesen)
Organization: Teradata Corp., Irvine
Lines: 27

In article <2350@cluster.cs.su.oz.au> andrewt@cluster.cs.su.oz.au (Andrew Taylor) writes:
>I'm suspicious of the assumption that the platypus lactation is
>a primitive charcteristic because the platypus is so highly specialised.
>Perhaps the nipple was lost in the platypus because the bill
>made it difficult for the young to suckle. I'm probably wrong but ...
>you've got to be careful.

Well, perhaps it is a specialization, but not for this reason.

All monotremes lack nipples, including the three species of echidna, which
are essentially 'anteaters', with long, tubular snouts.   The echidnas
would *very* good at suckling at nipples.


Also, I think I remember photos of newborn platypuses, and I seem to
remember that the bill is not yet well developed.   (I *could* be wrong
here, the memory is rather vague).


Quite honestly, I think that the lack of nipples is likely to be one of the
most certain primitive characteristics of monotremes.  The others could
easily be specializations, but this one is hard to explain any other way.
(Nipples are so much more efficient - they allow much better control over
milk production, and thus less waste).
-- 
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uunet!tdatirv!sarima				(Stanley Friesen)