Re: aussie gliders

[ornstn@inforamp.net (Ronald Orenstein)]

>On Wed, 10 Jan 1996, Nicholas R. Longrich wrote:
>
>>      I don't really want to open up the whole origin of birds things 
>> again, but I was reading a book my younger brother got for christmas and 
>> it made a couple of interesting comments. One was on the feathertail glider, 
>> a marsupial glider. The tail has on either side, a row of stiffened hairs 
>> that give the tail the featherlike appearance. One would think 
>> Archaeopteryx ancestors might have had something similar. The other was 
>> that the book claimed not one, not two, but THREE separate evolutions of 
>> gliding among marsupials. 
>> 
>
>And among mammals in general, I can add at least two more:  flying 
>squirrels and colugos/bats.

The following are the mammalian gliders I know of (Classification from
Walker's Mannals of the World, 5th ed.):

Order Marsupiala
     Family Petauridae
            Genus Petaurus (squirrel gliders, four species)
            Genus Petauroides (greater glider)
   
[these two gliding genera stem from different non-gliding lines within the
family (the Petaurinae and Pseudocheirinae respectively) so presumably
evolved gliding separately]

      Family Burramyidae
            Genus Acrobates [feathertail glider]

[This species is the one with the stiffened tail hairs; the family also
contains a non-gliding form, Distoechurus, with the same arrangement.  This
is the smallest marsupial glider.]

Order Dermoptera
       Family Cynocephalidae
              Genus Cynocephalus (colugo)

Order Primates
       Family Hominidae
               Genus Homo (mechanical aids necessary)

Order Rodentia
       Family Sciuridae
                Genus Petaurista (giant flying squirrels, six species)
                Genus Biswamayopterus (Namdapha flying squirrel)
                Genus Aeromys (large black flying squirrels, two species)
                Genus Eupetaurus (woolly flying squirrel)
                Genus Pteromys (old world flying squirrels, two species)
                Genus Glaucomys (new world flying squirrels, two species)
                Genus Hylopetes, arrow-tailed flying squirrels, eight species)
                Genus Petinomys (dwarf flying squirrels, seven species)
                Genus Aeretes (groove-toothed flying squirrel)
                Genus Trogopterus (complex-toothed flying squirrel)
                Genus Belomys (hairy-footed flying squirrel)
                Genus Pteromyscus (smoky flying squirrel)
                Genus Petaurillus (pygmy flying squirrels, three species)
                Genus Iomys (Horsfield's flying squirrel)

[this large and diverse group is often considered to form a distinct
subfamily within Sciuridae so I presume it is monophyletic; there are no
non-gliding forms in the group, so perhaps this represents a single gliding
radiation]

       Family Anomaluridae
                 Genus Idiurus (pygmy scalytails, two species)
                  Genus Anomalurus (scaly-tailed flying squirrels, four species)

[this African family is convergent to true flying squirrels, which are
absent from Africa; the group contains one non-gliding genus, Zenkerella.
The gliding membrane is supported in front by a rod of cartilage extending
from the elbow joint.]

That makes (if we leave out primates) at least six separate evolutions of
gliding membranes in Mammalia.  I don't include bats, all of which are of
course true flyers, not gliders.
--
Ronald I. Orenstein                           Phone: (905) 820-7886 (home)
International Wildlife Coalition              Fax/Modem: (905) 569-0116 (home)
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