Re: Extinct venomous mammals

[Christopher Taylor <ck.taylor@auckland.ac.nz>]

Actually, most recent phylogenies seem to put _Cimolestes_ and its nearest
and dearest just outside the placental crown group (see e.g. the
_Fruitafossor_ paper). Unfortunately, the Cimolesta sensu McKenna and Bell
is a bit of a hodge-podge of mostly Palaeogene, fairly unspecialised
eutherian taxa, most of which have not (to my knowledge) been recently
subjected to phylogenetic analysis relative to other eutherians - so they
may be related to _Cimolestes_, they may not.

    Cheers,

        Christopher Taylor

On 23/6/05 8:10 am, "Tim Williams" <twilliams_alpha@hotmail.com> wrote:

> 
> Fox, R.C. and Scott, C.S. (2005).  First evidence of a venom delivery
> apparatus in extinct mammals.  Nature 435: 1091-1093.
> 
> ABSTRACT: "Numerous non-mammalian vertebrates have evolved lethal venoms to
> aid either in securing prey or as protection from predators, but modern
> mammals that use venoms in these ways are rare, including only the
> duck-billed platypus (_Ornithorhynchus_), the Caribbean _Solenodon_, and a
> few shrews (Soricidae) (Order Insectivora).  Here we report evidence of a
> venom delivery apparatus in extinct mammals, documented by well-preserved
> specimens recovered from late Palaeocene rocks in Alberta, Canada.  Although
> classified within Eutheria, these mammals are phylogenetically remote from
> modern Insectivora and have evolved specialized teeth as salivary venom
> delivery systems (VDSs) that differ markedly from one another and from those
> of _Solenodon_ and shrews.  Our discoveries therefore show that mammals have
> been much more flexible in the evolution of VDSs than previously believed,
> contradicting currently held notions that modern insectivorans are
> representative of the supposedly limited role of salivary venoms in
> mammalian history.  Evidently, small predatory eutherians have paralleled
> colubroid snakes in evolving salivary venoms and their delivery systems
> several times independently."
> 
> The venomous furball in question is a small pantolestid named _Bisonalveus
> browni_.  It belongs to the "order" Cimolesta, an extinct group that is
> possibly related to pangolins (Pholidota) and carnivorans (something I
> didn't know).  The _Bisonalveus_ specimens come from the Paskapoo Formation
> (late Paleocene) of Alberta.   In one specimen, the canines are preserved in
> situ, with the upper canines modified to form special venom-conducting
> teeth.
> 
> OK, so these guys didn't scuttle around the feet of dinosaurs (except for
> the avian ones), but a pretty great discovery anyway.
> 
> Cheers
> 
> Tim
> 
> 
>