Cute but annoying

Since I'm still without a job to go to every day I've started working on some pet projects. Today I've started working on disproving my hypothesis that herbivores can evolve from carnivorous taxa but not the other way around. The one group of mammals that has so far presented the biggest threat to the validity of this hypothesis is the diprotodonia, the group of marsupials that includes most famously the kangaroos, koalas, walabees and wambats. With the exception of two families, the entire order is herbivorous. The exceptions are the Thylacoleonidae (the fossil marsupial lion) and the Burramyidae, which are pygmy possums. As one might expect, the marsupial lion is currently believed to be a carnivore. The pygmie possum is more of an omnivore, feeding on insects, tree sap and sometimes very small lizards (though how one of these little things could tackle even the smallest gecko is beyond me). the reason that these creatures are so bothersome is that their exact relationship to other members of the order is still up in the air. We simply don't know how they fit in. Kirsch et al. (1997) lumped the pygmie possum in with the phalangeridae, but I suspect that this may be the result of a shared tree climbing habit rather than a true relationship between these creatures. The shrew-like or possum like morphology seems to me to be the basal (see also primitive) condition for most marsupials, so I wouldn't be surprised if it turned out that the phylangeridae was a polyphyletic clade. If it were well known how these animals were all interrelated, I might be able to either go on with added confidence or be able stop right away and just admit that my hypothesis was wrong. I can take dissappointment, it's uncertainty that's a killer.