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Re: *Fruitafossor*



Christopher Taylor wrote:

MacPhee's separation of _Plesiorycteropus_ was due to a lack of
phylogenetic support for connecting _Plesiorycteropus_ to _Orycteropus_, as
opposed to e.g. any other ungulate or myrmecophage. However, nor did he find
any direct evidence that _Plesiorycteropus_ was _not_ related to
_Orycteropus_.

True. Interestingly, in a study that appeared recently in Nature, Zack et al. (2005) found that _Plesiorycteropus_ and _Orycteropus_ were sister taxa. I'd bet dollars to donuts that the two are closely related.



Nick Pharris wrote:

Well, molecular phylogenies are pretty consistent in placing Pholidota near
Carnivora and Xenarthra a long way away from either of those.

Molecular phylogenies are also pretty consistent in finding a clade that includes ruminants, whales and hippos to the exclusion of other (cet)artiodactyls. Yet this ruminant+"whippomorph" clade is not supported by the paleontological/morphological evidence. Even Boisserie et al. (2005) reject a unique relationship between ruminants, hippos and whales; instead they find an (anthracothere+hippo)+whale clade that is closer to pigs than to ruminants.


The point of this rambling is that I'm skeptical of this molecular-based Pholidota+Carnivora clade. True, it comes up in almost every molecular-based tree; and it does have some morphological support. However, these same molecular analyses typically find very weak support for the Pholidota+Carnivora clade (e.g., Murphy et al., 2001). I'd like to see more fossil data.

There is hope. The Afrotheria clade, which is canonical in molecular phylogenies, has come under attack from morphological studies - but it appears to be accruing support from the fossil record. For example, Zack et al. (2005) recently found a link between macroscelideans (elephant shrews) and a group of North American 'condylarths' called apheliscines ('Hyopsodontidae').



Tim