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Re: Archaeopteryx (rant)




T. Michael Keesey <mightyodinn@yahoo.com> wrote:

I've yet to see an explicit, universally applicable definition of "species".

AFAIK, there isn't one (At least not one that is universally accepted.)

The concept of 'species' is a little like pornography: difficult to define, but you know it when you see it.


David Marjanovic <david.marjanovic@gmx.at> wrote:

Even some old-fashioned dental similarities between Macroscelidea and Proboscidea have been found; search the archives for *Nementchatherium*. And of course the paleobiogeography largely fits (significant isolation of Africa before the Miocene). So I do think Afrotheria has good chances of
being found by morphological data.

The study David is referring to is:

Tabuce, R. et al. (2001). A new genus of Macroscelidea (Mammalia) from the Eocene of Algeria: a possible origin for elephant-shrews J. Vert. Paleont. 21: 535?546.

True, there is accruing support for a close relationship between Proboscidea (elephants) and Macroscelidea (elephant shrews). However, Tabuce et al. state: "The assumption of a unique group of condylarthran type at the origin of Afrotheria (macroscelids, tethytherians, tubulidentates, tenrecid and chrysochlorid insectivores) cannot be excluded, but the current paleontological data do not fit with that hypothesis." Admittedly, chrysochlorids (golden moles) have no pre-Miocene fossil record, AFAIK.





Tim

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