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Re: Miragaia paper online
[Sorry for inundating the list with stegosaur messages. This is my last for
the day, I promise. I had meant to sent this one out earlier, but it was
overtaken by other replies...]
Thomas R. Holtz, Jr. <email@example.com> wrote:
> OctÃvio Mateus, Susannah C.R Maidment & Nicolai A
> A new long-necked âsauropod-mimicâ stegosaur and the
> evolution of the plated
> Proc. R. Soc. B published online before print February 25,
Mateus &c suggest that the increased number of cervicals (to 17!) in _Miragaia_
could have either come about by cervicalization of the anterior dorsals;
insertions of new vertebrae to the cervical series; or both. The first
hypothesis (recruitment of pre-existing dorsals into the cervical series) would
lead to fewer dorsals (as Mateus &c mention). Strangely conspicuous by its
absence from the paper (especially in Table 1) is _Wuerhosaurus ordosensis_.
According to the original description (Dong, 1993), _W. ordosensis_ has 11
dorsal vertebrae, "the lowest number of dorsals known in any stegosaur" (which
remains true today, AFAIK). If this is the result of the anterior dorsals
being 'cervicalized', this would give _W. ordosensis_ a neck that was composed
of around 15 cervicals. That's less than _Miragaia_, but more than other
Maidment et al. (2008) referred _W. homheni_ (the type species) to
_Stegosaurus_, and regarded _W. ordosensis_ as a nomen dubium. But the latter
may be worth a second look.
Dong Z._M. (1993) A new species of stegosaur (Dinosauria) from the. Ordos
Basin, Inner Mongolia, Peopleâs Republic of China. Canadian Journal of Earth
Sciences 30: 2174â2176.
Maidment, S.C.R., Norman, D.B., Barrett, P.M., and Upchurch, P. (2008)
Systematics and phylogeny of Stegosauria (Dinosauria: Ornithischia). Journal
of Systematic Palaeontology 6: 367-407.