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Re: new dinosaurs

Tim Donovan wrote-

> Xinjiangovenator parvus (Rauhut et Xu 2005) is found
> to be a maniraptoran. It
> is based upon the articulated partial hindlimb
> previously referred to
> Phaedrolosaurus ilikensis, and is from the Lianmugin
> Formation (Valanginian-
> Albian) of China.

  Have there been recent excavations in that unit? I
doubt it is as young as Albian.

Why? Last time you brought this up, you could not defend an older age for these sediments. Recall that-
- Supposed Tsagantsabian key taxa Asiatosaurus and Prodeinodon are indeterminate, and thus cannot be used for biostratigraphy. You have yet to provide references for Dsungaripterus weii (not "Phobetor" parvus) remains from outside the Tugulu Group, thus its use as a 'key taxon' is also negated.
- Psittacosaurus is known from Late Barremian-Early Albian times in Liaoning, and P. xinjiangensis is known from the Lianmuqin Formation. This is evidence the Lianmuqin is later than Hauterivian, since Chaoyangsaurus and Hongshanosaurus (not Psittacosaurus) lived in these earlier times in Liaoning.
- Stegosaurs are too rare anywhere in Cretaceous Asia to take their absence from certain formations as evidence of absence.
- You have yet to specify which fossils are used to show equivalence of the Tugulu Group with the Tsagantsav Svita of Mongolia.
- The Tsagantsav Svita is Berriasian-Aptian according to absolute dating, and the reasons you provided to indicate this was in error were unsubstantiated. In particular, the overlap with Huhteeg Svita is only in possible dates, but not definite ones. The youngest Tsagantsav date is 120 +/- 5 Ma, compared to the Huhteeg value of 116 +/- 8 Ma. So the Huhteeg could be 108 Ma, and that part of the Tsagantsav 125 Ma, for instance. And the IGEM margins of error are comparable to the ARGI ones, the latter of which include a date that's latest Hauterivian at earliest (and mid Aptian at latest).

Mickey Mortimer