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RE: Nanningosaurus (was Re: Planet of the New Papers)

Nick Gardner wrote:

(a nice tree, at foot of message)

Two brief comments:

(1) WRT your tree, it shows _Gyposaurus_ and _Aralosaurus_ as consecutive outgroups. This implies that traditional Hadrosaurinae is paraphyletic. I'm not sure of the current definitions of Hadrosaurinae or Lambeosaurinae, although Sereno's (1998) stem-based definitions use _Saurolophus_ and _Parasaurolophus_ as mutually exclusive specifiers. (Incidentally, TaxonSearch revises these definitions, with the intention of including the name-giving genera as additional specifiers; but the exact definitions are addled with regard to content.)

(2) What happens when _Pararhabdodon_ is included?

Cheers, Tim

A week later, I finally got the chance to sit down and score
Nanningosaurus into Evans and Reisz's dataset. The results were 3
MPTs, TL 121, CI 0.835, RI 0.878
3 MPTs, 121 steps, CI- 0.834, RI 0.878
                             |  `--Parasaurolophus

Topology does not vary from that of the original authors (Evans and
Reisz), except for the presence of Nanningosaurus between Aralosaurus
and Tsintaosaurus. This does not conflict with the topology found by
Mo et al. given that they had scored Nanningosaurus into Horner et
al.'s dataset which I suspect was completed and submitted to the
reviewers for the Dinosauria II long before most of the recent
publications came out on Amurosaurus, Aralosaurus, Charonosaurus,
Olorotitan and so on. I'm being tolerably nice this evening and
cutting them some slack based on their dataset choice. Obviously, it'd
have been nice if they'd included it in something a little more
inclusive, such as Prieto-Marquez's work (which is a little bit better
than Horner et al.'s in some aspects), or a composite effort from
several different sources, or at the very least, scored in those
additional lambeosaurines. Horner et al.'s dataset is fairly
expansive, but seems to suffer from a bad case of "Amero-centrism",
largely ignoring a great deal of non-NAm taxa (I do believe what I
suggested earlier is the cause of this though).

As I get more time, I'll keep poking into this, I suppose.

Only 20.2% of the total characters were able to be scored-
'Nanningosaurus dashiensis'         ?????????? ????????11 011???????
?????????? ???????1?1 ?????11??0 000??????0 ??????01?? ????????11 1???


Evans, D.C. and Reisz, R. R. (2007). Anatomy and relationships of Lambeosaurus magnicristatus, a crested hadrosaurid dinosaur (Ornithischia) from the Dinosaur Park Formation, Alberta. Journal of Vertebrate Paleontology 27 (2): 373-393. Horner, J.R., Weishampel, D.B. and Forster, C.A. (2004). Hadrosauridae. Pp. 438-463 in The Dinosauria, 2nd ed., D. B. Weishampel, P. Dodson and H. Osmólska (eds.). University of California Press, Berkeley. Mo, J., Zhao, Z., Wang, W. and Xu, X. (2007). The First Hadrosaurid Dinosaur from Southern China. Acta Geologica Sinica 81 (4): 550-554. Prieto-Marquez, Gaete, Rivas, Galobart and Boada (2006). Hadrosauroid dinosaurs from the Late Cretaceous of Spain: Pararhabdodon isonensis revisited and Koutalisaurus kohlerorum, gen. et sp. nov. Journal of Vertebrate Paleontology 26(4): 929-943.

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