Quirks in the cladistic analysis of Lourinhasaurus by Mocho et al. (2014)

It's been barely a year since the second of the three Jurassic Portuguese sauropods, the brachiosaurid titanosauriform Lusotitan ataialensis, was put in a cladistic context by Mannion et. al. (2013) ten years after it was recognized as generically distinct from Brachiosaurus and Giraffatitan. Now, Mocho et. al. (2014) have published a paper re-assessing the cladistic position of the third described Portuguese sauropod, Lourinhasaurus alenquerensis, following in the footsteps of Mannion et. al. (2012, 2013) in putting all of Portugal's sauropod taxa in a phylogenetic context. While it's good that Mocho et al. update the osteology of this genus given that the uncertain placement of some macronarian and non-neosauropod taxa previously assigned to Camarasauridae, I happened to notice a few aspects of the phylogenetic analysis of Lourinhasaurus that seem inconsistent with current state-of-the-art knowledge of eusauropod systematics. Therefore, I have had the opportunity to carefully scrutinize the results of the Lourinhasaurus cladistic analyses by Mocho et al. (2014).

For starters, Lourinhasaurus was originally named as a new Apatosaurus species, A. alenquerensis, by Lapparent and Zbyszewski (1957) and later referred to Camarasaurus by McIntosh (1990a), although McIntosh (1990b) did not rule out the possibility of alenquerensis constituting its own genus due to its higher humerus to femur length ratio. Dantas et. al. (1998) removed alenquerensis from Camarasaurus  based on comparisons with known specimens of Camarasaurus and assigned it to a new genus, which they named Lourinhasaurus, while designating a partial postcranial skeleton from Moinho do Carmo among the syntype series as the lectotype for L. alenquerensis. Because the original description of this taxon had a rather inadequate diagnosis, Upchurch et. al. (2004) found it to be in an unstable position in Eusauropoda, raising the question about the precise placement of Lourinhasaurus among derived eusauropods, including neosauropods. 

Cladistic analyses of Lourinhasaurus by Mocho et al. (2014) using the Wilson (2002) matrix (top) and Upchurch et al. (2004) data matrix (bottom). Note that the Lourinhasaurus phylogeny using the Upchurch et al. (2004) matrix is partly flawed because it did not incorporate data from the cladistic analysis of Curry Roger and Forster (2001).  

When comparing the cladistic analyses of Lourinhasaurus by Mocho et. al. (2014) using the Wilson (2002) and Upchurch et al. (2004) data matrices, it's interesting that while both phylogenies recover a monophyletic Camarasauridae formed by Camarasaurus, Lourinhasaurus, and Tehuelchesaurus, the phylogeny based on the Upchurch et al. (2004) data matrix places Nemegtosaurus and Quaesitosaurus

as diplodocoids rather than titanosaurs and Haplocanthosaurus as a basal macronarian rather than a diplodocoid, while failing to support a monophyletic Euhelopodidae sensu D'Emic (2012). However, this is likely due to the failure of Mocho et. al. (2014) to incorporate characters from the cladistic analyses of D'Emic (2012) and Whitlock (2011) but also the redescription of  Nemegtosaurus and  Quaesitosaurus by Wilson (2005) into the data matrix of Upchurch et al. (2004). Indeed, the cladistic analysis of Titanosauria by Upchurch et al. (2004) did not incorporate characters from the data matrix by Curry Rogers and Forster (2001), although those authors did mention that cladistic results from the latter paper If Camarasauridae sensu Mocho et. al. (2014) holds up in future cladistic analyses concerning the interrelationships of non-titanosauriform macronarians, then Lourinhasaurus would be closely related to Camarasaurus as stated by McIntosh (1990). However, putative camarasaurids such as Dashanpusaurus from the Middle Jurassic of Sichuan, eastern China were not included by Mocho et. al. (2014), so it's unclear whether Camarasauridae had a cosmopolitan distribution in the Middle to Late Jurassic.

References:

Curry Rogers, K., and Forster, C.A., 2001. The last of the dinosaur titans: a new sauropod from Madagascar. Nature 412: 530–534.

D'Emic, M.D., 2012. The early evolution of titanosauriform sauropod dinosaurs. Zoological Journal of the Linnean Society 166 (3): 624–671.

Dantas, P., Sanz, J. L., Marques da Silva, C., Ortega, F., dos Santos V.F., and Cachão, M. 1998. Lourinhasaurus n. gen. Novo dinossáurio saurópode do Jurássico superior (Kimmeridgiano superior-Tithoniano inferior) de Portugal. Comunicações do Instituto Geológico e Mineiro 84 (1A): 91-94.

Lapparent, A.F. de and Zbyszewski, G., 1957. Les dinosauriens de Portugal. Mém. Serv. géol. Port. 2: 1-63.

Mannion, P. D., Upchurch P., Mateus O., Barnes R. N., and Jones M. E. H., 2012. New information on the anatomy and systematic position of Dinheirosaurus lourinhanensis (Sauropoda: Diplodocoidea) from the Late Jurassic of Portugal, with a review of European diplodocoids. Journal of Systematic Palaeontology 10(3), 521–551.

Mannion, P. D., Upchurch P., Barnes R. N., and Mateus O., 2013. Osteology of the Late Jurassic Portuguese sauropod dinosaur Lusotitan atalaiensis (Macronaria) and the evolutionary history of basal titanosauriforms. Zoological Journal of the Linnean Society 168: 98–206.

McIntosh, J.S. 1990a. Sauropoda. pp. 345-501. In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.). The Dinosauria. University of California Press, Berkeley.

McIntosh, J.S., 1990b. Species determination in sauropod dinosaurs with tentative suggestions for their classification. pp. 53-69. In: Carpenter, K., and Currie, P.J. (eds) Dinosaur systematics: approaches and perspectives. Cambridge: Cambridge University Press.

Mocho, P., Royo-Torres, R., and Ortega, F., 2014. Phylogenetic reassessment of Lourinhasaurus alenquerensis, a basal Macronaria (Sauropoda) from the Upper Jurassic of Portugal. Zoological Journal of the Linnean Society 170 (4): 875-916.  DOI: 10.1111/zoj.12113  http://onlinelibrary.wiley.com/doi/10.1111/zoj.12113/abstract

Upchurch, P., Barrett, P.M. and Dodson, P. 2004. Sauropoda. pp. 259-322. In: Weishampel, D.B.; Dodson, P.; & Osmólska, H. (eds.). The Dinosauria, 2nd edition. University of California Press, Berkeley.

Whitlock, J.A., 2011. A phylogenetic analysis of Diplodocoidea (Saurischia: Sauropoda). Zoological Journal of the Linnean Society 161: 872–915.

Wilson, J.A., 2002. Sauropod dinosaur phylogeny: critique and cladistic analysis. Zoological Journal of the Linnean Society 136 (2): 215–275.

Wilson, J.A, 2005. Redescription of the Mongolian sauropod Nemegtosaurus mongoliensis Nowinski (Dinosauria: Saurischia) and comments on Late Cretaceous sauropod diversity. Journal of Systematic Palaeontology 3 (3): 283-318. 10.1017/S1477201905001628.