Lourinhasaurus, AS A

Mocho, Pedro, Royo-Torres, Rafael & Ortega, Francisco, 2014, Phylogenetic reassessment of Lourinhasaurus alenquerensis, a basal Macronaria (Sauropoda) from the Upper Jurassic of Portugal, Zoological Journal of the Linnean Society 170 (4), pp. 875-916 : 901-902

LOURINHASAURUS AS A MEMBER OF NEOSAUROPODA

Lourinhasaurus has several features that support its placement within Neosauropoda. The presence of divided and large pleurocoels in cervical centra, present in Lourinhasaurus , is a common feature in neosauropods (character 110, Upchurch et al., 2004) that also occurs in some derived eusauropod nonneosauropods such as Jobaria ( Sereno et al., 1999) and Bellusaurus ( Dong, 1990) . Bellusaurus was recently recovered as a basal macronarian by Royo-Torres et al. (2006) or Carballido & Sander (2013). Among Neosauropoda, the presence of deep and ramified pleurocoels along the dorsal series is common in diplodocoids (excluding Dicraeosauridae, sensu Salgado et al., 1997 ) and basal macronarians ( Wedel, 2003; Upchurch et al., 2004). Some authors also consider this character state to be present in Bellusaurus , Jobaria , and Omeisaurus ( Wilson, 2002; Wedel, 2003; Upchurch et al., 2004). The dorsal –, not applicable; B, bootstrap value; BS, Bremer support values; DM, data matrix; n.s., not supported; Steps, number of steps more than with the first topology; U, Upchurch et al. (2004) data matrix; W, Wilson (2002) data matrix.

bifurcation of the cprl in dorsal vertebrae is considered a synapomorphy of Neosauropoda ( Upchurch, Barrett & Dodson, 2004; Carballido et al., 2011); the condition is present in Lourinhasaurus but absent in some basal titanosauriformes such as Tastavinsaurus (Royo-Torres et al., 2012) , Giraffatitan ( Janensch, 1950) , and Brachiosaurus ( Riggs, 1903) .

Lourinhasaurus also shares with derived eusauropods the presence of five sacral vertebrae ( Salgado et al., 1997; Wilson & Sereno, 1998; Wilson, 2002; Upchurch et al., 2004). The presence of deep excavations on the lateral face of the sacral centrum is a feature with a wide distribution within neosauropods, including diplodocids and macronarians (e.g. Marsh, 1879; Hatcher, 1903; Osborn, 1904; Osborn & Mook, 1921; Janensch, 1950; Salgado, 1993; Curry Rogers & Forster, 2001; Suteethorn et al., 2009), but is reversed in some derived titanosaurs ( Upchurch, 1998).

The caudal triangular transverse process consists of a short dorsal bar (e.g. Osborn & Mook, 1921; Canudo et al., 2008; Gallina & Otero, 2009) that is markedly distinct from the laterally developed transverse process of the caudal vertebrae of diplodocoids and Saltasaurinae (e.g. Lull, 1919; Gallina & Otero, 2009). The simple caudal neural spine is compressed transversely at the base of the spine (this feature is present in Aragosaurus, Sanz et al., 1987 , Camarasaurus, Ostrom & McIntosh, 1966 , Giraffatitan, Janensch, 1950 , and Tastavinsaurus, Canudo et al., 2008 ) and lacks a complex system of laminae and the transverse development observed in diplodocoids ( Wilson, 2002). Flat caudal articulation of proximal caudal vertebrae present in Lourinhasaurus is also common in basal macronarians (e.g. Camarasaurus , Tastavinsaurus , and Giraffatitan ) and some eusauropods and is distinct from the procoelous proximal caudal centra of flagellicaudatans and titanosaurs ( Salgado et al., 1997; Upchurch et al., 2004; Upchurch & Mannion, 2009) and some non-neosauropods such as Bellusaurus , Chuanjiesaurus , Losillasaurus , and Mamenchisaurus (e.g. Young & Zhao, 1972; Dong, 1990; Casanovas, Santafé & Sanz, 2001; Ouyang & Ye, 2002; Sekiya, 2011).

The Lourinhasaurus scapula shows several features that are common in neosauropods and sometimes also in members of its stem group (e.g. Omeisaurus ): (1) an acromion process that is more than 150% the minimum width of the scapular blade; (2) a well-developed and pronounced acromial ridge ( Upchurch et al., 2004); and (3) the presence of an excavated area behind the acromial ridge ( Upchurch et al., 2004). The lateral divergence of the preacetabular process of the ilium in dorsal view is generally shared by neosauropods ( Wilson & Sereno, 1998). The tibia of Lourinhasaurus bears a subcircular proximal articular surface, and the astragalus has a wedge-shaped contour in cranial view, both considered synapomorphies of this clade ( Wilson & Sereno, 1998; Wilson, 2002; Upchurch et al., 2004).