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[Ngala]

A new basal sauropodiform dinosaur from the Lower Jurassic of Yunnan Province, China
Xingxiulong chengi Wang, You & Wang, 2017

*This image is copyright of its original author

Figure 2: Representative elements of Xingxiulong chengi gen. et sp. nov. and reconstruction of the skeleton.
(a) Cervical vertebrae of LFGT-D0001 (3–10); (b) articulated posterior dorsal vertebrae (10–14) and dorsosacral of LFGT-D0001 in lateral and dorsal views; © scapula with articulated dorsal vertebrae of LFGT-D0003 in left lateral view; (d) left humerus of LFGT-D0003 in posterior and anterior views; (e) left forelimb of LFGT-D0003 in medial view; (f) right articulated humerus, ulna and radius in medial view, and detail of the proximal end of ulna and radius; (g) left ilium of LFGT-D0002 (photograph and line drawing) in lateral view; (h) right ilium of LFGT-D0003 in lateral view; (i) right ischium of LFGT-D0002 in lateral view; (j) left femur of LFGT-D0002 in anterior, lateral, posterior and medial views; (k) distal end of left tibia of LFGT-D0003 in anterior and distal views; (l) left astragalus of LFGT-D0002 in posterior view; (m) left pes of LFGT-D0002 in lateral and ventral views; (n) right pes of LFGT-D0002 in dorsal and ventral views, with detailed metatarsal I in dorsal view; (o) reconstruction of the skeleton of Xingxiulong chengi gen. et sp. nov. (scaled to the size of the holotype). Abbreviations: 4t, fourth trochanter; alp, anterolateral process; ds, dorsosacral; epls, expanded plate-like summit; it, internal tuberosity; ls, longitudinal sulcus; lt, lesser trochanter; mt I, metatarsal I; mt V, metatarsal V; plp, posterolateral process; pmb, posterior median bulge; pop, postacetabular process; prp, preacetabular process. Dashed lines represent highlighting (c,b, and f) or reconstruction (g and h). Scale bars equal 10 cm in (a–n) and 1 m in (o).

Abstract:
"The Lufeng Formation in Lufeng Basin of Yunnan Province, southwestern China preserves one of the richest terrestrial Lower Jurassic vertebrate faunas globally, especially for its basal sauropodomorphs, such as Lufengosaurus and Yunnanosaurus. Here we report a new taxon, Xingxiulong chengi gen. et sp. nov. represented by three partial skeletons with overlapping elements. Xingxiulong possesses a number of autapomorphies, such as transversely expanded plate-like summit on top of the neural spine of posterior dorsal vertebrae, four sacral vertebrae, robust scapula, and elongated pubic plate approximately 40% of the total length of the pubis. Phylogenetic analysis resolves Xingxiulong as a basal member of Sauropodiformes, and together with another two Lufeng basal sauropodiforms Jingshanosaurus and Yunnanosaurus, they represent the basalmost lineages of this clade, indicating its Asian origin. Although being relatively primitive, Xingxiulong displays some derived features normally occurred in advanced sauropodiforms including sauropods, such as a four sacral-sacrum, a robust scapula, and a pubis with elongated pubic plate. The discovery of Xingxiulong increases the diversity of basal sauropodomorphs from the Lufeng Formation and indicates a more complicated scenario in the early evolution of sauropodiforms." Reply