You, H.-L., D.-Q. Li, and P. Dodson. 2014. Gongpoquansaurus mazongshanensis (Lü, 1997) comb. nov. (Ornithischia: Hadrosauroidea) from the Early Cretaceous of Gansu Province, Northwestern China; chapter 4 in D. A. Eberth and D. C. Evans (eds.), Hadrosaurs. Indiana University Press, Bloomington, Indiana.
Appendix 3.1. Measurements of IVPP V 12534, the Holotype of Equijubus normani
| Anatomical features | Measurements (cm) |
| Right dentary, length of symphysis | 5.6 |
| Right dentary, total length along ventral margin | 38.7 |
| Right dentary, length of diastema, from predentary groove to rostral margin of first alveolus | 8.1 |
| Right dentary, depth at midpoint | 9.4 |
| Left dentary, height of coronoid process, from shelf at base of the process to the apex | 11.8 |
| Left dentary, greatest rostrocaudal width of coronoid process | 6.7 |
| Right jugal, dorsoventral depth of ventral flange | 5.4 |
| Right postorbital, rostrocaudal length of squamosal process along dorsal margin | 12.3 |
| Right quadrate, height along rostral margin | 27.4 |
| Right quadrate, greatest mediolateral width of ventral condyle | 7.2 |
| Right quadrate, greatest rostrocaudal width of ventral condyle | 3.3 |
| Cervical and dorsal vertebrae, centra lengths: | |
| C3 | 11.0 |
| C4 | 10.1 |
| C5 | 11.1 |
| C6 | 12.0 |
| C7 | 12.9 |
| C8 | 11.2 |
| C9 | 10.5 |
| C10 | 12.5 |
| C11 | 12.2 |
| D1 | 11.8 |
| D2 | 10.8 |
| D3 | 9.6 |
| D4 | 9.8 |
| D5 | 10.1 |
| D6 | 10.0 |
| D7 | 10.0 |
| D8 | 9.8 |
| D9 | 11.5 |
| D10 | 10.0 |
| D11 | 9.6 |
| D12 | 9.5 |
| D13 | 9.1 |
| D14 | 8.8 |
| D15 | 9.0 |
| D16 | 9.5 |
| D17 | Incomplete |
| Sacrum, craniocaudal length of preserved portion | 46.0 |
| Left sternal, craniocaudal length | 30.5 |
4
Gongpoquansaurus mazongshanensis (Lü, 1997) comb. nov. (Ornithischia: Hadrosauroidea) from the Early Cretaceous of Gansu Province, Northwestern China
Hai-lu You, Da-Qing Li, and Peter Dodson
ABSTRACT
This chapter proposes a new generic name “Gongpoquansaurus” for “Probactrosaurus” mazongshanensis Lü, 1997. Gongpoquansaurus mazongshanensis comb. nov. is a basal hadrosauroid distinguishable from other taxa by the unique combination of these cranial features: transversely elongated supratemporal fenestra, broad and flat dorsal surface of the parietals with a deep median groove, and large and straight nuchal crest. Recognizing its own generic status, rather than as a species of Probactrosaurus, increases basal hadrosauroids to four genera in the Early Cretaceous Mazongshan area of northwestern Gansu Province, China.
INTRODUCTION
Recent years have seen a surge of new basal hadrosauroid dinosaurs (the most inclusive taxon containing Parasaurolophus walkeri Parks, 1922, but not Iguanodon bernissartensis Boulenger [in Beneden, 1881]) in China. Among them, three genera (Equijubus normani You et al., 2003, Jintasaurus meniscus You and Li, 2009, and Xuwulong yueluni You et al., 2011) and one species (Probactrosaurus mazongshanensis Lü, 1997) were named based on material from the Early Cretaceous Xinminpu Group in the Mazongshan (also called Beishan) area of Gansu Province, northwestern China (Fig. 4.1), making it one of the richest hadrosauroid-yielding areas in the world. However, the assignment of the “mazongshanensis” species to “Probactrosaurus” has been questioned, and this taxon probably represents a new genus (Norman, 2002, 2004; Carpenter and Ishida, 2010; McDonald et al., 2010; Buffetaut and Suteethorn, 2011).
In this chapter, based on a review of previous comments on the status of Probactrosaurus mazongshanensis Lü, 1997 and new comparisons to its related taxa, a new generic name Gongpoquansaurus is proposed for “Probactrosaurus” mazongshanensis mainly based on its unique cranial features.
4.1. Localities of basal hadrosauriform dinosaurs from the Early Cretaceous Zhonggou Formation (Xinminpu Group) in the Mazongshan area of Gansu Province, northwestern China. (1) locality of Gongpoquansaurus mazongshanensis (Lü, 1997) comb. nov. and Equijubus normani You et al., 2003 in the Gongpoquan Basin; (2) locality of Jintasaurus meniscus You and Li, 2009, and Xuwulong yueluni You et al., 2011, in the Yujingzi Basin.
Institutional Abbreviations IVPP, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China.
SYSTEMATIC PALEONTOLOGY
DINOSAURIA Owen, 1842
ORNITHISCHIA Seeley, 1887
ORNITHOPODA Marsh, 1881
IGUANODONTIA Dollo, 1888
(sensu Sereno, 2005)
ANKYLOPOLLEXIA Sereno, 1986
(sensu Sereno, 2005)
STYRACOSTERNA Sereno, 1986
(sensu Sereno, 2005)
HADROSAURIFORMES Sereno, 1997
(sensu Sereno, 1998)
HADROSAUROIDEA Cope, 1870
(sensu Sereno, 2005)
GONGPOQUANSAURUS gen. nov.
Gongpoquansaurus mazongshanensis (Lü, 1997) comb. nov. Probactrosaurus mazongshanensis Lü, 1997 (original description). ?Probactrosaurus mazongshanensis (Norman, 2002, 2004). “Probactrosaurus” mazongshanensis (You and Li, 2009). “Probactrosaurus” mazongshanensis (McDonald et al., 2010). “Probactrosaurus” mazongshanensis (Carpenter and Ishida, 2010). “Probactrosaurus” mazongshanensis (Buffetaut and Suteethorn, 2011).
Type Species Gongpoquansaurus mazongshanensis (Lü, 1997) comb. nov.
Etymology Gongpoquan is the name of the basin where the material of the type species was recovered.
Diagnosis As for the type and only known species.
Holotype IVPP V. 11333 (Field Number 9208–21): Caudal part of an incomplete skull.
Referred Material IVPP V. 11334–16: part of the left quadrate; IVPP V. 11334–10, 11: two nearly complete maxillary teeth; IVPP V. 11334–12, 13, 14, 15: four isolated dentary teeth; IVPP V. 11334–1: four cervical vertebrae (including one nearly complete tenth cervical vertebra); IVPP V. 11334–2: second dorsal vertebra; IVPP V. 11334–3: nearly complete sacrum; IVPP V. 11334–4: two series of caudal vertebrae (some with neural spines and chevrons); IVPP V. 11334–17: complete left scapula; IVPP V. 11334–18: part of the left humerus; IVPP V. 11334–8: part of the preacetabular process of the left ilium; IVPP V. 11334–9: part of the postacetabular process of the right ilium; IVPP V. 11334–6, 7: parts of the right and left pubes; IVPP V. 11334–5: right femur missing the proximal part.
Locality