[D] Nanyangosaurus zhugeii [sG] [T]
Xu, Zhao, Lü, Huang, Li and Dong, 2000
Cretaceous Early ?Albian
Ornithischia Ornithopoda Iguanodontia Iguanodontidae
Sangping Formation of Neixiang, Henan, China
Genus - Typespecies
Comments by Mickey Mortimer
\\\"Zhuge\\\'s Nanyang lizard\\\", Zhuge Liang being an ancient strategist and philosopher and Nanyang being a place name.
Sangping Formation, Henan, China Albian?, Early Cretaceous holotype- (IVPP V 11821) eight dorsal vertebrae, sacrum (six true sacrals), thirty-six caudal vertebrae, three proximal chevrons, humerus, radius, ulna, incomplete manus, partial ischium, femur, tibia, fibula, astragalocalcaneum, pes diagnosis- partially fused metacarpals II-IV; metacarpal II more than 90% the length of subequal metacarpals III and IV; metacarpal IV more robust than other metacarpals and with a thick distal end; manual phalanx IV-1 wider transversely than proximodistally; metatarsal II dorsoventrally thicker than metatarsal III. main measurements - umerus 265 mm - radius 230 mm - ulna 243 mm - mcII 28 mm - mcIII 92 mm - mcIV 102 mm - mcV 102 mm - femur 517 mm - tibia 548 mm - fibula 503 mm - mtII 155 mm - mtIII 193 mm - mtIV 165 mm
This dinosaur was found in 1994, Mike Keesey had the name \\\"Nanyoungosaurus\\\" reported to him as a museum label, then it was announced in a 1999 SVP abstract. The specimen was 4.5 meters long. It is an adult because of the well fused vertebral centra and fused ischia. As I am not an iguanodont expert and the authors did a good job describing this taxon, the following description is based purely on the text. The first preserved dorsal is slightly opisthocoelous, the others are platycoelous. They have heart-shaped articular ends, the third through seventh preserved dorsals are fused together and only the fifth and sixth have a well-developed ventral keel. There are eight sacral vertebrae, including a sacrodorsal and a sacrocaudal. The anterior articular end is nearly round and the posterior articular end is flattened and circular.
The sacral centra are low and wide, not very constricted and there is a ventral groove on sacrals 4-8. The caudals are platycoelous and get lower and narrower transversely faster than they get shorter, so that the last caudals are elongate. The centra are subcircular (1-3), subrectangular (4-14), trapezoidal (15-17), irregular hexagonal (18-22), regular hexagonal (23-35) and rounded (36) in anterior and posterior view. The last transverse process is on caudal 20 and the neural spines are taller than corressponding chevrons.
The forelimb is comparatively slender and the humerus has an angular deltopectoral crest and dorsoventrally thick distal end (1.3 times as thick as transversely wide). The radial condyle is smaller than the ulnar condyle and extends further distally. Metacarpal I is absent, II-IV are fused and III and IV are ronust, with IV being more so with an expended distal end. The phalanges are robust and the unguals are hoof-shaped.
The distal ischium is moderately curved with a well-developed foot. The femur is straight laterally and the medial distal condyle is more than twice as wide as the lateral. The anterior intercondylar groove is tunnel-like, but the condyles are unfused. The tibia has a transversely wide proximal end and the fibula is semilunate proximally. The astragalocalcaneum is fused and rectangular anteriorly with a weak ascending process. Metatarsal I is absent, metatarsal II is deeper proximally than metatarsal III and the pedal unguals are hoof-shaped.
The authors perform a cladistic analysis, with Hypsilophodon, Camptosaurus, Iguanodon, Ouranosaurus, Probactosaurus, Nanyangosaurus and Hadrosauridae based on forty-five postcranial characters (in Chinese) and show a cladogram with the above taxa, in order, being progressively closer outgroups to the Hadrosauridae. Nanyangosaurus is more basal than hadrosaurs based on: - six true sacrals - proximal caudal centra rectangular or rounded It is their sister group based on: - caudal neural spines longer than corrsponding chevrons - angular ventral margin of deltopectoral crest - ulnar condyle larger than radial condyle - reduced carpus - slender metacarpals - metacarpal I absent - straight femur - tunnel-like anterior intercondylar groove of femur - transverse widening of proximal tibial head extending onto shaft - distal tarsals absent - metatarsal I absent
Carpenter & Ishida (2010) Early and “Middle” Cretaceous Iguanodonts in Time and Space Journal of Iberian Geology 36 (2) 145-164
Nanyangosaurus zhugeii Xu et al. 2000
People’s Republic of China.
Sangping Formation, Xiaguan Basin, Neixiang
Albian? (Xu et al. 2000)
Although the ilium is crushed, is was apparently long and low, with a straight preacetabular procprocess resulting in an extremely wide preacetabular notch. The postacetabular process is long and distally rounded; there is a prominent postacetabular notch below. The lateral iliac crest is moderately long, but does not extend to the distal end of the postacetabular process. The ischial peduncle is slightly developed on the lateral surface