page_title: Jianianhualong
section_title: Description
hierarchical_section_title: Jianianhualong / Description
caption_attribution_description: English: Figure 2: Cranium of Jianianhualong tengi holotype DLXH 1218. (a) Photograph and (b) line drawing of the skull and mandible. Scale bar, 2 cm. ax, axis; fg, groove with foramina; fo, fossa; imf, internal mandibular fenestra; la, left angular; ld, left dentary; lect, left ectopterygoid; lex, left exoccipital; lf; left frontal; lhy, left hyoid bone; lj, left jugal; lla, left lacrimal; lm, left maxilla; lmf, left maxillary fenestra; ln, left nasal; lp, left parietal; lpt?, left pterygoid?; lpa, left prearticular; lpo, left postorbital; lpsaf, left posterior surangular foramen; lsa, left surangular; lsp?, left splenial?; lso, left supraoccipital; lsq, left squamosal; mc, Meckelian canal; ra, right angular; rart, right articular; rd, right dentary; rf, right frontal; rhy, right hyoid bone; rm?, right maxilla?; rn; right nasal; rp, right parietal; rpa, right prearticular; rq?, right quadrate?; rsa; right surangular; rso, right supraoccipital; rsp; right splenial; rsq, right squamosal.
context_page_description: Jianianhualong is a genus of troodontid theropod dinosaur from the Early Cretaceous of China. It contains a single species, Jianianhualong tengi, named in 2017 by Xu Xing and colleagues based on an articulated skeleton preserving feathers. The feathers at the middle of the tail of Jianianhualong are asymmetric, being the first record of asymmetrical feathers among the troodontids. Despite aerodynamic differences from the flight feathers of modern birds, the feathers in the tail vane of Jianianhualong could have functioned in drag reduction whilst the animal was moving. The discovery of Jianianhualong supports the notion that asymmetrical feathers appeared early in the evolutionary history of the Paraves.
  Jianianhualong possesses a combination of traits seen in basal as well as traits seen in derived troodontids. This is consistent with its phylogenetically intermediate position among the troodontids. This mixture of traits shows a distinct spatial organization, with basal traits being present in the forelimbs and pelvis, and derived traits being present in the skull and hindlimbs.
context_section_description: The type specimen of Jianianhualong measures approximately 1 metre (3 ft 3 in) as preserved; since the back of the tail is missing, the animal would probably have been around 1.12 metres (3 ft 8 in) long in life. Scaling from a femoral length of 11.7 cm (4.6 in), Xu et al. found that it weighed 2.4 kilograms (5.3 lb). Despite its small size, the specimen was mature, as indicated by the fusion of the sutures in the vertebrae.
caption: Skull of J. tengi as preserved
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