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| Norellraptor barsboldi Wang, Ji, Cau, Kundrát, Liu, Wang & Ji, 2026 |
Abstract
The discovery of feathered dinosaurs revolutionized the studies on the origin of birds and the evolution of their flight. Among paravians (birds and their closest relatives), the microraptorine dromaeosaurids are unique in bearing several flight-related adaptations with a controversial evolutionary interpretation, supporting, alternatively, flight as ancestral to Paraves or having evolved multiple times among the latter. Here, we introduce an exquisitely-preserved member of Microraptorinae, Norellraptor barsboldi gen. et sp. nov., and describe in detail forelimb osteohistological features for that clade. Norellraptor nests among late-diverging microraptorines and supports step-wise assembly of aerial adaptations in that clade. About 30% of the microraptorine synapomorphies are convergently acquired by the bird lineage (Avialae). Yet, the sequences of flight-related novelties reconstructed along the two lineages differ consistently; combined with histological evidence which might indicate a peculiar limb growth model in Microraptorinae, these results dismiss a shared developmental pattern driving the evolution of the flying dinosaurs and support multiple and independent selective regimes at the origin of the winged taxa in Paraves.
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| Norellraptor barsboldi 130108-MHGU-F4281 a Whole specimen. b Skull in lateral view. c Close up of the rostrum. d Close up of the posterior part of skull. e Pectoral region. f Distal end of tail. aof, antorbital fossa; arm, ascending ramus of maxilla; at, anterior tympanic recess; bt, basal tuber; bp, basypterygoid process; cf, coracoid fenestra; ct, caudal tympanic recess; cnV, 5th cranial nerve opening; cnVII, 7th cranial nerve opening; cv, cervical vertebra; d1, first dorsal vertebra; de, dentary; dt, dorsal tympanic recess; fo, foramen; fr, frontal; fu, furcula; gl, glenoid; h, humerus; la, lacrimal; lat, laterosphenoid; lcv, last caudal vertebra; lp, lateral pneumatic recess; mc, metacarpus; mxf, maxillary fenestra; na, nasal; oc, otosphenoid crest; or, otic region; pa, parietal; paw, postantral wall; pmx, premaxilla; pp, paroccipital process; ppd, posterior processes of dentary; pt, pterygoid; pxf, promaxillary fenestra; r, radius; rp, retroarticular process; sa, surangular; sc, scapula; so, supraoccipital; sp, sternal plate; sr, sclerotic ring; u, ulna; up, uncinate process; vor, ventral otic recess. Arrow indicates point of histological sampling. Scale bar = 50 mm (a); 10 mm (b–f). |
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| Norellraptor barsboldi 130108-MHGU-F4281, appendicular elements. a Right hand. b Pubis. c Feet. am, acetabular margin; ap, apron; cs, claw soft tissue; gi, gastral impression; mcI-III, metacarpals I to III; mtI-V, metatarsals I to V; p, phalanx; pf, pubic foot; r, radius; sc, semilunate carpal; t, tibiotarsus; u, ulna; uI-III, unguals 1 to 3. Scale bar = 10 mm. |
Systematic palaeontology
Dinosauria Owen, 1842
Theropoda Marsh, 1881
Dromaeosauridae Matthew and Brown, 1922
Microraptorinae Senter et al., 2004
Microraptorini (Senter et al., 2004)
Norellraptor barsboldi gen. et sp. nov.
Locality and horizon: Lamadong Town, Jianchang County, western Liaoning, China. Jiufotang Formation, Lower Cretaceous. China.
Diagnosis: Microraptorine dromaeosaurid with the unique combination of features (autapomorphies marked by asterisk; Supplementary Fig. 2): premaxilla with length of prenarial part half the depth of the subnarial body; large promaxillary fenestra occupying the whole rostral third of the antorbital fossa*, and with long axis inclined 35° caudodorsally; pila promaxillaris narrower than the pila interfenestralis and both less than half the diameter of the maxillary fenestra*; pubis gently curved caudoventrally with small foot having the posterior projection less than the diameter of the pubic shaft*. Differential diagnosis: Norellraptor differs from Changyuraptor in having basally-constricted dentary crowns and in the semilunate carpal barely
Etymology: The genus name refers to the American palaeontologist Mark Allen Norell (1957-2025), with Latin word “raptor” (“robber”), a frequently used suffix in dromaeosaurid taxonomy. The species name refers to the Mongolian palaeontologist Rinchen Barsbold (1935-2025). The new taxon name remarks and honours the exceptional contributions by R. Barsbold and M. A. Norell to the study of the bird-like dinosaurs.
Xuri Wang, Yannan Ji, Andrea Cau, Martin Kundrát, Yichuan Liu, Yang Wang and Qiang Ji. 2026. Independent Assembly of the Flight Apparatus in A Non-avian Dinosaur Clade. Nature Communications. 17: 10074. DOI: doi.org/10.1038/s41467-026-77804-6 [29 September 2026]
