Jian changmaensis

Jian changmaensis was a feathered dromaeosaurid closely related to Microraptor. Its only known specimen is incomplete but unusually informative: a three-dimensionally preserved left shoulder and forelimb with a unique combination of proportions and openings in the bones. Jian is the first non-avian dinosaur body fossil described from the bird-rich Xiagou Formation near Changma. The animal was probably similar to other four-winged microraptorines, but feathers, hind limbs, skull and tail are not preserved in the holotype.

Its fossils occur between approximately 124 and 120 million years ago. Values shown here are approximate and reflect the current curated seed dataset.

Holotype GSGM-D050 contains a complete fused scapulocoracoid, humerus, radius and ulna. It is intermediate in skeletal dimensions between adult Microraptor and Sinornithosaurus. A proportionally long coracoid, cranially developed distal humeral condyles and a large foramen on the proximal radius diagnose the species. Fusion and bone-surface development indicate a mature or nearly mature individual.

• Fused scapula and coracoid in a mature or nearly mature individual
• Coracoid about 36 percent as long as the humerus
• Distinctive condyles on the front surface of the distal humerus
• Well-developed opening on the ventral proximal radius
• Microraptorine proportions intermediate between Microraptor and Sinornithosaurus

The specimen was collected near Changma village in Gansu Province and was first mentioned in a 2010 conference abstract. Ling-Qi Zhou, Matthew Lamanna, Ashley Poust, Da-Qing Li, Hai-Lu You and Jingmai O'Connor formally named it on 4 June 2026. Jian refers to a one-winged bird in Chinese mythology, matching both the animal's bird-like affinities and the single preserved forelimb; changmaensis honours the type locality.

Naming authors: Ling-Qi Zhou, Matthew C. Lamanna, Ashley W. Poust and 3 coauthors.

The lower Aptian Xiagou Formation at Changma records a lake setting about 124–120 million years ago. More than one hundred partial bird skeletons, many with soft tissues, have been recovered from the same deposits. Jian is currently the only described non-avian dinosaur body fossil from this locality, although footprints document other dinosaurs in the wider formation.

Long arm and hind-limb feathers and gliding are inferred from close microraptorine relatives, not preserved on GSGM-D050. Jian was carnivorous and large enough to have taken the small birds abundant at Changma, making it a plausible producer of crushed bird-bone pellets from the site. That ecological link remains a hypothesis: no pellet contains a Jian tooth and no gut contents preserve a bird meal.

• The holotype preserves only the left shoulder and arm—exactly one wing-like limb.
• Its name deliberately invokes the one-winged Jian bird of Chinese mythology.
• It is the first non-avian dinosaur body fossil described from the Changma bird locality.
• DinoTree leaves body length and mass blank because the paper does not preserve enough of the animal for a secure species-level estimate.

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1. 01
   First non-avian theropod (Dromaeosauridae, Microraptorinae) from the bird-bearing Lower Cretaceous Xiagou Formation of the Changma Basin, Gansu Province, northwestern China

   Ling-Qi Zhou, Matthew C. Lamanna, Ashley W. Poust and 3 coauthors · Annals of Carnegie Museum 92(2) · 2026

   Open source
2. 02
   New species of dinosaur, a cousin of Velociraptor, probably glided on four wings and hunted early birds

   Field Museum · 2026

   Open source