Open Paleo

Zhongjianosaurus

Xu & Qin, 2017 chung-CHEE-en-o-SOR-us

Named for Zhongjian Young (Yang Zhongjian), the father of Chinese vertebrate paleontology, combined with Greek 'sauros' meaning 'lizard'.

125.8–121.4 million years ago Barremian, Early Cretaceous
Early Cretaceous stages

Zhongjianosaurus is a genus of dromaeosaurid belonging to the Microraptoria. Believed to hail from the Yixian Formation, specifically the middle of the Jehol Biota, it is the smallest known microraptorine thus far discovered and one of the smallest non-avian theropod dinosaurs.

Diagnosis

  1. Proportionally long ossified uncinate processes fused to dorsal ribs
  2. Humeral proximal end strongly offset medially from humeral shaft
  3. Large fenestra within humeral deltopectoral crest
  4. Ulna slightly longer than humerus (brachial index 0.98)
  5. Arctometatarsalian pes with metatarsal II lacking ginglymus on distal end
  6. Phalanx II-2 lacking proximodorsal lip and strong dorsal arching
  7. Medial condyle of tibiotarsus distal end with prominent distal extension
  8. Metacarpal III laterally bowed with longitudinal ventral groove

Species

Zhongjianosaurus yangi Xu & Qin, 2017

Type species

Named for Yang Zhongjian (C.C. Young), the founder of vertebrate paleontology in China, with 'yangi' being the Latin genitive of the family name.

Holotype
IVPP V22775 , Institute of Vertebrate Paleontology and Paleoanthropology
Material
Partial postcranial articulated skeleton
Horizon
Yixian Formation, Barremian, Early Cretaceous , 125.8–121.4 million years ago
Locality
Sihedang, Lingyuan, Liaoning, China Xu and Qin (2017) give the horizon as "Possibly Yixian Formation, Aptian, Cretaceous" and state that the Yixian assignment of the Sihedang exposures "needs confirmation by additional stratigraphical, paleontological, and chronological data". Their Aptian follows an older placement of the stage base; the Yixian is Barremian on the ICS chart v2024/12.

References

  1. Xu, X.; Qin, Z. C. (2017). A new tiny dromaeosaurid dinosaur from the Lower Cretaceous Jehol Group of western Liaoning and niche differentiation among the Jehol dromaeosaurids. Vertebrata PalAsiatica 55(2): 129-144. xu2017a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Source of the body length and hip height estimates, and the appearance features.

    jones2026c