Open Paleo

Migmanychion

Wang et al., 2023 mig-mah-nee-shon

From Greek 'meigma' (mixture) and 'nychion' (claw); meaning 'claw mixture', referring to the mix of claw features in the specimen.

125.8–113.2 million years ago Barremian–Aptian, Early Cretaceous
Early Cretaceous stages

Migmanychion is an extinct genus of maniraptoran theropod dinosaur from the Early Cretaceous Longjiang Formation of China. The genus contains a single species, M. laiyang, known from an incomplete left forelimb.

Under dispute

Migmanychion laiyang is known only from a forelimb and is confidently referred only to Maniraptora. Its describers recovered it as the sister taxon of Fukuivenator (Wang and colleagues, 2023); forcing the pair into Therizinosauria, or Migmanychion into Oviraptorosauria or Paraves, costs only two or three steps. It is placed conservatively at Maniraptora incertae sedis.

Diagnosis

  1. Discoidal distal carpal 1 capping exclusively metacarpal I
  2. Sharp proximolateral flange on ventral surface of metacarpal I
  3. Manual phalanx II-1 with lateroventral ridge
  4. Metacarpal III extremely slender, no more than 40% width of metacarpal II at mid-shaft
  5. All manual ungual flexor tubercles distally displaced from proximal articular facet
  6. Manual ungual II with prominent proximodorsal lip and dorsal margin arched above articular facet level
  7. Three manual unguals markedly heterogeneous in size and proportion

Species

Migmanychion laiyang Wang et al., 2023

Type species

Named for the Shandong Laiyang Cretaceous National Geological Park, which houses the holotype specimen.

Holotype
LY 2022JZ3001 , Shandong Laiyang Cretaceous National Geological Park
Material
Incomplete skeleton including partial left forelimb with complete hand preserved as slab and counterslab
Horizon
upper Longjiang Formation, Barremian–Aptian, Early Cretaceous , 125.8–113.2 million years ago
Locality
Pigeon Hill, Inner Mongolia, China

References

  1. Wang, X.; Cau, A.; Wang, Z.; Yu, K.; Wu, W.; Wang, Y.; Liu, Y. (2023). A new theropod dinosaur from the Lower Cretaceous Longjiang Formation of Inner Mongolia (China). Cretaceous Research 151. Elsevier BV. doi:10.1016/j.cretres.2023.105605 wang2023a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

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

    jones2026c
  3. Wang, X.; Ju, S.; Wang, Y. (2019). First zircon U-Pb ages of the Pigeon Hill fossil locality of the Jehol Biota in the Greater Khingan Mountains, Inner Mongolia. Acta Geologica Sinica (English Edition) 93(4): 1142-1145. doi:10.1111/1755-6724.14348

    Dates the tuff of the Pigeon Hill fossil-bearing bed at 121.23 ± 0.74 Ma by zircon U-Pb.

    wang2019d