Open Paleo

Fukuiraptor

Azuma & Currie, 2000 foo-KOO-ee-RAP-tor

From Fukui (Fukui Prefecture, Japan, where it was found) + Latin raptor (thief/robber): 'thief of Fukui'.

121.4–113.2 million years ago Aptian, Early Cretaceous
Early Cretaceous stages

Fukuiraptor is a genus of medium-sized megaraptoran theropod dinosaur of the Early Cretaceous epoch (either Barremian or Aptian) that lived in what is now Japan. Fukuiraptor is known from the Kitadani Formation and possibly also the Sebayashi Formation. Fukuiraptor may have been one of the basalmost members of Megaraptora, or a sister taxon to Australovenator.

Under dispute

Fukuiraptor kitadaniensis is a megaraptoran theropod, originally placed within the allosauroid family Neovenatoridae (Benson and colleagues, 2010; Carrano and colleagues, 2012) but recovered by most recent analyses within Megaraptora, near Tyrannosauroidea rather than among carcharodontosaurians. It is placed at Megaraptora incertae sedis.

Diagnosis

  1. Fused interdental plates in both maxilla and dentary (convergent with dromaeosaurids)
  2. Narrow, mediolaterally compressed dentary
  3. Narrow blade-like teeth with oblique blood grooves (convergent with tyrannosaurids)
  4. Ulna-to-humerus ratio of 0.92, significantly higher than all other carnosaurs except Xuanhanosaurus
  5. Relatively larger hands with better-developed unguals than Allosaurus
  6. Pubic peduncle lateromedially wider than anteroposteriorly long; ascending process of astragalus taller than in all other known carnosaurs

Species

Fukuiraptor kitadaniensis Azuma & Currie, 2000

Type species

Named for the Kitadani Formation, the geological unit in Fukui Prefecture, Japan, where the holotype was discovered.

Holotype
FPMN 97122 , Fukui Prefectural Dinosaur Museum
Material
Associated skeleton including skull fragments, vertebrae, both humeri, right ulna, manual phalanges and unguals, ilium fragments, pubis, ischia, right femur, partial tibia and fibula, right astragalus, metatarsals I-III, and pedal phalanges; estimated 4.2 m long individual
Horizon
Bonebed I Bed, Kitadani Formation, Aptian, Early Cretaceous , 121.4–113.2 million years ago
Locality
Kitadani Dinosaur Quarry, Fukui, Japan The holotype came from Bonebed I, lowest of the four informally numbered levels Shibata and Azuma (2015) recognize at the quarry. The coordinate is the quarry's, given to the second by Azuma and colleagues (2016); earlier papers state it only to the minute.

Synonyms of the genus

Name Type Reason
Katsuyamasaurus nomen nudum Informal name; never met ICZN requirements for formal publication and is treated as referable to Fukuiraptor. Per Olshevsky's Dinosaur Genera List.
Kitadanisaurus nomen nudum Informal name used for material now considered referable to Fukuiraptor.

References

  1. Azuma, Y.; Currie, P. J. (2000). A new carnosaur (Dinosauria: Theropoda) from the Lower Cretaceous of Japan. Canadian Journal of Earth Sciences 37(12): 1735-1753. Canadian Science Publishing. doi:10.1139/e00-064 azuma2000a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Source of the hip height estimate.

    jones2026c
  3. Carrano, M. T.; Benson, R. B. J.; Sampson, S. D. (2012). The phylogeny of Tetanurae (Dinosauria: Theropoda). Journal of Systematic Palaeontology 10(2): 211-300. Informa UK Limited. doi:10.1080/14772019.2011.630927

    Tetanurae phylogeny recovering Fukuiraptor outside Megaraptora among carcharodontosaurians.

    carrano2012a
  4. Benson, R. B. J.; Carrano, M. T.; Brusatte, S. L. (2010). A new clade of archaic large-bodied predatory dinosaurs (Theropoda: Allosauroidea) that survived to the latest Mesozoic. Naturwissenschaften 97(1): 71-78. doi:10.1007/s00114-009-0614-x

    Named Fukuiraptor as a megaraptoran theropod within the allosauroid family Neovenatoridae

    benson2010d
  5. Azuma, Y.; Xu, X.; Shibata, M.; Kawabe, S.; Miyata, K.; Imai, T. (2016). A bizarre theropod from the Early Cretaceous of Japan highlighting mosaic evolution among coelurosaurians. Scientific Reports 6(1). Springer Science and Business Media LLC. doi:10.1038/srep20478

    Prints the Kitadani Dinosaur Quarry coordinate to the second.

    azuma2016a
  6. Shibata, M.; Azuma, Y. (2015). New basal hadrosauroid (Dinosauria: Ornithopoda) from the Lower Cretaceous Kitadani Formation, Fukui, central Japan. Zootaxa 3914(4). Magnolia Press. doi:10.11646/zootaxa.3914.4.3 shibata2015b