Fukuiraptor

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Fukuiraptor
Temporal range: Early Cretaceous, 127–115  Ma
Fukuiraptor Okayama.jpg
Reconstructed skeleton
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Clade: Megaraptora
Genus: Fukuiraptor
Azuma & Currie, 2000
Type species
Fukuiraptor kitadaniensis
Azuma & Currie, 2000

Fukuiraptor ("thief of Fukui") was a medium-sized megaraptoran theropod dinosaur of the Early Cretaceous epoch (either Barremian or Aptian) that lived in what is now Japan. [1] Fukuiraptor is known from the Kitadani Formation [2] and possibly also the Sebayashi Formation. [3]

Contents

History

Reconstructed skeleton and holotype fossils on the lower right hukuiraputorunoQuan Shen Gu Ge Hua Shi .jpg
Reconstructed skeleton and holotype fossils on the lower right

The type specimen is a partial skeleton (designated FPDM-V97122) discovered in the Kitadani quarry near Katsuyama in the Fukui prefecture. It is thought that this specimen was not mature and an adult may have been larger. The remains of many other individuals have been found in the quarry, with numerous humeri, femurs, and teeth being assigned to this species. [2] However, the other individuals recovered from the same locality are mostly juveniles that were smaller than the holotype (Currie & Azuma, 2006), in the smallest case less than a quarter of the holotype's size. A tooth (NDC-P0001) discovered in a block of conglomerate from the Sebayashi Formation has been referred to Fukuiraptor as well. [4]

Description

Size comparison Fukuiraptor scale diagram.png
Size comparison

As indicated by its slender phalanges, Fukuiraptor was a relatively lightly built animal, regardless of its maturity. [1] In 2010 Gregory Paul gave a length of 5 meters (16 ft) and a weight of 300 kg (660 lbs). [5] Molina-Pérez and Larramendi estimated a length of 4.3 meters (14.1 ft) and a weight of 590 kg (1,300 lbs) in 2016. [6]

The distinctive teeth of Fukuiraptor show similarities with both carcharodontosaurids (being very compressed and blade-like, as well as having wrinkled enamel) and tyrannosaurids (having oblique blood grooves near the serrations). [2] The holotype also had very large and flat manual unguals (hand claws), which played a role in its initial classification as a dromaeosaurid (as the hand claws were mistaken for foot claws) as well as its current classification as a megaraptoran. [7]

Classification

Initially considered a member of the Dromaeosauridae when first discovered, its initial describers considered it a carnosaur, related to Allosaurus . More recent studies consider it a megaraptoran, an enigmatic group which may have been part of the family Neovenatoridae. [7] However, more recently, another analysis has proposed that all megaraptorans are actually tyrannosauroids, which would reclassify Fukuiraptor as a tyrannosauroid coelurosaur. [8] Recent cladistic analysis of the theropod Gualicho has suggested that Fukuiraptor and other megaraptorans are either allosauroids, or non-tyrannosauroid basal coelurosaurs. [9]

It has been suggested that Fukuiraptor is a close relative to the Australian megaraptoran known as Australovenator , [10] however a subsequent study has placed Australovenator as a megaraptorid megaraptoran alongside other derived South American taxa, while Fukuiraptor remains a megaraptoran outside of Megaraptoridae. [11]

Below is a cladogram reconstructing the position of Fukuiraptor in the Megaraptora as per Delcourt and Grillo, 2018. [11]

Megaraptora

Fukuiraptor Fukuiraptor BW.jpg

Megaraptoridae

Murusraptor Murusraptor NT small.jpg

Tratayenia

Megaraptor MegaraptorNV.jpg

Orkoraptor Orkoraptor drawing.jpg

Aerosteon Aerosteon BW.jpg

Australovenator Australovenator Model.jpg

Palaeoecology

Stratigraphic positions of the non-avialan dinosaurs of the Kitadani Formation, Japan. Fukuivenator skeleton and stratigraphy.jpg
Stratigraphic positions of the non-avialan dinosaurs of the Kitadani Formation, Japan.

In the Kitadani Formation, where fossils of Fukuiraptor have been recovered, [1] fossils of other vertebrates have been preserved. Among the species that have been properly described and named are Fukuisaurus tetoriensis , [12] a styracostern ornithischian, Fukuititan nipponensis , [13] a titanosauriform sauropod, Koshisaurus katsuyama , [14] a hadrosauroid ornithischian, Fukuivenator paradoxus , [15] a therizinosaurian theropod, and Fukuipteryx prima , [16] an avialan as defined by the authors.

Related Research Articles

<i>Deltadromeus</i> Theropod dinosaur genus from mid-Cretaceous Period

Deltadromeus is a genus of theropod dinosaur from Northern Africa. It had long, unusually slender hind limbs for its size, suggesting that it was a swift runner. The skull is not known. One fossil specimen of a single species has been described, found in the Kem Kem Beds, which date to the mid-Cretaceous Period, about 95 million years ago. It may be a junior synonym of the contemporary Bahariasaurus. The classification of Deltadromeus has been in flux since its original description. In 2016, a South American theropod known as Gualicho shinyae was found to possess many similarities with Deltadromeus. Depending on the phylogenetic position of Gualicho, Deltadromeus may have been a neovenatorid carnosaur, a tyrannosauroid, or a basal coelurosaur if its close relation to Gualicho is legitimate. Other studies have considered it a ceratosaurian, more specifically a member of the family Noasauridae.

<i>Megaraptor</i> Extinct genus of dinosaurs

Megaraptor is a genus of large theropod dinosaur that lived in the ages of the Late Cretaceous. Its fossils have been discovered in the Patagonian Portezuelo Formation of Argentina, South America. Initially thought to have been a giant dromaeosaur-like coelurosaur, it was classified as a neovenatorid allosauroid in previous phylogenies, but more recent phylogeny and discoveries of related megaraptoran genera has placed it as either a basal tyrannosauroid or a basal coelurosaur with some studies still considering it a neovenatorid.

<span class="mw-page-title-main">Fukui Prefectural Dinosaur Museum</span> Natural history museum in Fukui Prefecture, Japan

The Fukui Prefectural Dinosaur Museum, located in Katsuyama, Fukui, Japan, is one of the leading dinosaur museums in Asia that is renowned for its exhibits of fossil specimens of dinosaurs and paleontological research. It is sited in the Nagaoyama Park near the Kitadani Dinosaur Quarry that the Lower Cretaceous Kitadani Formation of the Tetori Group is cropped out and a large number of dinosaur remains including Fukuiraptor kitadaniensis and Fukuisaurus tetoriensis are found and excavated.

<i>Aerosteon</i> Extinct genus of dinosaurs

Aerosteon is a genus of megaraptoran dinosaur from the Late Cretaceous period of Argentina. Its remains were discovered in 1996 in the Anacleto Formation, which is from the late Campanian. The type and only known species is A. riocoloradensis. Its specific name indicates that its remains were found 1 km north of the Río Colorado, in Mendoza Province, Argentina.

<span class="mw-page-title-main">Kitadani Formation</span>

The Kitadani Formation is a unit of Lower Cretaceous sedimentary rock which crops out near the city of Katsuyama in Fukui Prefecture, Japan, and it is the primary source of Cretaceous-aged non-marine vertebrate fossils in Japan. Dinosaur remains are among the fossils that have been recovered from the formation, but it also preserves a diverse assemblage of plants, invertebrates, and other vertebrates. Most, if not all, of the fossil specimens collected from the Kitadani Formation are reposited at the Fukui Prefectural Dinosaur Museum.

<i>Australovenator</i> Extinct genus of dinosaurs

Australovenator is a genus of megaraptoran theropod dinosaur from Cenomanian -age Winton Formation of Australia. It is known from partial cranial and postcranial remains which were described in 2009 by Scott Hocknull and colleagues, although additional descriptions and analyses continue to be published. It is the most complete predatory dinosaur discovered in Australia. It has been suggested that Australovenator is a sister taxon to Fukuiraptor, although some phylogenetic analyses find it to be a more derived member of the Megaraptora, possibly being part of the main Megaraptoridae family itself.

<span class="mw-page-title-main">Megaraptora</span> Extinct clade of dinosaurs

Megaraptora is a clade of carnivorous theropod dinosaurs. Its derived members, the Megaraptoridae are noted for their large hand claws and powerfully-built forelimbs, which are usually reduced in size in other large theropods.

The Sebayashi Formation is a Barremian to Albian geologic formation in Japan. Dinosaur remains are among the fossils that have been recovered from the formation, although only two species, Fukuivenator and Siamosaurus, have been referred to a specific genus.

<i>Fukuititan</i> Extinct genus of dinosaurs

Fukuititan is a genus of titanosauriform sauropod dinosaur that lived in the Early Cretaceous in what is now Japan. It is known from FPDM-V8468, the associated partial skeleton of a single individual, recovered from the Kitadani Dinosaur Quarry of the Tetori Group, at Katsuyama City. The type species, Fukuititan nipponensis, was described in 2010 by Japanese scientists Yoichi Azuma and Masateru Shibata of the Fukui Prefectural Dinosaur Museum. The discovery sheds light on Japanese titanosauriforms, which are poorly known in the region.

The Khok Kruat Formation is a rock formation found in northeastern Thailand. It is the uppermost formation of the Khorat Group. It is dated to the Aptian stage of the Early Cretaceous period, and is notable for its fossils of dinosaurs. It is equivalent to the Gres superieurs Formation of Laos. The group is a fluvial formation consisting primarily of red siltstones and sandstones.

<i>Siats</i> Extinct genus of theropod dinosaur

Siats (/see-ats/) is an extinct genus of large theropod dinosaur known from the Late Cretaceous Cedar Mountain Formation of Utah, United States. It contains a single species, Siats meekerorum. It was initially classified as a megaraptoran, a clade of large theropods with very controversial relationships. Siats may be a neovenatorid allosauroid, a coelurosaur of uncertain phylogenetic position, or a tyrannosauroid.

<i>Koshisaurus</i> Extinct genus of reptiles

Koshisaurus is a monospecific genus of basal hadrosauroid from the Kitadani Formation in Japan. The discovery of the genus suggests that hadrosauroids had higher diversity along the eastern margin of Asia in the Early Cretaceous. "Koshi" means an old Japanese regional name including Fukui prefecture where fossils of the genus were discovered.

<i>Fukuivenator</i> Extinct genus of dinosaurs

Fukuivenator is an extinct genus of maniraptoran theropod dinosaur from the Early Cretaceous of Japan.

Plagioolithus is an oogenus of fossil egg. It is from the Early Cretaceous of Japan. It was probably laid by a bird, making it the oldest known fossil bird egg.

<i>Murusraptor</i> Extinct genus of dinosaurs

Murusraptor is a genus of carnivorous megaraptoran theropod dinosaur from the Sierra Barrosa Formation, part of the Neuquén Group of Patagonia, in Argentina, South America. It is known from a single specimen that consists of a partial skull, ribs, partial pelvis, leg and other assorted skeletal elements.

<i>Phuwiangvenator</i> Extinct genus of dinosaurs

Phuwiangvenator is an extinct genus of megaraptoran theropod that lived during the Early Cretaceous period in what is now Thailand. It contains only the type species, P. yaemniyomi. The generic name of Phuwiangvenator comes from the Phu Wiang mountains, where the holotype was discovered, and the Latin word "venator" meaning hunter. The specific name, "yaemniyomi", is in honor of Sudham Yaemniyom, who was a historical paleontologist from Thailand and the first person to discover fossils there.

Siamraptor is an extinct genus of carcharodontosaurian dinosaur, containing the single species S. suwati, known from the Khok Kruat Formation of Thailand. It is the first definitive named carcharodontosaurian species known from Southeast Asia.

<i>Symmetrolestes</i> Extinct family of mammals

Symmetrolestes is an extinct genus of small spalacotheriid mammal from the Early Cretaceous period of Japan. The genus contains one species known as S. parvus, the type fossil is from fluvial deposits located in the Dinosaur Quarry in the Kitadani Formation, near the city of Katsuyama which lies alongside valley of the Sugiyamagawa River. It was described by Tsubamoto and Rougier in 2004 keeping the holotype at the National Science Museum, Tokyo, Japan.

<i>Fukuipteryx</i> Extinct genus of dinosaurs

Fukuipteryx is an extinct genus of basal avialan dinosaurs found in Early Cretaceous deposits from Japan's Kitadani Formation. It contains one species, Fukuipteryx prima.

<i>Tyrannomimus</i> Extinct genus of ornithomimosaurian dinosaurs

Tyrannomimus is an extinct genus of ornithomimosaurian theropod dinosaurs from the Kitadani Formation of Japan. The type species is Tyrannomimus fukuiensis.

References

  1. 1 2 3 Azuma, Yoichi; Philip J., Currie (2000). "A new carnosaur (Dinosauria: Theropoda) from the Lower Cretaceous of Japan" (PDF). Canadian Journal of Earth Sciences. 37 (12): 1735–1753. Bibcode:2000CaJES..37.1735A. doi:10.1139/e00-064.
  2. 1 2 3 Currie, P.J.; Azuma, Y. (2006). "New specimens, including a growth series, of Fukuiraptor (Dinosauria, Theropoda) from the Lower Cretaceous Kitadani Quarry of Japan". J. Paleont. Soc. Korea. 22 (1): 173–193 via ResearchGate.
  3. "A tooth of Fukuiraptor aff. F. kitadaniensis from the Lower Cretaceous Sebayashi Formation, Sanchu Cretaceous, Japan: 東京学芸大学リポジトリ". ir.u-gakugei.ac.jp. Retrieved 9 October 2020.
  4. Molnar, Ralph E.; Obata, Ikuwo; Tanimoto, Masahiro; Matsukawa, Masaki (2009). "A tooth of Fukuiraptor aff. F. kitadaniensis from the Lower Cretaceous Sebayashi Formation, Sanchu Cretaceous, Japan". Bulletin of Tokyo Gakugei University, Division of Natural Sciences. 61: 105–117 via ResearchGate.
  5. Paul, Gregory S. (2010). The Princeton Field Guide to Dinosaurs. New Jersey: Princeton University Press. p. 98.
  6. Molina-Pérez & Larramendi (2016). Récords y curiosidades de los dinosaurios Terópodos y otros dinosauromorfos. Barcelona, Spain: Larousse. p. 263.
  7. 1 2 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. Bibcode:2010NW.....97...71B. doi:10.1007/s00114-009-0614-x. PMID   19826771. S2CID   22646156.
  8. Novas, F. E.; Agnolín, F. L.; Ezcurra, M. D.; Canale, J. I.; Porfiri, J. D. (2012). "Megaraptorans as members of an unexpected evolutionary radiation of tyrant-reptiles in Gondwana". Ameghiniana . 49 (4(R): Suplemento Resúmenes [Abstracts]): R33.
  9. Apesteguía, Sebastián; Smith, Nathan D.; Valieri, Rubén Juárez; Makovicky, Peter J. (13 July 2016). "An Unusual New Theropod with a Didactyl Manus from the Upper Cretaceous of Patagonia, Argentina". PLOS ONE. 11 (7): e0157793. Bibcode:2016PLoSO..1157793A. doi: 10.1371/journal.pone.0157793 . ISSN   1932-6203. PMC   4943716 . PMID   27410683.
  10. Currie, Phillip J.; Coria, Rodolfo A. (20 July 2016). "A New Megaraptoran Dinosaur (Dinosauria, Theropoda, Megaraptoridae) from the Late Cretaceous of Patagonia". PLoS One.
  11. 1 2 Delcourt, Rafael; Grillo, Orlando Nelson (15 December 2018). "Tyrannosauroids from the Southern Hemisphere: Implications for biogeography, evolution, and taxonomy". Palaeogeography, Palaeoclimatology, Palaeoecology. 511: 379–387. doi:10.1016/j.palaeo.2018.09.003. ISSN   0031-0182. S2CID   133830150.
  12. Kobayashi, Yoshitsugu; Azuma, Yoichi (11 April 2003). "A new iguanodontian (Dinosauria: Ornithopoda) from the Lower Cretaceous Kitadani Formation of Fukui Prefecture, Japan". Journal of Vertebrate Paleontology. 23 (1): 166–175. doi:10.1671/0272-4634(2003)23[166:anidof]2.0.co;2. ISSN   0272-4634. S2CID   131386181.
  13. Azuma, Yoichi; Shibata, Masateru (2010). "Fukuititan nipponensis, A New Titanosauriform Sauropod from the Early Cretaceous Tetori Group of Fukui Prefecture, Japan". Acta Geologica Sinica - English Edition. 84 (3): 454–462. doi:10.1111/j.1755-6724.2010.00268.x. ISSN   1755-6724. S2CID   128897110.
  14. "New basal hadrosauroid (Dinosauria: Ornithopoda) from the Lower Cretaceous Kitadani Formation, Fukui, central Japan" (PDF). Zootaxa.
  15. Azuma, Yoichi; Xu, Xing; Shibata, Masateru; Kawabe, Soichiro; Miyata, Kazunori; Imai, Takuya (23 February 2016). "A bizarre theropod from the Early Cretaceous of Japan highlighting mosaic evolution among coelurosaurians". Scientific Reports. 6 (1): 20478. doi:10.1038/srep20478. ISSN   2045-2322. PMC   4763874 . PMID   26908367.
  16. Imai, Takuya; Azuma, Yoichi; Kawabe, Soichiro; Shibata, Masateru; Miyata, Kazunori; Wang, Min; Zhou, Zhonghe (14 November 2019). "An unusual bird (Theropoda, Avialae) from the Early Cretaceous of Japan suggests complex evolutionary history of basal birds". Communications Biology. 2 (1): 399. doi: 10.1038/s42003-019-0639-4 . ISSN   2399-3642. PMC   6856171 . PMID   31754639.