Gualicho

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Gualicho
Temporal range: Late Cretaceous, 91  Ma
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Gualicho.PNG
Skeletal reconstruction, with known elements in white
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Clade: Orionides
Clade: Avetheropoda
Genus: Gualicho
Apesteguía et al., 2016
Type species
Gualicho shinyae
Apesteguía et al., 2016
Synonyms

Gualicho (named in reference to the gualichu) is a genus of theropod dinosaur. The type species is Gualicho shinyae. It lived in what is now northern Patagonia, on what was then a South American island continent split off from the supercontinent Gondwana. The fossils were found in the Huincul Formation, dating to the late Cenomanian-early Turonian age of the upper Cretaceous Period, around 91 million years ago.

Discovery

Digits of the left hand Gualicho fingers.PNG
Digits of the left hand

On 13 February 2007, Akiko Shinya, preparator of the Field Museum of Natural History, east of the Ezequiel Ramos Mexía Reservoir at the Rancho Violante, discovered the skeleton of a theropod new to science. In 2016, the specimen was named and described by Sebastián Apesteguía, Nathan D. Smith, Rubén Juárez Valieri and Peter J. Makovicky. The generic name is derived from the gualichu , a demon of local folklore. The specific name honours Shinya as the animal's discoverer. [1]

The holotype, MPCN PV 0001, consists of a partial skeleton lacking the skull. It contains four vertebrae of the back, three vertebrae of the middle tail, ribs, a basket of belly-ribs, the left shoulder girdle, the left forelimb, the right lower arm, the lower ends of both pubic bones, the right thighbone, the lower end of the left thighbone, the upper ends of the right shinbone and calf bone, elements of both metatarsi and three toes of the right foot. Most bones were uncovered in their original anatomical position but much of the skeleton had been destroyed by erosion. [1]

Gualicho has been suggested to be synonymous with the megaraptoran Aoniraptor , also known from Huincul Formation and uncovered at the Violante site in view of similarities in their caudal vertebrae. [2] [3] If found to be true, the name Gualicho would have precedent and this would also add a second specimen to Gualicho known as MPCA-Pv 804/1 to 804/25, which would consist of the last sacral vertebra, six proximal caudal vertebrae, four mid-caudal vertebrae, and five haemal arches.

Description

Restoration Gualicho shinyae restoration.jpg
Restoration
Estimated size compared to a human Gualicho shinyae scale.jpg
Estimated size compared to a human

Like the well-known Tyrannosaurus , to which it has been compared, the 6–7 m (20–23 ft)Gualicho possesses reduced arms and possibly two fingered hands, although a 2020 study suggests enough of the third metacarpal is present for a third finger. [4] If it is an Allosauroid, this finding indicates that carnosaurs may have been subject to the same evolution of limb-reduction as tyrannosaurids and abelisaurids. [5]

Classification

Life restoration Gualicho NT small.jpg
Life restoration

Phylogenetically, Gualicho presents two scenarios; that megaraptorans and neovenatorids were carnosaurs, or that megaraptorans and neovenatorids were a grade of theropods more closely related to coelurosaurs than to carnosaurs. [1]

The cladogram below follows a 2016 analysis by Sebastián Apesteguía, Nathan D. Smith, Rubén Juarez Valieri, and Peter J. Makovicky. [1]

Allosauroidea  

The cladogram below follows the strict consensus (average result) of the twelve most parsimonious trees (the simplest evolutionary paths, in terms of the total amount of sampled features evolved or lost between sampled taxa) found by Porfiri et al. (2018)'s phylogenetic analysis. [6] Although the results are different, the methodology analysis was practically identical to that of Apesteguia et al. (2016), only differing in the fact that it incorporated Tratayenia and Murusraptor, two megaraptorans not sampled in the analysis of Apesteguia et al. [1]

Avetheropoda

Cau (2024) again placed Gualicho as the sister taxon as Deltadromeus. However, both taxa were recovered as members of Elaphrosaurinae. [7]

See also

Related Research Articles

<i>Fukuiraptor</i> Megaraptoran theropod dinosaur genus from the Early Cretaceous epoch

Fukuiraptor was a medium-sized megaraptoran theropod dinosaur of the Early Cretaceous epoch that lived in what is now Japan. Fukuiraptor is known from the Kitadani Formation and possibly also the Sebayashi Formation.

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

Bahariasaurus is an enigmatic genus of large theropod dinosaur. Bahariasaurus is known to have included at least 1 species, Bahariasaurus ingens, which was found in North African rock layers dating to the Cenomanian and Turonian ages of the Late Cretaceous. The only fossils confidently assigned to Bahariasaurus were found in the Bahariya Formation of the Bahariya oasis in Egypt by Ernst Stromer but were destroyed during a World War II bombing raid with the same raid taking out the holotype of Spinosaurus and Aegyptosaurus among other animals found in the Bahariya Formation. While there have been more fossils assigned to the genus such as some from the Farak Formation of Niger, these remains are referred to with much less certainty. Bahariasaurus is, by most estimations, one of the largest theropods, approaching the height and length of other large bodied theropods such as Tyrannosaurus rex and the contemporaneous Carcharodontosaurus. The aforementioned estimations tend to put it at around 11–12.2 metres in length and 4-4.8 tonnes in overall weight.

<i>Chilantaisaurus</i> Theropod dinosaur genus from the Late Cretaceous period

Chilantaisaurus is a genus of large theropod dinosaur, possibly a neovenatorid or a primitive coelurosaur, from the Late Cretaceous Ulansuhai Formation of China. The type species, C. tashuikouensis, was described by Hu in 1964.

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

Deltadromeus is a genus of theropod dinosaur from the Aoufous Formation of Morocco.

<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.

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

Orkoraptor is a genus of medium-sized megaraptoran theropod dinosaur from the late Cretaceous Period of Argentina. It is known from incomplete fossil remains including parts of the skull, teeth, tail vertebrae, and a partial tibia. The specialized teeth resemble those of some maniraptoriform theropods, namely the deinonychosaurs and compsognathids. This and other anatomical features led the authors who described it to suggest that it was a maniraptoran coelurosaur. However, subsequent studies found it to be a megaraptoran. Found in the Cerro Fortaleza Formation of Southern Patagonia, it is one of the southernmost carnivorous dinosaurs known from South America.

<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">Bahariasauridae</span> Probable family of averostran theropods

Bahariasauridae is a potential family of averostran theropods that might include a handful of African and South American genera, such as Aoniraptor, Bahariasaurus, Deltadromeus, and Gualicho. The placement of these theropods is controversial, with some studies placing them as basal ceratosaurs possibly related to Noasauridae, others classifying them as megaraptorans, basal neovenatorids, or basal coelurosaurs. There is also a possibility the group might not be monophyletic, as a monograph on the vertebrate diversity in the Kem Kem Beds published in 2020 found Bahariasaurus to be nomen dubium. In the same paper Deltadromeus is classified as an noasaurid, a result also recovered by some previous studies. A 2024 analysis found Aoniraptor, Bahariasaurus, Deltadromeus, Elaphrosaurus and Gualicho to form a monophyletic clade at the base of Ceratosauria.

<span class="mw-page-title-main">Neovenatoridae</span> Extinct family of dinosaurs

Neovenatoridae is a proposed clade of carcharodontosaurian dinosaurs uniting some primitive members of the group such as Neovenator with the Megaraptora, a group of theropods with controversial affinities. Other studies recover megaraptorans as basal coelurosaurs unrelated to carcharodontosaurs. Other theropods with uncertain affinities such as Gualicho, Chilantaisaurus and Deltadromeus are also sometimes included.

<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.

<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.

Aoniraptor is a megaraptoran theropod from the Late Cretaceous of Argentina.

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

Tratayenia is an extinct genus of megaraptoran theropod dinosaurs known from remains found in the Santonian-age Bajo de la Carpa Formation of Argentina. The type and only species, Tratayenia rosalesi, was described in March 2018.

Tralkasaurus is a genus of abelisaurid dinosaur from the Huincul Formation from Río Negro Province in Argentina. The type and only species is Tralkasaurus cuyi, named in 2020 by Mauricio Cerroni and colleagues based on an incomplete skeleton. A medium-sized abelisaurid, Tralkasaurus exhibits a conflicting blend of characteristics found among the early-diverging abelisauroids with others that characterize the highly specialized clade Brachyrostra, and thus its position within the clade is poorly-resolved.

Kaikaifilusaurus is an extinct genus of rhynchocephalians in the family Sphenodontidae from the Late Cretaceous of South America. Fossils of the genus were found in Cenomanian sediments of the Candeleros Formation and Turonian layers of the Huincul Formation, both of the Neuquén Basin and the Albian strata of the Cerro Barcino Formation in the Cañadón Asfalto Basin, all in Patagonia, Argentina. The genus contains two species, K. minimus and the type species K. calvoi.

<i>Overoraptor</i> Extinct genus of theropod dinosaurs

Overoraptor is an extinct genus of paravian theropod of uncertain affinities from the Late Cretaceous Huincul Formation of Argentinian Patagonia. The genus contains a single species, O. chimentoi, known from several bones of the hands, feet, and hips alongside some vertebrae.

<i>Meraxes</i> Genus of carcharodontosaurid dinosaurs

Meraxes is a genus of large carcharodontosaurid theropod dinosaur from the Late Cretaceous Huincul Formation of Patagonia, Argentina. The genus contains a single species, Meraxes gigas.

<i>Chucarosaurus</i> Genus of titanosaurian dinosaurs

Chucarosaurus is an extinct genus of titanosaurian dinosaur from the Late Cretaceous Huincul Formation of Argentina. The genus contains a single species, C. diripienda, known from various limb and pelvic bones.

Sidersaura is an extinct genus of rebbachisaurid sauropod dinosaur from the Late Cretaceous Huincul Formation of Argentina. The genus contains a single species, S. marae, known from the remains of four individuals. Sidersaura represents one of the largest known rebbachisaurids.

<i>Chakisaurus</i> Extinct genus of ornithopod dinosaurs

Chakisaurus is an extinct genus of elasmarian ornithopod dinosaur from the Late Cretaceous Huincul Formation of Argentina. The genus contains a single species, C. nekul, known from multiple partial skeletons belonging to individuals of different ages. Chakisaurus represents the first ornithischian species to be named from the Huincul Formation.

References

  1. 1 2 3 4 5 Apesteguía S, Smith ND, Juárez Valieri R, Makovicky PJ (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 . PMC   4943716 . PMID   27410683.
  2. Mortimer M (2016-07-13). "Is Gualicho Aoniraptor?". The Theropod Database Blog. Retrieved 14 July 2016.
  3. Cau A. "Nuovi resti di Aoniraptor? Ehm... Benvenuto Gualicho!". Theropoda. Retrieved 14 July 2016.
  4. Ibrahim, Nizar; Sereno, Paul C.; Varricchio, David J.; Martill, David M.; Dutheil, Didier B.; Unwin, David M.; Baidder, Lahssen; Larsson, Hans C. E.; Zouhri, Samir; Kaoukaya, Abdelhadi (2020-04-21). "Geology and paleontology of the Upper Cretaceous Kem Kem Group of eastern Morocco". ZooKeys (928): 1–216. doi: 10.3897/zookeys.928.47517 . ISSN   1313-2970. PMC   7188693 . PMID   32362741.
  5. Davis N (13 July 2016). "Meet Gualico shinyae, the puny armed distant relative of T-rex". The Guardian. Retrieved 13 July 2016.
  6. Porfiri JD, Juárez Valieri RD, Santos DD, Lamanna MC (March 2018). "A new megaraptoran theropod dinosaur from the Upper Cretaceous Bajo de la Carpa Formation of northwestern Patagonia". Cretaceous Research. 89: 302–319. doi:10.1016/j.cretres.2018.03.014. S2CID   134117648.
  7. Cau, Andrea (2024). "A Unified Framework for Predatory Dinosaur Macroevolution". Bollettino della Società Paleontologica Italiana. 63 (1): 1–19. doi:10.4435/BSPI.2024.08. ISSN   0375-7633.