# Labocania

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Labocania
> Markdown URL: https://mediated.wiki/source/Labocania.md
> Source: https://en.wikipedia.org/wiki/Labocania
> Source revision: 1324622382
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

Genus of tyrannosaurid dinosaurs

Labocania Temporal range: Late Cretaceous, possibly Cenomanian–Campanian PreꞒ Ꞓ O S D C P T J K Pg N Known remains of L. anomala Known remains of L. aguillonae Scientific classification Kingdom: Animalia Phylum: Chordata Class: Reptilia Clade: Dinosauria Clade: Saurischia Clade: Theropoda Superfamily: †Tyrannosauroidea Family: †Tyrannosauridae Clade: †Teratophoneini (?) Genus: †Labocania Molnar, 1974 Type species †Labocania anomala Molnar, 1974 Other species †L. aguillonae Rivera-Sylva & Longrich, 2024

***Labocania*** is an extinct [genus](/source/Genus) of [theropod](/source/Theropod) dinosaur of disputed affinities, known from the [Late Cretaceous](/source/Late_Cretaceous) of Mexico. Initially regarded as an indeterminate theropod, later studies have mentioned possible affinities with [tyrannosaurids](/source/Tyrannosaurid), [abelisaurids](/source/Abelisaurid), or [carcharodontosaurids](/source/Carcharodontosaurid). More recent research based on additional fossil material found support for a position within the [tyrannosaurine](/source/Tyrannosaurine) clade [Teratophoneini](/source/Teratophoneini). Two species have been proposed: ***L. anomala*** (the type species), likely from the [La Bocana Roja Formation](/source/La_Bocana_Roja_Formation), and ***L. aguillonae*** from the [Cerro del Pueblo Formation](/source/Cerro_del_Pueblo_Formation).

## Discovery

Known skull remains (left) and tooth (right) of *L. anomala*

In the summer of 1970, the [National Geographic Society](/source/National_Geographic_Society) and the [Los Angeles County Museum of Natural History](/source/Los_Angeles_County_Museum_of_Natural_History) organized a joint [paleontological](/source/Paleontological) expedition, led by [geologist](/source/Geologist) William J. Morris, to the [Arroyo del Rosario](https://en.wikipedia.org/w/index.php?title=Arroyo_del_Rosario&action=edit&redlink=1) in [Baja California](/source/Baja_California), Mexico. While prospecting, volunteer Harley J. Garbani discovered the fragmentary skeleton of a theropod north of [Punta Baja](https://en.wikipedia.org/w/index.php?title=Punta_Baja&action=edit&redlink=1) near [Cerro Rayado](https://en.wikipedia.org/w/index.php?title=Cerro_Rayado&action=edit&redlink=1).[1]

The collected specimen, IGM 5307 (formerly LACM 20877), was found in a layer of what is likely the [La Bocana Roja Formation](/source/La_Bocana_Roja_Formation), originally thought to date from the late [Campanian](/source/Campanian), about 73 million years old. More recent research has provided conflicting dates, possibly as old as around 93.6 million years old ([Cenomanian](/source/Cenomanian)–[Turonian](/source/Turonian)),[2] but vertebrate remains suggest a younger age.[3] The specimen consists of a very fragmentary skeleton with [skull](/source/Skull) elements, including a right [quadrate](/source/Quadrate_bone), a left [frontal](/source/Frontal_bone), a piece of the left [maxilla](/source/Maxilla), a fragment of the [dentary](/source/Dentary), a [chevron](/source/Chevron_(anatomy)), the upper parts of both [ischia](/source/Ischium), the middle shaft of the right [pubis](/source/Pubis_(bone)), most of the second right [metatarsal](/source/Metatarsal), a [toe bone](/source/Phalanx_bone) and several loose [teeth](/source/Teeth). The elements were found disarticulated and strongly weathered, dispersed over a surface of about two square meters. The remains were mixed with the ribs of a [hadrosauroid](/source/Hadrosauroid).[1]

In 1974, [Ralph Molnar](/source/Ralph_Molnar) [described](/source/Species_description) the [type species](/source/Type_species), *Labocania anomala*, based on these remains. The [generic name](/source/Genus) references the La Bocana Roja Formation, named after *la Bocana Roja*, "the red [estuary](/source/Estuary)". The [specific name](/source/Specific_name_(zoology)) means "anomalous" in [Latin](/source/Latin), in reference to the distinctive morphology.[1]

In 2024, Rivera-Sylva & Longrich described a second species, *Labocania aguillonae*, based on fragmentary remains found in the Campanian-aged [Cerro del Pueblo Formation](/source/Cerro_del_Pueblo_Formation) of [Coahuila](/source/Coahuila), Mexico. The specific name honors the discoverer of the specimen, Martha C. Aguillon, a long-time paleontologist based in Coahuila. The holotype, CPC 2974, comprises parts of a maxilla, the frontals, left lacrimal, nasals, left squamosal, cervical, dorsal, sacral, and caudal vertebrae, left [humerus](/source/Humerus), partial [pelvic girdle](/source/Pelvic_girdle), and partial left hindlimb. CPC 3077, a partial left dentary belonging to a larger, more mature individual, was tentatively referred to *L. aguillonae*.[3]

## Description

*Labocania* was a medium-sized carnivore. In 2010, [Gregory S. Paul](/source/Gregory_S._Paul) estimated the length of *L. anomala* at 7 metres (23 ft) and its weight at 1.5 long tons (1.7 short tons).[4] In 2016, Molina-Pérez & Larramendi gave a higher estimate of 8.2 metres (27 ft) meters long and 2.6 long tons (2.9 short tons) in weight.[5] The holotype of *L. aguillonae* which belongs to either a subadult or a young adult is smaller, at an estimated 6.3 metres (21 ft) long. A tentatively referred specimen belongs to a larger individual.[3]

The cranial elements are very robust, and the [frontals](/source/Frontal_bone) in particular are strongly thickened. The teeth of the maxilla are gradually recurving and rather flat; those of the [premaxilla](/source/Premaxilla) do not have a D-shaped cross-section.[1]

## Classification

Humerus and femur (left) and speculative [life restoration](/source/Life_restoration) (right) of *L. aguillonae*

Speculative life restoration of *L. anomala* feeding on a  [hadrosaur](/source/Hadrosauroidea)

Because *Labocania* is based on fragmentary material, its affinities are uncertain. Molnar (1974) noted certain similarities between *Labocania* and [tyrannosaurids](/source/Tyrannosaurids), especially in the form of the [ischium](/source/Ischium) which features a low triangular obturator process and a circular lateral scar on the upper end, but he did not assign *Labocania* to any family, placing it as [Theropoda](/source/Theropoda) *[incertae sedis](/source/Incertae_sedis)*. Molnar especially compared *Labocania* with "*[Chilantaisaurus](/source/Chilantaisaurus)*" *maortuensis* (later made the separate genus *[Shaochilong](/source/Shaochilong)*) and *[Indosaurus](/source/Indosaurus)*.[1] *Labocania* was considered as a possible tyrannosauroid in the 2004 review of the group by [Thomas R. Holtz Jr.](/source/Thomas_R._Holtz_Jr.), who pointed out that the similarities with the Tyrannosauridae were shared with the [Coelurosauria](/source/Coelurosauria) in general—no tyrannosauroid [synapomorphies](/source/Synapomorphies) were present—and that *Labocania* also showed some [abelisaurid](/source/Abelisaurid) traits such as the thick frontals and a reclining quadrate. The L-shaped chevron and the flattened outer side of the second metatarsal support a position in the [Tetanurae](/source/Tetanurae).[6]

In 2024, [Andrea Cau](/source/Andrea_Cau) included *L. anomala* in a large-scale phylogenetic dataset and recovered it as a [carcharodontosaurid](/source/Carcharodontosaurid) forming a clade with *Shaochilong.*[7]

In their description of theropod material assigned to the new *Labocania* species *L. aguillonae*, Rivera-Sylva & Longrich (2024) found support for a position within the [tyrannosaurine](/source/Tyrannosaurine) clade [Teratophoneini](/source/Teratophoneini). Their [phylogenetic analyses](/source/Phylogenetic_analyses) recovered *Labocania* in a clade with *[Bistahieversor](/source/Bistahieversor)*, *[Dynamoterror](/source/Dynamoterror)*, *[Teratophoneus](/source/Teratophoneus)*, and two unnamed taxa from the [Aguja](/source/Aguja_Formation) and [Two Medicine](/source/Two_Medicine_Formation) formations. Their results are displayed in the [cladogram](/source/Cladogram) below:[3]

Alioramini Tyrannosauridae Nanotyrannus Albertosaurinae Tyrannosaurinae Asiatyrannus Daspletosaurini Lythronax Nanuqsaurus Tyrannosaurini Tyrannosaurus spp. Tarbosaurus Zhuchengtyrannus Teratophoneini Dynamoterror Teratophoneus Aguja Fm. tyrannosaurine Bistahieversor Two Medicine Fm. tyrannosaurine Labocania anomala Labocania aguillonae

In their 2025 description of the early tyrannosauroid *[Khankhuuluu](/source/Khankhuuluu)*, Voris and colleagues regarded *L. aguillonae* as a *[nomen dubium](/source/Nomen_dubium)* due to a lack of clearly distinguishable traits compared to other southern tyrannosaurids, as they found none of the proposed diagnostic characters to be unique to this taxon.[8]

## References

- [Dinosaurs portal](https://en.wikipedia.org/wiki/Portal:Dinosaurs)
- [Mexico portal](https://en.wikipedia.org/wiki/Portal:Mexico)
- [Paleontology portal](https://en.wikipedia.org/wiki/Portal:Paleontology)

1. ^ [***a***](#cite_ref-Molnar1974_1-0) [***b***](#cite_ref-Molnar1974_1-1) [***c***](#cite_ref-Molnar1974_1-2) [***d***](#cite_ref-Molnar1974_1-3) [***e***](#cite_ref-Molnar1974_1-4) Molnar, R. E. (1974). "A distinctive theropod dinosaur from the Upper Cretaceous of Baja California (Mexico)". *[Journal of Paleontology](/source/Journal_of_Paleontology)*. **48** (5): 1009–1017. [JSTOR](/source/JSTOR_(identifier)) [1303299](https://www.jstor.org/stable/1303299).

1. **[^](#cite_ref-2)** Kane, I. A.; Hodgson, D. M.; Hubbard, S. M.; McArthur, A. D.; Poyatos-Moré, M.; Soutter, E. L.; Flint, S. S.; Matthews, W. (2022). ["Deep-water Tectono-Stratigraphy at a Plate Boundary Constrained by Large N-Detrital Zircon and Micropaleontological Approaches: Peninsular Ranges Forearc, Baja California, Mexico"](https://thesedimentaryrecord.scholasticahq.com/article/37652-deep-water-tectono-stratigraphy-at-a-plate-boundary-constrained-by-large-n-detrital-zircon-and-micropaleontological-approaches-peninsular-ranges-fore). *The Sedimentary Record*. **20** (1). [doi](/source/Doi_(identifier)):[10.2110/001c.37652](https://doi.org/10.2110%2F001c.37652). [S2CID](/source/S2CID_(identifier)) [59406495](https://api.semanticscholar.org/CorpusID:59406495).

1. ^ [***a***](#cite_ref-L.aguillonae_3-0) [***b***](#cite_ref-L.aguillonae_3-1) [***c***](#cite_ref-L.aguillonae_3-2) [***d***](#cite_ref-L.aguillonae_3-3) Rivera-Sylva, Héctor E.; Longrich, Nicholas R. (2024). ["A New Tyrant Dinosaur from the Late Campanian of Mexico Reveals a Tribe of Southern Tyrannosaurs"](https://doi.org/10.3390%2Ffossils2040012). *Fossil Studies*. **2** (4): 245–272. [doi](/source/Doi_(identifier)):[10.3390/fossils2040012](https://doi.org/10.3390%2Ffossils2040012).

1. **[^](#cite_ref-4)** Paul, G. S. (2010). [*The Princeton Field Guide to Dinosaurs*](https://archive.org/details/princetonfieldgu0000paul). Princeton University Press. p. [99](https://archive.org/details/princetonfieldgu0000paul/page/99). [ISBN](/source/ISBN_(identifier)) [978-0-691-13720-9](https://en.wikipedia.org/wiki/Special:BookSources/978-0-691-13720-9).

1. **[^](#cite_ref-5)** Molina-Pérez & Larramendi (2016). *Récords y curiosidades de los dinosaurios Terópodos y otros dinosauromorfos*. Barcelona, Spain: Larousse. p. 265.

1. **[^](#cite_ref-holtz2004_6-0)** [Holtz, Thomas R.](/source/Thomas_R._Holtz%2C_Jr.) (2004). "Tyrannosauroidea". In [Weishampel, David B.](/source/David_B._Weishampel); [Dodson, Peter](/source/Peter_Dodson); Osmólska, Halszka (eds.). (eds.). *The Dinosauria* (Second ed.). Berkeley: University of California Press. pp. 111–136. [ISBN](/source/ISBN_(identifier)) [0-520-24209-2](https://en.wikipedia.org/wiki/Special:BookSources/0-520-24209-2).

1. **[^](#cite_ref-7)** Cau, Andrea (2024). ["A Unified Framework for Predatory Dinosaur Macroevolution"](https://www.paleoitalia.it/wp-content/uploads/2024/05/01_Cau_2024_BSPI_631.pdf) (PDF). *Bollettino della Società Paleontologica Italiana*. **63** (1): 1–19. [doi](/source/Doi_(identifier)):[10.4435/BSPI.2024.08](https://doi.org/10.4435%2FBSPI.2024.08) (inactive 12 July 2025). [ISSN](/source/ISSN_(identifier)) [0375-7633](https://search.worldcat.org/issn/0375-7633).{{[cite journal](https://en.wikipedia.org/wiki/Template:Cite_journal)}}: CS1 maint: DOI inactive as of July 2025 ([link](https://en.wikipedia.org/wiki/Category:CS1_maint:_DOI_inactive_as_of_July_2025))

1. **[^](#cite_ref-8)** Voris, Jared T.; [Zelenitsky, Darla K.](/source/Darla_Zelenitsky); [Kobayashi, Yoshitsugu](/source/Yoshitsugu_Kobayashi); Modesto, Sean P.; Therrien, François; Tsutsumi, Hiroki; Chinzorig, Tsogtbaatar; Tsogtbaatar, Khishigjav (2025-06-11). "A new Mongolian tyrannosauroid and the evolution of Eutyrannosauria". *[Nature](/source/Nature_(journal))*. **642** (8069): 973–979. [doi](/source/Doi_(identifier)):[10.1038/s41586-025-08964-6](https://doi.org/10.1038%2Fs41586-025-08964-6). [ISSN](/source/ISSN_(identifier)) [0028-0836](https://search.worldcat.org/issn/0028-0836).

v t e Theropoda Kingdom: Animalia Phylum: Chordata Class: Sauropsida Clade: Avemetatarsalia Clade: Dinosauria Avemetatarsalia see Avemetatarsalia Theropoda see below↓ Theropoda Theropoda Anteavis Chindesaurus? Daemonosaurus? Eodromaeus? Erythrovenator Guaibasaurus? Nhandumirim? Tawa? Herrerasauria? Neotheropoda Dilophosaurus Dolichosuchus? Dracovenator Gojirasaurus Lepidus Liliensternus Lophostropheus Newtonsaurus Notatesseraeraptor Sarcosaurus Shuangbaisaurus Sinosaurus Tachiraptor Velocipes? Zupaysaurus Coelophysoidea Dracoraptor? Newtonsaurus? Panguraptor Pendraig Podokesaurus Powellvenator Coelophysidae Camposaurus Coelophysis Lucianovenator Megapnosaurus? Panguraptor? Procompsognathus Pterospondylus? Segisaurus Averostra see below↓ Dubious neotheropods Teinurosaurus Halticosaurus Averostra Averostra Dornraptor Lophostropheus? Ceratosauria Berberosaurus Camarillasaurus? Dandakosaurus? Fosterovenator Ostafrikasaurus? Saltriovenator Sarcosaurus? Spinostropheus? Neoceratosauria Ceratosauridae Ceratosaurus Genyodectes Abelisauroidea Bahariasaurus? Betasuchus Dahalokely Deltadromeus? Eoabelisaurus? Genusaurus Gualicho? Ligabueino Noasauridae Afromimus? Austrocheirus? Berthasaura Compsosuchus? Dahalokely? Genusaurus? Kiyacursor Ligabueino Spinostropheus Elaphrosaurinae Elaphrosaurus Huinculsaurus Limusaurus Noasaurinae Laevisuchus Masiakasaurus Noasaurus Velocisaurus Vespersaurus Abelisauridae Chenanisaurus Dryptosauroides? Eoabelisaurus Indosuchus Kryptops Kurupi Rugops Spectrovenator Tarascosaurus Tralkasaurus Vitosaura Xenotarsosaurus Majungasaurinae Arcovenator Dahalokely? Genusaurus Indosaurus Majungasaurus Rahiolisaurus? Rajasaurus Carnotaurinae Majungasaurinae? Brachyrostra Dahalokely? Ekrixinatosaurus Elemgasem Guemesia Ilokelesia Llukalkan Niebla Rahiolisaurus? Skorpiovenator Thanos Furileusauria Abelisaurus Aucasaurus Caletodraco Carnotaurus Elemgasem? Koleken Pycnonemosaurus Quilmesaurus Viavenator Tetanurae see below↓ Tetanurae Tetanurae Calamospondylus? Chienkosaurus? Chilesaurus? Chuandongocoelurus Cruxicheiros? Cryolophosaurus Kaijiangosaurus Kayentavenator Monolophosaurus Pandoravenator Sinosaurus? Szechuanosaurus Vectaerovenator Orionides Megalosauroidea Yunyangosaurus Piatnitzkysauridae Condorraptor Marshosaurus Piatnitzkysaurus Xuanhanosaurus? Megalosauria Streptospondylus? Megalosauridae Eustreptospondylus Megalosaurinae Duriavenator Megalosaurus Torvosaurus Wiehenvenator Afrovenatorinae Afrovenator Dubreuillosaurus Leshansaurus Magnosaurus Piveteausaurus Poekilopleuron? Spinosauridae Camarillasaurus? Cristatusaurus Iberospinus Ostafrikasaurus? Baryonychinae Baryonyx Protathlitis Riojavenatrix Suchosaurus? Vallibonavenatrix? Ceratosuchopsini Ceratosuchops Eocarcharia? Riparovenator Suchomimus Spinosaurinae Camarillasaurus? Ichthyovenator Irritator Oxalaia Siamosaurus Spinosaurini Sigilmassasaurus Spinosaurus Avetheropoda see below↓ Avetheropoda Avetheropoda Gasosaurus? Lourinhanosaurus? Carnosauria Altispinax Monolophosaurus? Megalosauridae? Spinosauridae? Allosauroidea Asfaltovenator Erectopus Xuanhanosaurus? Piatnitzkysauridae? Metriacanthosauridae Xuanhanosaurus? Yangchuanosaurus Yuanmouraptor Metriacanthosaurinae Alpkarakush Metriacanthosaurus Shidaisaurus Siamotyrannus Sinraptor Allosauria Allosauridae Allosaurus Antrodemus? Epanterias? Saurophaganax? Carcharodontosauria Datanglong Lusovenator Siamraptor Siats? Veterupristisaurus Neovenatoridae Chilantaisaurus? Gualicho? Neovenator Siats? Megaraptora? Carcharodontosauridae Acrocanthosaurus Altispinax? Concavenator Eocarcharia? Kelmayisaurus Lajasvenator Sauroniops Shaochilong Tameryraptor Ulughbegsaurus Veterupristisaurus Carcharodontosaurinae Carcharodontosaurus Giganotosaurini Giganotosaurus Mapusaurus Meraxes Taurovenator Tyrannotitan Megaraptora? Aoniraptor Bahariasaurus? Fukuiraptor Phuwiangvenator Rapator Siats? Chilantaisaurus? Megaraptoridae Aerosteon Australovenator Joaquinraptor Maip Megaraptor Murusraptor Orkoraptor Tratayenia Coelurosauria see below↓ Coelurosauria Coelurosauria Aratasaurus Asiamericana Bicentenaria Chilantaisaurus? Gualicho? Richardoestesia Sciurumimus? Vayuraptor Xinjiangovenator Zuolong Tyrannoraptora Tyrannosauroidea Chingkankousaurus Labocania? Coeluridae? Coelurus Tanycolagreus? Proceratosauridae Guanlong Kileskus Proceratosaurus Sinotyrannus Yutyrannus Pantyrannosauria Alectrosaurus Aviatyrannis Bagaraatan? Dilong Eotyrannus Jinbeisaurus Juratyrant Khankhuuluu Moros Santanaraptor Stokesosaurus Suskityrannus Timimus? Timurlengia Xiongguanlong Megaraptora? Eutyrannosauria Appalachiosaurus Bistahieversor? Dryptosaurus Nanotyrannus Tyrannosauridae Albertosaurinae Albertosaurus Gorgosaurus Tyrannosaurinae Asiatyrannus Nanuqsaurus Alioramini Alioramus Qianzhousaurus Daspletosaurini Daspletosaurus Thanatotheristes Teratophoneini Bistahieversor? Dynamoterror Labocania? Lythronax Teratophoneus Tyrannosaurini Tarbosaurus Tyrannosaurus Zhuchengtyrannus Maniraptoromorpha see below↓ Dubious coelurosaurs Iliosuchus Kakuru Phaedrolosaurus Shanyangosaurus Maniraptoromorpha Maniraptoromorpha Coelurus? Juravenator Ornitholestes Neocoelurosauria Aniksosaurus Compsognathidae Aniksosaurus? Aristosuchus Beipiaognathus? Compsognathus Huaxiagnathus? Mirischia? Scipionyx? Sinocalliopteryx? Sinosauropteryx? Xunmenglong Sinosauropterygidae? Huadanosaurus Huaxiagnathus Mirischia Sinocalliopteryx Sinosauropteryx Compsognathidae? Ornithomimosauria Arkansaurus Aviatyrannis? Calamosaurus? Hexing Kinnareemimus Nedcolbertia Nqwebasaurus Thecocoelurus? Valdoraptor Macrocheiriformes Harpymimus Pelecanimimus Shenzhousaurus Deinocheiridae Beishanlong Deinocheirus Garudimimus Harpymimus? Paraxenisaurus? Tyrannomimus Ornithomimidae Aepyornithomimus Anserimimus Archaeornithomimus "Coelosaurus" Dromiceiomimus Dzharacursor Gallimimus Mexidracon Ornithomimus Qiupalong Rativates Sinornithomimus Struthiomimus Tototlmimus Maniraptora see Maniraptora includes birds

Taxon identifiers Labocania Wikidata: Q1827222 EoL: 52570693 GBIF: 4821930 Open Tree of Life: 4128408 Paleobiology Database: 38627

---
Adapted from the Wikipedia article [Labocania](https://en.wikipedia.org/wiki/Labocania) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Labocania?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.