Biology:Lajasvenator

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Lajasvenator (meaning "Las Lajas hunter" after the city of Las Lajas in Neuquén, Argentina) is a genus of carcharodontosaurid dinosaur from the Mulichinco Formation from Neuquén Province in Argentina. The type and only species is Lajasvenator ascheriae. It was probably one of the smaller known Carcharodontosaurids, being slightly more than half the length of Concavenator, about 3.5 m (11 ft).[1]

Lajasvenator is known from two specimens, MLL-PV-005 (the holotype) and MLL-PV-007 (a referred specimen). The referred specimen includes the proximal end of a cervical rib that is identical to the seventh cervical rib of the holotype. It is possible that the early evolutionary stage for the Carcharodontosauridae started with medium-sized predators like Lajasvenator that later diversified into the heavily-built taxa such as Giganotosaurus and Mapusaurus. Lajasvenator is the oldest carcharodontosaur known from the Cretaceous of South America and is a key taxon for understanding the clade's evolutionary history.[1]

Classification

In their 2020 description of Lajasvenator, Coria et al. found it to be a carcharodontosaurid in a clade with Eocarcharia and Concavenator.[1] In their description of Meraxes, Canale et al. (2022) recovered similar relationships, with Lajasvenator in a polytomy with Lusovenator, Eocarcharia, and Concavenator.[2]

Carcharodontosauridae
  Neovenator
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Concavenator 75px

 
  Eocarcharia
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Lajasvenator

 
 

Lusovenator

 
 
  Acrocanthosaurus
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  Shaochilong
80px
 
Carcharodontosaurinae
  Carcharodontosaurus spp.
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Giganotosaurini
  Meraxes
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Tyrannotitan

 
 
  Giganotosaurus
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  Mapusaurus
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In his 2024 review of theropod relationships, Andrea Cau recovered Lajasvenator as a carcharodontosaurid as the sister taxon to the clade formed by Labocania and Shaochilong.[3]

Carcharodontosauridae
  Neovenator
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Sauroniops

 
 

Veterupristisaurus

 
 

Lusovenator

 
  Eocarcharia (type skull roof)
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Concavenator 75px

 
 
 
 

Carcharodontosaurus iguidensis (holotype maxilla)

 
 
  Acrocanthosaurus
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Eocarcharia (referred maxilla)

 
 
 
 
  Meraxes
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Carcharodontosaurus iguidensis (referred cranial material)

 
 
 
 

Lajasvenator

 
 
 

Labocania

 
  Shaochilong
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  Carcharodontosaurus saharicus (neotype)
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Carcharodontosaurus saharicus (described by Stromer in 1931)

 
 
 
 

Tyrannotitan

 
 
  Mapusaurus
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  Giganotosaurus
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References

  1. ↑ 1.0 1.1 1.2 Coria, Rodolfo A.; Currie, Philip J.; Ortega, Francisco; Baiano, Mattia A. (2020-07-01). "An Early Cretaceous, medium-sized carcharodontosaurid theropod (Dinosauria, Saurischia) from the Mulichinco Formation (upper Valanginian), Neuquén Province, Patagonia, Argentina" (in en). Cretaceous Research 111. doi:10.1016/j.cretres.2019.104319. ISSN 0195-6671. Bibcode: 2020CrRes.11104319C. 
  2. ↑ Canale, Juan I.; Apesteguía, Sebastián; Gallina, Pablo A.; Mitchell, Jonathan; Smith, Nathan D.; Cullen, Thomas M.; Shinya, Akiko; Haluza, Alejandro et al. (July 2022). "New giant carnivorous dinosaur reveals convergent evolutionary trends in theropod arm reduction" (in en). Current Biology 32 (14): 3195–3202.e5. doi:10.1016/j.cub.2022.05.057. PMID 35803271. 
  3. ↑ 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. https://www.paleoitalia.it/wp-content/uploads/2024/05/01_Cau_2024_BSPI_631.pdf. 

Wikidata ☰ Q76508453 entry