Genyodectes
Jaw bite; from Greek genys (jaw) and dektes (bite)
Genyodectes is a genus of ceratosaurian theropod dinosaur from the Lower Cretaceous (Aptian-Albian) of South America. The holotype material (MLP 26-39, Museo de La Plata, La Plata, Argentina) was collected from the Cerro Barcino Formation, Cañadón Grande, Departamento Paso de Indios in the Chubut Province of Argentina and consists of an incomplete snout, including the premaxillae, portions of both maxillae, the right and left dentary, many teeth, a fragment of the left splenial, and parts of the supradentaries. These elements are generally poorly preserved and some are in articulation. The premaxilla of Genyodectes possesses relatively large and protruding teeth, similar to those of Ceratosaurus. The specific name, serus, means "late". In 2016 it was estimated to be 6.25 meters (20.5 ft) in length and 790 kg (1,740 lb) in weight.
Diagnosis
- Premaxillary teeth closely spaced and arranged in an overlapping en-echelon pattern (shared, if at all, only with Ceratosaurus).
- Longest maxillary tooth crowns exceeding the minimal dorsoventral depth of the mandible in apicobasal length (shared, if at all, only with Ceratosaurus).
- Four premaxillary teeth, versus three in Ceratosaurus.
Species
Genyodectes serus Woodward, 1901
Type species
From Latin 'serus' meaning 'late', likely in reference to the Cretaceous age of the specimen relative to other ceratosaurian theropods.
- Holotype
- MLP 26-39 , Museo de La Plata
- Material
- Partial snout including both nearly complete premaxillae, fragments of both maxillae, both dentaries (all with teeth), parts of both supradentaries, and fragments of the left splenial.
- Horizon
- Cerro Barcino Formation, Aptian–Albian, Early Cretaceous , 121.4–100.5 million years ago
- Locality
- Cañadón Grande, Chubut, Argentina Rauhut (2004) narrows the horizon no further than the Cerro Barcino Formation, calling the Cerro Castaño Member the most likely candidate rather than a stated fact. Huene's account placing the site on the Rio Chubut near Gaiman is rejected there, no Mesozoic sediments cropping out within some 50 km of that town.
References
- Woodward, A. S. (1901). On some Extinct Reptiles from Patagonia, of the Genera Miolania, Dinilysia, and Genyodectes. Proceedings of the Zoological Society of London 70(2): 169-184. Wiley. doi:10.1111/j.1469-7998.1901.tb08537.x woodward1901a
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Rauhut, O. W. M. (2004). Provenance and anatomy of Genyodectes serus, a large-toothed ceratosaur (Dinosauria: Theropoda) from Patagonia. Journal of Vertebrate Paleontology 24(4): 894-902. Informa UK Limited. doi:10.1671/0272-4634(2004)024[0894:PAAOGS]2.0.CO;2
Redescription of the reprepared holotype MLP 26-39; gives the first formal diagnosis, argues ceratosaurid affinities, and assesses the provenance as Aptian-Albian, Cerro Barcino Formation.
rauhut2004a