Genyodectes

*Genyodectes serus*

***Genyodectes*** is a genus of ceratosaurian theropod dinosaur from the Lower Cretaceous (Aptian) of South America. The holotype material (MLP 26-39, Museo de La Plata, La Plata, Argentina) was collected from the Cañadón Grande, Departamento Paso de Indios in the Chubut Province of Argentina and consists of an incomplete snout, including the premaxillae, portions of both maxillas, 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* (Greek genys = "jaw" and dektes = "biter") possesses relatively large and protruding teeth, similar to those of Ceratosaurus. and it is for this feature that the genus was named. The specific name, serus, means "late". In 2016 it was estimated to be 6.25 meters in length and 790 kg in weight. It is the second non-avian dinosaur described from the South American continent, and it remained the most completely known South American theropod until the 1970s.

## Taxonomy and phylogeny

The taxon has long been considered a *nomen dubium*, owing to its fragmentary nature and some doubt as to its precise geographic and stratigraphic origins (see Tykoski et Rowe, 2004, p. 50). Genyodectes name translates as "jaw bite". The taxon has long been considered a nomen dubium, owing to its fragmentary nature and some doubt as to its origins However, a recent redescription of the type material by Rauhut (2004) has shed some light on these questions and seems to establish the taxonomic validity of *Genyodectes serus*, the only species referred to the genus. English paleontologist Sir Arthur S. Woodward described *Genyodectes* in 1901, and, after *Loncosaurus* (Ameghino, 1899; *nomen dubium*), it is the second non-avian dinosaur described from the South American continent, and it remained the most completely known South American theropod until the 1970s. Over the last decade, the holotype has been variously referred to as a megalosaurid, a tyrannosaurid, Theropoda incertae sedis, and a possible abelisaurid (perhaps even a senior synonym of *Abelisaurus*). However, the recent removal of the holotype from the "artificial matrix" in which it had long been displayed has permitted a reevaluation of the specimen. Rauhut (2004, p. 900) concluded that the specimen lacks important abelisaurid and tyrannosaurid synapomorphies, but found many neoceratosaurian traits. This would seem to imply *Genyodectes* was closer to *Ceratosaurus* than the more derived abelisaurs (that also descended from animals like *Ceratosaurus*). Also, by studying historical records and preservation of the bones, Rauhut (2004, p. 894) concluded that the specimen was likely collected from the Cerro Castaño Member of the Cerro Barcino Formation (Aptian-Albian).

Restoration of Genyodectes hunting an early mammalKnown material of GenyodectesSize of Genyodectes compared to a human
## Diagnosis

Rauhut (2004, p. 895-896) diagnoses *Genyodectes serus* as follows: "Differs from all theropods with the possible exception of *Ceratosaurus* in that the premaxillary teeth are arranged in an overlapping en-echelon pattern and the longest maxillary tooth crowns are longer apicobasally than the minimal dorsoventral depth of the mandible. Differs from *Ceratosaurus* in the presence of four, as opposed to three, premaxillary teeth."

## Appearance in other media

### *Jurassic Park*

* Genyodectes appeared in the Jurassic World toys.

## References

* https://www.smithsonianmag.com/science-nature/what-is-genyodectes-144686459/
* https://www.researchgate.net/publication/235907356\_Provenance\_and\_anatomy\_of\_Genyodectes\_serus\_a\_large-toothed\_Ceratosaur\_Dinosauria\_Theropoda\_from\_Patagonia
* https://www.jstor.org/stable/4524783
* https://www.jstor.org/stable/20490962
* https://books.google.com.tr/books?id=dXYi6j7QQ-YC&pg=PA444&lpg=PA444&dq=Genyodectes&source=bl&ots=PdROuBiidC&sig=ACfU3U0C\_DdWkWiL-g9S-GfF1ckuGsWPQQ&hl=en&sa=X&ved=2ahUKEwi-2bCOsLv1AhWWQfEDHacPCGQQ6AF6BAgqEAM#v=onepage&q=Genyodectes&f=false
* https://www.mindat.org/taxon-4822608.html
* https://kidadl.com/dinosaur-facts/genyodectes-facts