Tratayenia
| Tratayenia | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Order: | Saurischia |
| Suborder: | Theropoda |
| Clade: | †Megaraptora |
| Family: | †Megaraptoridae |
| Genus: | †Tratayenia |
| Type species | |
| †Tratayenia rosalesi Porfiri et al., 2018 | |
Tratayenia is an extinct genus of megaraptoran theropod dinosaur known from remains found in the Bajo de la Carpa Formation in Argentina. The type and only species, Tratayenia rosalesi, was described in March 2018.[1]
The holotype consists of a well-preserved, mostly articulated series of dorsal and sacral vertebrae, two partial dorsal ribs, much of the right ilium, and pubis and ischium fragments.
Discovery and naming
In 2018, some Santonian-aged fossil bones found in the Bajo de la Carpa Formation in Argentina were given the name Tratayenia.
Description
Tratayenia was a medium-sized megaraptoran, growing up to 8 metres (26 ft) long. It was closely related to genera such as Megaraptor, Australovenator, and Murusraptor. Like most other megaraptorans, Tratayenia probably had large claws on its hands for use in hunting prey. Analysis of the Baja de la Carpa indicates that Tratayenia may have been geologically the youngest megaraptoran yet discovered. Tratayenia is also the largest-bodied carnivorous animal named from the Bajo de la Carpa Formation, reinforcing the hypothesis that megaraptorids were apex predators in southern South America from the Turonian through the Santonian or early Campanian, following the extinction of carcharodontosaurids.[2][1]
Classification
Megaraptorans have very controversial relations to other theropods. The first mainstream hypothesis is that they are carnosaurs, distantly related to Allosaurus and more closely related to Neovenator and carcharodontosaurids. The second popular hypothesis considers them to be basal tyrannosauroids, part of the coelurosaur lineage which includes the crested proceratosaurids as well as the famous tyrannosaurids such as Tyrannosaurus.[3] A third hypothesis also considers them to be coelurosaurs, but outside Tyrannosauroidea and basal to practically all other groups of Coelurosauria. Porfiri et al.'s description of Tratayenia prefers this third hypothesis.[1]
The cladogram below follows the strict consensus (average result) of the 12 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.[1] 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.[3]
| Avetheropoda |
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Paleoecology
Tratayenia lived in the Bajo de la Carpa Formation alongside many lizards and turtles, the snake species Dinilysia patagonica, many birds such as Patagopteryx deferrariisi, a diverse amount of crocodylomorphs and many dinosaurs such as Viavenator exxoni and Traukutitan eocaudata.
References
- 1 2 3 4 Porfiri, Juan D; Juárez Valieri, Rubén D; Santos, Domenica D.D; Lamanna, Matthew C (2018). "A new megaraptoran theropod dinosaur from the Upper Cretaceous Bajo de la Carpa Formation of northwestern Patagonia". Cretaceous Research. doi:10.1016/j.cretres.2018.03.014.
- ↑ https://www.paleowire.com/just-out-a-new-megaraptoran-theropod-dinosaur-from-the-upper-cretaceous-bajo-de-la-carpa-formation-of-northwestern-patagonia-cretaceous-research/%5Bfull+citation+needed%5D
- 1 2 Apesteguía, Sebastián; Smith, Nathan D.; Juárez Valieri, Rubén; Makovicky, Peter J. (2016-07-13). "An Unusual New Theropod with a Didactyl Manus from the Upper Cretaceous of Patagonia, Argentina". PLoS ONE. 11 (7): e0157793. doi:10.1371/journal.pone.0157793. PMC 4943716. PMID 27410683.
