Llukalkan Temporal range: Santonian, | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | Saurischia |
Clade: | Theropoda |
Family: | † Abelisauridae |
Clade: | † Furileusauria |
Genus: | † Llukalkan Gianechini et al., 2021 |
Type species | |
†Llukalkan aliocranianus Gianechini et al., 2021 |
Llukalkan (Mapuche for "one who causes fear") is a genus of abelisaurid theropod dinosaur from the Late Cretaceous Bajo de la Carpa Formation of Argentina. The type species is Llukalkan aliocranianus. [1]
The holotype of Llukalkan, MAU-Pv-LI-581, consisting of a partial skull, was discovered during 2015 in the La Invernada site in Neuquén Province, Argentina, in the rocks of the Bajo de la Carpa Formation. It was discovered only 700 metres (2,300 ft) away from the remains of the contemporary abelisaurid Viavenator . It was described as belonging to the new taxon Llukalkan aliocranianus in 2021; the generic name is Mapuche for "one who scares" or "one who causes fear", and the specific name is Latin for "different skull".
Llukalkan is very similar to Viavenator, except that it is smaller and the holes in the skull through which the veins pass are larger and more widely separated from the supraoccipital crest, among other differences. It also has a small posterior air-filled sinus in the middle ear zone, a recessus tympanicus caudalis, that has not been found in any other abelisaurids and thus is an autapomorphy. [2]
On account of its unusual ear, it has been theorized than Llukalkan had a keener sense of hearing than other abelisaurids, almost like a crocodile's. [2]
Gianechini et al. place Llukalkan as a derived abelisaurid, in the clade Furileusauria. Their cladogram is shown below. [1]
Abelisauridae |
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Abelisaurus is a genus of predatory abelisaurid theropod dinosaur alive during the Late Cretaceous Period (Campanian) of what is now South America. It was a bipedal carnivore that probably reached about 7.4 metres in length, although this is uncertain as it is known from only one partial skull.
Rugops is a monospecific genus of basal abelisaurid theropod dinosaur from Niger that lived during the Late Cretaceous period in what is now the Echkar Formation. The type and only species, Rugops primus, is known only from a partial skull. It was named and described in 2004 by Paul Sereno, Jeffery Wilson and Jack Conrad. Rugops has an estimated length of 4.4–5.3 metres and weight of 410 kilograms. The top of its skull bears several pits which correlates with overlaying scale and the front of the snout would have had an armour-like dermis.
Aucasaurus is a genus of medium-sized abelisaurid theropod dinosaur from Argentina that lived during the Late Cretaceous of the Anacleto Formation. It was smaller than the related Carnotaurus, although more derived in some ways, such as its extremely reduced arms and almost total lack of fingers. The type skeleton is complete to the thirteenth caudal vertebra, and so is relatively well understood, and is the most complete abelisaurid yet described. However, the skull is damaged, causing some paleontologists to speculate that it was involved in a fight prior to death.
Ilokelesia is an extinct genus of abelisaurid theropod, preserved in the layers of the earliest Late Cretaceous of the Huincul Formation, Neuquén Group, located near Plaza Huincul, Neuquén Province, Argentina. The specimen, consisting of very fragmentary elements of the skull and the axial and appendicular skeleton, was described by Rodolfo Coria and Leonardo Salgado in late 1998.
Ekrixinatosaurus is a genus of abelisaurid theropod which lived approximately 100 to 97 million years ago during the Late Cretaceous period. Its fossils have been found in Argentina. Only one species is currently recognized, Ekrixinatosaurus novasi, from which the specific name honors of Dr. Fernando Novas for his contributions to the study of abelisaurid theropods, while the genus name refers to the dynamiting of the holotype specimen. It was a large abelisaur, measuring between 6.5 and 8 m in length and weighing 800 kg (1,800 lb).
Epachthosaurus was a genus of titanosaurian sauropod dinosaur from the Late Cretaceous. It was a basal lithostrotian titanosaur. Its fossils have been found in Central and Northern Patagonia in South America.
Pycnonemosaurus is a genus of carnivorous theropod dinosaur that belonged to the family Abelisauridae. It was found in the Upper Cretaceous red conglomerate sandstones of the "Cabembe Unit", Mato Grosso, Brazil, and it lived about 70 million years ago during the Late Cretaceous.
The Bajo de la Carpa Formation is a geologic formation of the Neuquén Basin that crops out in northern Patagonia, in the provinces of Río Negro and Neuquén, Argentina. It is the oldest of two formations belonging to the Río Colorado Subgroup within the Neuquén Group. Formerly, that subgroup was treated as a formation, and the Bajo de la Carpa Formation was known as the Bajo de la Carpa Member.
The Anacleto Formation is a geologic formation with outcrops in the Argentine Patagonian provinces of Mendoza, Río Negro, and Neuquén. It is the youngest formation within the Neuquén Group and belongs to the Río Colorado Subgroup. Formerly that subgroup was treated as a formation, and the Anacleto Formation was known as the Anacleto Member.
Achillesaurus is a genus of alvarezsaurid theropod dinosaur from the Santonian-age Upper Cretaceous Bajo de la Carpa Formation of Rio Negro, Argentina. It was named in reference to Achilles' heel, because diagnostic features are found there for these animals. The genus was a relatively large, basal alvarezsaurid, and a contemporary of Alvarezsaurus. Achillesaurus is based on MACN-PV-RN 1116, a partial skeleton including a sacral vertebra, four tail vertebrae, part of the left thighbone, shin and foot, and the left ilium. Agustín Martinelli and Ezequiel Vera, who described the specimen, performed a phylogenetic analysis and found their new genus to be an alvarezsaurid with an unresolved relationship to Alvarezsaurus and more derived alvarezsaurids. Makovicky, Apesteguía & Gianechini (2012) argued that Achillesaurus might actually be a junior synonym of Alvarezsaurus which, according to the authors, "is known from the same formation and from which it [i.e. Achillesaurus] differs trivially."
Carnotaurinae is a subfamily of the theropod dinosaur family Abelisauridae. It includes the dinosaurs Aucasaurus, Carnotaurus. The group was first proposed by American paleontologist Paul Sereno in 1998, defined as a clade containing all abelisaurids more closely related to Carnotaurus than to Majungasaurus.
Wargosuchus is an extinct genus of baurusuchid mesoeucrocodylian from the Late Cretaceous of Argentina. It is known from a fragmentary skull from the Santonian-age Bajo de la Carpa Formation of the Neuquén Group, found in the vicinity of Neuquén, Neuquén Province, and was described by Agustín Martinelli and Diego Pais in 2008. The type species, and so far the only species, is Wargosuchus australis.
Austroraptor is a genus of dromaeosaurid theropod dinosaur that lived during the Campanian and Maastrichtian ages of the Late Cretaceous period in what is now Argentina.
Pissarrachampsinae is a subfamily of baurusuchid crocodyliforms from the Late Cretaceous of Brazil and Argentina. It was named in 2011 with the description of Pissarrachampsa sera and includes P. sera from Brazil and the related Wargosuchus australis from Argentina. Pissarrachampsinae is one of two subfamilies of Baurusuchidae, the other being Baurusuchinae.
Viavenator is a genus of carnivorous abelisaurid theropod dinosaur discovered in Argentina's Bajo de la Carpa Formation. It coexisted with the megaraptoran Tratayenia rosalesi.
Furileusauria is an extinct clade of derived abelisaurid dinosaurs only known from South American fossil remains. They represent some of the largest members of the Abelisauridae, with an average length of 7.1 ± 2.1 m (23.3 ± 6.9 ft). The clade is defined as the most inclusive clade containing Carnotaurus sastrei but not Ilokelesia aguadagrandensis, Skorpiovenator bustingorryi, or Majungasaurus crenatissimus.
Tratayenia is an extinct genus of megaraptoran theropod dinosaurs known from remains found in the Santonian-age Bajo de la Carpa Formation of Argentina. The type and only species, Tratayenia rosalesi, was described in March 2018.
Tralkasaurus is a genus of abelisaurid dinosaur from the Huincul Formation from Río Negro Province in Argentina. The type and only species is Tralkasaurus cuyi, named in 2020 by Mauricio Cerroni and colleagues based on an incomplete skeleton. A medium-sized abelisaurid, Tralkasaurus exhibits a conflicting blend of characteristics found among the early-diverging abelisauroids with others that characterize the highly specialized clade Brachyrostra, and thus its position within the clade is poorly-resolved.
Inawentu is an extinct genus of titanosaurian sauropod dinosaur from the Late Cretaceous Bajo de la Carpa Formation of Argentina. The genus contains a single species, I. oslatus, known from a partial articulated skeleton including the skull. The square-shaped jaw of Inawentu demonstrates convergent characteristics with rebbachisaurids.