''Thanos'' (named for the Marvel Comics character) is a genus of carnivorous brachyrostran

abelisaurid Abelisauridae (meaning "Abel's lizards") is a family (or clade) of ceratosaurian theropod dinosaurs. Abelisaurids thrived during the Cretaceous period, on the ancient southern supercontinent of Gondwana, and today their fossil remains are foun ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

that lived in

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

during the

Santonian The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya (million years ago) and 83.6 ± 0.7 mya. ...

stage of the late

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

Period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

. It contains only a single species known as ''T. simonattoi''.

Discovery and naming

In 2014, it was reported in the scientific literature that Sérgio Luis Simonatto with a team of the ''Museu de Paleontologia "Prof. Antonio Celso de Arruda Campos"'' had found the front of a theropod axis near

São José do Rio Preto São José do Rio Preto () is a municipality in the state of São Paulo, Brazil. The city is located at the northwest portion of the state, 440 km (273 mi) from the city of São Paulo and 700 km (435 mi) from Brasília. As o ...

. Several years later Fabiano Vidoi Iori uncovered the rear part of the same vertebra. In 2018, the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specime ...

''Thanos simonattoi'' was named and described by Rafael Delcourt and Fabiano Vidoi Iori in an advance online publication in the journal ''

Historical Biology ''Historical Biology'' is a peer-reviewed scientific journal of paleobiology. It was established in 1988, and is published by Taylor & Francis. The journal is edited by Gareth J. Dyke (National Oceanography Centre). Abstracting & Indexing Th ...

''. The paper was later published in print in 2020, making it the official year of description. The generic name refers to the

Marvel Comics Marvel Comics is an American comic book publishing, publisher and the flagship property of Marvel Entertainment, a divsion of The Walt Disney Company since September 1, 2009. Evolving from Timely Comics in 1939, ''Magazine Management/Atlas Co ...

character

Thanos Thanos is a supervillain appearing in American comic books published by Marvel Comics. He was created by writer-artist Jim Starlin, and first appeared in '' The Invincible Iron Man'' #55 ( cover date February 1973). An Eternal– Deviant w ...

, invented by

Jim Starlin James P. Starlin (born October 9, 1949) is an American comics artist and writer. Beginning his career in the early 1970s, he is best known for space opera stories, for revamping the Marvel Comics characters Captain Marvel and Adam Warlock, an ...

; Thanos was the main antagonist of '' Avengers: Infinity War'', a high-grossing film released in 2018. The character's name is itself derived from the Greek θάνατος, ''thanatos'', "death". The specific name honours Simonatto. The holotype specimen, MPMA 08–0016/95, was found in the

São José do Rio Preto Formation SAO or Sao may refer to: Places * Sao civilisation, in Middle Africa from 6th century BC to 16th century AD * Sao, a town in Boussé Department, Burkina Faso * Saco Transportation Center (station code SAO), a train station in Saco, Maine, U. ...

, part of the

Bauru Group The Bauru Group is a geological group of the Bauru Sub-basin, Paraná Basin in Minas Gerais, São Paulo, General Salgado, Itapecuru-Mirim, Mato Grosso, Brazil whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils ...

and dating from the

; in 2014 it had been dated to the

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval ...

. It consists of an almost complete

axis An axis (plural ''axes'') is an imaginary line around which an object rotates or is symmetrical. Axis may also refer to: Mathematics * Axis of rotation: see rotation around a fixed axis * Axis (mathematics), a designator for a Cartesian-coordinat ...

fused with an axial intercentrum. It is missing several processes at the front, rear, and sides. The specimen is currently housed at the Museu de Paleontologia de Monte Alto, Brazil.

Description

The length of ''Thanos'' has been estimated at . Despite the incompleteness of the material, a number of diagnostic features are present; a well-developed keel becoming wider and deeper posteriorly on the ventral surface; two lateral small foramina separated by a relatively wide wall on each lateral surface of the centrum; and well-developed and deep prezygapophyseal spinodiapophyseal fossae. In view of these features, ''Thanos'' may have been more derived than other abelisaurids at the time.

Phylogeny

In their

phylogenetic analysis In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

, Delcourt and Iori (2020) recovered ''Thanos'' in a large

polytomy An internal node of a phylogenetic tree is described as a polytomy or multifurcation if (i) it is in a rooted tree and is linked to three or more child subtrees or (ii) it is in an unrooted tree and is attached to four or more branches. A tr ...

with other brachyrostrans within the

Abelisauridae Abelisauridae (meaning "Abel's lizards") is a family (or clade) of ceratosaurian theropod dinosaurs. Abelisaurids thrived during the Cretaceous period, on the ancient southern supercontinent of Gondwana, and today their fossil remains are fou ...

. Their resulting cladogram is shown below: ''Thanos'' shared only two synapomorphies with the Brachyrostra. The front articular facet of the axis is more than twice as high as the rear articular facet. The rear facet is inclined to the front under an angle of less than 75°.

Paleoecology

''Thanos'' shared its environment with an undescribed larger theropod believed to be a

megaraptoran Megaraptora is a clade of carnivorous tetanuran theropod dinosaurs with controversial relations to other theropods. Its derived members, the Megaraptoridae are noted for their elongated hand claws and proportionally large arms, which are usually ...

of which a vertebra, specimen MPMA 08–0003/94, has been found at

Ibirá Ibirá is a municipality in the state of São Paulo, Brazil. The population is 12,518 (2020 est.) in an area of 190 km². Ibirá is known as a tourist resort, due to the thermal waters. Neighboring municipalities * Potirendaba *Cedral *Uchoa *Cata ...

. This would imply that ''Thanos'' was not the

apex predator An apex predator, also known as a top predator, is a predator at the top of a food chain, without natural predators of its own. Apex predators are usually defined in terms of trophic dynamics, meaning that they occupy the highest trophic lev ...

of its

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

. It also coexisted with a dwarf saltasaurine sauropod '' Ibirania'' and an indeterminate

notosuchia Notosuchia is a suborder of primarily Gondwanan mesoeucrocodylian crocodylomorphs that lived during the Jurassic and Cretaceous. Some phylogenies recover Sebecosuchia as a clade within Notosuchia, others as a sister group (see below); if Sebecosu ...

References

{{Taxonbar, from=Q58809590 Brachyrostrans Late Cretaceous dinosaurs of South America Santonian life Cretaceous Brazil Fossils of Brazil Paraná Basin Fossil taxa described in 2020

Discovery and naming

Description

Phylogeny

Paleoecology

See also

References