''Sauroniops'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

of carnivorous basal

carcharodontosaurid Carcharodontosauridae (carcharodontosaurids; from the Greek καρχαροδοντόσαυρος, ''carcharodontósauros'': "shark-toothed lizards") is a group of carnivorous theropod dinosaurs. In 1931, Ernst Stromer named Carcharodontosaurida ...

theropod Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally ...

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 ...

known from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

( Cenomanian stage) of

Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria ...

Discovery

In the early twenty-first century a collector donated a dinosaur skull bone to the Italian Museo Paleontologico di Montevarchi. He had acquired the specimen from a Moroccan fossil dealer, who again had bought the piece from local fossil hunters near Taouz. Its exact provenance is therefore uncertain. Later research showed that it presented a new species that was in 2012 reported and described by Andrea Cau, Fabio Marco Dalla Vecchia and Matteo Fabbri. The same year, 2012, the specimen was, by the same authors, formally named in a subsequent publication as 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 specimen( ...

''Sauroniops pachytholus''. The generic name has the intended meaning of "

Eye of Sauron Sauron (pronounced ) is the title character and the primary antagonist, through the forging of the One Ring, of J. R. R. Tolkien's ''The Lord of the Rings'', where he rules the land of Mordor and has the ambition of ruling the whole of Midd ...

", a powerful entity from ''

The Lord of the Rings ''The Lord of the Rings'' is an Epic (genre), epic high-fantasy novel by English author and scholar J. R. R. Tolkien. Set in Middle-earth, intended to be Earth at some time in the distant past, the story began as a sequel to Tolkien's 1937 c ...

fantasy Fantasy is a genre of speculative fiction involving magical elements, typically set in a fictional universe and sometimes inspired by mythology and folklore. Its roots are in oral traditions, which then became fantasy literature and drama ...

novel by

J.R.R. Tolkien John Ronald Reuel Tolkien (, ; 3 January 1892 – 2 September 1973) was an English writer and philologist. He was the author of the high fantasy works '' The Hobbit'' and '' The Lord of the Rings''. From 1925 to 1945, Tolkien was the Ra ...

, combining his name with a

Classical Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...

ὄψ, ''ops'', "eye". Like in the novels the corporeal presence of

Sauron Sauron (pronounced ) is the title character and the primary antagonist, through the forging of the One Ring, of J. R. R. Tolkien's ''The Lord of the Rings'', where he rules the land of Mordor and has the ambition of ruling the whole of Middl ...

had largely been limited to a single searching eye, ''Sauroniops'' is only known from a single bone above the eye socket. The specific name is derived from Greek παχύς, ''pachys'', "thick", and θόλος, ''tholos'', "round building with conical roof", in reference to the thick vaulted skull roof. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of seve ...

, specimen MPM 2594, had probably been recovered from the

Kem Kem Group The Kem Kem Group (commonly known as the Kem Kem beds) is a geological group in the Kem Kem region of eastern Morocco, whose strata date back to the Cenomanian stage of the Late Cretaceous. Its strata are subdivided into two geological formations ...

, dating to the Cenomanian. It consists of a left

frontal Front may refer to: Arts, entertainment, and media Films * ''The Front'' (1943 film), a 1943 Soviet drama film * ''The Front'', 1976 film Music *The Front (band), an American rock band signed to Columbia Records and active in the 1980s and ea ...

bone. A later study in 2020 suggested that ''Sauroniops'' was a junior synonym of '' Carcharodontosaurus saharicus,'' though this statement has been criticized by Cau. A 2022 study published by Paterna and Cau reevaluated the reasoning of the 2020 study for considering ''Sauroniops'' a synonym of ''Carcharodontosaurus'', and found most of the supposed shared features were based on misinterpretations of the ''Sauroniops'' holotype. Accordingly, having also found several additional features distinguishing the two taxa, they dismissed the synonymy between ''Carcharodontosaurus'' and ''Sauroniops''.

Description

''Sauroniops'' was a large bipedal predator. The describers established several unique traits, differentiating ''Sauroniops'' from its relatives, such as ''

Carcharodontosaurus ''Carcharodontosaurus'' (; ) is a genus of large carcharodontosaurid theropod dinosaur that existed during the Cenomanian age of the Late Cretaceous in Northern Africa. The genus ''Carcharodontosaurus'' is named after the shark genus '' Car ...

'' which is found in the same layers. The nasal bone has an area of contact with the frontal bone over 40% of the latter's length. The frontal has in the left front corner a thick vaulted area. On the front upper rim the frontal has a trapezoid facet to contact the prefrontal, which is no part of the upper rim of the eye socket, and is separated from the facet for the

lacrimal bone The lacrimal bone is a small and fragile bone of the facial skeleton; it is roughly the size of the little fingernail. It is situated at the front part of the medial wall of the orbit. It has two surfaces and four borders. Several bony landmarks of ...

by a thin vertical ridge. The contact area with the lacrimal is D-shaped, extremely large and has four times the height of the facet with the

postorbital bone The ''postorbital'' is one of the bones in vertebrate skulls which forms a portion of the dermal skull roof and, sometimes, a ring about the orbit. Generally, it is located behind the postfrontal and posteriorly to the orbital fenestra. In some v ...

. On the rear inner side of the frontal an elevated rim is present that is joint to the front vaulted area by a saddle-shaped depression and more towards the front midline of the skull continues in a series of rugosities. The frontal has a preserved length of 186 millimetres. Near the contact with the lacrimal the bone is extremely thickened to a height of seventy-three millimetres and vaulted; a second thick area is present at the rear separated from the first by a hollow surface. Such a thickening of the skull roof is more typical of 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 ...

in which group however, it is the postorbital that shows the phenomenon. The authors explained the thickening as an adaptation for display or to strengthen the skull for intraspecific head-butting. The

of ''Sauroniops'' was originally interpreted as belonging to a derived member of the

Carcharodontosauridae Carcharodontosauridae (carcharodontosaurids; from the Greek καρχαροδοντόσαυρος, ''carcharodontósauros'': "shark-toothed lizards") is a group of carnivorous theropod dinosaurs. In 1931, Ernst Stromer named Carcharodontosaurida ...

. A more extensive

cladistic Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived ch ...

analysis in the naming paper showed a more basal position in the same group as a

sister species In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

of ''

Eocarcharia ''Eocarcharia'' (meaning "dawn shark") is a genus of carcharodontosaurid theropod dinosaur from the Early Cretaceous Elrhaz Formation that lived in the Sahara 112 million years ago, in what today is the country of Niger. It was discovered in 20 ...

''. The similarities to the abelisaurids would then be convergences.

References

{{Taxonbar, from=Q115197 Carcharodontosaurids Late Cretaceous dinosaurs of Africa Cenomanian life Cretaceous Morocco Fossils of Morocco Fossil taxa described in 2012 Organisms named after Tolkien and his works

Discovery

Description

See also

References