Sauroniops

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Sauroniops
Temporal range: Lower
Ma
Holotype specimen, a left frontal bone
(MPM 2594)
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Family: Carcharodontosauridae
Genus: Sauroniops
Cau et al., 2012[1]
Type species
Sauroniops pachytholus
Cau et al., 2012[1]
Synonyms[2]
  • Osteoporosia gigantea? Singer, 2015

Sauroniops is a controversial

Kem Kem Formation,[2] both of Morocco.[1] The type, and currently only, species is S. platytholus.[6]

Discovery

Diagram of the holotype

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.[6]

The same year, 2012, the specimen was, by the same authors, formally named in a subsequent publication as the

Classical Greek ὄψ, ops, "eye". Like in the novels the corporeal presence of Sauron 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.[1]

The holotype, specimen MPM 2594, had probably been recovered from the Gara Sbaa Formation, (originally reported as the Ifezouane Formation, but it is not fossiliferous)[7] Kem Kem Group, dating to the Lower Cenomanian. It consists of a left frontal bone.[1]

A 2019 theropod faunal list considered Osteoporosia gigantea, from the

Kem Kem Formation,[8] to be a synonym of Sauroniops pachytholus.[2] Its holotype is JP Cr340, a tooth, and an indeterminate posterior or dorsal neural arch is also assigned to O. gigantea.[8]

A later study in 2020 suggested that Sauroniops was a junior synonym of Carcharodontosaurus saharicus,[3] though this statement has been criticized by Cau (2020).[4]

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.[5]

Description

Location of the holotype in the skull

Sauroniops was a large bipedal predator. The describers established several unique traits, differentiating Sauroniops from its relatives, such as Carcharodontosaurus 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 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. 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.[1]

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 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.[1]

The

sister species of Eocarcharia. The similarities to the abelisaurids would then be convergences.[1]

Classification

The majority of studies recover Sauroniops as a Carcharodontosaurid closely related to Eocarcharia.[1][9]

Cau (2024) found Sauroniops to form a clade with Eocarcharia as well as Veterupristisaurus, Lusovenator, and Concavenator.[9]

Carcharodontosauridae
Neovenator

Carcharodontosaurus iguidensis
(holotype maxilla)

Acrocanthosaurus

Eocarcharia (referred maxilla)

Meraxes

Carcharodontosaurus iguidensis (referred cranial material)

Carcharodontosaurus saharicus (neotype)

Carcharodontosaurus saharicus (described by Stromer in 1931)

See also

References

  1. ^ .
  2. ^ .
  3. ^ .
  4. ^ a b Cau, Andrea (15 October 2020). "Sauroniops non è Carcharodontosaurus". Theropoda.
  5. ^
    S2CID 252856791
    .
  6. ^ .
  7. .
  8. ^ a b Singer (2015). JURAPARK NA TROPIE NOWYCH DINOZAURÓW Z MAROKA (Online).
  9. ^
    ISSN 0375-7633
    .