Sauroniops

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Sauroniops
Temporal range: Lower Cenomanian, 100  Ma
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Sauroniops holotype.png
Holotype specimen, a left frontal bone (MPM 2594)
Scientific classification OOjs UI icon edit-ltr.svg
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 [3] [4] [5] genus of carnivorous basal carcharodontosaurid theropod dinosaur known from the Late Cretaceous (Cenomanian stage) Gara Sbaa Formation, and possibly also the Kem Kem Formation, [2] both of Morocco. [1] The type, and currently only, species is S. platytholus. [6]

Contents

Discovery

Diagram of the holotype Sauroniops diagram.jpg
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 type species Sauroniops pachytholus. The generic name has the intended meaning of "Eye of Sauron", a powerful entity from The Lord of the Rings fantasy novel by J.R.R. Tolkien, combining his name with a 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 MPM2594.svg
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 holotype of Sauroniops was originally interpreted as belonging to a derived member of the Carcharodontosauridae. A more extensive cladistic analysis in the naming paper showed a more basal position in the same group as a 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
Neovenator.png

Carcharodontosaurus iguidensis (holotype maxilla)

Acrocanthosaurus
Acrocanthosaurus restoration.jpg

Eocarcharia (referred maxilla)

Meraxes
Meraxes gigas life restoration updated.png

Carcharodontosaurus iguidensis(referred cranial material)

Carcharodontosaurus saharicus (neotype)
Carcharodontosaurus.png

Carcharodontosaurus saharicus(described by Stromer in 1931)

See also

Related Research Articles

<i>Spinosaurus</i> Genus of spinosaurid dinosaur

Spinosaurus is a genus of spinosaurid dinosaur that lived in what now is North Africa during the Cenomanian stage of the Late Cretaceous period, about 100 to 94 million years ago. The genus was known first from Egyptian remains discovered in 1912 and described by German palaeontologist Ernst Stromer in 1915. The original remains were destroyed in World War II, but additional material came to light in the early 21st century. It is unclear whether one or two species are represented in the fossils reported in the scientific literature. The type species is S. aegyptiacus from Egypt and Morocco. Although a potential second dubious species, S. maroccanus, has been recovered from Morocco, this dubious species is likely a junior synonym of S. aegyptiacus. Other possible junior synonyms include Sigilmassasaurus from the Kem Kem beds in Morocco and Oxalaia from the Alcântara Formation in Brazil, though other researchers propose both genera to be distinct taxa.

<i>Giganotosaurus</i> Carcharodontosaurid dinosaur genus from the late Cretaceous period

Giganotosaurus is a genus of theropod dinosaur that lived in what is now Argentina, during the early Cenomanian age of the Late Cretaceous period, approximately 99.6 to 95 million years ago. The holotype specimen was discovered in the Candeleros Formation of Patagonia in 1993 and is almost 70% complete. The animal was named Giganotosaurus carolinii in 1995; the genus name translates to "giant southern lizard", and the specific name honors the discoverer, Ruben Carolini. A dentary bone, a tooth, and some tracks, discovered before the holotype, were later assigned to this animal. The genus attracted much interest and became part of a scientific debate about the maximum sizes of theropod dinosaurs.

<i>Acrocanthosaurus</i> Genus of carcharodontosaurid dinosaur from the Early Cretaceous

Acrocanthosaurus is a genus of carcharodontosaurid dinosaur that existed in what is now North America during the Aptian and early Albian stages of the Early Cretaceous, from 113 to 110 million years ago. Like most dinosaur genera, Acrocanthosaurus contains only a single species, A. atokensis. It had a continent-wide range, with fossil remains known from the U.S. states of Oklahoma, Texas, and Wyoming in the west, and Maryland in the east.

<i>Carcharodontosaurus</i> Genus of carcharodontosaurid dinosaur from the Cretaceous period

Carcharodontosaurus is a genus of carnivorous theropod dinosaur that lived in North Africa from about 100 to 94 million years ago during the Cenomanian age of the Late Cretaceous. Two teeth of the genus, now lost, were first described from Algeria by French paleontologists Charles Depéret and Justin Savornin as Megalosaurus saharicus. A partial skeleton was collected by crews of German paleontologist Ernst Stromer during a 1914 expedition to Egypt. Stromer did not report the Egyptian find until 1931, in which he dubbed the novel genus Carcharodontosaurus, making the type species C. saharicus. Unfortunately, this skeleton was destroyed during the Second World War. In 1995 a nearly complete skull of C. saharicus, the first well-preserved specimen to be found in almost a century, was discovered in the Kem Kem Beds of Morocco; it was designated the neotype in 1996. Fossils unearthed from the Echkar Formation of northern Niger were described and named as another species, C. iguidensis, in 2007.

<span class="mw-page-title-main">Carcharodontosauridae</span> Extinct family of dinosaurs

Carcharodontosauridae is a group of carnivorous theropod dinosaurs. In 1931, Ernst Stromer named Carcharodontosauridae as a family, which, in modern paleontology, indicates a clade within Carnosauria. Carcharodontosaurids include some of the largest land predators ever known: Giganotosaurus, Mapusaurus, Carcharodontosaurus, and Tyrannotitan all rivaled Tyrannosaurus in size. Estimates give a maximum weight of 8–10 metric tons for the largest carcharodontosaurids, while the smallest carcharodontosaurids were estimated to have weighed at least 500 kilograms (1,100 lb).

<i>Rugops</i> Genus of dinosaur

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 (14–17 ft) and weight of 410 kilograms (900 lb). 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.

<i>Bahariasaurus</i> Extinct genus of dinosaurs

Bahariasaurus is an enigmatic genus of large theropod dinosaur. The genus is known to have included at least 1 species, Bahariasaurus ingens, which was found in North African rock layers dating to the Cenomanian and Turonian ages of the Late Cretaceous. The only fossils confidently assigned to Bahariasaurus were found in the Bahariya Formation of the Bahariya oasis in Egypt by Ernst Stromer but were destroyed during a World War II bombing raid with the same raid taking out the holotype of Spinosaurus and Aegyptosaurus among other animals found in the Bahariya Formation. While there have been more fossils assigned to the genus such as some from the Farak Formation of Niger, these remains are referred to with much less certainty. Bahariasaurus is, by most estimations, one of the largest theropods, approaching the height and length of other large bodied theropods such as Tyrannosaurus rex and the contemporaneous Carcharodontosaurus. The aforementioned estimations tend to put it at around 11–12.2 metres in length and 4-4.8 tonnes in overall weight.

<i>Deltadromeus</i> Theropod dinosaur genus from mid-Cretaceous Period

Deltadromeus is a genus of theropod dinosaur from the Aoufous Formation of Morocco.

<i>Labocania</i> Extinct genus of dinosaurs

Labocania is a genus of carnivorous theropod dinosaur of disputed affinities from the Late Cretaceous of Mexico. Initially regarded as an indeterminate theropod, later studies mentioned possible affinities with tyrannosaurids, abelisaurids, or carcharodontosaurids. More recent research based on additional fossil material found support for a position within the tyrannosaurine clade Teratophoneini. Two species have been proposed: L. anomala, likely from the La Bocana Roja Formation, and L. aguillonae from the Cerro del Pueblo Formation.

<i>Rebbachisaurus</i> Extinct genus of dinosaurs

Rebbachisaurus is a genus of sauropod dinosaur of the superfamily Diplodocoidea, that lived during the Late Cretaceous period in Africa and possibly also South America about 99-97 million years ago. Remains attributed to Rebbachisaurus have been found in Morocco, Niger, Algeria, Tunisia and possibly also Argentina, although only the Moroccan remains can be referred to the genus without doubt. The discovery of Rayososaurus, a South American sauropod nearly identical to Rebbachisaurus which may have actually have been the same animal as Rebbachisaurus, supports the theory that there was still a land connection between Africa and South America during the Early Cretaceous, long after it was commonly thought the two continents had separated.

<i>Sigilmassasaurus</i> Spinosaurid theropod dinosaur genus from Cretaceous Period

Sigilmassasaurus is a controversial genus of spinosaurid dinosaur that lived approximately 100 to 94 million years ago during the Late Cretaceous Period in what is now northern Africa. Named in 1996 by Canadian paleontologist Dale Russell, it contains a single species, Sigilmassasaurus brevicollis. The identity of the genus has been debated by scientists, with some considering its fossils to represent material from the closely related species Spinosaurus aegyptiacus, while others have classified it as a separate taxon, forming the clade Spinosaurini with Spinosaurus as its sister taxon.

<i>Eocarcharia</i> Extinct genus of reptiles

Eocarcharia 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 2000 on an expedition led by University of Chicago paleontologist Paul Sereno. The type and only species is Eocarcharia dinops. Its teeth were shaped like blades and were used for disabling live prey and ripping apart body parts. Eocarcharia’s brow is swollen into a massive band of bone, giving it a menacing glare. It may have reached lengths of 6–8 m (19.7–26.2 ft).

<span class="mw-page-title-main">Kem Kem Group</span> Geological group in eastern Morocco

The Kem Kem Group 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, with the lower Ifezouane Formation and the upper Aoufous Formation used for the strata on the eastern side of the Atlas Mountains (Tinghir), with the Gara Sbaa Formation and Douira Formation used in the southern Tafilalt region. It is exposed on an escarpment along the Algeria–Morocco border.

Bahariasauridae is a potential family of averostran theropods that might include a handful of African and South American genera, such as Aoniraptor, Bahariasaurus, Deltadromeus, and Gualicho. The placement of these theropods is controversial, with some studies placing them as basal ceratosaurs possibly related to Noasauridae, others classifying them as megaraptorans, basal neovenatorids, or basal coelurosaurs. There is also a possibility the group might not be monophyletic, as a monograph on the vertebrate diversity in the Kem Kem Beds published in 2020 found Bahariasaurus to be nomen dubium. In the same paper Deltadromeus is classified as an noasaurid, a result also recovered by some previous studies. A 2024 phylogenetic analysis found Aoniraptor, Bahariasaurus, Deltadromeus, and Gualicho to form a monophyletic clade as the sister taxon to Elaphrosaurus near the base of Ceratosauria.

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Oniichthys is an extinct genus of gar in the family Lepisosteidae. It contains a single species, O. falipoui, known from the Late Cretaceous (Cenomanian) of Morocco.

Afrocascudo is a controversial genus of extinct neopterygian fish, either an ancient loricariid catfish or a juvenile obaichthyid lepisosteiform of the genus Obaichthys. It is known from the Late Cretaceous Douira Formation of Morocco. The genus contains a single species, A. saharaensis, known from a partial articulated specimen.

References

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  2. 1 2 3 Molina-Pérez, Rubén; Larramendi, Asier; Connolly, David; Ramírez Cruz, Gonzalo Ángel; Mazzei, Sante; Atuchin, Andrey (25 June 2019). Dinosaur Facts and Figures: The Theropods and Other Dinosauriformes. Princeton University Press. doi:10.1515/9780691190594-013. ISBN   978-0-691-19059-4. S2CID   241124870.
  3. 1 2 Ibrahim, Nizar; Sereno, Paul C.; Varricchio, David J.; Martill, David M.; Dutheil, Didier B.; Unwin, David M.; Baidder, Lahssen; Larsson, Hans C. E.; Zouhri, Samir; Kaoukaya, Abdelhadi (21 April 2020). "Geology and paleontology of the Upper Cretaceous Kem Kem Group of eastern Morocco". ZooKeys (928): 1–216. doi: 10.3897/zookeys.928.47517 . ISSN   1313-2970. PMC   7188693 . PMID   32362741.
  4. 1 2 Cau, Andrea (15 October 2020). "Sauroniops non è Carcharodontosaurus". Theropoda.
  5. 1 2 Paterna A, Cau A (2022). "New giant theropod material from the Kem Kem Compound Assemblage (Morocco) with implications on the diversity of the mid-Cretaceous carcharodontosaurids from North Africa". Historical Biology: An International Journal of Paleobiology. 35 (11): 1–9. doi:10.1080/08912963.2022.2131406. S2CID   252856791.
  6. 1 2 Cau, Andrea; Dalla Vecchia, Fabio Marco; Fabbri, Matteo (2012). "Evidence of a New Carcharodontosaurid from the Upper Cretaceous of Morocco". Acta Palaeontologica Polonica. 57 (3): 661–665. doi: 10.4202/app.2011.0043 .
  7. Ibrahim, Nizar; Sereno, Paul C.; Varricchio, David J.; Martill, David M.; Dutheil, Didier B.; Unwin, David M.; Baidder, Lahssen; Larsson, Hans C. E.; Zouhri, Samir; Kaoukaya, Abdelhadi (21 April 2020). "Geology and paleontology of the Upper Cretaceous Kem Kem Group of eastern Morocco". ZooKeys (928): 1–216. doi: 10.3897/zookeys.928.47517 . ISSN   1313-2970. PMC   188693 . PMID   32362741.
  8. 1 2 Singer (2015). JURAPARK NA TROPIE NOWYCH DINOZAURÓW Z MAROKA (Online).
  9. 1 2 Cau, Andrea (2024). "A Unified Framework for Predatory Dinosaur Macroevolution". Bollettino della Società Paleontologica Italiana. 63 (1): 1–19. doi:10.4435/BSPI.2024.08 (inactive 20 November 2024). ISSN   0375-7633.{{cite journal}}: CS1 maint: DOI inactive as of November 2024 (link)