Juratyrant

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Juratyrant
Temporal range: Tithonian
~149.3–149  Ma
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Juratyrant known elements skeletal.png
Restoration illustrating known fossil remains in white
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Superfamily: Tyrannosauroidea
Clade: Pantyrannosauria
Family: Stokesosauridae
Genus: Juratyrant
Brusatte & Benson, 2013
Type species
Juratyrant langhami
Benson, 2008
Synonyms

Juratyrant (meaning "Jurassic tyrant") is a tyrannosauroid dinosaur genus from the late Jurassic period (early Tithonian age) of England. The genus contains a single species, Juratyrant langhami, which was once classed as a species of Stokesosaurus .

Contents

Discovery

Restoration Juratyrant signed.jpg
Restoration

The species is known from a single specimen consisting of an "associated partial skeleton represented by a complete pelvis" as well as a partially complete leg and neck, back and tail vertebrae. [1] This skeleton was discovered in 1984 in Dorset. The specimen was mentioned in several papers, but was not formally described until 2008. The species was named in honor of commercial fossil collector [2] Peter Langham, who uncovered the specimen. The specimen was discovered in strata of the Kimmeridge Clay dating from the Tithonian, the final stage of the Late Jurassic, and belonging to the Pectinatites pectinatus ammonite zone, indicating the fossil is between 149.3 and 149 million years old. [1] [3]

Description

Paul (2010) listed it at 5 meters (16 ft) and 300 kg (660 lbs). [4] Another estimation gave a larger size of 6.7 meters (22 ft) and 760 kg (1,675 lbs). [5]

The holotype of Juratyrant is a partial skeleton composed of specimens OUMNH J.3311-1 through OUMNH J.3311-30. Its components include a cervical vertebra, five dorsal vertebrae, a complete sacrum, five caudal vertebrae, a complete pelvic girdle, both femurs, both tibiae, and various other fragments. Although initially considered a species of Stokesosaurus due to various traits of the ilium, subsequent review has shown that due to the limited amount of pelvic material for basal tyrannosauroids, these traits cannot be assumed to only be present in these two species and thus S. langhami must be placed in its own genera. Once separated from Stokesosaurus, Juratyrant can be characterized by four autapomorphies, as well as two assumed autapomorphies (which are difficult to assess due to preservation): [6]

Classification

Estimated size compared to a human Juratyrant size chart.png
Estimated size compared to a human

The species was originally assigned to the genus Stokesosaurus , as Stokesosaurus langhami, by Roger Benson in 2008. However, later studies showed that it was not necessarily a close relative of Stokesosaurus clevelandi, the type species of that genus. It was formally re-classified in its own genus, Juratyrant, by Benson and Stephen Brusatte in 2013 and placed as a sister taxon to Stokesosaurus clevelandi in a clade (also including Eotyrannus) of basal tyrannosauroids more advanced than Dilong. [6]

However, in 2013 Loewen et al. published a cladogram placing Juratyrant as a sister taxon to Stokesosaurus inside Proceratosauridae due to sharing with Sinotyrannus a narrow preacetabular notch. [7] Many basal tyrannosauroids have incomplete or unknown ilia and this trait may be more widespread than currently known. This cladogram is shown below.

Tyrannosauroidea
Proceratosauridae

Proceratosaurus bradleyi

Kileskus aristotocus

Guanlong wucaii

Sinotyrannus kazuoensis

Juratyrant langhami

Stokesosaurus clevelandi

Dilong paradoxus

Eotyrannus lengi

Bagaraatan ostromi

Raptorex kriegsteini

Dryptosaurus aquilunguis

Alectrosaurus olseni

Xiongguanlong baimoensis

Appalachiosaurus montgomeriensis

Alioramus altai

Alioramus remotus

Tyrannosauridae

However, a 2016 analysis by Brusatte and Carr utilizing both parsimonious and Bayesian phylogeny placed Stokesosaurus and Juratyrant as tyrannosauroids slightly more advanced than the Proceratosauridae and Dilong. In addition, Eotyrannus is recovered as a sister taxon of these genera in the parsimonious phylogeny. [8] The find of this animal in Europe puts in question to the purported Asian origin for these animals along with North American Stokesosaurus and European Aviatyrannis arguing for a more complex biogeography for tyrannosauroids.

See also

Related Research Articles

<i>Dilong paradoxus</i> Extinct species of dinosaur

Dilong is a genus of basal tyrannosauroid dinosaur. The only species in this genus is Dilong paradoxus. It is from the Lower Cretaceous Yixian Formation near Lujiatun, Beipiao, in the western Liaoning province of China. It lived about 126 million years ago. This theropod discovery was significant as it was one of the first tyrannosauroids with fossil evidence of simple feathers.

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

Iliosuchus is a genus of theropod dinosaur known from Bathonian–age rocks of England. It was perhaps 2 metres (6.6 ft) long.

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

Appalachiosaurus is a genus of basal eotyrannosaurian theropod dinosaur from the middle Campanian age of the Late Cretaceous period of what is now eastern North America. Like all theropods, it was a bipedal predator. Only a juvenile skeleton has been found, representing an animal approximately 6.5 metres (21 ft) long and weighing 623 kilograms (1,373 lb), which indicates an adult would have been significantly larger. It is the most completely known theropod from eastern North America.

<i>Cetiosaurus</i> Extinct species of reptile

Cetiosaurus meaning 'whale lizard', from the Greek keteios/κήτειος meaning 'sea monster' and sauros/σαυρος meaning 'lizard', is a genus of herbivorous sauropod dinosaur from the Middle Jurassic Period, living about 168 million years ago in what is now Britian.

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

Eotyrannus is a genus of tyrannosauroid theropod dinosaur hailing from the Early Cretaceous Wessex Formation beds, included in Wealden Group, located in the southwest coast of the Isle of Wight, United Kingdom. The remains (MIWG1997.550), consisting of assorted skull, axial skeleton and appendicular skeleton elements, from a juvenile or subadult, found in a plant debris clay bed, were described by Hutt et al. in early 2001. The etymology of the generic name refers to the animal's classification as an early tyrannosaur or "tyrant lizard", while the specific name honors the discoverer of the fossil.

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

Monolophosaurus is an extinct genus of tetanuran theropod dinosaur from the Middle Jurassic Shishugou Formation in what is now Xinjiang, China. It was named for the single crest on top of its skull. Monolophosaurus was a mid-sized theropod at about 5–5.5 metres (16–18 ft) long and weighed 475 kilograms (1,047 lb).

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

Stokesosaurus is a genus of small, carnivorous early tyrannosauroid theropod dinosaurs from the late Jurassic period of Utah, United States.

<span class="mw-page-title-main">Tyrannosauroidea</span> Extinct superfamily of dinosaurs

Tyrannosauroidea is a superfamily of coelurosaurian theropod dinosaurs that includes the family Tyrannosauridae as well as more basal relatives. Tyrannosauroids lived on the Laurasian supercontinent beginning in the Jurassic Period. By the end of the Cretaceous Period, tyrannosauroids were the dominant large predators in the Northern Hemisphere, culminating in the gigantic Tyrannosaurus. Fossils of tyrannosauroids have been recovered on what are now the continents of North America, Europe and Asia, with fragmentary remains possibly attributable to tyrannosaurs also known from South America and Australia.

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

Dryptosaurus is a genus of basal eotyrannosaurian theropod dinosaur that lived on the island continent of Appalachia approximately 67 million years ago during the end of the Maastrichtian age of the Late Cretaceous period. Dryptosaurus was a large, bipedal, ground-dwelling carnivore that could grow up to 7.5 metres (25 ft) long and weigh up to 1.5 metric tons. Although it is now largely unknown outside of academic circles, the famous 1897 painting of the genus by Charles R. Knight made Dryptosaurus one of the more widely known dinosaurs of its time, in spite of its poor fossil record. First described by Edward Drinker Cope in 1866 and later renamed by Othniel Charles Marsh in 1877, Dryptosaurus is among the very first theropod dinosaurs ever known to science.

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

Guanlong (冠龍) is a genus of extinct proceratosaurid tyrannosauroid dinosaur from the Late Jurassic of China. The taxon was first described in 2006 by Xu Xing et al., who found it to represent a new taxon related to Tyrannosaurus. The name is derived from Chinese, translating as "crown dragon". Two individuals are currently known, a partially complete adult and a nearly complete juvenile. These specimens come from the Oxfordian stage of the Chinese Shishugou Formation.

Chuandongocoelurus is a genus of carnivorous tetanuran theropod dinosaur from the Jurassic of China.

<span class="mw-page-title-main">Kimmeridge Clay</span> Geological formation

The Kimmeridge Clay is a sedimentary deposit of fossiliferous marine clay which is of Late Jurassic to lowermost Cretaceous age and occurs in southern and eastern England and in the North Sea. This rock formation is the major source rock for North Sea oil. The fossil fauna of the Kimmeridge Clay includes turtles, crocodiles, sauropods, plesiosaurs, pliosaurs and ichthyosaurs, as well as a number of invertebrate species.

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

Marshosaurus is a genus of medium-sized carnivorous theropod dinosaur, belonging to the Megalosauroidea, from the Late Jurassic Morrison Formation of Utah and possibly Colorado.

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

Pliosaurus is an extinct genus of thalassophonean pliosaurid known from the Kimmeridgian and Tithonian stages of Europe and South America. Their diet would have included fish, cephalopods, and marine reptiles. This genus has contained many species in the past but recent reviews found only six to be valid, while the validity of two additional species awaits a petition to the International Code of Zoological Nomenclature. Currently, P. brachyspondylus and P. macromerus are considered dubious, while P. portentificus is considered undiagnostic. Most species of Pliosaurus reached 8 metres (26 ft) in length and 5 metric tons in body mass, while P. rossicus and P. funkei may have reached or even exceeded 10 metres (33 ft) in length and 11 metric tons in body mass, being the largest plesiosaurs of all time. Species of this genus are differentiated from other pliosaurids based on seven autapomorphies, including teeth that are triangular in cross section.

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

Sinotyrannus is a genus of large basal tyrannosauroid dinosaur, known from a single incomplete fossil specimen including a partial skull, from the Early Cretaceous Jiufotang Formation of Liaoning, China. Specifically, it is a member of the Proceratosauridae, a family that originated in the Jurassic whose members are known from Europe and Asia. Though it is not much younger than primitive tyrannosauroids such as Dilong, it is similar in size to later forms such as Tyrannosaurus. It was much larger than contemporary tyrannosauroids, reaching a total estimated length of 9–10 m (30–33 ft), and was the largest known theropod from the Jiufotang Formation. The type species is S. kazuoensis, described by Ji et al., in 2009.

<span class="mw-page-title-main">Megaraptora</span> Extinct clade of dinosaurs

Megaraptora is a clade of carnivorous tetanuran theropod dinosaurs with controversial relations to other theropods. Its derived members, the Megaraptoridae are noted for their large hand claws and robust forelimbs, which are usually reduced in size in other large theropods.

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

Leshansaurus is a genus of theropod dinosaur from the Late Jurassic Shaximiao Formation of what is now China. It was described in 2009 by a team of Chinese paleontologists. The type species is Leshansaurus qianweiensis. Fossils of Leshansaurus were discovered in strata from the Shangshaximiao Formation, a formation rich in dinosaur fossils. Li et al. referred this taxon to Sinraptoridae – a group of carnosaurian theropods, but it may belong to Megalosauridae instead.

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

Proceratosauridae is a family or clade of tyrannosauroid theropod dinosaurs from the Middle Jurassic to the Early Cretaceous.

<i>Yutyrannus</i> Genus of proceratosaurid dinosaur from the Early Cretaceous period

Yutyrannus is a genus of proceratosaurid tyrannosauroid dinosaur which contains a single known species, Yutyrannus huali. This species lived during the early Cretaceous period in what is now northeastern China. Three fossils of Yutyrannus huali —all found in the rock beds of Liaoning Province— are currently the largest-known carnivorous dinosaur specimens that preserve direct evidence of feathers.

<i>Thalassodraco</i> Extinct genus of ophthalmosaurid ichthyosaur

Thalassodraco is an extinct genus of ophthalmosaurid ichthyosaur from the Late Jurassic (Tithonian) Kimmeridge Clay Formation of England. The type species, T. etchesi, was named in 2020, with the epithet in honour of the discoverer of the holotype, Steve Etches.

References

  1. 1 2 Benson, R.B.J. (2008). "New information on Stokesosaurus, a tyrannosauroid (Dinosauria: Theropoda) from North America and the United Kingdom". Journal of Vertebrate Paleontology. 28 (3): 732–750. doi:10.1671/0272-4634(2008)28[732:NIOSAT]2.0.CO;2. S2CID   129921557.
  2. Taylor, M.A. (1989). "'Fine Fossils For Sale' — the Professional Collector and the Museum". Geological Curator. 5 (2): 55–64.
  3. Etches, S.; Clarke, J.; Callomon, J. (2009). "Ammonite eggs and ammonitellae from the Kimmeridge Clay Formation (Upper Jurassic) of Dorset, England". Lethaia. 42 (2): 204–217. doi:10.1111/j.1502-3931.2008.00133.x.
  4. Paul, Gregory S. (2016). The Princeton Field Guide to Dinosaurs 2nd Edition. New Jersey: Princeton University Press. p. 105.
  5. Molina-Pérez & Larramendi (2016). Récords y curiosidades de los dinosaurios Terópodos y otros dinosauromorfos. Spain: Larousse. p. 265.
  6. 1 2 Brusatte, S.L.; Benson, R.B.J. (2013). "The systematics of Late Jurassic tyrannosauroids (Dinosauria: Theropoda) from Europe and North America". Acta Palaeontologica Polonica. 58 (1): 47–54. doi: 10.4202/app.2011.0141 .
  7. Loewen, M.A.; Irmis, R.B.; Sertich, J.J.W.; Currie, P. J.; Sampson, S. D. (2013). Evans, David C (ed.). "Tyrant Dinosaur Evolution Tracks the Rise and Fall of Late Cretaceous Oceans". PLoS ONE . 8 (11): e79420. Bibcode:2013PLoSO...879420L. doi: 10.1371/journal.pone.0079420 . PMC   3819173 . PMID   24223179.
  8. Brusatte, Stephen L.; Carr, Thomas D. (2016-02-02). "The phylogeny and evolutionary history of tyrannosauroid dinosaurs". Scientific Reports. 6 (1): 20252. Bibcode:2016NatSR...620252B. doi:10.1038/srep20252. ISSN   2045-2322. PMC   4735739 . PMID   26830019.