Tharosaurus

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Tharosaurus
Temporal range: Middle Jurassic, Early-Middle Bathonian
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Tharosaurus (cervical vertebrae).jpg
Cervical vertebrae of the holotype
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Sauropodomorpha
Clade: Sauropoda
Superfamily: Diplodocoidea
Family: Dicraeosauridae
Genus: Tharosaurus
Bajpai et al., 2023
Species:
T. indicus
Binomial name
Tharosaurus indicus
Bajpai et al., 2023

Tharosaurus (meaning "Thar desert lizard") is an extinct genus of dicraeosaurid sauropod dinosaur from the Middle Jurassic Jaisalmer Formation of India. The genus contains a single species, T. indicus, known from several vertebrae and a rib. Tharosaurus represents the earliest diplodocoid currently known and the first described from India. [1]

Contents

Discovery and naming

Life restoration Tharosaurus UDL.png
Life restoration

The Tharosaurus holotype specimen, RWR-241 (A–K), was discovered between 2019 and 2021 in sediments of the Jaisalmer Formation near Jethwai village in Jaisalmer district of Rajasthan state in western India. [2] The specimen consists of partial cervical, dorsal, and caudal vertebrae and a dorsal rib. [1]

In 2023, Bajpai et al. described Tharosaurus indicus as a new genus and species of dicraeosaurid sauropod based on these fossil remains. The generic name, "Tharosaurus", combines a reference to the Thar desert where the holotype was found with the Greek word "sauros", meaning "lizard". The specific name, "indicus", refers to the discovery of the specimen in India. [1]

Classification

Bajpai et al. (2023) recovered Tharosaurus as an early-diverging dicraeosaurid, suggesting it represents a relic of a lineage that evolved in India and later spread across the world. Tharosaurus is the oldest dicraeosaurid, as well as the oldest diplodocoid. The results of their phylogenetic analyses are shown in the cladogram below: [1]

Diplodocoidea
Rebbachisauridae
Xenoposeidon Rebachisaurid 2017.jpg
Flagellicaudata
Diplodocidae
Diplodocus carnegii.jpg
Dicraeosauridae

Suuwassea

Lingwulong Lingwulong UDL.png

Bajadasaurus Bajadasaurus SW.png

Tharosaurus Tharosaurus UDL.png

Pilmatueia

Amargatitanis
Amargatitanis LM.png

Brachytrachelopan

Dicraeosaurus hansemanni
Dicraeosaurus hansemanni22.jpg
Amargasaurus
Amargasaurus NT small.jpg

Paleoenvironment

The Jaisalmer Formation represents a deposit on the Tethyan coast of India. Other dinosaurs from this environment include a large theropod and a Turiasaur, both known only from teeth, [3] [4] along with a possible Spinosaurid known only from a phalanx. [5] Several ichnofossils are also known from the formation. [6]

Related Research Articles

<span class="mw-page-title-main">Spinosauridae</span> Family of dinosaurs

The Spinosauridae are a clade or family of tetanuran theropod dinosaurs comprising ten to seventeen known genera. Spinosaurid fossils have been recovered worldwide, including Africa, Europe, South America and Asia. Their remains have generally been attributed to the Early to Mid Cretaceous.

Amazonsaurus is a genus of diplodocoid sauropod dinosaur from the Early Cretaceous Period of what is now South America. It would have been a large-bodied quadrupedal herbivore with a long neck and whiplash tail. Although more derived diplodocoids were some of the longest animals ever to exist, Amazonsaurus was probably not more than 12 meters (40 ft) long. Gregory S. Paul estimated in 2010 its weight at 5000 kg.

Suuwassea is a genus of dicraeosaurid sauropod dinosaur found in the Upper Jurassic strata of the Morrison Formation, located in southern Carbon County, Montana, United States. The fossil remains were recovered in a series of expeditions during a period spanning the years 1999 and 2000 and were described by J.D. Harris and Peter Dodson in 2004. They consist of a disarticulated but associated partial skeleton, including partial vertebral series and limb bones.

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

Diplodocoidea is a superfamily of sauropod dinosaurs, which included some of the longest animals of all time, including slender giants like Supersaurus, Diplodocus, Apatosaurus, and Amphicoelias. Most had very long necks and long, whip-like tails; however, one family are the only known sauropods to have re-evolved a short neck, presumably an adaptation for feeding low to the ground. This adaptation was taken to the extreme in the highly specialized sauropod Brachytrachelopan. A study of snout shape and dental microwear in diplodocoids showed that the square snouts, large proportion of pits, and fine subparallel scratches in Apatosaurus, Diplodocus, Nigersaurus, and Rebbachisaurus suggest ground-height nonselective browsing; the narrow snouts of Dicraeosaurus, Suuwassea, and Tornieria and the coarse scratches and gouges on the teeth of Dicraeosaurus suggest mid-height selective browsing in those taxa. This taxon is also noteworthy because diplodocoid sauropods had the highest tooth replacement rates of any vertebrates, as exemplified by Nigersaurus, which had new teeth erupting every 30 days.

Jeffrey A. Wilson, also known as JAW, is a paleontologist and professor of geological sciences and assistant curator at the Museum of Paleontology at the University of Michigan.

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

Dicraeosauridae is a family of diplodocoid sauropods who are the sister group to Diplodocidae. Dicraeosaurids are a part of the Flagellicaudata, along with Diplodocidae. Dicraeosauridae includes genera such as Amargasaurus, Suuwassea, Dicraeosaurus, and Brachytrachelopan. Specimens of this family have been found in North America, Asia, Africa, and South America. In 2023, a dicraeosaurid fossil was discovered in India for the first time. Their temporal range is from the Early or Middle Jurassic to the Early Cretaceous. Few dicraeosaurids survived into the Cretaceous, the youngest of which was Amargasaurus.

<i>Dinheirosaurus</i> Genus of reptiles (fossil)

Dinheirosaurus is a genus of diplodocid sauropod dinosaur that is known from fossils uncovered in modern-day Portugal. It may represent a species of Supersaurus. The only species is Dinheirosaurus lourinhanensis, first described by José Bonaparte and Octávio Mateus in 1999 for vertebrae and some other material from the Lourinhã Formation. Although the precise age of the formation is not known, it can be dated around the early Tithonian of the Late Jurassic.

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

Turiasauria is an unranked clade of basal sauropod dinosaurs known from Middle Jurassic to Early Cretaceous deposits in Europe, North America, and Africa.

Amargatitanis is a genus of dicraeosaurid sauropod dinosaur from the Barremian-age La Amarga Formation of Neuquén, Argentina. It is known from a single, incomplete postcranial skeleton consisting of a partial hindlimb, ischium, and two vertebrae. These remains were unearthed by Argentine paleontologist José Bonaparte in 1983 during an expedition by the Museo Argentino de Ciencias Naturales and later described as a new genus and species, Amargatitanis macni by Sebastián Apesteguía. The genus name comes from the words Amarga, where the fossils were collected, and titanis meaning "titan". Its species name is in reference to the MACN, where the remains are stored.

<i>Nannolytoceras</i> Genus of molluscs (fossil)

Nannolytoceras is an extinct genus of lytoceratid ammonite, family Lytoceratidae, with a stratigraphic range extending from the Bajocian age to Bathonian age.

The Calcare di Cellina (Italian for Cellina Limestone, is a Hauterivian to Aptian geologic formation in Friulia-Venezia Giulia, Italy. Fossil sauropod tracks have been reported from the formation.

<i>Ostafrikasaurus</i> Genus of theropod dinosaur

Ostafrikasaurus is a genus of theropod dinosaur from the Late Jurassic period of what is now Lindi Region, Tanzania. It is known only from fossil teeth discovered sometime between 1909 and 1912, during an expedition to the Tendaguru Formation by the Natural History Museum of Berlin. Eight teeth were originally attributed to the dubious dinosaur genus Labrosaurus, and later to Ceratosaurus, both known from the North American Morrison Formation. Subsequent studies attributed two of these teeth to a spinosaurid dinosaur, and in 2012, Ostafrikasaurus crassiserratus was named by French palaeontologist Eric Buffetaut, with one tooth as the holotype, and the other referred to the same species. The generic name comes from the German word for German East Africa, the former name of the colony in which the fossils were found, while the specific name comes from the Latin words for "thick" and "serrated", in reference to the form of the animal's teeth.

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

Leinkupal is a genus of diplodocine sauropod known from the Early Cretaceous of the Bajada Colorada Formation, southeastern Neuquén Basin in the Neuquén Province of Argentina. It contains a single species, Leinkupal laticauda.

<i>Lingwulong</i> Dicraeosaurid dinosaur genus from Mid Jurassic China

Lingwulong is a genus of dicraeosaurid sauropod dinosaur from the Middle Jurassic of what is now Lingwu, Yinchuan, Ningxia, China. The type and only species is L. shenqi, known from several partial skeletons. It is the earliest-aged neosauropod ever discovered, as well as the only definite diplodocoid from east Asia.

<i>Pilmatueia</i> Sauropod dinosaur genus from the early Cretaceous Period

Pilmatueia is a diplodocoid sauropod belonging to the family Dicraeosauridae that lived in Argentina during the Early Cretaceous. Its type and only species is Pilmatueia faundezi. Pilmatueia was probably closely related to other South American dicraeosaurids such as Amargasaurus. Pilmatueia had relatively pneumatic vertebrae compared to other dicraeosaurids, which were otherwise characterized by a reduction in pneumaticity relative to other sauropods. Pilmatueia dates to the Valanginian, an age of the Cretaceous period for which dinosaur faunas are poorly known.

<i>Bajadasaurus</i> Genus of sauropod dinosaur

Bajadasaurus is a genus of sauropod dinosaur from the Early Cretaceous epoch of northern Patagonia, Argentina. It was first described in 2019 based on a single specimen found in 2010 that includes a largely complete skull and parts of the neck. The only species is Bajadasaurus pronuspinax. The genus is classified as a member of the Dicraeosauridae, a group of relatively small and short-necked sauropods.

<span class="mw-page-title-main">Sunil Bajpai</span> Indian Paleontologist

Sunil Bajpai is the Chair Professor of Vertebrate Paleontology in the Department of Earth Sciences, Indian Institute of Technology Roorkee. He is in service as a professor at IIT Roorkee since 1st January 1996 till September 2026. He also served as the director of the Birbal Sahni Institute of Palaeosciences from January 2013 to July 2018.

<span class="mw-page-title-main">Jaisalmer Formation</span> Geologic formation in India

The Jaisalmer Formation is a Middle to Late Jurassic-aged geologic formation located in India near the city of Jaisalmer that consists mainly of marine deposits. The formation was first identified and defined by geologist Richard Dixon Oldham in 1886.

This article records new taxa of every kind of fossil archosaur that were scheduled to be described during 2023, as well as other significant discoveries and events related to the paleontology of archosaurs that were published in 2023.

References

  1. 1 2 3 4 Bajpai, S.; Datta, D.; Pandey, P.; Ghosh, T.; Kumar, K.; Bhattacharya, D. (2023). "Fossils of the oldest diplodocoid dinosaur suggest India was a major centre for neosauropod radiation". Scientific Reports. 13 (1). 12680. Bibcode:2023NatSR..1312680B. doi: 10.1038/s41598-023-39759-2 . PMC   10403599 . PMID   37542094.
  2. Ghosh, Sahana (13 September 2023). "Fossil find is earliest record of a plant-eating dinosaur group". Nature India. Retrieved 19 October 2023.
  3. Sharma, A.; Hendrickx, C.; Singh, S. (2023). "First theropod record from the Marine Bathonian of Jaisalmer Basin, Tethyan Coast of Gondwanan India". Rivista Italiana di Paleontologia e Stratigrafia. 129 (1): 49–64. doi: 10.54103/2039-4942/18306 . S2CID   256347914.
  4. Sharma A, Singh S, Satheesh SR (2022). "The first turiasaurian sauropod of India reported from the Middle Jurassic (Bathonian) sediments of Jaisalmer Basin, Rajasthan, India". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 304 (2): 187–203. doi:10.1127/njgpa/2022/1064. S2CID   249030842.
  5. Sharma, Archana; Novas, Fernando E.; Singh, Sanjay (2023-10-27). "FIRST JURASSIC EVIDENCE OF A POSSIBLE SPINOSAURID PEDAL UNGUAL, FROM THE JAISALMER BASIN, INDIA". RIVISTA ITALIANA DI PALEONTOLOGIA E STRATIGRAFIA. 129 (3). doi: 10.54103/2039-4942/20032 . ISSN   2039-4942.
  6. Kulkarni, Kantimati; Borkar, Vidyadhar D.; Dashputre, Tejashree (2008). "Ichnofossils from the Fort Member (Middle Jurassic), Jaisalmer Formation, Rajasthan". Journal of the Geological Society of India. 71 (5): 731–738.