Thanatosdrakon (IPA: [θænətɒsdrɑːkɒn]) (meaning "dragon of death") is a genus of quetzalcoatline azhdarchid pterosaur from the Late Cretaceous (Upper Coniacian–Lower Santonian) Plottier Formation of the Neuquén Basin in western Argentina (Andes mountain range). The genus name is derived from the Greek words thanatos (=death) and drakon (=dragon), while the specific name is a Quechuan word meaning "flying serpent" and refers to the Incan deity Amaru. The type and only species is Thanatosdrakon amaru, known from two specimens consisting of several well-preserved axial and appendicular bones including material previously undescribed in giant azhdarchids (e.g. complete notarium, dorsosacral vertebrae and caudal vertebra). Thanatosdrakon is one of the oldest known members of the Quetzalcoatlinae.[1][2] T. amaru lived from about 90 to 86 million years ago.[1]

Thanatosdrakon
Temporal range: Upper ConiacianLower Santonian, ~89.6–86.3 Ma
Life restoration of T. amaru
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Order: Pterosauria
Suborder: Pterodactyloidea
Family: Azhdarchidae
Subfamily: Quetzalcoatlinae
Genus: Thanatosdrakon
Ortiz David et al., 2022
Species:
T. amaru
Binomial name
Thanatosdrakon amaru
Ortiz David et al., 2022

Description

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Thanatosdrakon is known from two well-preserved specimens first described in 2018.[3] The holotype, UNCUYO-LD 307, is a partial postcranial skeleton, and the paratype, UNCUYO-LD 350, is a complete left humerus. The holotype specimen, belonging to either a juvenile or a subadult, has a wingspan of approximately ~7 metres (23 ft), suggesting a wingspan of approximately 9 metres (30 ft) for the paratype, making Thanatosdrakon the largest known pterosaur from South America.[1][4] The species is represented by several axial and appendicular bones in three dimensions.[1]

Classification

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Ortiz David et al., (2022) recovered Thanatosdrakon in the Quetzalcoatlinae subfamily of Azhdarchidae, as a sister taxon to Quetzalcoatlus in a clade with Cryodrakon in a phylogenetic analysis. Their results are shown below:[1]

Quetzalcoatlinae

Palaeoecology

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Thanatosdrakon is known from the upper-most levels of the Plottier Formation, which represents a floodplain with ephemeral rivers and consists of mudstone, siltstone, claystone and sandstone, suggesting it lived in a continental environment created by the low-gradient wandering rivers that laid down alluvial deposits across the formation.[1]

Thanatosdrakon was contemporaneous with an indeterminate abelisaurid,[5] basal coelurosaurian, unenlagiine, aeolosaurin, saltasaurid, and ornithopod,[6] as well as the lithostrotian titanosaurs Antarctosaurus giganteus,[7] Notocolossus,[8] and Petrobrasaurus.[9][6] Non-dinosaurian taxa from the formation include freshwater bivalves, an indeterminate crocodyliforme and mesoeucrocodylian,[6] the chelid turtles Linderochelys[10] and Rionegrochelys,[11] and at least one indeterminate mammal. Ichnotaxa consist of the burrow ichnogenus Scoyenia sp., and insect ichnogenus Taenidium sp.[6]

References

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  1. ^ a b c d e f Ortiz David, Leonardo D.; González Riga, Bernardo J.; Kellner, Alexander W. A. (12 April 2022). "Thanatosdrakon amaru, gen. ET SP. NOV., a giant azhdarchid pterosaur from the upper Cretaceous of Argentina". Cretaceous Research. 135: 105228. Bibcode:2022CrRes.13705228O. doi:10.1016/j.cretres.2022.105228. S2CID 248140163. Retrieved 12 April 2022.
  2. ^ "Paleontologists uncover 'dragon of death' in Argentina. It's the largest pterosaur ever found in South America". ZME Science. 2022-05-25. Retrieved 2022-05-26.
  3. ^ Ortiz David, Leonardo D.; González Riga, Bernardo J.; Kellner, Alexander W. A. (2018). "Discovery of the largest pterosaur from South America". Cretaceous Research. 83: 40–46. Bibcode:2018CrRes..83...40O. doi:10.1016/j.cretres.2017.10.004. hdl:11336/41234.
  4. ^ Ortiz David, Leonardo D.; González Riga, Bernardo J.; Kellner, Alexander W. A. (2022). "ANATOMICAL PECULIARITIES OF THE GIANT PTEROSAUR THANATOSDRAKON AMARU (AZHDARCHIDAE, PTERODACTYLOIDEA) FROM UPPER CRETACEOUS DEPOSITS OF MENDOZA, ARGENTINA". 82nd Annual Meeting - SVP 2022 Program Guide (PDF). Society of Vertebrate Paleontology. p. 121.
  5. ^ Hendrickx, Christophe; Tschopp, Emanuel; Ezcurra, Martín d. (2020-04-01). "Taxonomic identification of isolated theropod teeth: The case of the shed tooth crown associated with Aerosteon (Theropoda: Megaraptora) and the dentition of Abelisauridae". Cretaceous Research. 108: 104312. Bibcode:2020CrRes.10804312H. doi:10.1016/j.cretres.2019.104312. ISSN 0195-6671. S2CID 210268523.
  6. ^ a b c d Plottier Formation at Fossilworks.org
  7. ^ Antarctosaurus giganteus type locality at Fossilworks.org
  8. ^ Notocolossus gonzalezparejasi type locality at Fossilworks.org
  9. ^ Petrobrasaurus puestohernandezi type at Fossilworks.org
  10. ^ Linderochelys rinconensis type locality at Fossilworks.org
  11. ^ Rionegrochelys caldieroi type locality at Fossilworks.org