Clasmodosaurus (meaning "fragmentary tooth reptile") is a genus of titanosaurian sauropod dinosaur from the Mata Amarilla Formation and the Cerro Fortaleza Formation.[1] It lived during the Late Cretaceous in what is now Argentina. It is known from five fossilized and assorted teeth, but is diagnosed by a unique combination of characters.[1][2]

Clasmodosaurus
Temporal range: Late Cretaceous
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Sauropodomorpha
Clade: Sauropoda
Clade: Macronaria
Clade: Titanosauria
Genus: Clasmodosaurus
Ameghino, 1898
Species:
C. spatula
Binomial name
Clasmodosaurus spatula
Ameghino, 1898

History

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Clasmodosaurus was named by Florentino Ameghino in 1898, but remained largely unknown for decades after its discovery.[3] It was originally considered a sauropod, but Friedrich von Huene suggested that it could be a coelurosaur or synonymous with Loncosaurus, which he considered to be a carnosaur.[2] Like Loncosaurus, its taxonomy remained unclear with it regarded as a theropod on the rare occasions it was mentioned.[2] However, Jaime Powell suggested that it was a dubious genus of sauropod in 1986, an identification which has been accepted since. Like diplodocoids and titanosaurs, it had narrow tooth crowns, and it is typically regarded as a titanosaur like most Late Cretaceous sauropods.[2] More recently, a revision of Ameghino's collection and new discoveries in the Cerro Fortaleza Formation find the taxon to also hail from this formation.[1]

Description

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The teeth of Clasmodosaurus spatula were polygonal in cross section rather than round, an unusual trait also found in the titanosaur Bonitasaura salgadoi.[4] However, these teeth are much larger and more robust than those of Bonitasaura, with well-defined longitudinal ridges and grooves, resembling diamantinasaur teeth in some aspects.[1]

References

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  1. ^ a b c d Agnolín, Federico L.; Álvarez Herrera, Gerardo; Rolando, Mauro Aranciaga; Motta, Matías; Rozadilla, Sebastián; Verdiquio, Lucía; D'Angelo, Julia S.; Moyano-Paz, Damián; Varela, Augusto N.; Sterli, Juliana; Bogan, Sergio; Miner, Santiago; Moreno Rodríguez, Ana; Muñoz, Gonzalo; Isasi, Marcelo P. (2024-02-01). "Fossil vertebrates from the Cerro Fortaleza Formation (Upper Cretaceous), Santa Cruz Province, Argentina". Cretaceous Research. 154: 105735. Bibcode:2024CrRes.15405735A. doi:10.1016/j.cretres.2023.105735. ISSN 0195-6671.
  2. ^ a b c d Powell JE. 2003. Revision of South American titanosaurid dinosaurs: palaeobiological, palaeobiogeographical and phylogenetic aspects. Records of the Queen Victoria Museum 111:1–173.
  3. ^ von Huene F. 1929. Los Saurisquios y ornithisquios del Cretaceo Argentino. Anales del Museo de la Plata.
  4. ^ Gallina, P. A.; Apesteguía, S. (2011). "Cranial anatomy and phylogenetic position of the titanosaurian sauropod Bonitasaura salgadoi". Acta Palaeontologica Polonica. 56 (1): 45–60. doi:10.4202/app.2010.0011. hdl:11336/192915.