Pararhabdodon

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Pararhabdodon
Temporal range: Late Cretaceous, 67.5–66 Ma
Pararhabdodon.png
Maxillae
Scientific classification edit
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Order: Ornithischia
Suborder: Ornithopoda
Family: Hadrosauridae
Tribe: Tsintaosaurini
Genus: Pararhabdodon
Casanovas-Cladellas, Santafé-Llopis & Isidro-Llorens, 1993
Type species
Pararhabdodon isonensis
Casanovas-Cladellas, Santafé-Llopis & Isidro-Llorens, 1993

Pararhabdodon (meaning "similar to Rhabdodon" ["bar-tooth"]) is a genus of tsintaosaurin hadrosaurid dinosaur, from the Maastrichtian-age Upper Cretaceous Tremp Formation of Spain. It is based on assorted postcranial remains, mostly vertebrae, and is notable for the reassignments it has undergone in regard to classification.

History[edit]

Restoration

In 1987, Casanovas et al. described remains of an ornithopod from Catalonia, including a cervical vertebra, some partial dorsals, a humerus, and a fragmentary scapula, as Rhabdodon sp.[1] New remains from this site (Tremp Formation, near Isona, Lleida, Spain) brought about a reconsideration of the material, and Casanovas-Cladellas et al. named Pararhabdodon isonense in 1993 from a middle caudal vertebra (IPS-SRA-15), referring additional material to their new genus.[2] At the time, it was considered to be a rhabdodont-like basal iguanodont, hence the name.[2]

Additional material from the type locality was collected in 1994, and the species name was corrected to isonensis in 1997 by Casanovas-Cladellas et al. and Laurent et al.[3][4] A dentary (IPS SRA 27) from a second quarry in the Tremp Formation was also referred to the genus, now considered to be a basal lambeosaurine hadrosaurid.[3] Laurent et al. referred additional remains (jaw material, vertebrae, and limb bones of multiple individuals of different ages) from the uppermost Cretaceous of Aude, France, to the genus,[4] but this was not discussed in the most recent review.[5] (Oddly, the second edition of The Dinosauria omitted this genus altogether)

Head (2001) disputed the assignment to the Lambeosaurinae, considering it more likely to be basal to the two hadrosaurid subfamilies.[6] This is the same conclusion that Prieto-Marquez et al. (2006) came to, finding it to be the sister group to Hadrosaurinae+Lambeosaurinae ( = Hadrosauridae in their analysis, although the definition of Hadrosauridae varies).[5] Prieto-Márquez assigned IPS SRA 27 to its own genus, Koutalisaurus, a more derived hadrosaurid.[5] More recent research by Prieto-Márquez and Wagner considers Koutalisaurus a probable synonym of Pararhabdodon, and Pararhabdodon a member of a lambeosaurine clade with the Chinese genus Tsintaosaurus.[7]

Paleobiology[edit]

Pararhabdodon most likely was a bipedal-quadrupedal herbivore, in the neighborhood of 6 m (19.7 ft) long, fully grown.[5] The dorsal and sacral neural spines were elongate, so the animal would have had a tall back, like other hadrosaurids. Because the material is sparse, more specific conclusions cannot be reached. Spanish material includes: a maxilla; four cervical, four dorsal, and a caudal vertebra; a sacrum; the end of an ischium; and a humerus.[5]

See also[edit]

References[edit]

  1. ^ Casanovas, M.L, Santafé, J.S., Sanz, J.L., and Buscalioni, A.D. (1987). Arcosaurios (Crocodilia, Dinosauria) del Cretácico superior de la Conca de Tremp (Lleida, España) [Archosaurs (Crocodilia, Dinosauria) from the Upper Cretaceous of the Tremp Basin (Lleida, Spain)]. Estudios Geológicos. Volumen extraordinario Galve-Tremp:95-110. [Spanish]
  2. ^ a b Casanovas-Cladellas, M.L., Santafé-Llopis, J.V., and Isidro-Llorens, A. (1993). Pararhabdodon isonensis n. gen. n. sp. (Dinosauria). Estudio mofológico, radio-tomográfico y consideraciones biomecanicas [Pararhabdodon isonense n. gen. n. sp. (Dinosauria). Morphology, radio-tomographic study, and biomechanic considerations]. Paleontologia i Evolució 26-27:121-131. [Spanish]
  3. ^ a b Casanovas, M.L, Pereda-Suberbiola, X., Santafé, J.V., and Weishampel, D.B. (1999). First lambeosaurine hadrosaurid from Europe: palaeobiogeographical implications. Geological Magazine 136(2):205-211.
  4. ^ a b Laurent, Y., LeLoeuff, J., & Buffetaut, E. (1997). Les Hadrosauridae (Dinosauria, Ornithopoda) du Maastrichtien supérieur des Corbières orientales (Aude, France) [The Hadrosauridae (Dinosauria, Ornithopoda) from the Upper Maastrichtian of the eastern Corbières (Aude, France)]. Revue de Paléobiologie 16:411-423. [French]
  5. ^ a b c d e Prieto-Marquez, A., Gaete, R., Rivas, G., Galobart, Á., and Boada, M. (2006). Hadrosauroid dinosaurs from the Late Cretaceous of Spain: Pararhabdodon isonensis revisited and Koutalisaurus kohlerorum, gen. et sp. nov. Journal of Vertebrate Paleontology 26(4): 929-943.
  6. ^ Head, J.J. (2001). A reanalysis of the phylogenetic position of Eolambia caroljonesa (Dinosauria, Iguanodontia). Journal of Vertebrate Paleontology 21(2):392-396.
  7. ^ Prieto-Márquez, A.; Wagner, J.R. (2009). "Pararhabdodon isonensis and Tsintaosaurus spinorhinus: a new clade of lambeosaurine hadrosaurids from Eurasia". Cretaceous Research. online preprint (5): 1238. doi:10.1016/j.cretres.2009.06.005.