Priosphenodon

Priosphenodon; Temporal range: Cenomanian-Turonian; ~100.5–89.8 Ma PreꞒ Ꞓ O S D C P T J K Pg N
	Reconstructed skeleton of P. avelesi, Carlos Ameghino Provincial Museum
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Sauropsida
Subclass:	Diapsida
Superorder:	Lepidosauria
Order:	Rhynchocephalia
Subfamily:	†Eilenodontinae
Genus:	†Priosphenodon; Apesteguia & Novas 2003
Species
	†P. avelesi Apestiguia & Novas 2003; †P. minimus Apestiguia & Carballido 2014;

Skulls of *P. avelasi* corresponding to different ontogenetic stages

Illustration of the skull in lateral view

Priosphenodon is an extinct rhynchocephalian known from the early Late Cretaceous of Argentina.^[1] It is believed to have been a fairly large herbivore, having a longer snout than modern tuatara, with teeth specialised for shearing plant matter, like other members of Eilenodontinae.^[1] The teeth are densely packed with a cone-in-cone structure, and have prismatic enamel structure similar to those of mammals and the lizard Uromastyx, which was likely an adaptation to wear resistance in the absence of tooth replacement.^[2] Two species are known, P. avelesi and P. minimus.^[3] The latter has also been considered a part of the separate genus Kaikaifilusaurus.^[4]

Fossils of the genus have been found in the Candeleros and Cerro Barcino Formations in Argentina.^{[citation needed]}

References

^ ^a ^b ^c ^d Apesteguía, Sebastián; Novas, Fernando E. (9 October 2003). "Large Cretaceous sphenodontian from Patagonia provides insight into lepidosaur evolution in Gondwana". Nature. 425 (6958): 609–612. Bibcode:2003Natur.425..609A. doi:10.1038/nature01995. PMID 14534584. S2CID 4425130.
^ LeBlanc, Aaron R. H.; Apesteguía, Sebastián; Larsson, Hans C. E.; Caldwell, Michael W. (4 May 2020). "Unique Tooth Morphology and Prismatic Enamel in Late Cretaceous Sphenodontians from Argentina". Current Biology. 30 (9): 1755–1761.e2. doi:10.1016/j.cub.2020.02.071. PMID 32220319. S2CID 214659416.
^ Apesteguia, Sebastian; Carballido, Jose L. (March 2014). "A new eilenodontine (Lepidosauria, Sphenodontidae) from the Lower Cretaceous of central Patagonia". Journal of Vertebrate Paleontology. 34 (2): 303–317. doi:10.1080/02724634.2013.803974. S2CID 130381621.
^ Gentil, Adriel R.; Agnolin, Federico L.; Garcia Marsà, Jordi A.; Motta, Matias J.; Novas, Fernando E. (June 2019). "Bridging the gap: Sphenodont remains from the Turonian (Upper Cretaceous) of Patagonia. Palaeobiological inferences". Cretaceous Research. 98: 72–83. doi:10.1016/j.cretres.2019.01.016.

[Apesteguia_and_Novas_2003-1] Apesteguía, Sebastián; Novas, Fernando E. (9 October 2003). "Large Cretaceous sphenodontian from Patagonia provides insight into lepidosaur evolution in Gondwana". Nature. 425 (6958): 609–612. Bibcode:2003Natur.425..609A. doi:10.1038/nature01995. PMID 14534584. S2CID 4425130.

[2] LeBlanc, Aaron R. H.; Apesteguía, Sebastián; Larsson, Hans C. E.; Caldwell, Michael W. (4 May 2020). "Unique Tooth Morphology and Prismatic Enamel in Late Cretaceous Sphenodontians from Argentina". Current Biology. 30 (9): 1755–1761.e2. doi:10.1016/j.cub.2020.02.071. PMID 32220319. S2CID 214659416.

[3] Apesteguia, Sebastian; Carballido, Jose L. (March 2014). "A new eilenodontine (Lepidosauria, Sphenodontidae) from the Lower Cretaceous of central Patagonia". Journal of Vertebrate Paleontology. 34 (2): 303–317. doi:10.1080/02724634.2013.803974. S2CID 130381621.

[4] Gentil, Adriel R.; Agnolin, Federico L.; Garcia Marsà, Jordi A.; Motta, Matias J.; Novas, Fernando E. (June 2019). "Bridging the gap: Sphenodont remains from the Turonian (Upper Cretaceous) of Patagonia. Palaeobiological inferences". Cretaceous Research. 98: 72–83. doi:10.1016/j.cretres.2019.01.016.

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