Squatirhina americana
Estes, 1964
Classification: Elasmobranchii Rajiformes incert. fam.
Reference of the original description
Fossil vertebrates from the Late Cretaceous Lance Formation, Eastern Wyoming. University of California Publications in Geological Sciences, 49, 1–180
Fossil vertebrates from the Late Cretaceous Lance Formation, Eastern Wyoming. University of California Publications in Geological Sciences, 49, 1–180
Description:
Citation: Squatirhina americana Estes, 1964: In: Database of fossil elasmobranch teeth www.shark-references.com, World Wide Web electronic publication, Version 08/2026
Description
Original diagnosis after Estes, 1964 [788]: Terminology follows that of Casier (1947 A-C). The crown is relatively broad-based in comparison to the needle-pointed central cusp. From the latter, crests slope laterally onto broad, rounded, shoulders which have a sharp and faintly wrinkled edge. The median border of the crown is drawn out anteroventrally into a marked projection, above which there are a few fine vertical striae. Posteriorly the median cusp bulges out slightly at the base above the central root canal. The root is strongly splayed laterally and has a prominent opening for the laterointernal canal on each side of the bulge mentioned above. The central root canal is open ventrally and a single foramen opens from its floor into the central cavity. The teeth are tiny; maximum root diameter ranges from 1.5 to 2mm.
Original diagnosis after Estes, 1964 [788]: Terminology follows that of Casier (1947 A-C). The crown is relatively broad-based in comparison to the needle-pointed central cusp. From the latter, crests slope laterally onto broad, rounded, shoulders which have a sharp and faintly wrinkled edge. The median border of the crown is drawn out anteroventrally into a marked projection, above which there are a few fine vertical striae. Posteriorly the median cusp bulges out slightly at the base above the central root canal. The root is strongly splayed laterally and has a prominent opening for the laterointernal canal on each side of the bulge mentioned above. The central root canal is open ventrally and a single foramen opens from its floor into the central cavity. The teeth are tiny; maximum root diameter ranges from 1.5 to 2mm.
Remarks
shark-references Species-ID=13950;
type species of Restesia Cook, Newbrey, Brinkman & Kirkland, 2014 [20267] by original designation (Art. 68.2 ICZN);
shark-references Species-ID=13950;
type species of Restesia Cook, Newbrey, Brinkman & Kirkland, 2014 [20267] by original designation (Art. 68.2 ICZN);
References
Paleoecology of the Gaddis site in the Upper Cretaceous Aguja Formation, Terlingua, Texas. Palaios, 31(7), 347–357
DOI: 10.2110/palo.2015.099
Vertebrate biostratigraphy of the Hell Creek Formation in southwestern North Dakota and northwestern South Dakota. Geological Society of America Special Paper, 361, 145–167
The Campanian Terlingua local fauna, with a summary of other vertebrates from the Aguja Formation, Trans-Pecos Texas. Journal of Vertebrate Paleontology, 12(4), 472–493
DOI: 10.1080/02724634.1992.10011475
Non-dinosaurian lower vertebrates across the Cretaceous-Tertiary boundary in northeastern Montana. University of California Publications in Geological Sciences, 134, 1–107
An aniliid snake and associated vertebrates from the Campanian of New Mexico. Journal of Paleontology, 52(2), 480–483
A Late Cretaceous vertebrate fauna from the St. Marys River Formation in Western Canada. Royal Ontario Museum Life Sciences Miscellaneous Publications, 114–133
Fossil vertebrates from the Late Cretaceous Lance Formation, Eastern Wyoming. University of California Publications in Geological Sciences, 49, 1–180
Paleoecology of the Gaddis site in the Upper Cretaceous Aguja Formation, Terlingua, Texas. Palaios, 31(7), 347–357
DOI: 10.2110/palo.2015.099
Vertebrate biostratigraphy of the Hell Creek Formation in southwestern North Dakota and northwestern South Dakota. Geological Society of America Special Paper, 361, 145–167
The Campanian Terlingua local fauna, with a summary of other vertebrates from the Aguja Formation, Trans-Pecos Texas. Journal of Vertebrate Paleontology, 12(4), 472–493
DOI: 10.1080/02724634.1992.10011475
Non-dinosaurian lower vertebrates across the Cretaceous-Tertiary boundary in northeastern Montana. University of California Publications in Geological Sciences, 134, 1–107
An aniliid snake and associated vertebrates from the Campanian of New Mexico. Journal of Paleontology, 52(2), 480–483
A Late Cretaceous vertebrate fauna from the St. Marys River Formation in Western Canada. Royal Ontario Museum Life Sciences Miscellaneous Publications, 114–133
Fossil vertebrates from the Late Cretaceous Lance Formation, Eastern Wyoming. University of California Publications in Geological Sciences, 49, 1–180
