Hypolophites beckeri
Maisch, 2019
Classification: Elasmobranchii Myliobatiformes Dasyatidae
Reference of the original description
A new species of Hypolophites (Chondrichthyes, Myliobatiformes) from the Lower Clayton Limestone Unit of the Midway Group (Paleocene), near Malvern, Arkansas, USA. Journal of Paleontology, 94(3), 548–556
A new species of Hypolophites (Chondrichthyes, Myliobatiformes) from the Lower Clayton Limestone Unit of the Midway Group (Paleocene), near Malvern, Arkansas, USA. Journal of Paleontology, 94(3), 548–556
Types
Hypolophites beckeri
Holotype: ANSP(fossil): VP25131; Paratype: ANSP(fossil): VP25128–25130; ANSP(fossil): VP25132; ANSP(fossil): VP25148–25152;
Hypolophites beckeri
Holotype: ANSP(fossil): VP25131; Paratype: ANSP(fossil): VP25128–25130; ANSP(fossil): VP25132; ANSP(fossil): VP25148–25152;
Description:
Citation: Hypolophites beckeri Maisch, 2019: In: Database of fossil elasmobranch teeth www.shark-references.com, World Wide Web electronic publication, Version 08/2026
Description
Original diagnosis after Maisch, 2019 [27823]: A Hypolophites species with median and lateral pavement teeth that have hexagonal and rhombus-shaped, trilobate, and finely pitted occlusal surfaces, heavily wrinkled crown edges, a “U- or V-shaped” labial uvula, and small lingual shelf. Occlusal surface pitting forms a vermiculate pattern and is more frequently preserved on lateral teeth. The occlusal surfaces of median and lateral teeth have a mesial-distal width that may exceed 5.0 mm. In general, the length between the lingual and labial surfaces is half the mesial-distal occlusal surface width. As seen in profile view, crown and root thicknesses of median and lateral teeth are nearly equivalent and teeth may exceed 4.0 mm in total height. The lingual tooth surfaces are concave and extensively wrinkled, while the labial tooth surfaces are flat to slightly convex with dorso-ventrally oriented furrows. Roots of median and lateral teeth are generally bilobate, terminate with rounded bases, and may contain several foramina within the nutritive groove and on the edges of the root lobes. The roots of some median teeth may contain two nutritive grooves that asymmetrically divide the root.
Original diagnosis after Maisch, 2019 [27823]: A Hypolophites species with median and lateral pavement teeth that have hexagonal and rhombus-shaped, trilobate, and finely pitted occlusal surfaces, heavily wrinkled crown edges, a “U- or V-shaped” labial uvula, and small lingual shelf. Occlusal surface pitting forms a vermiculate pattern and is more frequently preserved on lateral teeth. The occlusal surfaces of median and lateral teeth have a mesial-distal width that may exceed 5.0 mm. In general, the length between the lingual and labial surfaces is half the mesial-distal occlusal surface width. As seen in profile view, crown and root thicknesses of median and lateral teeth are nearly equivalent and teeth may exceed 4.0 mm in total height. The lingual tooth surfaces are concave and extensively wrinkled, while the labial tooth surfaces are flat to slightly convex with dorso-ventrally oriented furrows. Roots of median and lateral teeth are generally bilobate, terminate with rounded bases, and may contain several foramina within the nutritive groove and on the edges of the root lobes. The roots of some median teeth may contain two nutritive grooves that asymmetrically divide the root.
Remarks
shark-references Species-ID=15591;
shark-references Species-ID=15591;
References
Global impact and selectivity of the Cretaceous-Paleogene mass extinction among sharks, skates, and rays. Science, 379, 802–806
DOI: 10.1126/science.abn2080
A new species of Hypolophites (Chondrichthyes, Myliobatiformes) from the Lower Clayton Limestone Unit of the Midway Group (Paleocene), near Malvern, Arkansas, USA. Journal of Paleontology, 94(3), 548–556
DOI: 10.1017/jpa.2019.99

Global impact and selectivity of the Cretaceous-Paleogene mass extinction among sharks, skates, and rays. Science, 379, 802–806
DOI: 10.1126/science.abn2080

A new species of Hypolophites (Chondrichthyes, Myliobatiformes) from the Lower Clayton Limestone Unit of the Midway Group (Paleocene), near Malvern, Arkansas, USA. Journal of Paleontology, 94(3), 548–556
DOI: 10.1017/jpa.2019.99







