Protolamna ricaurtei

Carrillo-Briceño, Parra & Luque, 2019


Classification: Elasmobranchii Lamniformes Eoptolamnidae

Reference of the original description
Carrillo-Briceño, J.D. & Parra, J.D. & Luque, J. (2019)
A new lamniform shark Protolamna ricaurtei sp. nov. from the Lower Cretaceous of Colombia. Cretaceous Research, 95, 336–340

Types
Protolamna ricaurtei
Holotype: CIP: FCG-CBP-93;

Images of types

Description:


Citation: Protolamna ricaurtei Carrillo-Briceño, Parra & Luque, 2019: In: Database of fossil elasmobranch teeth www.shark-references.com, World Wide Web electronic publication, Version 01/2023

Please send your images of "Protolamna ricaurtei" to info@shark-references.com

Protolamna ricaurtei sp. nov., holotype, (UAP-01.148a1) (FCG-CBP-93) from the upper Barremian - lower Aptian deposits of the Paja Formation near Villa de Leyva, Colombia © Carrillo-Briceño et al. (2019)

Description
Original diagnose after Carrillo-Briceño et al. (2019) p. 338 [27069]: Species characterized by the following features: 1) teeth characterized by a triangular, thick, and short mainly cusp, 2) proportionally smaller bulky lateral cusplets and 3) a massive root with a prominent and bulky lingual protuberance. Description. At least 29 teeth can be observed in the tooth set, of which only 13 are complete, while the rest are represented by crown and root fragments. Five tooth rows (teeth arranged mesiodistally and parallel to the jaw edge) and at least seven tooth files (series of teeth perpendicular to the jawedge, sensu Cappetta, 2012) in lingual view are identified (Fig. 2 A-D). Most of the tooth files are laterals, with the most distal tooth file presumably being a posterior one. The arrangement pattern suggests that there are no definite signs of overlap between root lobes of successive tooth files within a tooth row. Tooth measurements of the most complete and visible teeth, range between 10.9 and 18.4 mm in height and between 6.5 and 10.9 mm in width. During preparation, two teeth were removed from the tooth set (Fig. 2 E-J), allowing a detailed study of the lingual and labial side of the specimens. Complete teeth are characterized by a slightly inclined, triangular, thick, and short main cusp with smooth cutting edges. A single pair of lateral, bulky, triangular cusplets are widely separated and inclined slightly towards a more labial position than the main cusp. The labial face of the main cusp is nearly flat, forming a typical, distinctly concave crown-root boundary. Vertical and parallel enameloid folds are present, extending from the base almost to the apex. These folds can also be observed in the labial side of the lateral cusplets. The lingual face of the main cusp is convex and forms vertical and parallel folds, extending from the base up to less than the middle part of the cusp. At the base of the cusp, a well-developed lingual neck is noted. The root is high (at least half as high as the complete tooth), and is characterized by long subparallel lobes and a prominent and bulky lingual protuberance. No nutrient grooves can be observed at the center of the lingual protuberance, but more or less large central foramina can be observed in the well-preserved specimens.

Remarks
valid after Carrillo-Briceño et al. (2019) p. 338 [27069];


References
Carrillo-Briceño, J.D. & Parra, J.D. & Luque, J. (2019)
A new lamniform shark Protolamna ricaurtei sp. nov. from the Lower Cretaceous of Colombia. Cretaceous Research, 95, 336–340
DOI: 10.1016/j.cretres.2018.12.007