A new hybodontiform shark (Strophodus Agassiz 1838) from the Lower Cretaceous (Valanginian-Hauterivian) of Colombia

Abstract

The vertebrate marine faunas that inhabited northern South America during the Cretaceous are still poorly known. This study is a contribution to a growing wave of new studies on Lower Cretaceous vertebrates from Colombia. Here we report and describe a new species of a hybodontiform shark of the genus Strophodus, which we named Strophodus rebecae sp. nov., based on isolated teeth, that were collected in Valanginian-Hauterivian rocks of the Rosa Blanca Formation (Carrizal and El Sapo Members) near the town of Zapatoca, Santander Department, Andes of Colombia. In addition, we describe two other fragmented teeth assigned to Strophodus sp. from the Rosa Blanca Fm. The new species from Colombia represents the only Cretaceous record of Strophodus from Gondwana, offering new insights into the paleogeographic distribution of the genus, as well as increasing the knowledge about the scarce hybodontiform paleodiversity known from South America. The presence of Strophodus in the Rosa Blanca Formation suggests that these durophagous (shell-crushing) fishes played an important role as predators of the abundant and diverse invertebrate fauna present in these ancient tropical coastal ecosystems of Gondwana.

The oldest Gondwanan record of the extinct durophagous hybodontiform chondrichthyan, Strophodus from the Bajocian of Morocco

“…The descriptive dental terminology employed in this study largely follows that of Cappetta (2012), whereas higher systematic relationships correspond to those of Maisey (1989), although we acknowledge that currently available phylogenetic hypotheses for hybodontiforms are unsatisfactory (Rees, 2008;Stumpf et al, 2021aStumpf et al, , 2021b. (Peyer, 1946); Strophodus udulfensis (Leuzinger et al, 2017); Strophodus dunaii (Szabó & Főzy, 2020)…”

“…Second lateral teeth of S. smithwoodwardi, although morphologically similar, are readily distinguished from those of PIMUZ A/I 5181 by possessing a more complex ornamentation, which displays a prominent reticulate pattern that turns into frequently branching folds towards the edges of the crown (Peyer, 1946). Strophodus rebecae from the Valanginian-Hauterivian of Colombia, which is the stratigraphically youngest known Strophodus species, is easily distinguishable from PIMUZ A/I 5181 in having smaller and less elongated second lateral teeth with a parallelogram-shaped occlusal outline and rather low and flat crowns (Carrillo-Briceño & Cadena, 2022). In addition, first lateral teeth of S. rebecae have a trapezoidal rather than triangular outline in occlusal view.…”

“…The dental traits displayed by specimen PIMUZ A/I 5181 from the Bajocian of the Moroccan High Atlas Mountains are consistent with referral to the genus Strophodus, whose stratigraphic range spans from the Middle Triassic to the Early Cretaceous. Strophodus has frequently been reported from numerous localities across the globe (compare Carrillo-Briceño & Cadena, 2022;Rees & Underwood, 2008;Stumpf et al, 2022;Szabó & Főzy, 2020), making it one of the most common and geographically widespread Mesozoic hybodontiforms to ever have lived.…”

“…The extinct hybodontiform chondrichthyan Strophodus Agassiz, 1838, with an estimated maximum body length of up to three meters and its massive, powerful jaws equipped with highly specialized crushing teeth suitable for breaking up various kinds of marine hard-shelled invertebrate prey, is one of the most iconic durophagous predators that ever roamed the Mesozoic seas (e.g., Cappetta, 2012;Szabó & Főzy, 2020). Extending for more than 130 million years, from the Middle Triassic (Anisian-Ladinian) to the Early Cretaceous (Albian) (Cappetta, 2012), Strophodus boasts an extensive fossil record that is mainly dominated by its characteristic teeth, which occur frequently in a wide variety of depositional environments, providing discrete combinations of dental characters for use in species identification and establishing reliable diagnoses (e.g., Carrillo-Briceño & Cadena, 2022;Leuzinger et al, 2017;Peyer, 1946;Rees & Underwood, 2008;Rigal & Cuny, 2016;Stumpf et al, 2022;Szabó, 2021;Szabó & Főzy, 2020).…”

A Synoptic Review of the Cartilaginous Fishes (Chondrichthyes: Holocephali, Elasmobranchii) from the Upper Jurassic Konservat-Lagerstätten of Southern Germany: Taxonomy, Diversity, and Faunal Relationships

“…† Strophodus is a speciose genus that thrived the Mesozoic seas for more than 130 million years, from the Middle Triassic to the Early Cretaceous [ 181 – 183 ]. The Solnhofen Archipelago has yielded rare dental and skeletal material attributable to † Strophodus , including an articulated but crushed set of jaws with teeth from the lower Tithonian of Mühlheim ( Figure 12 ).…”