First record of elasmobranchs from the Lower Cretaceous of Argentina (Neuquén Basin)

Abstract

The material reported herein comes from the Lower Cretaceous Agrio Formation (Neuqu en Basin, westcentral Argentina). These fishes dwelled in a Pacific Ocean embayment in southwestern Gondwana before the establishment of the Andean Cordillera. The material consists of an incomplete dorsal fin spine of the widespread Hybodontoidea clade (from upper Valanginian beds) and a partial tooth of one of the earliest known lamniforms (from upper Hauterivian beds).

A new lamniform shark Protolamna ricaurtei sp. nov. from the Lower Cretaceous of Colombia

“…The genus †Protolamna is probably one of the most ancient lamniforms (Rees, 2005;Kriwet et al, 2008;Cappetta, 2012), with a chronostratigraphic distribution ranging from the Valanginian (Early Cretaceous) to the Maastrichtian (Late Cretaceous). The fossil record of †Protolamna includes Africa, Asia, Australia, Europa and North and South America (e.g., Cappetta, 2012;Gouiric-Cavalli et al, 2018). †Protolamna was originally described on the basis of isolated teeth from the upper Aptian of France ( †Protolamna sokolovi Cappetta, 1980), and a detailed discussion about the taxonomic status of the genus is presented by Müller and Diedrich, 1991, and †Protolamna carteri Cappetta and Case, 1999, from the Cenomanian, of Europe and North American, and †Protolamna borodini Cappetta and Case, 1975, from the Maastrichtian of North America and Campanian of Europe (Siverson 1992;Vullo, 2005).…”

“…Albian of Peru, and †Protolamna sp. from the upper Hauterivian of Argentina (Gouiric-Cavalli et al, 2018). A detailed discussion about the taxonomic status of †P.…”

“…,Cappetta (2012),Vullo and Courville (2014) andGouiric-Cavalli et al (2018).The combination of different morphological characters as a triangular, thick, and short main cusp with and proportionally smaller bulky lateral cusplets, and a massive root with a…”