Origin of the white shark Carcharodon (Lamniformes: Lamnidae) based on recalibration of the Upper Neogene Pisco Formation of Peru

Abstract

The taxonomic origin of the white shark, Carcharodon, is a highly debated subject. New fossil evidence presented in this study suggests that the genus is derived from the broad‐toothed ‘mako’, Carcharodon (Cosmopolitodus) hastalis, and includes the new species C. hubbelli sp. nov. – a taxon that demonstrates a transition between C. hastalis and Carcharodon carcharias. Specimens from the Pisco Formation clearly demonstrate an evolutionary mosaic of characters of both recent C. carcharias and fossil C. hastalis. Characters diagnostic to C. carcharias include the presence tooth serrations and a symmetrical first upper anterior tooth that is the largest in the tooth row, while those indicative of C. hastalis include a mesially slanted third anterior (intermediate) tooth. We also provide a recalibration of critical fossil horizons within the Pisco Formation, Peru using zircon U‐Pb dating and strontium‐ratio isotopic analysis. The recalibration of the absolute dates suggests that Carcharodon hubbelli sp. nov. is Late Miocene (6–8 Ma) in age. This research revises and elucidates lamnid shark evolution based on the calibration of the Neogene Pisco Formation.

Stratigraphic framework of the late Miocene Pisco Formation at Cerro Los Quesos (Ica Desert, Peru)

“…Brand, Esperante, Chadwick, Poma Porras, & Alomía, 2004;Ehret et al, 2012;Esperante, Brand, Chadwick, & Poma, 2015;Esperante, Brand, Nick, Poma, & Urbina, 2008;Gariboldi et al, 2015;Lambert, Bianucci, & de Muizon, 2008;Lambert, Bianucci, & Post, 2009Lambert, Bianucci, Post, de Muizon, et al, 2010;Lambert, Bianucci, & Beatty, 2014;Lambert, de Muizon, & Bianucci, 2014;Lambert et al, 2015;Collareta et al, 2015). However, despite the growing significance of the vertebrate fauna of the Pisco Formation, a comprehensive stratigraphic framework for individual fossil-bearing localities and their position relative to one another has yet to be established (Brand, Urbina, Chadwick, DeVries, & Esperante, 2011;Di Celma et al, in press).…”

Pleistocene survival of an archaic dwarf baleen whale (Mysticeti: Cetotheriidae)

“…The Aguada de Lomas and Sud-Sacaco levels of the Pisco Formation are roughly 8-7 and 5-4 Ma (Messinian and Piacenzian, respectively; Muizon and deVries 1985). More recently, Ehret et al (2012) have reported a series of strontium isotope dates for the Pisco Formation, which in particular has resulted in a reevaluation of the age of Sud-Sacaco, which has yielded a 87 Sr-86 Sr date of 5.89 Ma. The geochronologic range of Piscobalaena can be summarized as 8-5.89 Ma (Muizon and deVries 1985;Ehret et al, 2012).…”

No deep diving: evidence of predation on epipelagic fish for a stem beaked whale from the Late Miocene of Peru

“…On the other hand, the locality of the youngest stem ziphiid (Ninoziphius platyrostris, Sud-Sacaco, Sacaco Basin, Peru; Muizon, 1984 [44]) was recently re-dated to the Late Miocene (possibly early Messinian [50]). The extinction of stem ziphiids may thus be roughly synchronous with the Late Miocene appearance and early diversification of modern delphinoid families, including delphinids for which divergence date estimates fall within the Tortonian or-a less likely result considering the fossil record-the latest Messinian [47][48][49][51][52][53].…”