Did the giant extinct shark Carcharocles megalodon target small prey? Bite marks on marine mammal remains from the late Miocene of Peru

• Published in: Palaeogeography, palaeoclimatology, palaeoecology Vol. 469; pp. 84 - 91
• Main Authors: Collareta, Alberto, Lambert, Olivier, Landini, Walter, Di Celma, Claudio, Malinverno, Elisa, Varas-Malca, Rafael, Urbina, Mario, Bianucci, Giovanni
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2017
• Subjects: Co-extinction; Megatooth shark; Piscobalaena nana; Predation; Scavenging; Shark bite marks; Piscobalaena nana; Predation; Shark bite marks; Co-extinction; Scavenging; Megatooth shark
• ISSN: 0031-0182; 1872-616X
• DOI: 10.1016/j.palaeo.2017.01.001

We report on bite marks incising fossil mammal bones collected from upper Miocene deposits of the Pisco Formation exposed at Aguada de Lomas (southern Peru) and attributed to the giant megatooth shark Carcharocles megalodon. The bitten material includes skull remains referred to small-sized baleen whales as well as fragmentary cetacean and pinniped postcrania. These occurrences, the first in their kind from the Southern Hemisphere, significantly expand the still scarce record of bite marks for C. megalodon; moreover, for the first time a prey (or scavenging item) of C. megalodon is identified at the species level (as Piscobalaena nana, a diminutive member of the extinct mysticete family Cetotheriidae). Due to the fragmentary nature of the studied material, the exact origin of the detected marks (i.e., by scavenging or by active predation) cannot be ascertained. Nevertheless, relying on actualistic observations and size-based considerations, we propose that diminutive mysticetes (e.g., cetotheriids) were some of the target prey of adult C. megalodon, at least along the coast of present-day Peru. C. megalodon is thus here interpreted as an apex predator whose trophic spectrum was focused on relatively small-sized prey. Lastly, we propose a link between the recent collapse of various lineages of diminutive mysticetes (observed around 3Ma) and the extinction of C. megalodon (occurring around the end of the Pliocene). [Display omitted] •We report on shark bite marks affecting late Miocene marine mammal bones of Peru.•The bite marks are referred to the extinct giant shark species Carcharocles megalodon.•The bitten items include small mysticetes (e.g., Piscobalaena nana) and pinnipeds.•The trophic spectrum of C. megalodon could have been focused on relatively small prey.•We support a new ecological hypothesis about the extinction of C. megalodon.