Carcharocles-bitten sperm whale tooth from the Neogene of the Coastal Eastern United States

Abstract

A description and analysis is given of a single physeteroid tooth, from the Neogene of the Nutrien Aurora Phosphate Mine (formerly known as the Lee Creek Mine, Aurora, North Carolina, USA), that was bitten either by the extinct megatoothed shark Otodus chubutensis or Otodus megalodon. The tooth shows three gouges, one of which also preserves raking bite traces, made as the serrations on the Otodus sp. tooth struck and cut into its surface. We do not know if these bite traces came about as a result of scavenging or active predation. However, because the bite traces occur on part of the skull, this suggests a predatory interaction. This tooth preserves the first evidence in the fossil record of a predatory/antagonistic interaction between a sperm whale and a megatoothed shark.

Cenozoic megatooth sharks occupied extremely high trophic positions

“…2B ) and a trophic level range from 3.3 in the lowest δ 15 N EB individual to 9.6 in the highest δ 15 N EB individual, using a mid-range TDF of 2.5‰. This conclusion provides quantitative, integrative geochemical evidence of a very high, and flexible, trophic level for O. megalodon , and generally supports previous inferences from tooth morphology, fossilized bite marks on marine mammal bones, and tooth enameloid δ 44/42 Ca data ( 2 , 7 , 28 – 30 ).…”

“…O. megalodon is widely assumed to have been an apex predator of the Neogene ocean. Its large, triangular, serrated teeth [e.g., ( 2 )] and bite marks in fossil cetacean and pinniped bones suggest that adult O. megalodon had a diet of marine mammals [( 28 – 30 ) and references therein]. While this evidence is compelling, the morphological trend observed in the megatooth shark lineage may not necessarily suggest any possible dietary preference or shift ( 31 ), and bite marks reflect brief events that may not represent the overall diet of O. megalodon .…”

The extinct shark Otodus megalodon was a transoceanic superpredator: Inferences from 3D modeling

“…Accordingly, the analogs used to inform the reconstruction of O. megalodon encompass only the lamniforms that share similar diet, feeding strategy, and thermoregulatory physiologies ( 15 ). These include the family Lamnidae ( 49 – 52 ) but exclude ectothermic filter feeders (families Cetorhinidae and Megachasmidae) and the family Alopiidae, which includes a mesothermic species but displays anatomical adaptations (i.e., enlarged caudal fins) for a specialized hunting behavior ( 53 ) unlikely to be analogous to O. megalodon ( 18 – 21 ). Hence, the purported lack of a relationship between body form and thermophysiology in extant lamniforms based on the inclusion of species not analogous to O. megalodon ( 48 ) is not only irrelevant to the reconstruction of the extinct species as proposed in ( 15 ) but also at odds with previous studies demonstrating body form convergence among mesothermic taxa, including lamnid sharks, tunas ( 49 , 50 ), and ichthyosaurs ( 54 , 55 ).…”

“…Fossil evidence of bite marks on bones has shed some light on the autoecology of O. megalodon (18)(19)(20)(21). For instance, it has been hypothesized that O. megalodon preferentially preyed on small-to medium-size cetaceans [e.g., 2.5 to 7 m; (19,20)] such as the extinct Piscobalaena nana (19) and Xiphiacetus bossi (20).…”

Sperm whales (Physeteroidea) from the Pisco Formation, Peru, and their trophic role as fat sources for late Miocene sharks

“…Because of the speckled distribution of the bite marks, they were interpreted as reflecting scavenging events. More recently, an isolated tooth from another physeteroid exhibiting three bite marks was reported from the Miocene of North Carolina [12]. Unfortunately, as this is an isolated finding, it cannot be positively recognized as resulting from either active predation or scavenging.…”