Named By: Louis Agassiz - 1843.
Synonyms: Carcharodon mexicanus, Carcharodon productus, Megaselachus chubutensis.
Classification: Chordata, Chondrichthyes, Elasmobranchii, Lamniformes.
Species: C. chubutensis.
Size: Estimated at up to 12.2 meters long.
Known locations: Worldwide.
Time period: Chattian of the Oligocene through to the Messinian of the Miocene.
Fossil representation: Mostly teeth but some vertebral centra are also known.
chubutensis would have been an active apex predator in its
however it had to share the prehistoric oceans with not just raptorial
sperm whales but an even bigger closely related shark called C.
megalodon. Despite this competition, C.
chubutensis managed to
survive for about twenty-three million years in the fossil record
disappearing only a few million years before C. megalodon
Not only did C. chubutensis share the seas with C. megalodom, the two sharks were also related to one another with the majority of researchers thinking that they had a common lineage within the Carcharocles genus. This places C. chubutensis within an informal group known as the megatoothed sharks which also include Carcharocles angustidens and Carcharocles auriculatus. However some researchers think that all of these megatoothed sharks actually belong within the Carcharocles genus that includes the great white shark.
This belief is based upon the superficial similarity of all these sharks which is centred on all of the teeth being triangular and serrated. Counter to this theory however is the closer inspection of the megatoothed shark teeth that reveal several key differences between them and the teeth of the great white. Additionally the teeth of different members also show a reduction in teeth cusps that correlates with the appearance and disappearance of different species. For example, one of the earliest members, C. auriculatus has well defined tooth cusps. C. angustidens which is later has reduced cusps, and the teeth of C. chubutensis and C. megalodon have no cusps at all. This is why some researchers place the megatoothed sharks separate from the great white by placing them within the Carcharocles genus. Doing so also suggests a lineage of the megatoothed sharks going back to another large prehistoric shark called Otodus.