Carcharocles augustidens

Name Meaning:  Glorious Tooth

Geologic Era:  Oligocene to Miocene

Size:  9.3 meters (31 feet) based on New Zealand specimen

Range:  Worldwide (comparable to modern Great White shark)

Extinction Date:  Late Miocene

This shark’s name is under dispute, the same as Carcharodon megalodon.  The alternate name would be Carcharodon augustidens.  Both names have a similar amount of support, and a definitive conclusion cannot be reached until a full skeleton is found of either species.  Therein lies the problem, as shark skeletons are primarily composed of cartilage.  Cartilage is soft tissue, and rarely fossilizes.  Sometimes the occasional shark vertebral centrum will mineralize to the extent that fossilization is possible, but this is rare.  However, mineralization in life usually indicates an older animal, which does give an estimate of maximum size.  Other fragmentary remains suggest a higher maximal size for C. augustidens, but how much higher is still up for speculation.

The overall body plan of sharks has not changed drastically in 200 million years.  It is therefore safe to assume that C. augustidens probably resembled a scaled up version of a modern Great White or tiger shark.  Most sharks share the same streamlined body plan, with the exceptions being bottom dwelling sharks.  Many sharks are ambush predators, relying on their speed and strength for a quick kill.  C. augustidens attack pattern may have been to strike prey from underneath, as modern Great Whites do.  Many whale bones from this time show gash marks from teeth that support this attack pattern, the gashes being concentrated on the tail vertebrae and the flippers (see Squalodon chevron for examples of similar marks).

C. augustiden’s only real competitors for food would have been the larger, primitive sperm whales of its day.  It probably would have fed on smaller whales, dolphins, and fish.  Incidentally, the Squalodon tail chevron in our collection has tooth marks that are consistent with a small C. augustidens.  Squalodon was the size of a large dolphin, and well within the size range for acceptable prey. 

C. augustidens is considered one of the megatoothed sharks, no matter its ultimate classification.  One feature that it retains that was lost in later sharks is the small cusps (mini teeth) on either side of the main tooth.  These teeth show serrations, just as the larger ones do.  These tooth cusps are much more prominent in earlier sharks of this lineage. 

Image Credits:
Life Reconstruction:http://www.prehistoric-wildlife.com/species/c/carcharocles-angustidens.html