Cusps of mega-toothed shark

[Jerrychang]

We should all agree that the side cusps  of these shark gradually disappeared with evolution, but how did they deform in the process of shrinking and disappearing ?

Does the cusps’s tip gradually move closer to the middle crown and fuse together?

Just like the two teeth in the picture below, is the brown specimen older than the other?

[Miocene_Mason]

It appears less that the cusps moved in, rather the crown moved out. C. megalodon is much more triangular, less “lanceolate” as we say. They were kind of engulfed rather than disappearing. Recent evidence suggest they pose no structural problem, them being lost is simply a side effect of the crown becoming larger and wider.

[Gareth_]

I agree with the comments above.... as the genus evolved through time, the cusplets got swallowed up by the crown as the crown got wider. I'm not sure in which species the cusplets became officially vestigial, but they are an adaptation for gripping fish. As the genus got larger, the target prey got larger and less fish based, which is where the need for a more robust tooth developed from.