These past few days, I’ve also been reading the various suggestions in the comments, so I made some refinements to the previous reconstruction and proposed several other possibilities as well. Therefore, these are four different reconstructions of the Megalodon.
By combining a reconstruction of the megalodon’s head—based here on the latest study of its dentition—with a comparison to a cranial reconstruction of Livyatan melvillei, it is evident that, although the megalodon’s head was smaller than that of Livyatan melvillei, it possessed a larger bite area, which suggests greater damaging potential. We also compared the body size of the megalodon and Livyatan melvillei (using the maximum estimated size of the holotype specimen of Livyatan melvillei). Although the megalodon was longer, its body mass would not have held a substantial advantage. Taken together, this indicates that the difference between the two was minimal, and in the event of a confrontation, neither could be certain of being able to kill the other.
This reconstruction of Megalodon was modeled with reference to lamnid sharks such as the Shortfin Mako Shark. My interpretation is that it likely did not require an excessively massive, bulky body plan; instead, it may have relied on a more streamlined and agile morphology to dispatch prey with greater speed and efficiency.
So we set it size to be 18 meters in length and 55 tons in weight.
The Megalodon used the estimated body size and the maximum estimated size of Livyatan Holotype （21m Megalodon VS 17.5m Livyatan）