Angustidens (above left)

Charcharocles Angustidens was around approximately 20 to 25 million years ago and had teeth almost 5 inches in slant length.  Its teeth are distinguishable by the fact it had a fully serrated (Charcharocles) narrow crown when compared to its length.  It also had extremely pronounced side cusps with a well defined center serration on each one (almost like each side cusp has its own tip).  Angustidens is considered by many to be the first true ancestor of Megalodon with the Genus - Charcharocles.

 

Chubutensis (above center)

Charcharocles Chubutensis is a controversial term used to describe the evolution of the species as it transitioned from Charcarocles Angustidens to Charcharocles Megalodon.  There are many who do not believe it to be an actual species, but rather just the early version of the Megalodon.  I, however; believe it to be its own species.

It lived approximately 18 to 20 million years ago and had teeth up to 5 inches.  Its teeth are similar to that of Angustidens, but with slight differences.  They had a fully serrated, but wider, crown when compared to Angustidens.  It also had  developed side cusps, but with a weaker cusp center serration, and in some cases no defined center serration at all, just a rounded side cusp.

 

Megalodon (above right)

Charcharocles Megalodon evolved about 20 million years ago.  Many experts believe that this amazing beast grew to over 65 feet in length and weighed over 25 tons.  They produced teeth up to 7 inches when measured along the slant length.