There is currently great controversy among paleontologists and "amateur experts" concerning the origins, ancestors, relatives and lineages of some of our favorite sharks.  Please do not read any of the following as "Fact".  Unless someone invents a Time Machine, we will never know the true lineage of some of these great beasts.  The following is simply speculation and OUR "amateur expert" opinion based on 29 years of studying literally thousands of shark teeth, all the arguments, and a little common sense thrown in for good measure.

NOTES:
1.)    The discussion below refers to the drawing at the bottom of the page - Figure 1.  Please refer to it often as you read the text.
2.)    We do not believe in "splitting species" for every little change in tooth structure, therefore you will not find references to some sharks in the following discussion.  "Genus" like Cosmopolitodus; "Species" like Isurus denticulatus, I. novus, I. shoutedeni, I. winkleri, I. xiphodon; Carcharocles turgidus, C. sokolowi, C. debrayi, C. gibesi, C. nodai will not be considered in the following text.  Nor will you see mentioned I. hastalis "Narrow-Form" and "Broad-Form"; Carcharodon carcharias "small-toothed" and "large-toothed".
3.)    Please do not be confused by the family terms Great White and Giant White.  The first term refers to the group of sharks leading up to the Modern Great White.  The second term refers to the group leading up to the extinct C. megalodon and is commonly accepted usage.
4.)    The terms in red are Geologic Epochs and Stages.  For an expanded and chronological view of these "time chunks" click on:   A Long History of DeepTime    The ages noted with the different species are the approximate time period during which the shark evolved.
5.)    One group of paleontologists believes that the Great White is a direct descendant of or a brother to the largest of all shark predators - megalodon.  Another group believes that the megalodon was the last of a group known as the Giant White sharks and that the Great White descended in a separate branch that also produced the 2 modern Mako sharks.  The former group calls the extinct animal "Carcharodon megalodon", and the latter group calls her "Carcharocles megalodon".  We will take the side of the latter group and defend the theory that the Carcharocles megalodon died out as a species and left no descendants.
6.)    All materials on this page (and WebSite) such as titles, writings, descriptions, drawings, webpage design, works of art, captions, and photographs are subject to copyright protection and may not be copied by others without the written permission of MegMawL.com

Sharks and rays evolved out of the other Vertebrata sometime between 400 and 450 million years ago.  Sharks of the Superorder Galeomorphii are the ancestors of the sharks we are interested in in this discussion.  The small amount of evidence we have suggests that the Order Lamniformes may have evolved out of this group during the late Jurassic Period, about 150 million years ago.

Daddy of Them All

The genus of sharks known as Cretolamna, in the order Lamniformes, was the ancestor of at least three branches of species of sharks.  During the Late Paleocene (58 MYA) an explosion of shark species occurred, due in part to the rich abundance of food which followed the mass extinction at the end of the Cretaceous Period.  Some of these branches evolved into modern sharks and some led to evolutionary dead ends.  Cretolamna appendiculata evolved during the part of the Cretaceous Period called the Cenomanian Stage - 99 to 94 million years ago (MYA) - and had small, triangular, non-serrated teeth that had side cusplets.

See:     Cretolamna Shark Teeth

Cretolamna Line #1

One of the progeny of the Cretolamna was Paleocarcharodon orientalis, the Pigmy White Shark, which lived during the Paleocene Epoch, Danian Stage, (65 to 61 MYA) and had developed teeth with serrated edges.  It was not successful as a species and produced no descendants.

See:     Paleocarcharodon Shark Teeth

Cretolamna Line #2

Another "child" of Cretolamna was Otodus obliquus, the Giant Mackerel shark.  This animal evolved during the Maastrichtian Stage of the Cretaceous period (70 MYA) and lived during the Paleocene and Early Eocene Epochs (65 mya to 50 mya).  Otodus had non-serrated teeth with cusplets like its parent but they were much larger and thicker.  The largest teeth being about 4".

To see some of these teeth start at:     Moroccan MainPage

Otodus produced two lines.  The first line was the False Mako Shark - Parotodus benedeni which lived during the Oligocene Epoch (34 to 23 MYA).  The thick, robust teeth of this shark had no cusplets and no serrations.  This animal failed in its effort to survive as a species and came to an evolutionary dead end.  The teeth of this animal are very rare and expensive sometimes costing over $100 per inch for the larger, higher quality teeth.

For a photo of one of these teeth from Lee Creek, click on:     P. benedeni

The second line was more successful and led to the Giant White; Carcharocles genera of sharks.  The first was the Eocene Epoch (55 to 34 MYA) animal, Carcharocles auriculatus.  The teeth from this fish had thick roots and blades, cusplets like his ancestors and had also developed serrated edges.  The largest of these teeth grow to about 4 3/4".

The next species in the evolutionary chain was given the name Carcharocles angustidens.  This predator lived during the Oligocene (34 to 23 MYA).  The teeth are larger than those of its parent (over 5") with a broader, thinner blade and less of a thick, V-shaped root.

To see some of these teeth start at:   C. angustidens MainPage 
and:    C. angustidens Teeth From Lee Creek

During the Early Miocene Epoch, Aquitanian Stage (23 to 22 MYA), C. angustidens evolved into the species, Carcharocles chubutensis which had teeth that had poorly defined, rounded cusplets that in some geographic locations approached 6" in slant height.  This animal flourished during the Early to Mid Miocene Epoch (23 to 14 MYA)

To see some of these teeth from Lee Creek, click on:     C. chubutensis from Lee Creek

Carcharocles subauriculatus.  We have found Miocene teeth that do not fit in either Carcharocles angustidens or Carcharocles chubutensis species.  They have characteristics of both species but certainly not C. auriculatus and C. angustidens, as the paleontologist who misnamed them apparently intended.  We will call them by an old/new name just to differentiate them.  Carcharocles subangustidens would be a much more appropriate name, but this one could not be found in old taxa nomenclature.  We believe them to be species variant of the C. chubutensis and will go with the name Carcharocles subauriculatus.

To see some of these teeth from Lee Creek, click on:     C. subauriculatus from Lee Creek

Photo 1 shows these three species together.  On the C. subauriculatus, note the C. angustidens type cusplet on one side and the C. chubutensis type cusplet on the other.  What the photo does not show clearly is the progression in root size, blade thickness, bourrelet size and serration size.

The final animal in the Giant White lineage was the Carcharocles megalodon which evolved around 14 MYA during the Miocene Epoch (23 to 5 MYA).  The massive fossilized teeth of this animal sometimes reach a slant height of 7 5/8 inches and weigh nearly 2 pounds.  The teeth are serrated like those of the megalodon's immediate ancestors but do not have side cusplets.

To see some of these teeth, click on:     MegMawL.com Megalodon Teeth

Cretolamna Line #3

Another line of descendants from Cretolamna appendiculata successfully led to the Isurus and Great White lines.  It is from this branch that the modern Makos and the Modern Great White sharks descended.  These sharks lost the cusplets on their teeth early in the evolutionary cycle and a couple of descendants developed serrated edges.

The third "child" of Cretolamna appendiculata was the Eocene Epoch, Ypresian Stage (55 to 50 MYA) Mako - Isurus praecursor.  The teeth of this beast were very similar to it's father's except for the loss of cusplets.

Isurus praecursor produced at least 3 lines of Mako sharks.  The first animal of the first line was the Eocene Epoch (about 50 MYA) Mako - Isurus desori.  This animal had teeth that were very similar to its father's but larger and longer.  I. desori survived a very long time as a species, about 50 million years.  Fossilized teeth can be found in Summerville, SC, in Pliocene sediments about the time that it became extinct.

Isurus desori produced one descendant (maybe two, see below) - the shark named Isurus oxyrinchus (oxyrhinchus).   This animal evolved during the Early Miocene, Aquitanian Stage (23 to 22 MYA) and it swims the oceans today commonly called the Shortfin Mako.

The first animal of the second line from the Isurus preacursor was the Oligocene Epoch (about 30 MYA) Mako - Isurus retroflexus.  The teeth are larger than those of the I. preacuror and I. desori and are easily identified by the horizontal groove in the root right above the blade on the flat side of the tooth.

For a photo of 3 of these teeth from Holland, click on:     Isurus retroflexus Display Side

Isurus retroflexus produced one descendant - the shark named Isurus paucus.   This animal evolved during the Chattian Stage of the Late Oligocene (about 25 MYA) and it swims the oceans today commonly called the Longfin Mako.

The third and most interesting line produced by Isurus preacursor was the Great White lineage of sharks.  This line was fathered by the Oligocene Epoch (about 30 MYA) shark, Isurus hastalis, the most prolific producer of fossil shark teeth the world has ever known.  Teeth of this animal approach 3 1/2" in slant height.  This animal fathered 3 descendants.

One of the daughters of Isurus hastalis was the Miocene Epoch, Langhian Stage (about 16 MYA) animal known as Isurus planus.  This shark only roamed the Pacific Ocean and never spread into the other oceans of the world. We think this animal went extinct without leaving any descendants but we have no idea when because about 14 millions years ago the oceans receded from the existing land masses and the progression of teeth from this animal were lost in what is now deep water.  The teeth of this animal are known for their graceful curves along the midline always toward the back of the jaw. 

Another possible daughter of Isurus hastalis was the Miocene (about 15 MYA) shark - Isurus escheri.  The tooth shape and size point to another possible ancestor such as I. desori.  Isurus escheri only roamed the Northern Atlantic Ocean although some claims have been made for teeth found in one place in the Pacific.  Some paleontologists believe that this shark was the father of the Great White Shark based on the fine serrations found along the blade edge.  We do not agree with this and will explain in the next section.  For this reason we will just note that this shark went extinct without any descendants.

The third (second?) daughter of Isurus hastalis is the infamous Great White Shark - Carcharodon carcharias - which evolved NO LATER THAN the Late Miocene Epoch, Tortonian Stage (10 - 7.6 MYA).  Fossil teeth of this animal grew to a maximum size of about 3 3/8".

There are about 6 different theories by very qualified paleontologists dealing with the ancestry of the Great White.  The most prominent people who have an opinion on this will gladly tell you that the Great White DID NOT EVOLVE DIRECTLY from I. hastalis, but either from I. escheri or from a presently unnamed Isurus species loosely called "Transitional".  Very few of these professionals have access to the huge quantities of fossils that pass through the hands of a dealer.  We will take an empirical, common sense approach based on the thousands of teeth that we have seen and collected over the years.

We have about 50 of the "Transitional" teeth from Peru and Chile.  None of these teeth actually "transition" from a non-serrated, knife edge to a uniformly serrated edge.  These teeth are characterized by their HUGE, COARSE serrations on the upper part of the blade edge, medium to fine serrations on the middle section and no serrations on the lower edge toward the tip.

NONE of the thousands of teeth we buy each year from these countries have fine serrations gradually changing into the coarse serrations characterized by the Great White Shark.  Evidence from the other shark species who have evolved the serrated edge (and common sense) would indicate that Nature would not go directly from no serrations on the upper blade edge to HUGE serrations.  If Nature could do or did this magic trick, why not go DIRECTLY from non-serrated to full blown, coarse serrations on the ENTIRE blade edge?

Several scientists and some "expert amateurs" have written articles and papers justifying the view that the Great White descended from the South American "Transitional".  Many of these arguments are based on a paper -  Geology and Paleontology of Late Cenozoic Marine Deposits in the Sacaco Area (Peru);    By: Christian de Muizon,  and Thomas J. DeVries;    Geologische Rundschau 74/3, 1985, S. 547-563. 

Paleontology is like religion in that one can try to prove a point by taking material out of context.  Muizon,  and DeVries write of finding I. hastalis teeth alone in 8.8 Million Year Old layers, I hastalis and "Transitionals" together in ~6 MYO layers, "Transitionals" and Great Whites together in ~5 MYO layers and Great Whites alone in 3.9 MYO layers.  The arguments by the Interent authors supporting the view that Peru "Transitional" was the father of the Great White Shark would lead you to believe that Great White did not exist as a species during the Miocene or before and that it evolved from Isurus (or Carcharodon) "Transitional" during the Pliocene.

One can just as easily argue that at the 8.8 MYO point in Peru the Great White had fully evolved on the Eastern Coast of North America and was beginning to spread throughout the oceans of the world - not yet found in Peru.  Further one could say that the "Transitional" was a "Chronomorph" - an aberrant geographic experiment that failed and had no descendants because the Great White Shark had moved into it's feeding area about 5 MYA and (having fully serrated teeth) drove it and I. hastalis into extinction.

Other statements in the article are not mentioned by Internet authors:  "On the Peruvian Coast, therefore, C. carcharias constitutes a good Pliocene indicator and I. hastalis (including transitional forms) a good Miocene indicator.  The situation was perhaps different on the Eastern Coast of North American where some C. carcharias-like teeth have been discovered in the Choptank Formation (late Miocene) of Maryland (R. Purdy, pers. comm. to C. M.)". 

Things to consider:

(1.)  On November 8th, 2003, in our personal conversation with Bob Purdy of the Smithsonian he stated that the Great White Shark evolved during the Eocene Epoch (34 to 55 MYA) and not from the "Transitional".

(2.)  Rick Martin on his excellent WebPage:
http://www.elasmo-research.org/education/evolution/carcharodon.htm
details another lineage with the Great White evolving from Cosmopolitodus hastalis, through Cosmopolitodus escheri, some 11 million years ago.

(3.)  We also have several Great White teeth in our collection that were found in non-reformulated Calvert Formation Members.  These teeth are completely serrated and are 14 MYO. 

There is no way that the Great White Shark could have evolved from the 6 Million Year Old, South American "Transitional".

Now to the hypothesis that the Great White Shark evolved from the Atlantic species - Isurus escheri.  This animal's fossil teeth are characterized by very fine serrations along the entire blade edge. This meets the evolutionary and common sense criteria for the gradual change from a non-serrated edge to a very finely serrated edge.  One problem with viewing this species as the son of Isurus hastalis and father of the Great White is that the teeth are nowhere near as big as either the Isurus hastalis or the Great White.  As we have seen in the progression of the Carcharocles line above, teeth of the children tend to be as large or larger than teeth of the parent.  Another problem is that none of the hundreds of teeth we have seen transition to the larger serrations or larger size that characterize the fossil Great White teeth.

Teeth of I. hastalis and C. carcharias are almost identical in size, shape, thickness, etc.  The only significant difference is the serrated edge.

We do not have a fossil record of the teeth that would show the change from Isurus hastalis to the Great White shark.  These teeth would have been the same size and shape as the father and son (and the "Transitionals").  They would have fine serrations along the entire blade edge like the I. escheri, gradually changing over millions of years into medium serrations and then the coarse serrations.  The data suggest that these serrations are continuing to evolve larger and larger.  Modern Great White teeth serrations are quite a bit larger uniformly, than those of the Great Whites of 3 million years ago.

The absence in the fossil record of teeth beginning to serrate can be explained by noting that during the time I. hastalis was evolving into C. carcharias the earth was in an intense period of glaciation.  During the transition between the Mako and the Great White, much of the world's water was tied up in ice caps and glaciers which caused the ocean water to recede from the continental edges.  Teeth from this "change-over species" would have been lost in what was then shallow water but is now deep water and have not been recovered for study.

This gap in the fossil record can be seen in several areas, for example Lee Creek, NC.  There are no marine fossil formations to be found at this site between the ages of 14 million years old and 5 million years old.  When the ice melted and the ocean returned 5 million years ago, it formed the Yorktown Formation.   In this formation can be found coarse, completely serrated Great White teeth indicative of a species that was well established, having evolved long before these were lost.    More information at:    Lee Creek Shark Teeth    Lee Creek Mine Stratigraphy  and  Definitions - Ice Age    See Isurus planus above for something similar with its extinction time.  Similarly, scarce sediments of mid-Ypresian age account for lack of fossil shark teeth that show the transition between the non-serrated Otodus obliquus and it's child, the serrated-toothed, Carcharocles auriculatus.  To complicate matters, HUGE QUANTITIES of fossils which could have added to the fossil record have been lost forever to the action of Plate Tectonics Subduction.  In general, when a thin, dense oceanic plate meets a thick, light continental plate, the oceanic plate is forced under the continental plate and the fossils it contains are destroyed.

It is our belief that there is NO NEED for another "species" between Isurus hastalis and the Great White Shark.   The teeth are almost identical in every aspect except the edge.   Unlike being "sort of pregnant", the edge is either non-serrated (Isurus hastalis) or serrated (Great White).   There is no such thing as an edge being "semi-serrated".

This progression represents MegMawL's current "Best Guess" based on empirical data, observation and common sense criteria.  Teeth characteristics are variable, even within species, due to factors like sex, position in the jaw, age and pathology.  Further complications come from changes due to ontogenetic stages in the development of an individual shark and species variation due to relative geographical isolation.  We would know a lot more about the lineage of these sharks if we had full dentitions of every species that ever lived, mummified remains or well preserved skeletons for detailed studies.  Since the shark family skeleton is cartilaginous and does not fossilize well, very little remains to study except for the teeth and even then, only the ones that we have recovered.