Northport Shark Tooth Id

[Pool Man]

Hi all, obviously this is a tiger shark,but I usually only find the extant type teeth. This looks like the extinct version(contorus?). It was found in the same layer as a Megalodon, in Northport. What do ya'll think? This would be the first I've found.It measures 1" across the top and 1 1/8" down the long side.

Thanks,

Dan

[Synechodus]

Hi all, obviously this is a tiger shark,but I usually only find the extant type teeth. This looks like the extinct version(contorus?). It was found in the same layer as a Megalodon, in Northport. What do ya'll think? This would be the first I've found.It measures 1" across the top and 1 1/8" down the long side.

Thanks,

Dan

Hi Dan,

I think I can relate to why you are thinking about a P. contortus, but ..... to me the main cusp is too broad for a P. contortus. Also, the distinctive "dip" in the mesial cutting edge is not so pronounced As I would expect for a P. contortus.

What would help would be if you could take some shots perpendicular to the first two, i.e. mesial --> distal and vice versa.

BTW. nowadays the name Physogaleus contortus is used for that you were refrerring to.

So its Galeocerdo aduncus

and Physogaleus contortus .

Cheers,

Paul

[Harry Pristis]

Hi Dan,

I think I can relate to why you are thinking about a P. contortus, but ..... to me the main cusp is too broad for a P. contortus. Also, the distinctive "dip" in the mesial cutting edge is not so pronounced As I would expect for a P. contortus.

What would help would be if you could take some shots perpendicular to the first two, i.e. mesial --> distal and vice versa.

BTW. nowadays the name Physogaleus contortus is used for that you were refrerring to.

So its Galeocerdo aduncus

and Physogaleus contortus .

Cheers,

Paul

Thanks, Paul, for illustrating your remarks with good images.

Here's what Hulbert says about these tiger sharks:

The teeth of

Galeocerdo aduncus

. . . have narrower cusps than

G. cuvier

. The teeth of

Galeocerdo (Physogaleus) contortus

have a much more narrow and slender cusp, weaker serrations that are usually not complex, and the mesial cutting edge is twisted or sigmoidally curved in mesial view. . . .

G. contortus

persisted to the end of the Miocene in Florida, while

G. aduncus

graded into

G. cuvier

during this epoch.

Hulbert mentions, citing Cappetta (1987), that while G. aduncas is known from many regions of the world, G. contortus is known only from North America. I didn't realize that.

[Synechodus]

.....

Hulbert mentions, citing Cappetta (1987), that while G. aduncas is known from many regions of the world, G. contortus is known only from North America. I didn't realize that.

I do, we don't find them over here ..... though I know some teeth that have led to extensive discussion whether they are indeed P. contortus or "just a certain position" within the G. aduncus dentition.

Cheers,

Paul

[Gatorman]

Sweet Tooth Dan! I'm gonna say its a Galeocerdo cuvier with a little twist to the tip.

[Guest bmorefossil]

Sweet Tooth Dan! I'm gonna say its a Galeocerdo cuvier with a little twist to the tip.

yea it looks like a cuvier to me

[Northern Sharks]

I would also agree with G.cuvier based on size. G.aduncus didn't get as large and seem to max out at about 3/4" long. Regarding Harry's post about aduncus evolving into cuvier, Richard Chandler (on Elasmo.com) supports the theory of G.latidens->G.mayumbensis->G.cuvier and states he doesn't know exactly where G.aduncus fits in but suggests possibly G.mayumbesis as the father of both G.aduncus (small tooth Tiger) and G.cuvier (large tooth Tiger)

[Pool Man]

Thanks every one!