Extant Galeocerdo cuvier (Tiger Shark) jaw

[MarcoSr]

Here is a Galeocerdo cuvier (Tiger Shark) jaw that I recently acquired. The jaw is 11” wide and 7” inches high. I did not purchase one of the large collector jaws because I believe that encourages fishing for the larger tigers for the jaw trade. This jaw came from the regular fishing industry.

Here is the overall jaw:

To better see tooth details double clique the below pictures. If you mouse over the pictures you will see the file name which has additional positional information.

If you look closely at the pictures like the one below you can see compound serrations (serrations on serrations) which Galeocerdo cuvier teeth display.

According to Compagno 1988 Galeocerdo have medial, symphyseal, anterolateral and posterior teeth.

Upper jaw symphysis with one file of medial teeth (red):

Two pictures of the lower jaw symphysis with two files of symphyseal teeth (according to Compagno 1988) (blue) and one file of medial teeth (red). The symphyseal teeth in this jaw are much larger than the normal symphyseal teeth that I see and I’m not really sure why Compagno didn’t call them anterolaterals. :

Again according to Compagno 1988 Galeocerdo cuvier have two posterior teeth on either side in both the upper and lower jaws.

Upper jaw left and right side posterior teeth:

Lower jaw left and right side posterior teeth (Note the posterior teeth have a very nondescript crown shape on the right side):

Continued in the next reply:

Marco Sr.

[MarcoSr]

Here are the upper jaw anterolateral teeth left side:

Here are the upper jaw anterolateral teeth right side:

Continued in the next reply:

Marco Sr.

Edited February 12, 2016 by MarcoSr

[MarcoSr]

Here are the upper jaw anterolateral teeth right side (Continued):

Here are the lower jaw anterolateral teeth left side:

Continued in the next reply:

Marco Sr.

Edited February 12, 2016 by MarcoSr

[MarcoSr]

Here are the lower jaw anterolateral teeth right side (Note that the extreme right side of this jaw seems to be lacking an anterolateral tooth file.):

Here are pictures that show the number of rows of teeth in this jaw:

I can see 4 rows of upper teeth:

I can see 4 rows of lower teeth:

The upper jaw has 11 tooth files left and 11 tooth files right of the medial file.

The lower jaw has 11 tooth files left and 10 tooth files right of the medial file and symphyseal file.

To get a complete feel for Galeocerdo cuvier jaws and teeth you would really need to look at a lot of different jaws from different localities.

Marco Sr.

Edited February 12, 2016 by MarcoSr

[Plantguy]

Thanks for all the different shark jaw species photos! Makes me wonder even more about the isolated teeth I have been fortunate to find.

Regards, Chris

[MarcoSr]

Thanks for all the different shark jaw species photos! Makes me wonder even more about the isolated teeth I have been fortunate to find.

Regards, Chris

Chris

This is one of the few jaws that I acquired that I could confirm the species without research although I did check my reference materials to see what shark researchers had written on the species. For most of the extant jaws that I have it has been very difficult to 100% confirm the species id because of a lack of good reference material on the jaws/teeth and conflicting information by the different shark researchers. I had thought jaw id would be really easy but because extant species are described based upon physical characteristics like colors, gills, fins, snouts, eye lids, size etc.and not jaws and teeth it has actually been difficult. One thing I'm seeing is a lot of misidentified jaws on the internet. If you don't have extremely clear pictures of the jaw and teeth on sites like e-bay and can't id the jaw from the pictures, don't rely on the id in the post. A lot are incorrect. There are bull shark jaws being sold as great white jaws. There are a lot of different species being sold as bull and dusky jaws. A lot of hammerheads are misidentified to the species or not hammerhead jaws at all. A lot of shark species can't be 100% identified by the jaw and teeth alone. So if you don't see the actual shark and match it to the species description you will never be able to identify some jaws with 100% confidence. Also after seeing the variance of teeth features in an individual shark jaw and among different jaws from the same species and the similarity of teeth of different species I have much less confidence in the id of an individual fossil tooth than I used to. I started this shark jaw project to be better able to id individual fossil shark teeth but so far the result has been to give me less confidence in fossil shark tooth ids.

Marco Sr.

[Plantguy]

Appreciate the insight! I like your focus. I'm not sure what project I'm currently working on...thanks again.

Regards, Chris