Symphysial Squalicorax

[creto]

This is an image of a symphysial Squalicorax yangaensis tooth. Notice the side cusps. This is not a pathological tooth-I have found another that is nearly identical.

[Auspex]

I would have had no idea what this tooth was!

[creto]

The first one I found has a cross section that is very round without any hint of carina, this one is slightly flattened. The first one had no serrations on the main cusp at all but the side cusps were serrated. These teeth are also considerably smaller than any other S. yangaensis teeth at this site(~5mm).

[Vordigern]

nice find! I had 4 but gave one to a friend and the 3 remaining are among my most prized teeth in my collection

[siteseer]

Creto,

Interesting tooth. What formation/site is it from? Is S. yangaensis the only species of Squalicorax found at that site.

It's possible the teeth are so rare that there was only one symphyseal file in the jaw or not all individuals had even one symphyseal file. They seem to be rarer than Hexanchus or Notorynchus symphyseals but I don't have any numbers to back that up. Maybe someone else has more to add on that.

I have seen a tooth from Edgemont, South Dakota (Carlile Shale, Turonian) very similar to that but slightly larger (almost 7mm high) and straighter. One side cusplet is separated from the crown but the other is connected to the crown. It was Identified as a symphyseal of S. falcatus - the most common or perhaps the only species of the genus at Edgemont.

There was a time when a lot of teeth were being collected at Edgemont and they were even commercially available (I bought a Squalicorax falcatus tooth in a small matrix piece at a Natural Wonders, a natural history store chain no longer in business in the late 80's). However, either the BLM or the National Park Service took over the area - collecting has not been permitted for years.

Jess

This is an image of a symphysial Squalicorax yangaensis tooth. Notice the side cusps. This is not a pathological tooth-I have found another that is nearly identical.

[Boneman007]

Is there any way you can post a actual photo of the tooth? A lot of cannot see photobucket pics.

[siteseer]

Boneman007,

I did an image capture. Here it is:

Is there any way you can post a actual photo of the tooth? A lot of cannot see photobucket pics.

Edited May 4, 2013 by siteseer

[sixgill pete]

creto, what an awesome find. Symphyseal's and parasymphyseal's are among my favorite teeth to find. They are so uncommon and some species, downright rare. One of my most prized teeth is a parasymphyseal auriculatus. Congrats!!!!!

[Boneman007]

Boneman007,

I did an image capture. Here it is:

squalicorax.tiff

WOW!

I have a bazillion (actual count) squalicorax teeth and have NEVER seen anything even close to that!

[creto]

My guess is that these teeth are only associated with one species-S. cf yangaensis. I don't have a bazillion of them, I've found more like dozens. I got another one today, my third. The newest one does not have side cusps- instead it has a major constriction at the neck. All three are about the same size.

[Al Dente]

Here are a couple of Squalicorax teeth that have a similar shape to your sympheseal tooth. In the case of my teeth, I think they are more likely anterior teeth than symphyseal. These teeth are Squalicorax bassanii from the Black Creek Group of North Carolina. The elasmo.com site has started calling these S. yangaensis, I think they look more like S. bassanii.

The lower right tooth is 15 mm long.

[creto]

Those are familiar tooth positions to me. The two narrower teeth are definitely anteriors and the wider tooth a lateral. The associated symphysial teeth are much smaller(~5mm). I agree with elasmo on this one. This seems to be closest to S. yangaensis, which is a little different still. S. bassanii are considerably thicker than these. I'm pretty sure this is an American species and probably needs a name of its own. The complex compound serrations are distinctive.

[non-remanié]

Al Dente's 2 anterior specimens match well with anterior-most latest Campanian forms found here in NJ, specifically the Wenonah fm. Probably these are just slightly younger than the NC yangaensis. Squalicorax kaupi has been the long accepted ID for these in the Wenonah, but it seems that Squalicorax lindstromi may be gaining favor for a good portion of the fauna but there may be other forms. There is surely also S. pristodontus, but it seems to be an early possibly transitional form that grades upward from the kaupi/lindstromi line. Just a tad later in the overlying Mt. Laurel and/or Navesink fm. S. pristodontus morphology seems to match better what is seen elsewhere and the transition seems complete.

Creto's possible symphyseal teeth from NM match well with a couple kaupi/lindstromi type teeth that I have collected from the Wenonah fm and had considered symphyseal. These teeth are extraordinarily rare here, probably 1/5000+. The best match is pictured first, and is also cusped, and one side is unserrated. The root is also odd and thumb-nail like compared to other tooth positions. Another symphyseal tooth very similar to this one was collected by a friend and can now be seen on Patrick Hendrik's page under NJ squalicorax category. http://www.patricksharkteeth.com/

But here are a couple more teeth that are possible symphyseals that I have from NJ but they don't exactly conform to this (and Creto's), but I think seem more like symphyseals than anteriors. It could be that the Squalicorax lindstromi/kaupi line was in the process of losing its symphyseal tooth file or had likely already done so and these are atavistic/holdover specimens, so each one might have been a little different. Exactly what Jess was saying. It definitely seems like not all squalicorax must have had this tooth position.

Also I also included a picture which shows some other interesting, odd, and/or anterior specimens from NJ. Ignore the numbers, they were for another purpose.

[non-remanié]

nice find! I had 4 but gave one to a friend and the 3 remaining are among my most prized teeth in my collection

Would love to see a pic. But yours are probably from the Englishtown/Woodbury transitional beds, right?

[creto]

Here is a couple of pics of two symphysials. The third pic is the symphysials compared to some more normally sized anteriors. I found both symphysials this week. The symphysials are not serrated all the way down the blade and stop where it is pinched.

Edited May 9, 2013 by creto

[MarcoSr]

Creto,

Interesting tooth. What formation/site is it from? Is S. yangaensis the only species of Squalicorax found at that site.

It's possible the teeth are so rare that there was only one symphyseal file in the jaw or not all individuals had even one symphyseal file. They seem to be rarer than Hexanchus or Notorynchus symphyseals but I don't have any numbers to back that up. Maybe someone else has more to add on that.

I have seen a tooth from Edgemont, South Dakota (Carlile Shale, Turonian) very similar to that but slightly larger (almost 7mm high) and straighter. One side cusplet is separated from the crown but the other is connected to the crown. It was Identified as a symphyseal of S. falcatus - the most common or perhaps the only species of the genus at Edgemont.

There was a time when a lot of teeth were being collected at Edgemont and they were even commercially available (I bought a Squalicorax falcatus tooth in a small matrix piece at a Natural Wonders, a natural history store chain no longer in business in the late 80's). However, either the BLM or the National Park Service took over the area - collecting has not been permitted for years.

Jess

Jess

Attached is the picture of another tooth from the same site as creto's tooth. It is 7mm and seems to match pretty well your description of the Edgemont symphyseal of S. falcatus. What do you think? From NMMNH Bulletin 52 the Squalicorax or similar genus Scindocorax found at the site include: Scindocorax novimexicanus, Scindocorax sp. aff. S. novimexicanus, Squalicorax sp. cf. S. Lindstromi, Squalicorax sp. aff S. yangaensis, and Squalicorax cf. S. yangaensis. However, Scindocorax is a small tooth with a lot of specimens around 5mm.

Marco Sr.

[siteseer]

MarcoSr.,

Yes, that tooth does look very similar to the Edgemont tooth. The crown on your tooth is just a little straighter.and maybe slightly higher in relation to the root. I would say that they are variations of the same jaw position.

At some point I will try to get a photo of it and of a specimen from the Late Cretaceous of Mississippi (Barton Bluffs area, Santonian?).

Jess

Jess

Attached is the picture of another tooth from the same site as creto's tooth. It is 7mm and seems to match pretty well your description of the Edgemont symphyseal of S. falcatus. What do you think? From NMMNH Bulletin 52 the Squalicorax or similar genus Scindocorax found at the site include: Scindocorax novimexicanus, Scindocorax sp. aff. S. novimexicanus, Squalicorax sp. cf. S. Lindstromi, Squalicorax sp. aff S. yangaensis, and Squalicorax cf. S. yangaensis. However, Scindocorax is a small tooth with a lot of specimens around 5mm.

Symphyseal 7mm.jpg

Marco Sr.

[MarcoSr]

MarcoSr.,

Yes, that tooth does look very similar to the Edgemont tooth. The crown on your tooth is just a little straighter.and maybe slightly higher in relation to the root. I would say that they are variations of the same jaw position.

At some point I will try to get a photo of it and of a specimen from the Late Cretaceous of Mississippi (Barton Bluffs area, Santonian?).

Jess

Jess

I would definitely like to see photos of those other two specimens.

Marco Sr.