Shark Tooth

[missingdigits]

I found this in the blue hill shale, carlile formation, upper Cretaceous(Kansas ). It was complete when I found it but the root broke off during cleaning. When I picked it up I thought squalicorax but after I cleaned it I could not identify it. Searched all over Oceans of Kansas website. Note the little cusplet like nubs (for lack of a better word)on the sides. Probably an easy one and I am disappointed I couldn't figure it out. Thanks in advance!

Note: about 1 cm wide.

Edited January 23, 2013 by missingdigits

[missingdigits]

Just an anecdote, but right by this tooth I found a mudball with a partially pyritized scaphite.

Edited January 23, 2013 by missingdigits

[Missourian]

Too bad about the tooth root. Can it be reattached?

[missingdigits]

Too bad about the tooth root. Can it be reattached?

Nope. It disintegrated.

[Mudduck]

Nice, Profound Serations. The little cuspettes throw me. I don't know the species very well there in Kansas, but at first glance, I thought it was a Great White. GW's don't have cusps. How thin or robust is the tooth? Can you take a photo of the reverse side of the tooth as well as the profile of the tooth? I have found many Makos and GW's and it is very hard to find one with the root not broken. Interesting.

Very nice find!

[missingdigits]

Thanks for the reply. It is very thin. Can't take another photo at the moment. The second photo posted is the reverse. I'm still thinking its some squalicorax that I just don't know about. Just can't find any pictures like this.

[THobern]

Definitely not a Great White. It's a Squalicorax, but I think the loss of the root will make it harder to identify to a species level. That probably wouldn't have been a cusp, which still wouldn't have ruled out Squalicorax, but a bulge in the root.

[Gizmo]

Squalicorax Falcatus?

http://www.oceansofk...-2/squali02.jpg

[MikeDOTB]

I was thinking falcatus as well....

[KansasFossilHunter]

Squalicorax Falcatus?

http://www.oceansofkansas.com/sharks/Sharks-2/squali02.jpg

The funny thing is- not all of those in the picture are S. falcatus...

[missingdigits]

Squalicorax Falcatus?

http://www.oceansofk...-2/squali02.jpg

That's what I first thought as well. However, it does not have the sort of sloped side like a falcatus. Also, none of the falcatus have those odd little points on the sides at the bottom. When the root was on it was more obvious that this looked like the point of a falcatus without the sloped side( I don't know what else to call it-sorry) Maybe it's just an abnormal tooth. I don't know, just looks strange to me.

Edited January 23, 2013 by missingdigits

[THobern]

That's what I first thought as well. However, it does not have the sort of sloped side like a falcatus. Also, none of the falcatus have those odd little points on the sides at the bottom. When the root was on it was more obvious that this looked like the point of a falcatus without the sloped side( I don't know what else to call it-sorry) Maybe it's just an abnormal tooth. I don't know, just looks strange to me.

A tooth without a root is decontextualised. It was likely a sloped tooth, not because of an asymmetrical crown, but because of a lop-sided and bulbous root. I've seen the same thing in megalodon tooth; a bulbous root almost spilling over the crown.

Squalicorax teeth have a wide range of shapes across the jaw position, so it's not that surprising to see a shape like that. How well preserved are the roots in the area?

[Gizmo]

The funny thing is- not all of those in the picture are S. falcatus...

It's right off the web site - http://www.oceansofkansas.com/sharks.html

[RickNC]

Nice, Profound Serations. The little cuspettes throw me. I don't know the species very well there in Kansas, but at first glance, I thought it was a Great White. GW's don't have cusps. How thin or robust is the tooth? Can you take a photo of the reverse side of the tooth as well as the profile of the tooth? I have found many Makos and GW's and it is very hard to find one with the root not broken. Interesting.

Very nice find!

I thought the same thing until I saw the location. GW's do have cusps sometimes when young. I have a few with cusps.

[THobern]

I thought the same thing until I saw the location. GW's do have cusps sometimes when young. I have a few with cusps.

Same here, in both fossil and extant.

[Mudduck]

I thought the same thing until I saw the location. GW's do have cusps sometimes when young. I have a few with cusps.

Same here, in both fossil and extant.

I would love to see pics!

[Al Dente]

The funny thing is- not all of those in the picture are S. falcatus...

I'm curious, why don't you think these are all S. falcatus?

[missingdigits]

A tooth without a root is decontextualised. It was likely a sloped tooth, not because of an asymmetrical crown, but because of a lop-sided and bulbous root.

When the root was still attached I looked for this but I did not see any signs of this. Wish it would not have disintegrated- might it look like such an idiot then. Thanks for the help everyone. It's appreciated!

[KansasFossilHunter]

Some of the teeth are from a currently unnamed species of Squalicorax... that only occurs in the low chalk ... They never get very big.. and always have the rounded rear cusp (not serrated).

[KansasFossilHunter]

For example, the forth tooth from the left , center row, is defiantly not a S. falcatus... I see about three teeth with the rounded cusp. I have pictures of a near complete set, if you'd like to see (not mine)

[Hieronymus]

Just want to chime in on the species. Squalicorax falcatus is indeed often regarded as a wastebin species, containing multiple types of teeth (and hence, probably multiple species). I think one could compare the problem with the extant genus Carcharhinus. When you take sharkteeth of this genus and throw them on a pile, it's very difficult -if not impossible- to correctly sort them by species. Different tooth positions and the difference between teeth of the upper and lower jaw don't make the task easier...

The same thing counts for many Squalicorax species of the Turonian and Cenomanian.

[Boneman007]

Just want to chime in on the species. Squalicorax falcatus is indeed often regarded as a wastebin species, containing multiple types of teeth (and hence, probably multiple species). I think one could compare the problem with the extant genus Carcharhinus. When you take sharkteeth of this genus and throw them on a pile, it's very difficult -if not impossible- to correctly sort them by species. Different tooth positions and the difference between teeth of the upper and lower jaw don't make the task easier...

The same thing counts for many Squalicorax species of the Turonian and Cenomanian.

I disagree. S. falcatus is very well defined. It's just that most fossil hunters have not kept up with the new squalicorax species.

The smaller S. sp. teeth are now being attributed to S. volgensis

There is another, lower cretaceous species of squalicorax as well. S. pawpawensis. Again, a smaller, more compact sqaulicorax tooth, similar to S. volgensis.

[Boneman007]

Some of the teeth are from a currently unnamed species of Squalicorax... that only occurs in the low chalk ... They never get very big.. and always have the rounded rear cusp (not serrated).

These smaller more compact teeth are Squalicorax volgensis.

[Al Dente]

I disagree. S. falcatus is very well defined. It's just that most fossil hunters have not kept up with the new squalicorax species.

The smaller S. sp. teeth are now being attributed to S. volgensis

There is another, lower cretaceous species of squalicorax as well. S. pawpawensis. Again, a smaller, more compact sqaulicorax tooth, similar to S. volgensis.

Siverson, Lindgren and Kelly (2006) revised S. volgensis. It is now two different species, S. priscoserratus and S. pawpawensis. As you stated, they are found in the lower Cretaceous. I'm not sure of the range of Squalicorax falcatus but I know they are found in the upper Cretaceous.

[Hieronymus]

I disagree. S. falcatus is very well defined. It's just that most fossil hunters have not kept up with the new squalicorax species.

The smaller S. sp. teeth are now being attributed to S. volgensis

There is another, lower cretaceous species of squalicorax as well. S. pawpawensis. Again, a smaller, more compact sqaulicorax tooth, similar to S. volgensis.

As Al Dente stated, S. volgensis is no more. S. pawpawensis is characterized by small teeth with irregular serrations that may even be absent, and look nothing like the ones pictured (see Underwood & Cumbaa, 2010).

The same article says it well (I paraphrase):

Subsequent descriptions of Squalicorax from the northern part of the Western Interior Seaway have recognized two morphotypes, and have either included all in S. falcatus Agassiz, 1843 (e.g. Case et al. 1990) or have separated them into S. falcatus and S. curvatus (e.g. Cumbaa et al. 2006; Shimada et al. 2006). Although some teeth can readily be placed into one of these morphotypes, others cannot, and Shimada et al. (2006) comment that the teeth they identify as S. falcatus appear to grade into S. curvatus and S. sp. (the last probably representing lower anterior teeth as described here). It is now recognized that the diversity of anacoracids is rather higher than was previously appreciated (e.g. Cappetta and Case 1999; Siverson et al. 2007), and some

names, especially Squalicorax falcatus, have been used for a number of different species.

Cappetta & Case (1999) argumented the following on the original description of S. falcatus by Williston:

La série paraît hétérogène et regroupe certainement des dents de plusieurs espèces, comme le laissait entendre d'ailleurs l'auteur lui-même.

Or in English: The series appears to be heterogenous and definitely regroups teeth of multiple species, which the author himself has recognized before.

Teeth that include "a wide morphological range" such as Welton & Farish (1993), and Shimada et al. (2006) argue, are not really "well defined". They acknowledge that something is going on with this species, but don't go into detail on the matter. The latter even state:

it is possible that our S. falcatus specimens may actually include some teeth of these Squalicorax taxa (they refer to S. curvatus and S. sp.).

If it would be a well defined species, they would not have difficulties keeping them apart from other species, or would they?

Anyway, saying that S. falcatus is well defined doesn't seem congruent with all the hassle on the species in recent literature. If it was well defined, there wouldn't be a discussion...

Edited January 24, 2013 by Hieronymus