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ReptileTooth

Awesome finds but father and son working together is even better!:meg:

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fossilsonwheels
19 minutes ago, ReptileTooth said:

Awesome finds but father and son working together is even better!:meg:

I agree 100%. I am having the best time of my life doing this with him.

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Al Dente
6 hours ago, fossilsonwheels said:

This also allows him to draw S. texanus in a more Sand Tiger like form which we both think it was.

Is there a reason why you think S. texanus is a sand tiger?

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Tidgy's Dad

Very nice.:)

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fossilsonwheels
6 hours ago, Al Dente said:

Is there a reason why you think S. texanus is a sand tiger?

 The lack of intermediate teeth for texanus is a major difference in dentition and points to it possibly being a much different shark. This information came from one of the people who described S. puercoensis and wrote some excellent stuff for Elasmo about Scapanorhynchus. The depth of water that texanus inhabited is also a difference. They are found in near shore environments and other Scapanorhynchus species, plus modern Goblin Sharks, are deep water. I found the information compelling enough to change how I view S. texanus or at least question it a bit.

 

 

 

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non-remanié

What's the evidence that Scapanorhynchus puercoensis inhabited deep waters?  The New Mexico 2012 documented  fauna is  not a deep water fauna from what I recall. 

 

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Al Dente
4 hours ago, fossilsonwheels said:

The lack of intermediate teeth for texanus is a major difference in dentition and points to it possibly being a much different shark.

Modern goblin sharks also lack intermediate teeth while modern sand tiger sharks have intermediate teeth. I would think that makes S. texanus more similar to modern goblin sharks than sand tigers.

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siteseer
1 hour ago, Al Dente said:

Modern goblin sharks also lack intermediate teeth while modern sand tiger sharks have intermediate teeth. I would think that makes S. texanus more similar to modern goblin sharks than sand tigers.

 

 

Yes, and the lack of intermediate teeth might more accurately indicate a loss of at least one tooth file across a lineage.  Scapanorhychus lewisii has been described as having one intermediate file (and that may be open to interpretation).  S. texanus does not.  This can be explained as a dentition becoming more efficient within a lineage over time (doing the same work with less teeth/less energy).  We see this in other sharks.  Parasymphyseal teeth of Otodus are occasionally found - not enough though to assume that it was a "normal condition."  They become even rarer in its descendants, Parotodus and Carcharocles until they seem to disappear entirely from those genera by the Middle Miocene. 

 

Jess

 

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siteseer
4 hours ago, non-remanié said:

What's the evidence that Scapanorhynchus puercoensis inhabited deep waters?  The New Mexico 2012 documented  fauna is  not a deep water fauna from what I recall. 

 

 

Mr. Non-Remanie,

 

Yes, in fact in that paper (Bourdon et al., 2011) the paleoenvironment is described as a range from "fluvio-deltaic to offshore sandbar," which a fancy way of say the mouth of a river and its delta to the limit of where sand has been deposited away from that mouth and that is shallow water.

 

Jess

 

Bourdon, J., K. Wright, S.G. Lucas, J. A. Spielmann, and R. Pence.  2011. 

Selachians from the Upper Cretaceous (Santonian) Hosta Tongue of the Point Lookout Sandstone, central New Mexico. New Mex. Mus. Nat. His. and Sc., Bulletin 52; 54pp.

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fossilsonwheels
On 2/2/2019 at 11:55 AM, non-remanié said:

What's the evidence that Scapanorhynchus puercoensis inhabited deep waters?  The New Mexico 2012 documented  fauna is  not a deep water fauna from what I recall. 

 

I did not specifically mention S. puercoensis as a deep water species.

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fossilsonwheels
On 2/2/2019 at 2:27 PM, Al Dente said:

Modern goblin sharks also lack intermediate teeth while modern sand tiger sharks have intermediate teeth. I would think that makes S. texanus more similar to modern goblin sharks than sand tigers.

You make a good point to which I have no answer no answer. I do not have the expertise to say one way or another. I am still going with the theory that is possible they were a different shark than other Scapanorhynchus species. The gentleman who gave me the teeth and co-authored the paper @siteseer quoted made a good case that they MAY be different. It is a fun theory to discuss with kids and ultimately that is what matters to me.

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non-remanié
9 minutes ago, fossilsonwheels said:

I did not specifically mention S. puercoensis as a deep water species.

 

You are correct.  It just seemed like that is what you were referring to when you wrote that "other Scanorhynchus" in addition to extant goblin sharks inhabited deep water.    I guess what you meant is that S. lewisii inhabited deep water.  Is that correct?  Or did you really only mean to refer to extant goblin sharks?  

 

 

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non-remanié
17 minutes ago, fossilsonwheels said:

You make a good point to which I have no answer no answer. I do not have the expertise to say one way or another. I am still going with the theory that is possible they were a different shark than other Scapanorhynchus species. The gentleman who gave me the teeth and co-authored the paper @siteseer quoted made a good case that they MAY be different. It is a fun theory to discuss with kids and ultimately that is what matters to me.

 

I think what the gentleman may have more specifically meant to say was that the ecological niche occupied by S. puercoensis is more similar to the niche today filled by sand tiger sharks.   

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fossilsonwheels
10 minutes ago, non-remanié said:

 

I think what the gentleman may have more specifically meant to say was that the ecological niche occupied by S. puercoensis is more similar to the niche today filled by sand tiger sharks.   

The discussion was about S. texanus possibly occupying a niche similar to modern sand tigers. It was not a lengthy discussion but we share the opinion that it is possible S. texanus was more sand tiger like in that sense.

 

I am curious, do you know of any fossil material from S. texanus other than teeth ?

 

31 minutes ago, non-remanié said:

 

You are correct.  It just seemed like that is what you were referring to when you wrote that "other Scanorhynchus" in addition to extant goblin sharks inhabited deep water.    I guess what you meant is that S. lewisii inhabited deep water.  Is that correct?  Or did you really only mean to refer to extant goblin sharks?  

 

 

I meant Lewisii, extant Goblins and possibly other extinct species. I am assuming there were other deep water goblins more than suggesting there were. I can not claim to know what is known about other species in the genus. I am far from an expert on this though so I appreciate any knowledge that others have.  I was not super clear about this either. My apologies.

Truth be told, I just love the idea of there being variations within the genus because it one of my favorites. We actually devote a pretty good amount of time to Scapanorhynchus in our education presentations so any and all information and discussion is welcome.

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