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Plesiosaur Tooth From Nj?


DCW

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I already had referred DCW to more information (taken below from the Oceans of Kansas website) and HE (with tooth in hand) was quite convinced as he makes clear. The cross section shape and faceting is key and is apparent in the pictures, although a complete cross-section picture would be better evidence for the doubters!!!

leidy-65.jpgRELATED HISTORICAL NOTE:Leidy (1856) gave a short description of a single tooth found in the Cretaceous marl of New Jersey and named it Polygonodon vetus:

"Based on a specimen of the crown of a tooth found in the marl (cretaceous) of Burlington County by L. T. Germain, Esq., Length three times the breadth; transverse section elliptical; with trenchant borders; with six planes on one side and seven on the other. Length 1½ inches, breadth ½ an inch. May be an incisor of Mososaurus [sic]?"

Leidy (1865) described the tooth in greater detail and included three figures (left) showing what it looked like in (12) posterior, (13) external view, and in cross section. Still believing the tooth to be reptilian, he thought it "may have belonged to Discosaurus or Cimoliasaurus, but the matter must be left for future determination."

The tooth was later determined to be from a sister species of Xiphactinus audax, raising the issue of which genus name should have priority... Polygonodon Leidy 1856 or Xiphactinus Leidy 1870? See Schwimmer, et al. (1997) for a more detailed explanation. Most likely it will remain Xiphactinus.

FossilDAWG also nails it more precisely.

The lines are basically just fine cracks in the enamel, not striations or anything further. It is common on NJ specimens.

Also, to very quickly distinguish it from Enchodus in this case, there is no hollow space in an Enchodus tooth like there is with Xiphactinus. See Fossildawg's illustration from the Schwimmer paper for evidence of this. I have seen 100s of large Enchodus fangs and they are completely solid, no hollow space inside.

---Wie Wasser schleift den Stein, wir steigen und fallen---

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I already had referred DCW to more information (taken below from the Oceans of Kansas website) and HE (with tooth in hand) was quite convinced as he makes clear. The cross section shape and faceting is key and is apparent in the pictures, although a complete cross-section picture would be better evidence for the doubters!!!

leidy-65.jpgRELATED HISTORICAL NOTE:Leidy (1856) gave a short description of a single tooth found in the Cretaceous marl of New Jersey and named it Polygonodon vetus:

"Based on a specimen of the crown of a tooth found in the marl (cretaceous) of Burlington County by L. T. Germain, Esq., Length three times the breadth; transverse section elliptical; with trenchant borders; with six planes on one side and seven on the other. Length 1½ inches, breadth ½ an inch. May be an incisor of Mososaurus [sic]?"

Leidy (1865) described the tooth in greater detail and included three figures (left) showing what it looked like in (12) posterior, (13) external view, and in cross section. Still believing the tooth to be reptilian, he thought it "may have belonged to Discosaurus or Cimoliasaurus, but the matter must be left for future determination."

The tooth was later determined to be from a sister species of Xiphactinus audax, raising the issue of which genus name should have priority... Polygonodon Leidy 1856 or Xiphactinus Leidy 1870? See Schwimmer, et al. (1997) for a more detailed explanation. Most likely it will remain Xiphactinus.

FossilDAWG also nails it more precisely.

The lines are basically just fine cracks in the enamel, not striations or anything further. It is common on NJ specimens.

Also, to very quickly distinguish it from Enchodus in this case, there is no hollow space in an Enchodus tooth like there is with Xiphactinus. See Fossildawg's illustration from the Schwimmer paper for evidence of this. I have seen 100s of large Enchodus fangs and they are completely solid, no hollow space inside.

Not to disagree (OK, yes, to disagree)...those aren't cracks, they are striations. The striations are indicative of Enchodus fangs. I have found dozens of them (and hundreds of Xiphactinus teeth) and am confident that that is a partial palatine fang from Enchodus petrosus. And some broken Enchodus fangs do indeed have the hollow space.

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Case in point, my Enchodus tooth. Although I could hardly argue that it did not become hollow through stream ware, but the tooth could not have been in the stream for to long, as it has a lot of it's enamel still on it.

DCW, If you would be so kind, perhaps some more pictures with a little more light would help some of the doubters

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"It is difficult to get a man to understand something when his salary depends upon his not understanding it."

Upton Sinclair

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I will get some new pics up by the weekend, folks. I'm enjoying the spirited debate about this tooth, though. I just have to reply from the smartphone, as I work long hours until Thursday.

A few things to clarify:

There is no flat section to this tooth as one if the pics suggests. (Well, the tip is flattened)

There are heavy striations, not cracks as I recall.

The tooth is very lens like.

It is unlike any enchodus tooth I've ever seen, matching nearly identically to the chart posted by toothpuller.

It's enamel is very fragile and thin, and it can be easily flaked off with a fingernail. (Not that I'm doing it, but its evident from the abrasions to the side)

More to follow!

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Not to be argumentative with a truly great collector who is more than well versed in Xiphactinus, but from any one of DCW's pictures alone I could confidently ID this as a typical NJ Xiphactinus tooth. I would put my life on the line against my identification. :) Identifying NJ material can be very challenging from pictures when you aren't familiar with it. Even just the way the very thin enamel is worn off screams a typical large NJ Xiphactinus tooth. Look at fossilDAWG's diagram from the Schwimmer paper. Specimens, M, N and O show the same sort of faint lines in the enamel. I believe they are growth cracks at most, but these are not striations and they are seen often on NJ specimens. I'm sure fossilDAWG, who has access to the entire paper could confirm that the teeth and enamel are described as smooth, possibly with growth cracks, but surely no striations. Differences in lighting can bring out or subdue these small differences. Below are a large and smaller Xiphactinus from NJ. The faceting on the smaller specimen is more apparent and growth cracks in the enamel are more apparent in the larger one. In NJ, there is a lot of debate and confusion among collectors over what constitutes striations and I suffered through the same period of confusion myself.

DCW: Although you seem to agree with Xiphactinus, I see that you say the lines are, in fact, striations. Please take another look (perhaps under magnification) and compare with a well preserved Enchodus fang (if you have one) or lordpiney's Plesiosaur tooth posted in this thread, or even a Scapanorhynchus texanus anterior tooth. I think you will conclude that the lines on your specimen are not really striations.

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---Wie Wasser schleift den Stein, wir steigen und fallen---

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Here are some Enchodus fragments showing the straitions and a very large complete fang. Note also the thin enamel. Toothpuller, I'll still disagree with you, but I don't like the wager! ;)post-98-0-23680100-1301450256_thumb.jpgpost-98-0-56915900-1301450267_thumb.jpg

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yep thats some heavily striated enchodus right there!! i would say compare how the broken exposed bone on yours look with the more layered texture evident on the break in my specimen( barely visible since the pic isnt from the right angle) but also its much more evident on DCW's tooth.

---Wie Wasser schleift den Stein, wir steigen und fallen---

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Besides the fact that New Jersey fossils are harder to Id than most and that Toothpuller's ID's are always spot on, there are also not many people in the state with more material or knowledge about NJ fossils than him, so if he feels that strong about it, then I would have to go with it being a Xiphactinus.

The only reason that I even questioned it was not because of my knowledge of Xiphactinus teeth but because it looked so much like my Enchodus tooth.

"It is difficult to get a man to understand something when his salary depends upon his not understanding it."

Upton Sinclair

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I have also seen people refer to the cutting edge as a "keel" but that is in older publications. Cutting edge is a universally used term for shark teeth. I have seen carina used for dinosaur/reptile teeth and fish teeth mostly. You will also see teeth referred to as "carinate" (=having a carina).

Bob,

A carina is a cutting edge to a tooth.

Cheers,

Don

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Here are some new pics that I promised.

As a recap, this tooth is 1.25 in long and around .45in thick. It was found in Big Brook, New Jersey. I originaly thought that it was a plesiosaur tooth, but the carinae (cutting edge)ruled that out. A spirited debate then broke out whether this was from Xiphactinus or Enchodus, both large bony fish that roamed the Atlantic Seaboard in the Cretaceous era. A forum member currently has his life on the line on its positive identification. I believe the new photos clearly show that this tooth belonged to Xiphactinus, and that toothpuller will live to screen another creek. What say you???

First the back side of the tooth, which has no scuffs on the enamel.

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The cross section, pretty lense like.

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I guess I can agree that these "striations" could really be growth cracks in the enamel. But, they are very pronounced.

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If we can agree on Xiphactinus, can we decide if it is Xiphactinus Audax or Xiphactinus Vetus? It appears to me that Xiphactinus Audax is not represented in Big Brook.

Thanks for all the comments. This was fun

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Whew! Toothpuller lives to see another day. I'll concede and move to the X. vetus camp. Thanks for the new pix. Toothpuller, I enjoyed the debate!

It's not a X. audax for sure. So you can rule that out.

All that being said, any of you eastern folk want to trade a vetus for an audax? Guess I need one of those in the ol' collection!

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Very good pictures. I'm sure this will put a rest to the identification on this piece. Excellent find!

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whew! :) some people refer to the NJ and ACP specimens as Xiphactinus audax vetus, but we can probably go with X. vetus and follow Schwimmer. i'm not sure if true X. audax occurs in monmouth county, but specimens from the marshalltown have been attributed to it.

---Wie Wasser schleift den Stein, wir steigen und fallen---

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  • 1 month later...

I found a tooth in North Carolina last month and at first I thought it was Plesiosaur but I have several Plesiosaur teeth but none of them have faceted sides. While I have mosasaur teeth with facets, I have not seen a plesiosaur tooth with them. So I did some searching and it turns out that it is Xiphactinus vetus. X. vetus is an east coast fish and is younger than X. audax. X. audax runs into the early Campanian while X. vetus runs from the middle Campanian to the Maastrichtian. One of the identification keys is the presence of facets along with the fore/aft cutting edges (which aren't all that sharp unlike a shark). I actually found a second tooth but it is not much more than just the tip. The tooth is 42mm from tip to the long edge of the break.

Xiphactinus015.jpg

Xiphactinus016.jpg

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