North Sulphur River First 2022 Trip

[flyingpenut]

I finally took a trip to the North Sulphur river last week. There have been a couple good rains so I was hoping that would uncover some stuff. The last couple of trips in 2021 were terrible. All muddy and picked over. This trip was still pretty muddy and little in terms of quality mosasaur material. However I went low and found a lot of smaller material.

 

I wonder if the recent muddyness of the river is due to the lake construction or if the river just hasn't had enough rain lately? 

Is picture 2 an enchodus jaw? 

I believe the pictures of item 3 are of a really chipped piece of mosasaur tooth. Still never found a whole one this color. 

Are the pictures of item 4 pachyrhizodus? I have seen people say these are really small mosasaur but I have always doubted this. 

Any way to identify item 5? Maybe xiphactinus? 

Item 6 are the few decent mosasaur pieces i found. Is the second one a phalanges bone? 

Any idea about 7? It is heavily fossilized so i was thinking cretaceous but the shape makes me think of more recent like pleistocene.

And my final question. Is item 8 coprolite? Im terrible at identifying the stuff. 

 

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10.

[Jared C]

#2 I would say is a fish jaw, but I don't think Enchodus. Better pictures would help

#3 is a piece of a large mosasaur tooth. At that size, it's probably Tylosaurus proriger, as other very large mosasaurs like Mosasaurus are not as likely in the campanian of Texas. 

#4 is tough, but it seems  in your picture that there are distinct striations, and that would remind me more of a mosasaur origin. I'll wait for someone who's more knowledgeable than me to see

#7 looks to be cretaceous chunkasaur to me

 

[Castle Rock]

I believe that #7 is likely to be a piece of mosasaur rib.

[pachy-pleuro-whatnot-odon]

Nice finds! Wish I'd come back with such a haul after a day's searching! But I guess that's just not the case here in Europe (of I don't know the right spots)

 

#2 is definitely a fish jaw. And even though I (or rather someone more skilled in the identification of fish remains; @Fossildude19, maybe?) would need better pictures to properly identify it, my first impression based on the conical, rather mosasaur-like tooth, would be Pachyrhizodus sp..

 

#3 Looks like a big reptile tooth, but hard to say whether it's mosasaur or plesiosaur. I don't think large/any crocodilians are known from NSR, right? Seems a bit large for plesiosaur, though, so likely indeed mosasaur. But hard to tell just from these two photographs, especially since the specimen looks so flat in the second photograph...

 

#4 Although it looks a lot like a plioplatecarpine mosasaur tooth, and determinations of these teeth can be difficult, from what I understand Pachyrhizodus-teeth are a bit blockier than mosasaur-teeth. The easiest place to see this would be the cross-section, which is round to lens-shaped in mosasaur teeth, but has "a slight flattening on one side" (source) in Pachyrhizodus-teeth. Refer to the below two images, especially the cross-sections, all identified as Pachyrhizodus (ibid.). What makes it confusing in this case is that the weathering of the enamel makes it look like there are striae on the tooth, which my guess is there aren't. In any case, Pachyrhizodus.

 

 

#5 Bony fish vertebra is all I can say. Could well be Xiphactinus sp., but I'll defer identification to those more knowledgable on the matter.

 

#6 First seems to be a weathered mosasaur vertebra, the second does indeed look like a phalanx. Considering how short and wide it is, possible from the first digit (mc1 or mt1 in the figure below).

 

Reconstructed right front paddle of Mosasaurus hobetsuensis from Hokkaido in Japan (source)

 

Prognathodon overtoni hind paddles (figure 10; Konishi, Brinkman, Massare & Caldwell, 2011)

 

31 minutes ago, Castle Rock said:

I believe that #7 is likely to be a piece of mosasaur rib.

 

#7 Does look like a marine reptile rib chunk, but it'd be difficult to say what from. Doesn't look like turtle, but might be plesiosaur as much as mosasaur...

 

#8 Hard to say whether this is a coprolite or not. It does look like it has some spiral structure, but as I don't know how coprolites are supposed to look in NSR, I can't make a direct comparison, as it does look a bit like simply a phosphatic nodule as well. May be @GeschWhat or @MarcoSr have an opinion about this.

 

#9 Again looks like a worn mosasaur vertebra.

 

#10 Bone? But hard to see what it might be. Need better photographs of this.

[FossilDAWG]

I'm fairly confident that #8 is a shark coprolite.

 

Don

[JohnJ]

#9 @flyingpenut

 

Do you have additional views?  The open cells of the cancellous bone look more mammalian than reptilian.  Mosasaur bone tends to have light colored calcite permeating these tiny voids.

[BudB]

Very nice finds! Mud was just about all I found on my last NSR visit.

[GeschWhat]

Don got it right. #8 is a beautiful little amphipolar spiral coprolite.

[fossil_lover_2277]

Could #3 be a broken piece of mastodon tooth? Not saying that’s for sure what it is, it likely could be part of a large reptile tooth.

Edited June 28, 2022 by fossil_lover_2277