missingdigits Posted June 23, 2013 Share Posted June 23, 2013 Hello everyone. I found this guy last week in the Blue Hill Shale of Kansas. I immediatly thought it was a Cretodus crassidens as I found another one close by last year and have found several large Cretodus in the Blue Hill Shale. However when I got home I noticed that the cusplets appeared to be missing. Upon closer inspection I found that they were not missing/broken and the tooth was in perfect shape. I have about 8 of these anterior Cretodus teeth and all of cusplets or clear breaks where they were. This one does not. Could it be I am looking at something other than Cretodus (Cretoxyrhina?) or just an unusual Cretodus tooth? It's not a big deal, but I would like to know. Thanks in advance! Link to comment Share on other sites More sharing options...
missingdigits Posted June 23, 2013 Author Share Posted June 23, 2013 Link to comment Share on other sites More sharing options...
NSRhunter Posted June 23, 2013 Share Posted June 23, 2013 Looks like cretoxhyrina. Nice big one too Link to comment Share on other sites More sharing options...
missingdigits Posted June 23, 2013 Author Share Posted June 23, 2013 Looks like cretoxhyrina. Nice big one too Thanks so much for the input. Is there any particular reason why you would i.d. it as such? Just so I know what to look for? Link to comment Share on other sites More sharing options...
MarcoSr Posted June 24, 2013 Share Posted June 24, 2013 Jamie Really nice tooth!!!! The tooth is an anterior from the shape. Looking at the pictures it looks to be around 60mm on the longest side. There are only a couple of options that I am aware of for a tooth this size from Kansas, a Cretoxyrhina mantelli or a Cretodus crassidens. I'm not seeing evidence of cusps in your photos or any short longitudinal ridges and enameloid plications at the crown foot on the cusp and cusplets so for me that would rule out Cretodus crassidens. However the tooth does have rippling by the base of the crown. I don't know if anterior Cretoxyrhina mantelli can have this. I know the laterals and posteriors can have short blade-like cusplets at the extreme ends of the crown foot. All this being said my best guess would also be Cretoxyrhina. Marco Sr. "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
Tony Eaton Posted June 24, 2013 Share Posted June 24, 2013 Wow, that is a nice tooth. I think this is probably a Cretoxyrhina too. It would be cool to see a pic of some of the other anteriors with cusplets if you have not yet already posted them. From what I've found, all Cretodus, even the anteriors, have "broad shoulders" on the lingual root. (The root protuberance is more horizontally oblong and pronounced, especially compared to other species with the same tooth positions.) If the tooth is laying flat does the root form an even hill or is it more like a plateau or two hills. Maybe you found the almost mythic Cretalamna woodwardi? ;-) Cardabiodon ricki is another big shark swimming around at that time (the current name for Cretalamna woodwardi if memory serves correct). From what I've seen documented I'd expect the blade to flair out compared to the blade on your tooth if it were Cardabiodon. Link to comment Share on other sites More sharing options...
missingdigits Posted June 27, 2013 Author Share Posted June 27, 2013 (edited) Thanks so much guys. I really appreciate it. I need to brush up on my terminololgy to make more sense of the replies. I'll consult my Welton and Farrish tonight to be sure. As requested here are a few photos of other Cretodus crassidens (at least I think they are). I did have had at least one of these positively identified by an expert so at least I have a good reference point. These are just the ones I have handy and I sure wish I had the rest of them available. For scale the tooth on left is about 60mm as Marco pointed out. I suppose the thing that makes me so curious is that I have never found a Cretoxyrhina in the Blue Hill Shale and that the teeth are so similar except for the lack of cusplets (or malformed?) on the tooth in question. I'll go with you guys though as I am certainly no expert! Thanks! Edited June 27, 2013 by missingdigits Link to comment Share on other sites More sharing options...
missingdigits Posted June 27, 2013 Author Share Posted June 27, 2013 Here is a side-by-side of the tooth in question with a Cretodus that is of very similiar size and shape. Link to comment Share on other sites More sharing options...
siteseer Posted June 28, 2013 Share Posted June 28, 2013 Missingdigits, I agree. That's a Cretoxyrhina - second lower anterior. There's an article on Cretoxyrhina and Cardabiodon you can download free here: http://www.app.pan.pl/issue.html?issue=198 It has some nice figures. As Tony Eaton noted, the anteriors of Cardabiodon flare out to give the crown more of a lanceolate shape in labial or lingual view and the laterals are more broad-based. Jess Here is a side-by-side of the tooth in question with a Cretodus that is of very similiar size and shape. photo 3.JPG photo 4.JPG photo 1-2.JPG Link to comment Share on other sites More sharing options...
MarcoSr Posted June 28, 2013 Share Posted June 28, 2013 Wow, that is a nice tooth. I think this is probably a Cretoxyrhina too. It would be cool to see a pic of some of the other anteriors with cusplets if you have not yet already posted them. From what I've found, all Cretodus, even the anteriors, have "broad shoulders" on the lingual root. (The root protuberance is more horizontally oblong and pronounced, especially compared to other species with the same tooth positions.) If the tooth is laying flat does the root form an even hill or is it more like a plateau or two hills. Maybe you found the almost mythic Cretalamna woodwardi? ;-) Cardabiodon ricki is another big shark swimming around at that time (the current name for Cretalamna woodwardi if memory serves correct). From what I've seen documented I'd expect the blade to flair out compared to the blade on your tooth if it were Cardabiodon. Missingdigits, I agree. That's a Cretoxyrhina - second lower anterior. There's an article on Cretoxyrhina and Cardabiodon you can download free here: http://www.app.pan.pl/issue.html?issue=198 It has some nice figures. As Tony Eaton noted, the anteriors of Cardabiodon flare out to give the crown more of a lanceolate shape in labial or lingual view and the laterals are more broad-based. Jess What is the maximum reported size of the teeth of Cardabiodon and/or Cretalamna woodwardi? I thought that they were much smaller than Jamie's 60mm tooth. Marco Sr. "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
MarcoSr Posted June 28, 2013 Share Posted June 28, 2013 Thanks so much guys. I really appreciate it. I need to brush up on my terminololgy to make more sense of the replies. I'll consult my Welton and Farrish tonight to be sure. As requested here are a few photos of other Cretodus crassidens (at least I think they are). I did have had at least one of these positively identified by an expert so at least I have a good reference point. These are just the ones I have handy and I sure wish I had the rest of them available. For scale the tooth on left is about 60mm as Marco pointed out. I suppose the thing that makes me so curious is that I have never found a Cretoxyrhina in the Blue Hill Shale and that the teeth are so similar except for the lack of cusplets (or malformed?) on the tooth in question. I'll go with you guys though as I am certainly no expert! Thanks! photo 2-1.JPG photo 1-1.JPG Jamie Really nice teeth!!!! Marco Sr. "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
NSRhunter Posted June 28, 2013 Share Posted June 28, 2013 (edited) Sorry took me long to reply. Yes I agree with the other two because it shows no indication of cusps at all. Sweet finds!!!! Edited June 28, 2013 by NSR King Link to comment Share on other sites More sharing options...
MikaelS Posted June 29, 2013 Share Posted June 29, 2013 It is a Cretodus. Link to comment Share on other sites More sharing options...
MarcoSr Posted June 29, 2013 Share Posted June 29, 2013 (edited) It is a Cretodus. Do you believe that the cusplets are broken off or that Cretodus crassidens anteriors can be without cusplets? I have read that Cappetta states " the evolution of the genus (Cretodus) involves a perceptible decrease in the folds on the lingual face of the cusp and a tendency to loose lateral cusplets as in Cretodus crassidens". However, other than possibly Jamie's tooth, every time I see an anterior Cretodus crassidens or a picture of one, the specimens have cusplets or evidence that they were broken off. I have seen the rippling (like in Jamie's tooth) or serations between the cusplets and base of the cutting edges of the cusp before. Can you give a couple of diagnostic features which support Cretodus versus Cretoxyrhina for the identification of this tooth? Marco Sr. Edited June 29, 2013 by MarcoSr "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
MikaelS Posted June 29, 2013 Share Posted June 29, 2013 Cretoxyrhina teeth of that height, which they rarely reach, have a broader more triangular cusp. Even though the tooth is a bit corroded the labial root/crown boundary is very distinct. Cretoxyrhina, on the other hand, has a rather diffuse labial root/crown boundary as the enameloid is very thin towards the base of the crown (see Siverson et al. 2013, Alcheringa v. 37 (1):87-104). Finally, the neck is much wider medially in anteriors of Cretoxyrhina around 60mm in height. Cretodus teeth have an unusually narrow neck (collar). The lack of cusplets in this particular tooth is unusual but not extraordinary. Link to comment Share on other sites More sharing options...
MarcoSr Posted June 29, 2013 Share Posted June 29, 2013 Cretoxyrhina teeth of that height, which they rarely reach, have a broader more triangular cusp. Even though the tooth is a bit corroded the labial root/crown boundary is very distinct. Cretoxyrhina, on the other hand, has a rather diffuse labial root/crown boundary as the enameloid is very thin towards the base of the crown (see Siverson et al. 2013, Alcheringa v. 37 (1):87-104). Finally, the neck is much wider medially in anteriors of Cretoxyrhina around 60mm in height. Cretodus teeth have an unusually narrow neck (collar). The lack of cusplets in this particular tooth is unusual but not extraordinary. Thank you for the explanation of your id. It will definitely help me in the future if I am trying to distinguish Cretodus and Cretoxyrhina. Jamie now you have your answer! Marco Sr. "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
missingdigits Posted June 29, 2013 Author Share Posted June 29, 2013 Thanks so much everyone. I appreciate it. Cretodus it is! Link to comment Share on other sites More sharing options...
MikaelS Posted June 30, 2013 Share Posted June 30, 2013 Nothing mythical about woodwardi but it is certainly no Cretalamna (see Siverson, 1999, Transactions of the Royal Society of Edinburgh). Its the designated type species of Dwardius. I illustrated a tooth of this species from Russia in the 2013 Alcheringa paper and it is one of the largest I have seen of this species (just over 4cm in height). I have the paratype dentition of D. woodwardi sitting on my desk and I will describe it over the next year. There is no way you can build a Cretalamna dentition out of this lot of teeth. Speaking about Cretalamna I have a big manuscript (> 500 photographs) hopefully in press very soon reviewing Late Cretaceous species of C. appendiculata type. I have thus far not seen any Dwardius from North America. This genus seems to have preferred more normal marine environments (the WIS was an unusual body of water in many regards). The biggest Cardabiodon teeth I have come across were in a private collection from the Mosby area, Montana (Fairport Member). They were a bit more than 4cm tall. Wow, that is a nice tooth. I think this is probably a Cretoxyrhina too. It would be cool to see a pic of some of the other anteriors with cusplets if you have not yet already posted them. From what I've found, all Cretodus, even the anteriors, have "broad shoulders" on the lingual root. (The root protuberance is more horizontally oblong and pronounced, especially compared to other species with the same tooth positions.) If the tooth is laying flat does the root form an even hill or is it more like a plateau or two hills. Maybe you found the almost mythic Cretalamna woodwardi? ;-) Cardabiodon ricki is another big shark swimming around at that time (the current name for Cretalamna woodwardi if memory serves correct). From what I've seen documented I'd expect the blade to flair out compared to the blade on your tooth if it were Cardabiodon. Link to comment Share on other sites More sharing options...
Tony Eaton Posted June 30, 2013 Share Posted June 30, 2013 missingdigits, interesting to see the teeth you have found. I am sure a lot of others are impressed with your Cretodus teeth finds as I am. In general this is very interesting information. I am taking a second look at some of my old identifications now. Dr. Siversson, I plan to read your current and new publication when they come out. They sound very interesting. Link to comment Share on other sites More sharing options...
MarcoSr Posted June 30, 2013 Share Posted June 30, 2013 Nothing mythical about woodwardi but it is certainly no Cretalamna (see Siverson, 1999, Transactions of the Royal Society of Edinburgh). Its the designated type species of Dwardius. I illustrated a tooth of this species from Russia in the 2013 Alcheringa paper and it is one of the largest I have seen of this species (just over 4cm in height). I have the paratype dentition of D. woodwardi sitting on my desk and I will describe it over the next year. There is no way you can build a Cretalamna dentition out of this lot of teeth. Speaking about Cretalamna I have a big manuscript (> 500 photographs) hopefully in press very soon reviewing Late Cretaceous species of C. appendiculata type. I have thus far not seen any Dwardius from North America. This genus seems to have preferred more normal marine environments (the WIS was an unusual body of water in many regards). The biggest Cardabiodon teeth I have come across were in a private collection from the Mosby area, Montana (Fairport Member). They were a bit more than 4cm tall. I look forward to your future papers. The size information for the Dwardius and Cardabiodon is very helpful. Marco Sr. "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
missingdigits Posted July 1, 2013 Author Share Posted July 1, 2013 missingdigits, interesting to see the teeth you have found. I am sure a lot of others are impressed with your Cretodus teeth finds as I am. Thank you Tony, that was a nice thing to say. I will try to post some more photos in my gallery soon. Just an anecdote, but I find it kind of funny/odd that not many people bother to look in the Blue Hill Shale. Granted, it's a lot of hard walking with finds few and far between-and those are usually in bad shape, but they are in there. It's mostly Squalicorax, Ptychodus, Cretolamna and the occasional Scapanorhyncus but it's pretty exciting to just see a large Cretodus on the surface twenty feet away which occasionally happens. The ammonites and mud balls are pretty neat too. Here is what a typical exposure of the shale looks like. Link to comment Share on other sites More sharing options...
Bullsnake Posted July 1, 2013 Share Posted July 1, 2013 Just found this post yesterday, got sidetracked, and forgot to reply. Well done, Jamie! Congratulations! Steve Link to comment Share on other sites More sharing options...
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