sixgill pete Posted September 26, 2016 Share Posted September 26, 2016 Ok, I found this tooth in the Lee Creek mine in 2007. Over the years I have gone back and forth as to the species of mako; hastalis, oxyrhincus, desori. So now I am asking for your opinion. I don't think I have posted this tooth on here before so I hope you all enjoy, I think it's a beauty. I would like to post this one on the collections area, but I want to be much more sure about a positive species before I do so. It is just ovewr 2" ( about 2 1/8) and has great color. Bulldozers and dirt Bulldozers and dirt behind the trailer, my desert Them red clay piles are heaven on earth I get my rocks off, bulldozers and dirt Patterson Hood; Drive-By Truckers May 2016 May 2012 Aug 2013, May 2016, Apr 2020 Oct 2022 Link to comment Share on other sites More sharing options...
sagacious Posted September 26, 2016 Share Posted September 26, 2016 To my mind, Carcharodon hastalis seems like a less likely fit. Compared to what I'm used to, the root seems too compact, the lobes seem too gracile, and the lingual prominence seems far to shallow apicobasally for a C hastalis lower anterior tooth. Likewise, the crown seems too slender mesiodistally as compared to the C hastalis lower anterior teeth in my collection. The slightly increased convexity at the distal top 1/3 of the crown also reinforces my opinion that this tooth is Isurus oxyrinchus/desori and not Carcharodon. Definitely a beautiful tooth. 1 Link to comment Share on other sites More sharing options...
caldigger Posted September 26, 2016 Share Posted September 26, 2016 I was kind of thinking along the same lines. The root doesn't seem right for hastalis, too tight and perpendicular to the crown. Although, I am not familiar with the other species listed, I am feeling a "no" toward C. hastalis. Link to comment Share on other sites More sharing options...
sixgill pete Posted September 26, 2016 Author Share Posted September 26, 2016 15 minutes ago, sagacious said: To my mind, Carcharodon hastalis seems like a less likely fit. Compared to what I'm used to, the root seems too compact, the lobes seem too gracile, and the lingual prominence seems far to shallow apicobasally for a C hastalis lower anterior tooth. Likewise, the crown seems too slender mesiodistally as compared to the C hastalis lower anterior teeth in my collection. The slightly increased convexity at the distal top 1/3 of the crown also reinforces my opinion that this tooth is Isurus oxyrinchus/desori and not Carcharodon. Definitely a beautiful tooth. 7 minutes ago, caldigger said: I was kind of thinking along the same lines. The root doesn't seem right for hastalis, too tight and perpendicular to the crown. Although, I am not familiar with the other species listed, I am feeling a "no" toward C. hastalis. Thanks to both of you. Your thoughts on this have helped me confirm my own thoughts. The last label I put on this tooth was Isurus desori. I now believe that is the correct ID. Thanks again. Bulldozers and dirt Bulldozers and dirt behind the trailer, my desert Them red clay piles are heaven on earth I get my rocks off, bulldozers and dirt Patterson Hood; Drive-By Truckers May 2016 May 2012 Aug 2013, May 2016, Apr 2020 Oct 2022 Link to comment Share on other sites More sharing options...
Past Hunter Posted September 26, 2016 Share Posted September 26, 2016 I have a few that look similar to that one. I always thought they were desori. They are the three on the bottom right. I will be interested to know what they are also. "If you choose not to decide. You still have made a choice." - Rush Link to comment Share on other sites More sharing options...
sagacious Posted September 26, 2016 Share Posted September 26, 2016 56 minutes ago, Past Hunter said: I have a few that look similar to that one. I always thought they were desori. They are the three on the bottom right. I will be interested to know what they are also. To my eye, the fifth tooth and the last six teeth in the fifth row are Isurus oxyrinchus/desori, as well as number four in the fourth row. Very nice collection. Link to comment Share on other sites More sharing options...
njfossilhunter Posted September 26, 2016 Share Posted September 26, 2016 Past Hunter.....That a very nice collection of mako's you have..... TonyThe Brooks Are Like A Box Of Chocolates,,,, You Never Know What You'll Find. I Told You I Don't Have Alzheimer's.....I Have Sometimers. Some Times I Remember And Some Times I Forget.... I Mostly Forget. Link to comment Share on other sites More sharing options...
siteseer Posted October 19, 2016 Share Posted October 19, 2016 On September 25, 2016 at 7:02 PM, sagacious said: To my mind, Carcharodon hastalis seems like a less likely fit. Compared to what I'm used to, the root seems too compact, the lobes seem too gracile, and the lingual prominence seems far to shallow apicobasally for a C hastalis lower anterior tooth. Likewise, the crown seems too slender mesiodistally as compared to the C hastalis lower anterior teeth in my collection. The slightly increased convexity at the distal top 1/3 of the crown also reinforces my opinion that this tooth is Isurus oxyrinchus/desori and not Carcharodon. Definitely a beautiful tooth. I have been meaning to get to this thread for a few weeks but lost track of where it was until now (thought it was titled something else). I looked at Isurus oxyrinchus/desori and Carcharodon hastalis teeth I have from the Sharktooth Hill Bonebed (largest sample I have of C. hastalis and where hastalis has a greater size range) and Pyramid Hill Sand (where I. oxyrinchus is present but not C. hastalis). I agree with you as well. C. hastalis anteriors are flatter - less of a labiolingual recurve and not much of a lingual protuberance when compared to I. oxyrinchus. I think the tooth could be a first lower anterior though the angle formed by the lobes looks like it should be more acute than that for that position - maybe a second anterior. Link to comment Share on other sites More sharing options...
siteseer Posted October 19, 2016 Share Posted October 19, 2016 On September 25, 2016 at 7:10 PM, caldigger said: I was kind of thinking along the same lines. The root doesn't seem right for hastalis, too tight and perpendicular to the crown. Although, I am not familiar with the other species listed, I am feeling a "no" toward C. hastalis. I. desori is kind of a "gray area species." I have understood it to be the name for fossil I. oxyrinchus (modern short fin mako) older than the Pliocene but it seems to have been used less in the past 20-25 years. Most pre-Pliocene teeth are smaller on average than what you tend to see from the Pliocene or modern form and that seemed like enough justification to separate the species but I have also seen teeth (rare though they may be) at least as large as any Pliocene-Recent teeth from Late Oligocene-Early Miocene sites. I haven't noticed any tooth character to separate desori or oxyrinchus and would be interested in reading more comments about desori/oxyrinchus. If the teeth do belong to one species, it is at least one of the oldest of all modern sharks. This is a very interesting thread and I thought there would be more comments from the "shark people." Link to comment Share on other sites More sharing options...
siteseer Posted October 19, 2016 Share Posted October 19, 2016 Just as an added comment, that is certainly a large tooth for I. oxyrinchus. It doesn't look like it's from the Yorktown Formation. I'm thinking one of the Pleistocene formations (James City most likely?) rather than the Pungo River. Link to comment Share on other sites More sharing options...
sagacious Posted October 21, 2016 Share Posted October 21, 2016 On 10/19/2016 at 1:07 PM, siteseer said: I have been meaning to get to this thread for a few weeks but lost track of where it was until now (thought it was titled something else). I looked at Isurus oxyrinchus/desori and Carcharodon hastalis teeth I have from the Sharktooth Hill Bonebed (largest sample I have of C. hastalis and where hastalis has a greater size range) and Pyramid Hill Sand (where I. oxyrinchus is present but not C. hastalis). I agree with you as well. C. hastalis anteriors are flatter - less of a labiolingual recurve and not much of a lingual protuberance when compared to I. oxyrinchus. I think the tooth could be a first lower anterior though the angle formed by the lobes looks like it should be more acute than that for that position - maybe a second anterior. I agree, the tooth appears to be a second lower anterior. While the tooth looks to be mostly intact, with only minor abrasive wear, the tips of the root lobes (especially the mesial lobe) appear broken and have lost the distinctive slender tips characteristic of I. oxyrinchus anterior lower teeth. I think that aspect of root wear/damage has helped confuse the species identification. I suspect that if the root lobes were completely intact and undamaged, the species ID would likely be without doubt. Link to comment Share on other sites More sharing options...
sixgill pete Posted October 21, 2016 Author Share Posted October 21, 2016 Jess, thanks for your responses. I have often been puzzled about the desori / oxyrhinchus species. I have seen teeth assigned to one or the other based on age, but also teeth from older deposits using oxyrhinchus. Jams City Fm would a good candidate I agree. It did not come out of Yorktown sediments, that I can say for sure. agacious, the root lobes are worn some and the one side broken slightly. That may have in fact been part of my flip flopping on the ID. Thanks. Bulldozers and dirt Bulldozers and dirt behind the trailer, my desert Them red clay piles are heaven on earth I get my rocks off, bulldozers and dirt Patterson Hood; Drive-By Truckers May 2016 May 2012 Aug 2013, May 2016, Apr 2020 Oct 2022 Link to comment Share on other sites More sharing options...
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