worthy 55 Posted March 9, 2008 Share Posted March 9, 2008 What type of shark tooth is this ? It looks like a Cosmopolitodus Hastalis to me, but I am new to collecting shark teeth. If it's a Mako tooth what kind is it? It's my bone!!! Link to comment Share on other sites More sharing options...
Northern Sharks Posted March 9, 2008 Share Posted March 9, 2008 It's a Mako. Most would call it the narrow form of Isurus hastalis, but Cosmopolitodus may be correct in the future (it looks as though there is a debate still raging according to elasmo.com) There's no limit to what you can accomplish when you're supposed to be doing something else Link to comment Share on other sites More sharing options...
worthy 55 Posted March 9, 2008 Author Share Posted March 9, 2008 The reason I am asking is because of the way the tooth curves outward. I looked in elasmo to come to this conclusion. Thanks It's my bone!!! Link to comment Share on other sites More sharing options...
Northern Sharks Posted March 9, 2008 Share Posted March 9, 2008 The curve is a pathology There's no limit to what you can accomplish when you're supposed to be doing something else Link to comment Share on other sites More sharing options...
Gatorman Posted March 9, 2008 Share Posted March 9, 2008 I have a meg that curves out like that. Link to comment Share on other sites More sharing options...
Boesse Posted March 12, 2008 Share Posted March 12, 2008 I personally don't buy the possibility of there being a 'narrow' and 'broad' form mako. In California, I've always seen both morphs co-occur together wherever they're found, and there is a middle ground in those samples. They are probably the exact same species, and it is probably just interspecific variation. Also, I should note that Purdy et al. 2001 make extensive usage of the broad/narrow tooth forms to try and refute the Isurus/Cosmopolitodus-Carcharodon link. Either way, If I had to pigeon hole it, that looks pretty broad to me. But they're all Isurus/Cosmopolitodus hastalis. Isurus xiphodon is a joke, and was only resurrected by Purdy et al. 2001 to 'disprove' any Isurus-Carcharodon link. So basically by definition, extant Carcharodon is basically just an overgrown mako. Bobby 2 Link to comment Share on other sites More sharing options...
worthy 55 Posted March 12, 2008 Author Share Posted March 12, 2008 Thanks for the info. It's my bone!!! Link to comment Share on other sites More sharing options...
PaleoRon Posted March 12, 2008 Share Posted March 12, 2008 It is unfortunate that someone in the Smithsonian steadfastly refuses to believe what most people are capable of seeing without any training at all. Given a decent sampling of teeth it is very obvious that the mako transitions into a semi-serrated form and on to the fully serrated Carcharodon carcharias. When Purdy finally retires this particular "debate" will vanish. He thinks that C. carcharias is directly decended from Paleocarcharodon but has no explanation for the huge gap of tens of millions of years between the two species. There is a broad range of tooth forms in Isurus hastalis. If you look at a modern mako jaw you will see that there are several "species" of teeth in one jaw and I see no reason why there would not be variation in the various fossil species as well. 1 Link to comment Share on other sites More sharing options...
Northern Sharks Posted March 13, 2008 Share Posted March 13, 2008 I have to agree with this as well. I don't recognize Isurus xiphodon as a species. Wide form or narrow form, they're all hastalis. As for the Great White lineage, I believe they are descended from the makos. Here is a photo showing 3 lower anterior teeth. On the left is a smooth blade Isurus hastalis. On the right is a fully serrated Carcharodon carcharias, the Great White. In the middle is a transitional form. These can vary from nearly no serrations to almost fully serrated. Some refer to these teeth as Isurus escheri, but my own opinion is that that name should belong only to the teeth from northern Europe. Those teeth have serrations that look more like ripples along the entire blade length. There are better comparison photos out there, but I think this one is plain enough. All 3 teeth are from Chile 1 There's no limit to what you can accomplish when you're supposed to be doing something else Link to comment Share on other sites More sharing options...
Bill Posted May 30, 2008 Share Posted May 30, 2008 Hi All, Worthy 55's second pic appears to show a nutrition groove in the root. I believe that, from what I've seen and read, Isurus/Cosmopolitodus hastalis don't have nutrition grooves. KOF, Bill. Welcome to the forum, all new members www.ukfossils check it out. Link to comment Share on other sites More sharing options...
Northern Sharks Posted May 30, 2008 Share Posted May 30, 2008 Worthy could answer this better, but the photos are all of the same tooth, with different lighting. I think the groove is a bit of damage/erosion in the area of the nutrient pores magnified by less than favorable lighting. It doesn't show up as much in the better lit pic. You're right though, Mako's will not have a nutrient groove. There's no limit to what you can accomplish when you're supposed to be doing something else Link to comment Share on other sites More sharing options...
Cody Posted May 30, 2008 Share Posted May 30, 2008 Deff. looks mako to me. Even with that curve it dosent change it. Lowes Farm Krew For Life! ~C*J*J*D*D*G*P~ My Shark Teeth Website.MANSFIELD EXCLUSIVES!! Link to comment Share on other sites More sharing options...
Boesse Posted May 30, 2008 Share Posted May 30, 2008 Thats not a true nutrient groove. Thats some sort of damage to the tooth. Lamniforme sharks typically have nutrient pores right there, which can be large in some cases. Sometime soon I'll post a picture of the Isurus hastalis-Carcharodon carcharias transition in the Purisima Formation of California. Bobby Link to comment Share on other sites More sharing options...
worthy 55 Posted May 31, 2008 Author Share Posted May 31, 2008 Guys, I looked at the tooth and I realy can't tell if that is damage or not. I'll try to take some better pictures later for you guys. But thanks for all the input. It's my bone!!! Link to comment Share on other sites More sharing options...
Cody Posted May 31, 2008 Share Posted May 31, 2008 Darn worty those are some killer teeth!! Lowes Farm Krew For Life! ~C*J*J*D*D*G*P~ My Shark Teeth Website.MANSFIELD EXCLUSIVES!! Link to comment Share on other sites More sharing options...
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