Hemipristis or Prionace tooth?

[Dino9876]

Hello,

 

I saw this tooth for sale on the Internet. Unfortunately the photo was very bad, so I tried to creat a vector graphic.

I'm not sure if the tooth belongs to a hemipristis or a blue shark.

 

Can you help me with this? The tooth measures a little over 1cm to the tip and was found in Indonesia (Pacific ocean).

 

Best regards from Germany!

[fossilselachian]

Looks like Hemipristis

[Coco]

Hi,

 

OK with Hemipristis.

 

Coco

[Dino9876]

Thank you all!

[siteseer]

Fossil Prionace teeth have finer serrations and a narrower crown and tend to be smaller overall.  It's a little trickier with modern teeth because Hemipristis exists today as a smaller species and the teeth are similar.  You can still tell the difference in upper lateral teeth like that one because the serrations on the distal cutting edge (the trailing edge) tend to be noticeably larger.   That particular tooth is easier to ID because has a broader crown more like the extinct species.

 

Maybe thirty years ago, I had a chance to sort out a large lot of shark teeth from an Early Pliocene site in California (Oceanside).  They had been collected years before that.  The vast majority were great whites (Carcharodon carcharias) with some makos (Isurus oxyrinchus) and Carcharhinus (two forms that appeared to be dusky shark and bronze whaler).  Out of the whole nearly full beer flat there were just a few angel shark teeth and a few teeth that I thought were odd little Hemipristis.  The two upper teeth had smaller serrations than I'd seen with Hemipristis.  It was a couple of years later that I read that Prionace was known from the site and I started seeing Prionace from the Pliocene of Peru not too long after that and I made the connection.

[Dino9876]

10 hours ago, siteseer said:

Fossil Prionace teeth have finer serrations and a narrower crown and tend to be smaller overall.  It's a little trickier with modern teeth because Hemipristis exists today as a smaller species and the teeth are similar.  You can still tell the difference in upper lateral teeth like that one because the serrations on the distal cutting edge (the trailing edge) tend to be noticeably larger.   That particular tooth is easier to ID because has a broader crown more like the extinct species.

 

Maybe thirty years ago, I had a chance to sort out a large lot of shark teeth from an Early Pliocene site in California (Oceanside).  They had been collected years before that.  The vast majority were great whites (Carcharodon carcharias) with some makos (Isurus oxyrinchus) and Carcharhinus (two forms that appeared to be dusky shark and bronze whaler).  Out of the whole nearly full beer flat there were just a few angel shark teeth and a few teeth that I thought were odd little Hemipristis.  The two upper teeth had smaller serrations than I'd seen with Hemipristis.  It was a couple of years later that I read that Prionace was known from the site and I started seeing Prionace from the Pliocene of Peru not too long after that and I made the connection.

Thank you for the explanation!