A shark tooth and a Catfish spine

[Shellseeker]

I was out yesterday... No fantastic finds but a few interesting ones.  A Shark tooth, 38 x 23 mm.  I thought it was a Shortfin Mako,  my friend said giant thresher.  Help  @Al Dente, @MarcoSr.  What differentiates the two...  

 

The 2nd is a fish spine.

 

 

I am used to seeing Catfish spines that look like the one below..... I am wondering and usually pleasantly surprised, when I reach out fro detailed knowledge on any fossil topic, in this case identification of catfish spines.

 

[JorisVV]

It's a shortfin mako tooth. I've found several 100% pieces and are not as thick as Tresher teeth

 

[Al Dente]

I’m not sure if the tooth is mako or hastalis. The bone looks like a pectoral fin spine.

[MarcoSr]

1 hour ago, Al Dente said:

I’m not sure if the tooth is mako or hastalis. The bone looks like a pectoral fin spine.

 

I agree with Eric on the tooth, mako or hastalis.  Definitely not an A. grandis tooth.

 

Marco Sr.

[Shellseeker]

Thanks for the excellent responses. 

I laid out this tooth with a couple of Peace River Threshers ( I only have found 3 or 4 over 13 years) .  I note the straight line around the bourlette and definite sharp curve on the blade.

 

On the Pectoral spine, it seems different on both longitudinal groove and attachment point, from my normal catfish barb.  I'll try to narrow the ID if I get time to search the internet.    Thanks Jack