Billfish Rostrum ID Help

[Lone wolf]

I am reposting in and attempt to get a definitive ID on the rostrum .

Thanks to AL Dente I believe it is a billfish rostrum his thoughts were Istiphoridae or Xiphiorhynchus Kimblocki . A Google search has not yielded much information on my quest to positively ID the rostrum.

I am asking for something that may be difficult or impossible to do without a hand on inspection but a definitive ID would be awesome. Any information would be appreciated thanks

[Lone wolf]

One more photo

[Fossildude19]

Not sure you will get much further than genus here,... see this pic.

Here are a few links for you.

LINK 1

LINK 2

You might consider sending an e-mail to John Maisey at the AMNH.

Regards,

[Shellseeker]

I guess the question is "What are the distinguishing characteristics of a rostrum? Here is one that looks a lot like yours?

https://www.fossilera.com/fossils/10-fossil-marlin-swordfish-rostrum-miocene

[Al Dente]

Here's a chart from Fierrstine and Applegate 1974:

Here are a couple of mine from the Eocene Castle Hayne Formation of NC. You can see the central canal and two pairs of canals to the side which should make these Xiphiorhynchus. I'm not sure how close to the tip these canals will go.

[Al Dente]

Just for fun, here is a marlin premaxilla and a couple of predentaries from the Pliocene Yorktown Formation of NC.

[Lone wolf]

I would like to thank everybody For helping me identify this as a billfish rostrum ,your wealth of knowledge is a powerful tool .

After being educated on what a rostrum looks like I decided to take a look through my modest box of Eocene whale bones on the off chance that there could be another rostrum. And this is what I found!. It's approximately 4 1/2 inches long and after cleaning I am holding in my hand what I believe to be a second billfish rostrum! I am trying to contain my excitement until confirmation from one of the members on TFF. Any help would be appreciated

[Al Dente]

I am holding in my hand what I believe to be a second billfish rostrum!

I think you are right.