Smalltooth Sawfish Rostrum (Pristis Pectinata) From Peace River

[evannorton]

Hi FF,

This was my best find from a day at the Peace River over spring break.

I believe this to be a rostrum from a smalltooth sawfish (Pristis pectinata), but I thought I would solicit others' opinions.

The amazing thing is that this fish/ray still lives in the world although it is on the critical endangered species list - and has existed for nearly 56 million years.

It is possible that this may be a modern specimen, but given the other material found in the same layer and how endangered the species is, I would suspect this to be a fossil.

Any thoughts welcome.

Evan

[fossilized6s]

I believe you are correct with your ID. Very cool and rare find! Congrats.

[Auspex]

What great find! Congratulations!

[sixgill pete]

Very very nice

[amour 25]

looks pretty old to me.

Nice find.

[evannorton]

Thanks, Charlie.

I spent the day with Mark Renz (fossil expeditions). Other than a few individual rostrum teeth (although they are not really teeth) - including one I found a few years back. Mark has never found a large piece of a rostrum.

Picture of rostral below:

[evannorton]

[Plantguy]

Wow, that's pretty neat. Great find! Regards, Chris

[digit]

I'd agree that it looks fossilized and not at all modern.

Probably not a lot of sawfish on the west coast of Florida (though I'm sure the odd one pops up occasionally--people who fish can correct me). The closest sawfish I know to southern Florida would be across the Gulf Stream over in the Bahamian island of Andros. The west coast of this island has the perfect habitat for these prehistoric beasties. It's been on my bucket list to go over there and snorkel with them one of these days. I've known a few people who've done it so I have the right contacts but the opportunity just hasn't presented itself yet. A bucket list with no items on the list would be pointless so, luckily, I keep mine well stocked.

I've found a few rostral "teeth" as well in the Peace but never any significant chunk of the rostrum--congrats!

Cheers.

-Ken

[Shellseeker]

Anything I find pushes my curiosity.

So I found some Sawfish Rostral teeth, good -- but which species, which genus? Is Evan correct in allocating this extremely rare section of rostrum to Pristis Pectinata? What kind of studies exist on Sawfish fossils from the Peace River (almost none)?

Two modern genera, Pristis and Anoxypristis (there are more fossil genera some of which may actually be sawsharks vice sawfish-which is a type of ray). Pristis has a wide shallow groove along the posterior edge.

The only extant Sawfish in Florida waters today is Pristis Pectinata (Smalltooth Sawfish). They are listed as endangered.

I have been communicating with a Marine Biologist from U of F, Gainesville,

The photo of the section of rostrum is interesting. The alveoli appear rather closer together than what one might expect for Pristis. However, the rostral teeth of Anoxypristis are spaced rather close together in the distal 1/3 of rostrum in the living species, A. cuspidata. Thus, it looks like the rostral section may be of Anoxypristis. However, how deep do those alveoli (the tooth sockets) extend into the rostral cartilage? I ask because the extinct pristid genus Propristis has only very shallow alveoli, and we should be able to rule this genus out by looking at the depth of the alveoli. I haven't heard or ever collected Propristis from Florida but that doesn't mean it never occurred here.

Cicimurri, D.J. 2007. A partial rostrum of the sawfish Pristis lathami Galeotti, 1837, from the Eocene of South Carolina. J. Paleontol. 81:597-601.

From the above 5 page paper, it is clear that the Rostal teeth I found http://www.thefossilforum.com/index.php?/topic/49883-sorting-spring-fossil-finds/?hl=sawfish are Anoxyprostis and it is the longer Rostral teeth with the "groove" that are Pristis (lathami). These 2 genus have been found in the Peace River.

So I popped open this thread because I am searching for additional Sawfish material from the SouthEast US and specifically the Peace River; and I am collecting photos of such material. Here is one from my Peace River hunting partner:

NOTE: LOTS of Pristis teeth, few Anoxypristis, and possibly an additional type.

Also I would like to know which Sawfish had Evan's Rostrum section.

[caldigger]

Are these "modern" sawfish know to inhabit fresh water??? If not, wouldn't that be your go ahead to assume (there's that word again!) that it would be at least from one of the past ages in which that area was covered by sea?

[Shellseeker]

Are these "modern" sawfish know to inhabit fresh water??? If not, wouldn't that be your go ahead to assume (there's that word again!) that it would be at least from one of the past ages in which that area was covered by sea?

No fresh water. Absolutely it has been covered!! Florida has zero Dinosaur fossil since it was covered by deep salt water until the Eocene (approximately 50 mya ago). The southern parts of Florida have been covered and uncovered 100s of times in the last 50 mya. The sea water covering most of the Peace River formation has been calculated at 200 feet deep and the Sawfish is generally a shallow water creature.

The Peace River tends to be Miocene (25-5 mya ago) at its oldest.

So we are takling about which genus of Sawfish have been found in the SouthEast US and specifically in Florida as fossils. The only sawfish found today in Florida salt waters is the Smalltooth Sawfish of the Pristis genus. There are fossil teeth that are very similar to the Knifetooth Sawfish, which today only exists in the Indo-Pacific Oceans.

[caldigger]

I only mentioned the bit about being in fresh water, cause I know some species of salt water sharks can swim up fresh water rivers for some distance. I wasn't sure about sawfish. Thanks for the info.