I found these bones at Rio Beni - Bolivia

[Cydone]

I thought I should share with you this find I made back in 2011 on a trip to Bolivia.

This was on the shores of Rio Beni that joins up with Rio Guapare, then Rio Madre de Dios, then Madeira and finally spills out into the Amazon Basin east of Manaus.

We came out of the jungle at Rio Beni in Bolivia, a few miles upstream from Rurrenabaque, after a few days trekking, and on the shore was this carcass of a huge catfish. The only thing that was left were some bones, and these incredible "fangs" or pictoral fin swords.

I took out the "fangs", and have kept them ever since!

Reading up on it, I think perhaps they are from a big Bristlenose, but maybe you guys can shed more light on them?

This guy must have been close to a meter long! and what? 40cm wide with the pictoral fins spread out.

Looking at the pics, I really wanna go back there!

[Narwhal72]

Really impressive. Imagine if plecos were predatory fish. Using those pectorals to grip their prey as they sucked them dry like a lamprey.

Would make me seriously rethink ever diving in the Amazon.

[bekateen]

Hi Cydone,

Yes, I agree that those look like pectoral fin spines. Very cool!

Cheers, Eric

[Silurus]

I'm pretty sure those are doradid or auchenipterid pectoral spines (given their size, more likely the former).

[Fundulopanchax76]

And i think these are lower jaws of anaconda. You know their lower jaw has two parts and can stretch enourmously. Are you sure these bones are from pleco ?

[Jools]

I totally agree with Silurus, here are the bones in context.



Jools

[bekateen]

These wouldn't be any kind of jawbone as far as I know (fish, snake, other) because their tooth-like projections are sticking equally out of both sides of each bone. Teeth would point only to one side or along a narrow range of angles off the jaw (not 180 degrees apart) because the teeth would need to point into the oral cavity... stabbing yourself in the chin with your own teeth wouldn't make any sense.

Cheers, Eric

[Bas Pels]

Too bad Jools´picture does not unfuld

[porinocoense]

I think it may be the pectoral spines of the Megalodoras Irwini. They are a large doradid found throughout much of South America. The skeleton Jools posted very closely resembles this catfish.