It looks like a tuna vertebrae, however relatively strong process developed laterally seems different from tuna vertebrae I have seen before. Hope this helps.
Sorry, I am not familiar with Scombridae and not intending to make a confusion, but my question to you is: are you sure that the last two pictures of vertebra are of the FISH vertebra?
In fact, on the hint for zygosphenes and zyganthra at the top-sides of neural arches and on the shape of the centrum surface, that looks to me a snake's vertebra.
Philippe Béarez: Thank You, I'll check the verts of that group :)
Predrag Simonovic: Well, I saw similar fish verts on the web, but no exact matching. As far as I know, snake verts are very differ from this specimen, and based on the size, if it'd be a snake's vert, the living animal should have been a python sized animal, or bigger... the locality has terrestrial influence (mammals and birds), and also has squamate remains, but fishes are the most abundant. So I'd be sceptic with that it is a snake's vert.
But Thank You for Your time, to write the comment, I truly appreciate it :)!!!!!!!!!!!