Early Oligocene/late Eocene Fossil (Ne Spain)

[Jack9909]

This fossil was found in a sandstone (not clear if marine or terrestrial) overlying reefal limestones (with solitary corals, bivalves and alveolina) and underlying a terrestrial conglomerate.

First thoughts were possibly a large gastropod (due to a hint of concentric rings inside) or some kind of vertebrae. Any help with ID would be much appreciated.

Also apologies about the dirty grain size card for scale, has been used solidly for a month in the field so not in peak condition)

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[Auspex]

My first impression is that it is a section of a high-spired gastropod; something like an ornate Turritella.

[Carl]

I get the same signal: High-spired gastropod.