THE PHOTO:
I think this a shell – or a large fish fin…

POST-PROCESSING:
Straighten, Crop, Velvia Vision, Sharpen, and Unsharp Mask.

EXIF:

• Aperture: ƒ/4.5
• Camera: NIKON D70
• Focal length: 70mm
• ISO: 200
• Shutter speed: 1/750s