This is the fruit of a water caltrop (*Trapa natans*). It is also known as buffalo nut, bat nut, or devil pod.
More info on this species here:
https://www.invasiveplantatlas.org/subject.html?sub=3499
https://en.wikipedia.org/wiki/Water_caltrop
Accession Number: 222.17
Captured with Artec Spider 3D Scanner
https://www.artec3d.com/portable-3d-scanners/artec-spider-v2