Helicolocellus cantori is an extinct sponge from the late Ediacaran, found in the Dengying Formation of South China and possibly related to the Hexactinellida.

[1] The holotype fossil of Helicolocellus was found in the Dengying Formation of South China in 2019, and formally described in 2024.

[1] The generic name Helicolocellus derives from the Greek words helix, to mean twisted; and locellus, to mean small box.

With both the large size of the fossil material, and a “boxy” appearance, it has been proposed that Helicolocellus is a glass sponge.

However, the authors of the paper describing Helicolocellus put this method into doubt, as earlier softer sponges would most likely not preserve properly, let alone their spicules.