Sand Dino’s?

[BTimms]

During a water change some sand was moved, revealing these...stock like things.
It’s algae like in texture but no idea what it is.

Any thoughts?

 

[taricha]

worm homes.

 

[DE FISH]

I can’t see any dinos there

 

[BTimms]

worm homes.

What type of worms might they be?

 

[taricha]

What type of worms might they be?

many different kinds, but an example...
spionid worm