some type of hard coral help

[54seaweed]

was sifting through my sand and found a bunch of these
they seem to be growing out of the sand and some are as long as 6 inches
the one pictured is only about a inch
they look just like a birds nest but dead
what would be making these things
have a few of those spinoid worm things think that's what they were called but the casings are totally different from these

thanks for any help to solve the mystery

just found a big one looks like a sculpture but I can't reach behind the rock to get it and they are real brittle but hard forgot to mention that
if that makes any sense

 

[Sniperhank]

I'd agree that it is a beat up branch of birds nest.