Merritt Island Matrix - Traces and echinoid spine?

[GeschWhat]

I decided to take a break from coprolites and scan through some of Sacha's Merritt Island Matrix. One thing I see a lot are these vine-shaped traces on many of the shells in the matrix. Does anyone know the trace maker? Secondly, I came across this spiky thing. It looks modern. Is it an echinoid spine of some sort? Thanks for looking!

 

 

[ynot]

The second one is a fish fin spine. No idea about the first.

[GeschWhat]

I posted this on an ichnology forum. They identified the traces as bryozoan borings. 

[Plantguy]

Hi Lori, dont know about the borings...I think I have some of those somewhere now that you show em/remind me... Maybe shoot Roger Portell in Gainesville a couple photos and he probably can tell you which kind...

 

Interesting finds..

 

Regards, Chris