Is this a fossilized plant or some kind of urchin?

[Gianky]

Hello,

I just found this strange rock on a rocky beach in southern Italy - Europe.

The rock is flat and well levigated all around... the central part has some blackish shades... and as You can see has all those strange lines/spikes starting from center... at first I thought about a sea urchin... but what attracted me most are those ramifications at top of the spikes and in between them... this detail make me wonder if is some kind of plant...

Is it a fossil or is just my imagination that makes me believe that?

 

Thanks for the attention...

[Rockwood]

Could be a colony of the tabulate coral aulopora.

[abyssunder]

Welcome to the Forum!
It is a nice example of trace fossil. Those are borings.

[Rockwood]

Agreed. Until I zoomed in my thought was cornulites maybe. Guess I got side tracked.

[Rockwood]

3 hours ago, Rockwood said:

Agreed. Until I zoomed in my thought was cornulites maybe. Guess I got side tracked.

In case I lost anyone there; the look in the center of this is similar to that associated with cornulites fossils.

[Kosmoceras]

You get rocks like this all over the Mediteranian. I believe they are modern sea urchin borings.

[Rockwood]

59 minutes ago, Kosmoceras said:

You get rocks like this all over the Mediteranian. I believe they are modern sea urchin borings.

And I thought stepping on them hurt !

[abyssunder]

Here  is a pebble from Croatia with similar borings, and a comparative one here from the UK. It seems that the borings are made by sponges.

 

Entobia isp. from Rhodes (picture from here )