Please help ID

[HerbDean]

Found this at Beaumaris bay in Melbourne Australia, not sure what it is but it looks like it could be a thing? It’s my first time fossil hunting so apologies if this is just a random rock 

[val horn]

Not bone not tooth. Possible piece of sand dollar notice v shaped row of small hash lines with small circle in center and rear opening.on broad side.

[Coco]

Hi,

 

Could be. At the bottom of the first photo we see two series of small streaks that could be part of the ambulacras.

 

Coco

[Oxyrinchus1]

That is a piece of a fossilised sand dollar called Fellaster incisa.