Antique sterling silver stylistic dolphin sea creature ring

Hi

I purchased this very unique ring from an antique dealer a couple of days ago- I just fell in love with it the moment I saw it!

It is solid silver and marked 900, I know this is continental and means 90% silver but I am struggling to date this piece! I believe it is a stylised dolphin (back in the day before we discovered Dolphins were mammals and not fish!)
I'm usually quite good and dating pieces and specialise in victorian jewellery but this piece is throwing me!

Any ideas would be very helpful!

Thank you!