Mushroom turtle garden statue

I was wondering about the origin of the item.
I have found a few others online, nearly identical, also made of concrete. Two on ebay, one is made into a lamp.
There are two companies that currently cast them in concrete, with reduced details. I have reached out to them as well, awaiting response.
I have one that is made of ceramic or plaster. It's hollow. It also appears to have finer details than the concrete version. Does anyone know anything about the original artist or studio that produced these types of turtle/mushroom?
Would this be from the 60s era or 70s?

Any information you can provide, about the origin of these cute turtles, would be most helpful to me!