Hi I’m new to this form. I’ve had this fish pottery for about 2 years. Never could find any info on it. Hoping someone can shine some light on it. It has the look and feel of be primitive. But honestly I’m not sure
Reeves, that style of flat bottom isn't terribly common on ancient pottery from the Eastern US. It shows up on some styles (cups/mugs/cylinders) more than others, but it isn't nearly as common here as it is in Central American pottery where it would be more common than not. It became a more common feature on later made for trade pieces that were intended to sit on a table or shelf (a hard flat surface), like much of the Catawba pottery, in the 1800s and later.
I really don't know what it is other than to say I don't think it's normal Mississippian pottery from the eastern part of the US.