Sturgeon is a relict fish, which have appeared in the fossil record approximately 250-200 million years ago, during the Triassic period, right after the Great Permian Extinction or as it is called Great Dying.  It was the most sever known extinction event ever recorded in the history of the Earth, unlike it is generally accepted to think that "Cretaceous-Paleogene (K-Pg) extinction" was the biggest, somewhere around 66 million years ago, during which dinosaurs disappeared from the face of the earth.  In Great Dying, 96% of all marine life, 70% of all terrestrial vertebrates went extinct and it is only one know mass extinction of insects. It took the longest time to recover, around 10 million years.  All of this makes to appreciate sturgeon, who over lived the dinosaurs, making them one of the most ancient actinopterygian fishes.  Since that time, sturgeons have undergone remarkably little morphological change, indicating that their evolution has been exceptionally slow and earning them informal status as living fossils.

During the Triassic period, all of the land mass was included in a single supercontinent located more or less around the equator, Pangaea "the entire land".  By the end of this period and into the Jurassic period, Pangaea started to split in to two parts going in a different direction, Laurasia going to the north and Gondwana to the south.  It just so happened that sturgeon's natural habitat is only in present Northern Hemisphere, in the waters where temperature ranges from cold to temperate.  This leads to believe that sturgeons were mostly present around Laurasia during the big split and for some reason didn't go beyond the equator to Gondwana side, probably due to the dislike of a worm water.  They are anadromous, meaning that they are born in freshwater and migrate from sea into rivers to spawn but unlike salmon they don't die during this process but happy and healthy return back into the sea.  There are some freshwater sturgeons who are restricted only to rivers, like sterlet or sibirian sturgeon.  Nevertheless, just like their sea cousins they migrate, but only within the river basin, from up the stream all the way to the river delta, thus we can call them anadromous as well, just for the sake of justice.