These anomalous forms may be called living fossils; they have endured to the present day, from having inhabited a confined area, and from having been exposed to less varied, and therefore less severe, competition.
Species and groups of species which are called aberrant, and which may fancifully be called living fossils, will aid us in forming a picture of the ancient forms of life.
If the definition of a living fossil is an organism that's basically unchanged over long periods of time, then we got a whole world of living fossils around us!
But just one of the problems with the idea of " living fossils" is that there are actually many plants and animals that look a lot like their distant ancestors.