A Pinnacle Species is a species with the ability for fine-grained manipulation of physical reality (e.g., a species with an opposing thumb).
Because a pinnacle species has the ability to manipulate physical creation, only a pinnacle species has the potential to create the technology required to develop World Systems capable of achieving Stage Eight (see Evolutionary Stages))
"Potential" does not always translate into reality. Many things can go wrong on the evolutionary path towards Graduation.
A pinnacle species is not a superior species. Dolphins, though highly intelligent and empathic, are not a pinnacle species because they cannot manipulate physical matter. Dolphin life, in fact all life, is no less significant or important than the life of the pinnacle species.