Whenever these seven are given any priority, so too are other groups of animals including the four-footed egglayers, four-footed live-bearers, humans ([TEXT NOT REPRODUCIBLE IN ASCII]: lit.
It is now well established that certain kinds, those seven identified as greatest kinds in History of Animals I 6 (12) in addition to humans, four-footed live-bearers, four-footed egg-layers and snakes, feature into the organizational structure of History of Animals and Parts of Animals.
It seems that this passage can only be taken as definitive evidence that the four-footed live-bearers and the four-footed egg-layers are greatest kinds if we read [TEXT NOT REPRODUCIBLE IN ASCII] at line 28 to refer to the greatest kinds (or even the greatest kinds that are blooded).
As I demonstrate below, the kind of four-footed live-bearers and the kind of four-footed egg-layers do play a conspicuous role in the organization of explanations in Aristotle's biological treatises.
humans with the four-footed live-bearers, birds with the four-footed egg-layers, and so on), Aristotle often moves from one of the commonly recognized kinds to the next in the discussion.