Well, you got me. I used the wrong word. Ok, terms aside, how many transitional forms must there be between, say, a rat and a bat? Let's not misunderstand again. To go from a one celled animal to the diversity of creatures we have now, how many transitional forms must there have been?
I have no idea how many transitional species are between a Rat and a Bat, but it would not take many. They are both rodents and very closely related.
I must admit that I have not studied the genealogy of the bat.
However, the Trilobites are a most interesting subset of animals and have a long and well documented history. I learned many things by studying the historical record of the Trilobites.
If you want to see thousands of transition species, study the history of the Trilobites.