We're crossing wires here because you have an inaccurate conception of what a transitional species IS.

You appear to have this mental image of a dinosaurian morphing into a bird from the top down; first the reptile head turns into a beak, then the forelimbs turn into (feathered) wings, and for the last step the clawed reptilian feet suddenly turn bird-thin and webbed between the toes.

It is the "Crocoduck" silliness promoted by scoundrels such as the ICR.

A real example is something like, say, Plesiadapis, a late Paleocene mammal that sits close to the base of primates and Scandentia (modern tree shrews). It doesn't look like a monkey with the head of a squirrel! Nor does it look like a koala (as a representar of the earlier marsupials) crossed with a cow (representing Class Mammalia!)

It is a thing shaped like itself. Slender, furry, with a splendid bushy tail, an aboreal omnivore with a small brain case, mixed dentition, and strong curved claws.