NAME: Enantiornithes is a large diversified group, distributed world wide, with over a dozen distinct known species. They show morphological features suggesting an enhanced flying capacity, but they also exhibit a broad morphological range. Eg. Some had teeth some did not. Sizes and shapes, wing spans, ect. were all very different.
The Debate: They do not know wether they are from the Archaeopteryxes or a relative. This group of birds may in fact, be as old as the Archaeopteryx.
NAME: Neornithes is a group that very much looks, like and is linked to the modern birds of today. Again, we are not sure of its relationship with the other groups
LOOK AT TIME SCALE CHART ABOVE:
OUR CONCEPTIONS OF THE EVOLUTION OF BIRDS IS CHANGING EVERYDAY WITH NEW
AND EXCITING DISCOVERIES. IT WILL PROBABLY TAKE ANOTHER HUNDRED YEARS,
IF NOT MORE BEFORE WE EVEN HAVE A CLEAR UNDERSTANDING OF THE RELATIONSHIPS
BETWEEN FLIGHT, EVOLUTION AND BIRDS.