Of Primates and Theropods

[bh480@scn.org (Ben Creisler)]

The whole argument that maniraptoran dinosaurs (best known 
from the Cretaceous) can't be related to the ancestry of 
birds that date from the Jurassic "because you can't be 
older than your ancestors" sounds suspiciously like that 
old saw "if humans evolved from apes, how come apes are 
still around?" used by supporters of that forbidden c-
word. In fact, as I believe somebody has pointed out 
before, living primates provide the best rebuttal to this 
faulty line of reasoning. The modern world contains 
prosimians, lemurs, Old-World monkeys, New-World monkeys, 
apes and humans--each representing a different 
evolutionary grade from the point of view of brain-power 
and bipedal movement. Go far enough back in time and 
virtually all primates would look like lemurs. If no 
fossil lemurs were known, though, would any serious 
scientist argue that living lemurs DON'T provide a good 
model for animals ancestral to monkeys, apes and humans?
Most instructivly, each type of primate still survives 
perfectly well (barring habitat destruction) in the modern 
world, in some cases happily living alongside one another. 
For example, jungles in parts of Southeast Asia contain 
prosimians, monkeys, apes (gibbons and orangutans) and 
humans. This situation seems analogous to the formations 
in the China in which various types of primitive to 
advanced (maniraptoran) theropods coexisted with various 
lineages of avians, including Confuciusornis, as well as 
enantiornithe and more advanced ornithine birds.