New Evolutionary Tree Analysis Shows Birds Related To Dinosaurs

[Richard W Travsky <rtravsky@uwyo.edu>]

http://news.bbc.co.uk/hi/english/sci/tech/newsid_2036000/2036458.stm

Scientists have produced the most detailed family tree of dinosaurs yet,
showing how the great beasts were related to each other and how they
evolved.

The researchers, from the University of Bristol, UK, took over 150
previously published evolutionary trees of dinosaurs and combined them
into a new supertree of 277 dinosaur species.

This new look at dinosaur evolution clearly shows that birds are descended
from dinosaurs, a matter of much debate in recent years.

Bristol's Professor Mike Benton said: "It is not complete, but it is the
most detailed and comprehensive single evolutionary tree ever produced for
the dinosaurs, and indeed for almost any other group." 
...
original evolutionary trees worked out for small families of dinosaurs to
produce the "best fit" that allows them all to be combined into a single,
big picture.

Bristol researcher Davide Pisani told BBC News Online: "Our tree is an
objective synopsis of the status of our knowledge of dinosaurs.

"It is an ideal tool for future studies of dinosaur evolution."

The supertree method is not just being applied to dinosaurs but to plants
and microbes as well. It is part of the Tree Of Life initiative to
document all species current and extinct. 
...
But because it summarises what is already known, some doubt this method of
analysis, while interesting, can produce anything new.

However, other scientists disagree, and are keen to point out that
supertree analysis is helping to settle a long-running controversy: are
birds descended from dinosaurs?

The supertree analysis says "yes". Birds are positioned very close to
so-called dromaeosaurids like Deinonychus and the Velociraptor, made
famous by the film Jurassic Park.

Professor Benton said: "We hope this supertree will represent a solid
framework for future study of dinosaur evolution and will stimulate
further studies towards the less well understood areas of dinosaur
classification.

"And knowing that birds are descended from Velociraptor will make many
look at our feathered friends rather differently from now on."