Many people think the reason they can’t understand why palaeontologists think as they do is because the palaeontologists are using more sophisticated thinking or more obscure knowledge. Scott Adams blogs about this:
http://dilbertblog.typepad.com/the_dilbert_blog/2007/09/fossils-still-b.html

Generating these family trees is an exercise in the use of numerical statistics (on biological entities) to generate belief.

It truly is a miracle that those such as the majority of palaeontologists, gain a greater insight into such areas from their geology undergraduate degree than those who disagree with them and who have either postgrad qualifications in subjects around information and knowledge processing, or who have done foundation work in developing cladistics algorithms (such as Felsenstein) but who do not endorse the palaeontologists’ conclusions.

Even more astonishing is the amazing superiority of insight those who merely aim to study palaeontology when they leave school have, over those whose opinions one might otherwise have considered valid due to their background.

Having said that though… the Turner et al 2007 paper produced the most realistic family tree yet!

This bothers me, because in the midst of all the evidence to the contrary, paleontologists steadfastly block out any idea that deinonychosaurs are secondarily flightless. It’s certainly POSSIBLE, but that possibility is rarely brought up.

1: The entire lot were descended from flying ancestry, some losing it later.

2: Flight evolved more than once in this group.

Now ask yourself why the authors choose the latter, and consider it so obvious a choice that they don’t consider it worth defending.

Also, ask why the authors made the arbitrary, undefended decision to put Archaeopteryx some way away from the root node, when they could have indicated the whole tree was descended from something very close to Archaeopteryx by giving the root Archaeopteryx as one daughter and the rest of the tree as the other. After all, they’ve already opined that the root species was … – matching Archaeopteryx perfectly. Making the earliest type a daughter of the root minimises the total (ghost) lineage of a cladogram; having a cladogram with excessive ghost lineage (which this one has – I tested it yesterday) invalidates it as a tree that could have been produced by evolutionary processes.

Now ask yourself why we should waste time on deciding whether Jinfengopteryx was a bird or a troodont.

Now ask what the ancestor of Archaeopteryx was if all the birdlike types shown here are descended from “something extremely similar to Archaeopteryx”. Oviraptors? Allosaurs?

This paper has convinced people to write stuff like:
“This finding will have to be taken into consideration in future hypotheses about the origin of flight.” Why just future hypotheses? Why not honour the duty the authors owe to the public and tell them about some of the other theories that have been knocking around for decades? After all science is supposed to be about comparing theories.
Also:
“The small size of birds was not an adaptation to flight.” Evidence is observations better accounted for by one theory than another. There’s plenty in this paper that is better explained by the theory that the ancestor of troodonts and dromaeosaurs (the non-”bird” parts of the cladogram) could fly.
It’s a mistake to choose an alternative, and a scandal to suggest to the public that only those alternatives exist.

Marco

Earlier studies have pointed to those groups as close relatives of dinosaurs before

Should this actually say “close relatives of birds“?

The analysis that Turner et al. used did not include modern birds. What is shown on the figure is only the eumaniraptoran (= Avialae + Deinonychosauria) part of the larger theropod analysis included in the supplementary data.

By the way, the paper is available here and the supplementary data here.

a real comment on the contents: i’m dismayed that the upper (bird) clade in the diagram does not continue to the present. is this an oversight or an artifact of incomplete taaxonomic coverage?

Well…..it simply means the ur-dromaeosaurid _may_ have not engaged in flight, you still have the
ur-deinonychosaurid and further-back, the ur-paravid, either which may have been flighted(if I’m reading the tree correctly).Semantics I know

Let’s not even talk about Rahonavis seeming to have re-aquired flight btw *Buitreraptor* and *Uenlagia*

Dang, maniraptorans are just devious little stick insects they are!