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Re: Flight capablities of Archie & Confucius? Not so good...

> Yes, you have to wonder what _Archaeopteryx_ was actually,
> you know... GOOD AT??
> It couldn't fly very well (if at all).
> It couldn't climb very well (if at all).
> It couldn't perch very well (if at all).
> It couldn't run very well - the hindlimb proportions were
> not highly cursorial.
> I'm even doubtful if _Archaeopteryx_ was any good at
> catching prey.  Those big maniraptoran hands could only
> be used to catch large prey in a two-handed fashion, as
> deployed by _Velociraptor_ (for example).  Archie
> presumably targeted small prey - but maniraptoran hands were
> not much good for catching small prey, because the critters
> would slip through their long, stiff fingers.
> So what business did _Archaeopteryx_ have evolving in the
> first place?  It's something I've been wondering about
> quite a lot...

To be successful in evolution, there's no need to be good at anything. It is 
sufficient to be a) better than anyone in one thing, or b) better than most in 
a few things. If it would require excellence in a lot of things, humans would 
not exist.

To the list of Archie mysteries, one can add "how did the adults look like, and 
where did they live?"

In any case, Archie was certainly one of the most (if not the single one) 
volant dinosaurs *of its time and place*. That in itself would probably be 
enough to ensure its survival. It may even have become a victim of its own 
success - there is nothing to suggest that its lineage led anywhere, so its 
descendants might have stayed in its niche, remained barely volant, only to be 
displaced when Enantiornithes came along.

As to lifestyle, I don't see a big problem there. It could fly better than a 
brick, it was nimble enough to scramble on top of some elevated spot (no matter 
what, if it was not too high - a cycad, a fallen trunk, a rock, a coral 
head...) and use it as a lookout. Simply spreading its wings and jumping in the 
right direction would have been a mechanism to escape predators and capture 
prey that could not be matched even remotely by anything competing for the same 
niche. Anything elevated half a meter above the surrounding (level) ground 
would have extended its range of vision so much as to give it a major 
advantage, while at the same time giving it all the heigth above ground it 
would need to exploit its marginal flight capabilities to the fullest.

For it probably couldn't steer well while airborne; the pronounced trend to 
caudal vertebrae reduction in more modern "birds" indicates that a tetanuran 
tail was not very useful as an airborne steering mechanism - perhaps worse than 
effectively no tail at all, as per _Confuciusornis_. So why bother with being 
airborne for prolonged distances? Gliding a dozen meters or so, even a few 
dozen meters, was entirely possible for it. The rachises would not have to 
withstand such high forces as in flapping flight, and the asymmetric feathers 
are not well explainable except by there having been significant amount of 
airflow over them.

In any case, the Archie-type alterations to the basic avialan bauplan must have 
been very successful, because they independently (in all probability, given the 
spatial/temporal distance) evolved, or at least were fine-tuned, in 
_Jixiangornis_, _Shenzhouraptor_, _Rahonavis_... also.

Watching the pigeons gliding down from the roof above me to the construction 
site below, where the workers have broken up the ground to reveal something 
appealing to pigeons, the bigger question for me is: how did Archie land? A 
tail-braking spot landing, brute-forcing itself below stall speed? A running 
landing? Perhaps more likely the latter; dropping out of the air is generally 
not recommended if you have alternatives (which Archie, with its ancestors' 
histroy of cursoriality, did have).

All things considered, Archie might have been the theropod equivalent of Otto 
Getting up some elevated spot, a stiff-winged "steers like a cow"-type glide 
down, to the amazement of bystanders (because such behaviour was radically 
novel at their time), an awkward running landing, brief success followed by 
premature death and, ultimately, inconsequence except as a well-known side-note 
in the evolution of flight - because others, who followed a technically 
different approach, were more successful.