Re: Archaeopteryx flight

["David Marjanovic" <david.marjanovic@gmx.at>]

> >however, looking at recent
> >ecosystems, there are always plenty of potentially competing fish eaters.
> >I've seen dolphins on TV hunting a large swarm of IIRC anchovis just
below
> >the surface -- gulls took advantage of this and picked some fish up from
> >above, and a few seals joined in too. [snip] So it seems like there
> >normally are >enough fish to share around.
>
> The waterways that separated the islands of the European archipelago were
a
> lot different to the open ocean.

Yes. The above example was very close to a coast.

> Also, _Archaeopteryx_ probably not have
> the aerial prowess that gulls have to coast above the sea and dive down
> whenever it spotted a fish.

Of course. I didn't imply that, I hope. I just wanted to say "several
different fish eaters can live in the same place & time".

> _Archaeopteryx_ would probably have had to hunt
> for fish close to the shore - and the hypoxic lagoons that the specimens
> came to grief in were probably rather short on biomass (at least of the
> oxygen-breathing vertebrate variety).

Probably.
What if the pterosaurs hunted farther away, at more productive sites farther
out which they could easily reach, while Archie had its lagoons alone? Just
speculation...

> >I disagree: the fingers flexed, and the claws pointed, more or less at a
> >right angle to the wing feathers. The exceptional development of finger
III
> >in *Confuciusornis* shows that it was still used for something.
>
> Climbing.  Holding onto branches.

Probable.

> >Indeed he thinks (or thought in 1988) that *Archaeopteryx* had a similar
> >locomotory repertoire to young hoatzins. I think that climbing is largely
> >ruled out, however.
>
> And on what evidence why do you rule this out?

- lack of a perching foot, unlike *Confuciusornis* (and all basal
Pygostylia);
- apparent lack of high trees (is it possible that the few ginkgo trunks
that are sometimes mentioned are driftwood?);
- probable lack of sufficient flight abilities.