[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

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

Eike wrote:

<Actually, that's where it gets complicated. All we know is that what 
seems by all accounts to be *immature* individuals were drifting around 
near the shore of islets.

The adults *might* have lived 
on what larger islands were in the vicinity - and which also had 
something that might be called "forest" IIRC -, and which are more 
likely to have had Archie-predators than the islets where the carcasses 
wound up.>

  It is suspected, at least when you lump all the specimens into a complex 
[1,2,3,4,5], that the Solnhofen specimen (unless you call it *Wellnhoferia 
grandis* [6]) was adult compared to the other taxa. Relative ontogeny has been 
used by several authors [1,2,3] to explain the proportionate differences as 
they largely form a cline, with the exception of an occassional outlying 
specimen to the metric [2,3]. Morphology of the specimens may trump ontogeny 
[1], but so far few of the taxa presented have been shown to bear to 
osteological disparity required to show dichotomy in the statistics, even 
though the cline is representative of a trend that can be comparable across two 
or more very, very closely related taxa.

  So, if there were more than one taxon, we would be finding 1) immature 
specimens of both or more of them, and very very few adults; 2) their 
ontogenetic trajectories would be identical and that they would likely attain 
maturity in roughly the same time period. I am not quite certain, as the 
subject hasn't come up for me to delve into it, but I recall reading that local 
avian predators tend to time their ontogenetic growth differently from one 
another so that fledging (and therefore nest-partaking) occur differentially; 
parasitic-nesting taxa, such as some cuckoos and most sparrows, avoid this and 
rarely raise their own young.

[1] Bennett, S. C. 2008. Ontogeny and *Archaeopteryx.* Journal of Vertebrate 
Paleontology 28(2):535-542.
[2] Houck, M. A., J. A. Gauthier, and R. E. Strauss. 1990. Allometric scaling 
in the earliest fossil bird, Archaeopteryx lithographica. Science 247:195–198.
[3] Senter, P. and J. H. Robins. 2003. Taxonomic status of the specimens of 
Archaeopteryx. Journal of Vertebrate Paleontology 23:961–965.
[4] Mayr, G., B. Pohl, and D. S. Peters. 2005. A well-presreved Archaeopteryx 
specimen with theropod features. Science 310:1483–1486.
[5] Mayr, G., B. Pohl, S. Hartman, and D. S. Peters, 2007. The tenth skeletal 
specimen of Archaeopteryx. Zoological Journal of the Linnean Society 149:97–116.

[6] Elzanowski, A. 2002. Archaeopterygidae (Upper Jurassic of Germany), 
pp. 129–159 in L. M. Chiappe and L. M. Witmer (eds.), Mesozoic Birds, 
Above the Heads of Dinosaurs. University of California Press, Berkeley, 


Jaime A. Headden
The Bite Stuff (site v2)

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

"Ever since man first left his cave and met a stranger with a
different language and a new way of looking at things, the human race
has had a dream: to kill him, so we don't have to learn his language or
his new way of looking at things." --- Zapp Brannigan (Beast With a Billion 
The New Busy think 9 to 5 is a cute idea. Combine multiple calendars with