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RE: Archaeopteryx London specimen made neotype by ICZN



> From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu] 
> On Behalf Of evelyn sobielski

[snip]

> Glad to see this case finally closed. BTW the holotype is 
> probably a subadult, being somewhat smaller than the Berlin 
> one and markedly smaller than _"Wellnhoferia"_. All the 
> material (except _"Wellnhoferia"_ and perhaps the Berlin and 
> Haarlem specimens) seems to be immature. 
> That's interesting, because we have to assume that the actual 
> habitat was not the islands but the adjacent larger landmass: 
> the lineage must have gotten to the Solnhofen lagoon area 
> somehow, and certainly they did not arrive from the open sea...
> So it seems that an above-average proportion of immatures 
> ended up in the water. Possibly the volancy (not the 
> technical flight capability, but the extent to what the 
> aminals used it) declined towards maturity, with adults 
> flying less often and less far than they *physically* could 
> have - i.e. they had learned their limits and knew better 
> than to take off in strong land winds? 

[snip]

> In any case, the taphonomic bias is remarkable. But in the 
> absence of additional adults, we can only speculate. It may 
> be chance. But if not, I suspect it's due to the fact that 
> Archie's flight capability was not at all fully active, 
> meaning it relied to a considerable extent on forces it could 
> not control (i.e. the wind).*

This is unusual from an avian (sensu strictu = Neornithes) point of view, but 
not for a general dinosaurian point of view. The vast
majority of dinosaur fossils are from subadults, not fully adult individuals.

If, as previous work indicates, the modern avian growth mode (where fully body 
sized is achieved in <1 yr) did not evolve until deep
within Avialae, then there is no unusual phenomenon to explain. It is simply 
the general dinosaurian growth pattern at work.


Thomas R. Holtz, Jr.
Email: tholtz@umd.edu   Phone: 301-405-4084
Office: Centreville 1216                        
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
http://www.geol.umd.edu/~tholtz/
Fax: 301-314-9661               

Faculty Director, Science & Global Change Program, College Park Scholars
http://www.geol.umd.edu/sgc
Fax: 301-314-9843

Mailing Address:        Thomas R. Holtz, Jr.
                        Department of Geology
                        Building 237, Room 1117
                        University of Maryland
                        College Park, MD 20742 USA