Re: Dinosaurs Had Sex As Youths, Study Says

[tholtz@geol.umd.edu]

> Question; on what criteria are they judging when the dinosaurs were
> "adults"?

"Adults" in this context was the ending of the rapid phase of growth,
which can be seen in histological sections by a shift to extremely closely
spaced growth rings (the External Fundamental System) rather than typical
LAGS.

> Modern dinosaurs are capable of laying eggs that hatch into young when
> they
> are adolescents, just as humans are.   It isn't particularly good for
> them,
> nor for the babies.    If some of the larger ancient dinosaurs kept
> growing
> throughout life, how would one judge when they were full grown?

See above. Dinosaurs do seem to reach a point when they are barely growing
larger each year: the end of their rapid phase of growth.

                Thomas R. Holtz, Jr.
        Senior Lecturer, Vertebrate Paleontology
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
        Mailing Address:
                Building 237, Room 1117
                College Park, MD  20742

http://www.geol.umd.edu/~tholtz/
http://www.geol.umd.edu/~jmerck/eltsite
Phone:  301-405-4084    Email:  tholtz@geol.umd.edu
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