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

Re: mammal mystery



At 01:52 AM 2/18/97 -0500, you wrote:
>Here's an interesting thought that occurred to me some time back. Does it not
>seem likely that at least *once* during the long course of the Mesozoic,
>there might have been a localised exception to the "dominance" of dinosaurs
>in terrestrial ecosystems. It would seem that all that's needed is a chain of
>volcanic islands, a Galapagos or Hawaii. It seems highly unlikely that
>non-avian dinosaurs would have ever reached such remote loacles, since they,
>like large land mammals, would have been ill-suited for sea crossing. 

Indeed.  However, our knowledge of the terrestrial environments on oceanic
volcanic islands from the Mesozoic is just about nil, since they have that
annoying habit of sinking...

>What *would* be expected would be arrival of most of the groups we see
>populating new islands today: various groups of reptiles, avian dinosaurs,
>insects, arachnids, amphibians, and small *mammals*. In an enviroment devoid
>of comepetion with dinosaurs, perhaps there were a few exceptions, and from
>time to time isolated, mammal dominated ecosystems arose.

Amphibians might be a problem, since they don't like oceanic crossings too
much (except in logs, etc.).

A pterosaur dominated ecosystem would have been interesting...

Thomas R. Holtz, Jr.
Vertebrate Paleontologist     Webpage: http://www.geol.umd.edu
Dept. of Geology              Email:th81@umail.umd.edu
University of Maryland        Phone:301-405-4084
College Park, MD  20742       Fax:  301-314-9661

"To trace that life in its manifold changes through past ages to the present
is a ... difficult task, but one from which modern science does not shrink.
In this wide field, every earnest effort will meet with some degree of
success; every year will add new and important facts; and every generation
will bring to light some law, in accordance with which ancient life has been
changed into life as we see it around us to-day."
        --O.C. Marsh, Vice Presidential Address, AAAS, August 30, 1877