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At 04:31 PM 12/18/97 -0800, the Armadillo wrote:
>> Actually, not true. Middle Jurassic mammal jaws were known from the time of
>> Sir Richard Owen, and G.G. Simpson (one of the greats of vert paleo in the
>> first half of the century, and into the second half) did a lot of work on
>> Mesozoic mammals.
>I was just looking through "Wildlife of Gondwana" By Patricia Vickers-Rich
>this morning and it looks like from the charts that they could go back as
>far as the Triassic. Is there any evidence on this or is it just the chart
>p[laying tricks on my eyes?
Depending on the definition used, mammals date back as far as the Late
Triassic (Sinoconodon, Adelobasileus) or as recent as the Middle Jurassic
(the docodonts, which seem phylogenetically to fall out as crown-group
mammals, within the clade joining Monotremata and Theria).
In any case, mammals spent much of their history in the shadow of the dinosaurs.
Thomas R. Holtz, Jr.
Vertebrate Paleontologist Webpage: http://www.geol.umd.edu
Dept. of Geology Email:firstname.lastname@example.org
University of Maryland Phone:301-405-4084
College Park, MD 20742 Fax: 301-314-9661