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T. rex's forelimbs
My wife just forwarded the enclosed article to me from a USENET
newsgroup. It looks like some of our subscribers and ersatz
subscribers are duking it out at SVP :-) (note that the reporter
misspelled Dan Chure's last name).
Subject: Scientists Study T. Rex Arms
Date: Fri, 3 Nov 1995 0:50:14 PST
From: C-ap@clari.net (AP)
Organization: Copyright 1995 by The Associated Press
Newsgroups: clari.tw.science
PITTSBURGH (AP) -- Did Tyrannosaurus rex use its tiny arms for
fighting, loving or nothing at all?
Millions of years after the last tyrant lizard disappeared,
the world's foremost paleontologists are trying to figure out why
the dinosaur's arms were only 3 feet long when the rest was so big.
``It's a hotly debated topic. Paleontologists call each
other names over it,'' said the Carnegie Museum's K. Christopher
Beard, one of about 700 scientists at the Society of Vertebrate
Paleontology meeting this week in Pittsburgh.
T. rex roamed parts of western North America about 70
million years ago. The towering meat-eater stood nearly 20 feet
tall, weighed between 6 and 8 tons, and had powerful hind legs. But
the arms were only about as long as the average length of a man's
arm.
Jack Horner, curator of paleontology at the Museum of the
Rockies in Bozeman, Mont., argues T. rex's forelimbs may have simply
been a vestige of an evolutionary ancestor.
Kenneth Carpenter of the Denver Museum of Natural History
disagrees.
Carpenter said he believes the well-developed forelimb
muscles show the T. rex used the arms to grab its prey and impale
the animal with its claws before killing with its teeth.
Thomas R. Holtz Jr. of the University of Maryland doubts the
forelimbs were used for grappling or holding because the bone
structure shows they had a limited range of movement.
But he said other scientists think the males may have used
the forelimbs ``to steady females during sex.''
The arms also may have been simply for display, just as the
flightless ostrich uses its wings for show, Holtz said.
Another paleontologist offers a different explanation.
``The forelimbs may have been specialized for doing
something we don't have a modern explanation for,'' said Dan Chute
of Dinosaur National Monument on the Utah-Colorado state line.
The question is just one of many about T. rex puzzling
paleontologists.
``We don't know what color they were, what sounds they
made,'' Carpenter said.
Scientists also disagree on whether the T. rex was primarily
a hunter or a scavenger, whether it was warmblooded or coldblooded
and whether it hopped or moved with a loping ``Groucho Marx''
stride.
Paleontologists sometimes wistfully long for a time machine
that would allow them to see living dinosaurs, although Carpenter
isn't one of them.
``Part of the glamor and the mystery of paleontology is that
we have all these unknowns,'' he said.