Coelophysis (long)

[rowe@maestro.geo.utexas.edu (Timothy Rowe)]

        I had the good fortune of working in a second generation of
excavations at the Ghost Ranch Coelophysis quarry -- one of the most
amazing and memorable experiences I've ever had.
        The first generation of excavations was carried out by the American
Museum of Natural History, Under Edwin H.  Colbert's direction, between (as
I recall) 1948 and 1951.  Dr. Colbert told me that his excavations were
stopped after three years because he had collected a huge amount of
material -- almost more than he knew what to do with -- but that more bones
remained in  the ground.
        In the late 1970's, I worked at the Museum of Northern Arizona in
Flagstaff with Dr. Colbert.  As part of an initiative to build a new
natural history museum in New Mexico, we approached Reverend Jim and Ruth
Hall, who were the directors of Ghost Ranch, and asked if the Coelophysis
quarry could be re-opened.  Our goal was to excavate several display
specimens for the proposed museum, as well as one for our own museum, and
to let the public and legislature of New Mexico know that there is a great
wealth of important fossils yet to be recovered in their state and good
reason to build a new museum.  As the museum initiative gained strength,
the Halls granted permission to have the quarry re-opened.  (The new museum
was eventually funded and is now in operation in Albuquerque, and Dr.
Spencer Lucas is  its Curator of Paleontology).
        In June of 1981, a collaborative group from Museum of Northern
Arizona, the Carnegie Museum, and Yale University met at Ghost Ranch to
re-open the quarry.  Dr. Colbert was there with his quarry maps and photos
from the original excavations to help us re-locate the site, which by then
had silted in and could not be seen.  We quickly found the site, and after
several days of shoveling we had removed all the silt from the original
quarry and could start looking for new bones to collect.
        One of the first things we did was to identify the edge
bone-bearing layer, where the first excavators had ended their work.  As we
brushed it off the first fossil to appear was the complete, articulated and
beautifully preserved hand of a juvenile Coelophisis.   We followed the
edge of the bone bed to either side, and found articulated pelves,
vertebral columns, hindlimbs -- all exquisitely perserved.  It was utterly
amazing to see so many bones that were so beautifully preserved and so
densely packed in a single locality.  This is probably be the richest
dinosaur locality ever discovered.
        It turned out to be very difficult to remove individual bones
because they were preserved in such great density, one lying on top of
another.  Instead of collecting the bones one at a time, we decided to
remove large blocks of the bone bed from the quarry walls.   As we tried to
excavated these blocks, the bone bed continued on into the hillside and
there was no end in sight to it.  We looked for natural gaps in the bone
accumulation to mark the edges of the blocks, but none appeared -- and the
blocks got bigger and bigger, taking on a life of their own.  We eventually
used a chain saw with a carbide-steel blade to slice through the bone bed
so that we could jacket the blocks and send them back to our respective
museums.
        The block that we took to the Museum of Northern Arizona was about
16 feet long, 8 feet wide, about 2 feet thick, and weighed well over 5 tons
(we brough ropes along that could hold 5 tons, but they all broke when we
tried to pull the block with them).  Because I had anticipated collecting
much smaller blocks, I hadn't thought to measure the doors of our lab and
when the block arrived in Flagstaff it almost didn't fit.  We shaved about
2 inches of plaster off the jacket and used a backhoe to help push the
block into the lab, and after 12 hours of anxious labor we finally got the
block into our lab.  We collected an even larger block that was sent to the
Carnegie Museum, and I understand that it was so heavy  it broke the
foundation of the Museum's loading dock.
        Work at the Coelophysis quarry continued on for another year and
specimens from the second generation of excavations were shipped to the
Smithsonian, among other museums.  The Smithsonian has its block on
display, where a preparator is still working to extract individual bones
and skeletons from it.  It is a wonderful exhibit -- you can watch actual
work on the block through a large window and yor can remotely operate a
video camera that can zoom in on whatever parts of the block you choose and
see them on a TV monitor.  The specimens that have been prepared from it
are among the finest dinosaur specimens known.  Other specimens are on
display in Flagstaff, at the American Museum fo Natural History in New
York,  the Museum of Comparative Zoology at Harvard, the Carnegie Museum,
the Tyrell Musem, the New Mexico Museum of Natural History, the Ghost Ranch
Museum, and possibly elsewhere.
        I once asked Dr. Colber what his greatest thrill in palentology
was, and his answer was the discovery and excavation of Coelophysis at
Ghost Ranch.  I understand that Dr. Colbert has been working on a book on
the little dinosaurs of Ghost Ranch -- which may be finished by now.  He
also described his experiences in his autobiography (A Fossil Hunter's
Notebook, published by  E. P. Dutton in 1980) and in a number of articles
published over the last 30 years.


Timothy Rowe
Professor
Department of Geological Sciences
The University of Texas
Austin Texas 78712

phone: (512) 471-1725
fax: (512) 471-9425
e-mail: rowe@maestro.geo.utexas.edu