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Thermopolis crocodile excavation, MT

During her Master's Thesis fieldwork on the vertebrate taphonomy and sedimentology of the Thermopolis Formation, Cathy Lash discovered an articulated marine crocodile. This skeleton includes the front half of the animal, including the skull, jaws, vertebral column, both forelimbs, ribcage, and dorsal osteoderms (scutes). The croc skeleton took three weekends to collect, each visit requiring more field hands and more sophisticated tools. Eventually, the use of a small jackhammer was required, and a truck with a small crane and winch on the back to drag the 800-900 lb plaster jacket up the hill.

Heading down to the 'Cathy's Croc' locality. (Dave Varricchio on the left, and Mike Knell on the right; second weekend.)
Cathy Lash (left) and Dave Varricchio (right) inspecting bones exposed in outcrop at 'Cathy's Croc'. This is after we spent about an hour
collecting approximately 20 lbs of float.

Our crew at 'Cathy's Croc' during the first weekend of the excavation. These are all exposures of the Thermopolis Formation.

Initial size of the excavation, after two days (first weekend). The elongate mound in the middle of the pit is the croc skeleton.

The right forelimb of the crocodilian skeleton. This was jacketed separately; the croc is laying on its left side, and the left forelimb is tucked under the thorax. The humerus is the large bone in the center (second weekend).

Shadow of the crew during the second weekend of the excavation.

Ash Poust gingerly using a railroad pick to remove overburden while Mike Knell (doing nothing) and Dave Varricchio (with shovel) look on (second weekend).

The rest of the field crew working on the excavation (second weekend); Mike Knell (in blue plaid), Dave Varrichio (in back), Cathy Lash (kneeling), and Ash Poust (adjusting patriotic bandana).

Navigating the fairly sketchy road to the locality at the end of the second weekend. Note Dave Varricchio (driver, last car) holding the driver door closed; it had broken earlier in the day when Mike Knell drove to Billings for burlap.