( id referring to how they first had fou...)Trotting with emus to walk with dinosaurs

What emus revealed, says Breithaupt, is that many mysterious dinosaur tracks became quite easily understood when a live animal was seen in action.

Breithaupt will be presenting some of his team's emu track discoveries on Wednesday, 25 October at the Annual Meeting of the Geological Society of America in Philadelphia. Theresearch was funded by the Bureau of Land Management and National Science Foundation.

Among the emu revelations was one that helped resolve a mysterious "crossing over" track pattern seen at Red Gulch. Researchers had found that sometimes a dinosaur's tracks became crossed ?that is, the left foot crossing over the right and the right crossing over the left. That seemed pretty strange and hard to explain on the face of it. But after watching emus, it became clear that the crossing over is partially the result of the very narrow "straddle" of the trackways, meaning their legs were close together. Emus share that characteristic and can be seen crossing over feet all the time, said Breithaupt.

The rest of the mystery was solved by observing what else emus do as they walk.

"Often they are looking around as they walk," said Breithaupt of the crossed foot tracks. "Sometimes they stop in mid-stride and look around." Walking theropods appear to have been doing the same thing. So the trackways of walking dinosaurs may also represent those animals stopping in mid-stride as they observe their environment."

Tracks at Red Gulch and those at the emu ranch were carefully documented using state-of-the-art photogrammetric techniques, which allowed detailed sub-millimeter accuracy photos to be taken. These can be computer
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Source:Geological Society of America