e had our first joint field trip with the Houston Geological Society and the Houston Gem and Mineral Society, and it was a complete success. We have always had a mixing between societies and I wanted to show the HGS folks that HGMS has lots to offer. Our leader for this activity was Glen Kuban, who has been publishing on trackways in general and on the Paluxy River dinosaur tracks in particular. Even after the pillaging of the Glen Rose trackways by New Yorkers in the 1930s, Dinosaur Valley State Park and environs are still among the best places in the world to see theropod and sauropod trackways.

All the guidebooks have been telling you this for years—“you need a native guide to see the sights,” and Glen was ours. I bet you have been to the park and thought that most of the tracks were collected 70 years ago. Not true. Glen took us to trackways that run for more than 30 steps down the river. He showed us tracks where the fillings are harder than the tracks and so the tracks stand in relief! He even showed us the real story behind the disputed “Paluxy Man Tracks.”  Glen has worked with the Parks people for so long that we were given extraordinary access and taken through back gates and across fields to reach prime areas.

We got many strange looks from other visitors when we descended to the river level and started to clean the riverbed with our brooms. The negative relief trackways collect sediment and frequently are covered by luxurious blooms of algae. Though it looks like King Canute sweeping back the sea, this process really works to make the tracks visible. The river flow quickly clears the area of stirred up sediment.

One of the great benefits of doing the field trip literally in the river is that the children had a great time playing in the water and providing small feet for scale in the pictures. The tracks look ever so much bigger with a kid-sized foot for scale.

We got to see a string of tracks where some are so eroded that they look like they were made by a really huge human foot. In the same string are some uneroded tracks where you can see that the elongation of the track is from the dinosaur heel (metatarsal). Theropods normally walk on their toes, but sometimes their heel comes in contact with the ground (bad posture? flat feet? tired?). In this case, the sediment was so soft that it filled in the claw marks, which become “toes” on an eroded track.

The Houston Gem and Mineral Society and the Houston Geological Society have many members in common and have similar interests in seeing geology in the field. I became a geologist because I enjoyed rockhounding as a child.