Hello to the K. B. Polk 4th graders!

I enjoyed your visit to Cedar Ridge Natural Preserve.  As I told some of you, I'm a scientist and I was going out to South Texas that weekend to find some dinosaur prints.  I told your teachers I'd write a letter about my adventures, because scientists love having adventures.

I saw the footprint -- I think it's a footprint -- about a year ago on a trip to look at rock art.  As I was hurrying across the flat limestone beside the river I stepped right over a strange-looking depression in the rock.  "Looks like a dinosaur footprint!" I said to myself and snapped a quick picture as I hurried toward the rock art.  After all, I'm an anthropologist and my interest is rock art.  "I'll take the picture back to the paleontologists at the Dallas Museum of Nature and Science," I said to myself.  "They'll know if it's a footprint or not."

After I got back from that trip, I showed them the photo and they said that although it COULD be a dinosaur footprint, it could just be strange erosion patterns on the rock.  The only way to know would be to go back and take a mold (impression) of the track.  But the rock art site is closed for most of the year -- and so I had to wait to go back out. 

I told some of you that the first thing a scientist does when they come across something strange is research.  So I checked books on geology to make sure that dinosaur tracks had been found in this layer of limestone (they had -- in fact, this is the same limestone as Glen Rose, where the famous Texas dinosaur footprints are found.)  I talked with paleontologists about how to measure and record footprints and how to take a "cast" of a footprint.  I talked to a company that sells molding compounds to the museum -- the stuff they use when they go study dinosaur footprints in Alaska.  And I helped the museum work on some footprint casts that they'd brought back from Alaska.

So I was pretty well prepared for the trip.  When the day came, I drove to Del Rio... a long 8 hour drive. 

This area of Texas is a desert, and the animals and vegetation are very different than you see in Dallas.  I drove past some of the areas that had been burned by wildfires the week before -- it was shocking to see long stretches of charred trees and grass. 

Saturday morning I met the tour group to go to the rock art area -- they'd look at the rock art, but I was going to look for those dinosaur footprints.  I took along lunch, plenty of water, a measuring stick, camera, and everything else I could think of.  What I hadn't counted on was geology.

You remember us talking about erosion?  Well, when you have a stretch of rock along a river, the river floods.  Soil erodes out of hillsides and bare places and floats in the water as sediment.  When the flood goes down, it leaves sediment (mud) everywhere.

When I got down to the rock bedway, I saw that it was now covered with dried hard mud... and there was no clue where my footprints were now!   It was just a flat stretch of dried mud and rock that was as wide as two classrooms and almost a half a mile long.  That's a BIG area to hunt for a dinosaur footprint that's only about 15 inches long!

I spent five hours wandering all over the place and rubbing at depressions in the mud with my bare hands (my fingertips were awfully sore the next day) and still didn't find them!  The back of my neck (the one place I didn't put sunscreen) was burned, too.

So, scientists aren't always successful at everything.  I saw a few things that COULD be dinosaur footprints -- but they could have been just strange erosion patterns in the rocks.  I wasn't going to use my expensive rubber compound to get a model of something that was probably just rock.  I think I could have found them if I had a second day out there, but they won't have another tour of the site till fall.

And so I came home.  When I told the paleontologists about my adventures, they laughed and said "It was a reconnaissance mission!"  I teased them that they forgot to tell me about what happens to geology when rain hits the dirt and rock.

It really was fun, though.  I saw a lot of interesting things on the way down there (including a bird called a "caracara" (http://en.wikipedia.org/wiki/Crested_Caracara) and some wild turkeys along the roadside.  I'm planning on going back this fall.  THIS time I'm bringing along a scrub brush and some other tools.  I'm not letting a little mud stop me from finding them again!

I hope you will go out and have some science adventures, too!