Central Texas Fossil Finds

Jul 13

This week, we took a trip to the Texas Hill Country near Boerne, Texas. I have relatives there that let us poke around their land for fossils. We haven’t searched for fossils there yet, so it was an adventure!

The first day, we only had a little time before dark, so we walked around to see what the terrain was like. We found that we’d be searching on a terraced limestone hill that held lots of yellow clay and LOTS of fossils!

The next morning, my husband and I started early and spent around 3-4 hours just walking the hillside. We found tons of bivalves - a few different types of clams. My favorite is the “Texas Deer Heart” (so named because of its resemblance to a heart). We also found several large gastropods that looked like big snails that I believe to be Lunatia Pedernalis. We have a few smaller ones that might be other species.

My husband found a cool echinoid (urchin) that looks to still have some of the shell intact, and we found some that are definitely steinkerns (internal fossils where minerals have filled in the original shape of the organism, but the outside shell has dissolved away over millions of years).

*Echinoid (urchin) with some of the original patterned shell showing*

One of the cooler things we found were nerinea gastropods. Well, we thought they were cool because we’d never found any before. My husband found two huge partial ones, and then we found LOTS of tiny ones.

*small Nerinea gastropods still in their limestone matrix*

For some variety and much needed cooling off, we took the afternoon to kayak on the Guadalupe River. We spent some time paddling, and some time searching gravel bars for fossils. What we found was just tons of smooth river rock, lol! This was very different from our experiences in the Colorado and North Sulphur Rivers where we always find lots of goodies. So, we enjoyed the cool water and nice views. Then, we went back to our hill to search some more!

On our last morning in the hill country, we decided to go back to find the nerinea gastropods again. We happened upon a section of a terrace that was FILLED with the tiny fossils! We also found tiny bivalves, tiny snail gastropods, and something we later discovered to be orbitolina texana, a type of foraminifera fossil. These are tiny, tiny circles that look like confetti. When we researched what we had found, we learned that these itty bitty shells are very important to paleontology and geology. There are tens of thousands of different species of forams, each one very specific to an exact time and place. Based on what spieces of forams are found in an area, scientists can determine the geological age of other fossils found there. Pretty cool that these tiny confetti pieces are so important.