Naturally Bexar

Salado Fossils

Time Traveling

Under a modern bridge that spans the Salado Creek there is evidence of the area’s ancient past.

Walk down into the depths of a washout under the structure’s concrete footing and you’ll find fossils. Lots of them.

It is a trip back in time, perhaps 60 or more million years ago, and it’s no surprise really. Scientists say that more than 100,000 different species of fossils have been identified in the state of Texas.

They are the well preserved reminders of the plants and animals that inhabited the enlarged Gulf of Mexico that used to cover this region. Researchers say in ancient times as the water retreated and then returned, evidence was left behind in what used to be beaches and sea floors.

The very first fossil my eight-year-old assistant and I found beside the stream was cause for much rejoicing. About as big as my hand, and a hefty three or four pounds, it is unmistakably from the sea. The elements have transformed the layers of the ancient mollusk shell and there are pock marks drilled by water. In the bright light of day, tiny crystalline deposits in the giant oyster-like shell shimmer in the sun.

Racing home to research our find we locate a drawing that looks much like our treasure and we call its name: Exogyra ponderosa, of the Upper Cretaceous period. Here’s a common name we like even better: Devil’s Toenail.

Further research reveals that many areas along the Salado Creek are packed with evidence of life from the Lower Cretaceous period, roughly 75 to 120 million years ago. Wow!

Inspired and anxious to find more relics, we return to the same area. Imbedded in the sides of a deep ravine we spot one, then two, then many fossil shells peeking out of the crumbling clay-like walls.

The ditch is about five feet deep and barely wide enough to navigate. Dry in some spots but slick and slippery in others, it is overhung with vines and overrun with ants.

It is a perfect place for a child armed with imagination and a pick.

Most days we share a policy with many people who cherish and respect nature: Take only photographs, leave only footprints. Usually we don’t collect things we find along the way, but this day we make an exception. Since these fossils are being lost to erosion anyway, we collect a few for further study.

If you would like to know more about the geology of the Salado Creek area, check out The Roadside Geology of Texas by Darwin R. Spearing or A Field Guide to Fossils of Texas, Second Edition by Charles Finsley.

Texas Fossils, An Amateur Collector’s Handbook by William H. Matthews III is also very helpful. I found my copy at Texas Lapidaries, a wonderful mom and pop rock shop on San Antonio’s south side. If you like fossils you will love this place.

If you just want to be amazed at nature’s bounty, slip down under a nearby Salado bridge someday soon and go on a fossil hunt. Even if you fail to find a fossil, you’ll find a big adventure…right in your own backyard.

Choose and mark the best answer to each question.

Fossils are

0 things found underground

0 very old people

0 remains of ancient plants or animals

0 fragile

Fossils can be found in the Salado watershed because

0 early miners left them behind

0 ancient seas used to cover the area

0 the soil has a lot of clay

0 construction projects uncover them

Many Salado fossils come from the period known as

0 Jurassic

0 Permian

0 Exogyra

0 Cretaceous

A mollusk is

0 a creature that lives in a shell

0 a form of mole

0 a crystalline substance

0 like a toenail

In this story the word erosion means

0 roller coaster

0 washing away

0 clay-like soil

0 remains of ancient animals

Email us
saladocreek@hotmail.com