Discovery! Mass Burial of Ancient Red Beds Amphibians Uncovered

PhD scientists aren’t the only ones to make spectacular new fossil finds. Case in point: a skilled bulldozer operator digging a cattle tank in Baylor County caught a glimpse of fossils – hundreds of tree trunks, branches, leaves and…skulls! It’s the biggest discovery ever of flat-headed, bottom-living frog-relatives in the famous Clear Fork beds.

Background of Discovery – the “Age of Frog-oids”

The north Texas Red Beds from the Early Permian Period are most famous for the fin-back reptile Dimetrodon, a tiger-sized predator who was close to the direct ancestry of furry mammals, including us. But the Red Beds habitats swarmed with amphibians too, creatures who hatched from frog-like eggs and breathed with gills early in life the way salamanders do today. So common and diverse were Red Beds amphibians that this geological time-zone can be called: “The Age of Frog-oids.”

Some frog-oids were huge and armed with alligator-shaped skulls. Some were tiny and squirmed through the mud like squatty snakes. Others ruled the pond bottoms and stream beds, hugging the mud with low, wide bodies and wide, flat jaws – a design ideal for ambushing crustaceans and fish passing overhead. One of the dominant bottom-huggers was the “Panzer Mudpuppy,” a twenty-pound amphibian with powerful jaws, curved fangs, and big eyes that scanned the water above. Known technically as Trimerorhachis (“Three-Part-Spine”, in honor of the vertebrae, which were composed of three sections), this flat-bodied hunter was an extraordinary geological success. It survived for twenty or thirty million years, a constant companion to the big Dimetrodons who prowled on shore.

The “Panzer” part of the nickname comes from the armored skin. Amphibians today have mostly naked, frog-oid/toad-oid skin. Red Beds amphibians were different. Their bodies usually were completely covered with thin bone scales that worked like the scale-armor suits of medieval warriors. Darwinian theorists have suspected that “Panzer Mudpuppies” were key elements in the Dimetrodon diet. Few land herbivores were available, so the fin-back predators may well have waded into the water to snag amphibians. If the theory is true, then Trimerorohachis played a vital role in the survival of our reptilian ancestors.

Gaps in the geological record

Despite 130 years of intensive study, “Panzer-Mudpuppy” history still had gaps. This amphibian was very common in the earlier Red Beds, like those in Archer County. But then it became rare. In the later Red Beds, the Clear Fork Group, good skulls and bodies are few and far between. What happened? Were there local habitats where “Panzer Mudpuppies” enjoyed reproducing and growing in Clear Fork time? No one knew, until Jimmy Smajstrla and his bulldozer arrived at the Craddock Ranch. Thanks to the generosity of Mr. Bill Whitley, ranch owner, the Houston Museum has been surveying all the fossil sites in the Clear Fork sediments that outcrop in the ranch. Bits and pieces of “Panzer Mudpuppies” were recovered but no specimen had a complete skull or jaws.

The Discovery

Mr. Smajstrla had a ranch job to perform: excavate a new tank to trap water for the cattle. However, he also had a talent for paleontological discovery. When his twenty-year-old Caterpillar, named “YSOB,” was digging down to the ten foot depth, the blade overturned grey clay chock full of fossilized plant parts. Smajstrla salvaged many valuable chunks and led the HMNS party to the spot. Fossil wood is rare in the Clear Fork, so the discovery was exciting.

Then came what no digger had dared to hope for. Even deeper went the ‘dozer. Fossil parts were in the bed below the plants. Not botanical remains this time, but what thrills the heart of every paleontologist: skulls and jaws, dozens and dozens of them, many perfect. For the very first time, science had a beautiful sample of later “Panzer Mudpuppies.” Some of the heads were larger than any previous discoveries. The official name of the skull-bed is “The Judy Site,” in honor of Mrs. Judy Whitley. What will the “Judy Site” tell us? Lots. We’ll know much more about the habitat choice of the “Panzer Mudpuppies.” And we’ll be able to detect micro-evolutionary changes. Investigations have just begun.

We look forward to sharing updates on our investigations as well as new finds with you. Stay tuned!