My son with his hand next one of the largest examples of the mollusk fossil we found.

A few days back we went to the park for a little recreation and my youngest, as usual, wanted to get down into the creekbed. This is something I have mixed feelings about — on the one hand, I remember how much enjoyment I got from wandering around waterey places when I was little. On the other hand, I have fear that there might be germs down there. So I compromise and go with him.

Exposed beds of limestone comprise most of the creeks that criss-cross Tarrant county. Today, there are puddles in the limestone, even though it hasn’t rained in at least a week or two.

We found fossils in the stone, and, by using Google Image Search on “Texas Fossil in Creekbed” I found out what they are: a creature called the “Tarantoceras sellardsi.” Of course, that answer doesn’t really provide me with any new information, it might as well be called the “Heba-Jeba-Sebalator,” so I put “Tarantoceras sellardsi” in the search engine. First it tells me to try a different spelling, and then when I do, there’s no hits.

Apparently the “Tarantoceras sellardsi” is not well known, throwing me back on my own resources.

It seems to be a type of mollusk, and the image I found of a similar fossil was unearthed, you guessed it, here in Tarrant County. So I have decided to name this strange creature the “Tarrant County Mullusk.” It is said to come from the Cretaceous period, so at least we have a good idea of how long the rock has been down there at the park: somewhere between 65 and 144 million years.

Editor’s note: image comes from creekbed in Kellis Park, in South Hills.