paleoaerie

Home » Education » Holiday Fun in Arkadelphia

Holiday Fun in Arkadelphia

Wow. I can not believe that I have not posted anything here since Halloween. My New Year’s Resolution is to not let that happen again. I have no excuses. But as was said on the Syfy show The Expanse, “We can not change the things we’ve done, but we can all change the things we do next.”

For this post, I want to relate the trip I took to Arkadelphia just before the Christmas holidays to visit the Goza Middle School on the invitation of one of their science teachers, Trent Smith. That trip will benefit many people in the future, and it also provided a chance to see some Arkansas geology and paleontology that may prove interesting to fossil enthusiasts.

The fossils that started this off. Picture by Trent Smith

The fossils that started this off. Picture by Trent Smith

This all started with an email I got from Trent Smith, who had found some fossils he wanted help identifying. After looking at the attached photo, I tentatively identified most of them as specimens of Exogyra ponderosa, a common oyster from the Cretaceous Period. There also appeared to be a goniatite ammonoid, a Cretaceous Period cephalopod, or squid relative. I could not be sure just from looking at the pictures, so I offered coming down to take a look at them in person. Trent was amenable to that and after a few emails back and forth, we arranged to not only look at his fossils, but talk to his eighth grade science class while I was there. It turned out that the school was interested in me talking to multiple classes, which all told was about 160 students. They suggested I could either give one talk to all of them at once, or I could do multiple talks to individual classes. I much prefer the smaller groups where people can get a more hands on experience with the fossils and have more opportunity for students to ask questions, so I opted to give several talks. I wound up giving seven talks, with two of the talks to combined classes. So I had the opportunity to speak with a lot of students.

When I got there, Trent helped me bring in my boxes and took me to his room to start setting up. Goza Middle School students are fortunate to have great science teachers who are passionate about science and education. Trent’s classroom fossil collection was by far the largest fossil collection I have ever seen in a public school classroom. They have a good variety of most of the invertebrate fossils that can be found in Arkansas. They also had a fabulous nautiloid ammonoid 4″ across or more. I had a shell of a modern Nautilus, a genus of the only extant ammonoids, so the students were able to compare a modern version with one over 70 million years old.

For each class, I gave a short introduction to the fossils that can be found in the state, which is much more diverse than most people realize. I also gave them a quick demonstration of the immense expanse of time we were discussing. I have a timeline that stretches eighteen feet and covers 600 million years. People are usually suitably impressed with that timeline, but when I tell them how much space our civilization represents on the timeline, they are stunned. At that scale, all of human recorded civilization is approximately the width of one human hair. Afterwards, we let the students look at the fossils I brought and ask questions. The students were more reluctant to get out of their seats and approach the front table than the younger kids I usually talk to, which I found interesting and speaks to how quickly we train our students to sit and listen without interaction. But once they got over their training, they enjoyed being able to handle the fossils and examine them close up. The students were uniformly polite and well behaved and were a pleasure to talk with. Midway through, the teachers treated me to a tasty potluck lunch.

My new favorite shirt

My new favorite shirt

If everything was left at that, it would have been a great trip and I would be happy to return, but they really went above and beyond. In addition to lunch and a small donation (I have generally not asked for payment for classroom visits in the past and as a result, getting paid for it almost never happens, but getting paid means I can go to more classes so is greatly appreciated), they provided me with even more. They gave me my first two Paleoaerie shirts, which they designed and they did a fantastic job. On the front of both shirts is a dinosaur foot that looks like the foot of Arkansaurus, the only dinosaur bones ever found in the state, and my name, Dr. Daniel. On the back of one shirt, it has the dinosaur foot with the words PALEONTOLOGY above it and DIGGING UP KNOWLEDGE below it. On the back of the second shirt, it says PALEOAERIE.ORG followed by my three statements of what guides my efforts: The universe is endlessly amazing, knowledge is useful only when it is shared, and you can’t really know something unless you understand how and why we think we know it. The shirts are going to be my uniform for future talks.

Exogyra ponderosa (Cretaceous oysters) collected in Arkadelphia by Trent Smith.

Exogyra ponderosa (Cretaceous oysters) collected in Arkadelphia by Trent Smith.

After school was over, Trent showed me a spot he has collected fossils from on Wp Malone Road, just west of I-30. According to the Arkansas Geological Survey’s geologic map of the Arkadelphia quadrangle, the area is listed as being in the Nacatah Sand, an Upper Cretaceous formation consisting of a mix of unconsolidated sediments deposited in a nearshore marine environment. However, the marl, a limey clay, we found in the creek looked more like it came from the Marlbrook Marl, a formation that lies underneath the Nacatah and separated from it by the Saratoga Chalk formation. The Saratoga Chalk is not thick in this area, so it is quite easy to go from the Nacatah to the Marlbrook in a very short distance. In this particular locale, the Marlbrook is close by and it is likely that what we found was washed downstream to where we found it. As I recall, Trent mentioned that fossils were more common the farther upstream one went, which would support this idea. The Marlbrook Marl, when fresh, is a blue-gray lime clay, or marl, laid down in nearshore, shallow marine environments, just like the Nacatah Sand, but without the sand contribution. The upper part of the Marlbrook is also famous for being extremely fossiliferous and this site was no exception. I initially attempted to collect what I found, but very quickly realized there were so many shells that it was impossible to carry them all. The great majority of what we found were shells of Exogyra ponderosa, but the numbers would have allowed us to quickly fill a crate with specimens. We also found a few snail shells (of what type I am not sure) and a terebratulid brachiopod, but the numbers of everything else did not begin to compare with the shells of Exogyra. On other trips, Trent collected numerous Exogyra shells and gave me two boxes full of shells. Thanks to him, I will be able to supply many Arkansas classrooms with actual Arkansas Cretaceous fossils.

Collection locality. Marlbrook (outlined teal-colored area) is upstream just west of collecting site.

Collection locality. Marlbrook (outlined teal-colored area) is upstream just west of collecting site. Click to enlarge.

Poorly preserved snails and clams. Little orignal material remains, leaving only the internal molds.

Poorly preserved snails and clams. Little orignal material remains, leaving only the internal molds.

This area is a nice place to collect. As long as one is on public land (or with the permission of the land owner), you can collect any of the invertebrates you want, so you can feel free to collect Exogyra shells here. But the Marlbrook also contains more than just oysters, brachiopods, and snails. It has also yielded mosasaurs and even the occasional elasmosaur. There is even the possibility that a dinosaur was washed out to sea and could be found there. So if you collect in this area and find some bones, give me a call.

Many thanks to Trent Smith and the whole of Goza Middle School, not just for your hospitality, but for living the statement of Dr. Scott the Paleontologist on Dinosaur Train: “Get outside, get into nature, and make your own discoveries.”


2 Comments

  1. Chase says:

    Very interesting post. I didn’t think the Marlbrook Marl was that productive, but I see now that it is very much so. Has any good mosasaur or elasmosaur material come out of the sediment, and if so, has it been published on?

    The picture of the boxes of Exogyra shells reminds me of the large Exogyra collection the MAPS (Monmouth Amateur Paleontological Society) has. If you’re in New Jersey sometime, you should definitely try to go see it if you haven’t already. Cheers.

    • paleoaerie says:

      The Marlbrook has had a lot come out of it. Sadly, there has been almost no publications concerning the material. There has been some good fossils found, but they have thus only been mentioned briefly in articles about other areas or in abstracts of meetings, with very few exceptions. Sadly, at one point in our history, mosasaur fossils were fairly common in Arkansas, but little was published about them before the good specimens disappeared. Elasmosaur fossils are rarer and I do not know of any skulls that have been found, but some remarkably well preserved vertebrae have been found. Kelly Irwin of the Arkansas Geological Survey is the expert on marine reptiles in the state. Publications are sorely lacking in this area and is just begging for a grad student.

      I have heard of some of the collections in New Jersey and the surrounding states. I have not yet had a chance to visit them, but I hope to rectify that at some point.

Comments are welcomed, although please be considerate. This site is moderated and rudeness will be ruthlessly eliminated.

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: