The lake was drained Jan. 3. This is the fifth year the lake has been drained. Mammoth Spring State Park Superintendent Dave Jackson said the lake has been drained annually in an effort to kill the dense aquatic vegetation (lake weeds) that grows in most all the lake.
Jackson said one of the fossils is believed to be a partial trilobite, and the other is an insect he thinks is a dragonfly. Jackson said that both fossils would be classified as arthropods.
"Arthropods have segmented bodies and paired, jointed limbs, a hard external covering, flexible joints and well developed circulatory, nervous, digestive and reproductive systems. There are over a million species. This is divided into classes and two of the most important classes are trilobites and insects," the park superintendent said.
Jackson said trilobites are extinct arthropods of great diversity and importance as paleozoic guide fossils. "The body has three major divisions and the thorax has three lobed segments. They were probably bottom-feeding scavengers and predators," he said.
Dwight Crass from the park's maintenance department found the fossils. Jackson said it is not unusual to find items at the bottom of the lake once it is drained.
"We have found lots of different things in the lake bed once it is drained. It is like a time capsule. We have found lots of old glass medicine and alcohol bottles that may have been thrown off the bridge 100 years ago. Once we found an old Western Union sign that came from the train station 100 years ago or so. It was made of porcelain," he said.
The park superintendent said he did not know how old the fossils might be. "We will just keep them at the park. I'll probably show them to my boss because he is interested," Jackson said.
The park takes on a different look with the lake water gone. Jackson said he is hoping by next month the weather will turn cooler and freeze the lake weeds and kill them.
"The reason there is such a high concentration of weeds in the lake is due to the high nitrogen content in the lake," he said. He said the lake is usually drained this time of year, and if the weeds freeze it will retard the growth of the vegetation.
"The largest problem with the vegetation is that it is unsightly and many visitors to the park do not find it attractive," he said. He said vegetation will not harm anything in the lake.
Besides trying to freeze the plants there are not many options for getting rid of the weeds. He said the park system has considered hiring a lake management consultant to look into the problem of the vegetation and that dredging the lake may be an option sometime down the road.