Rare fossil of late Cretaceous plesiosaur discovered

The initial discovery, made June 20 by middle-school student Noah Traylor during a UA-hosted expedition, was later identified as part of a large neck vertebra of an elasmosaur, which is a subgroup of the late Cretaceous plesiosaurs.

Elasmosaurid plesiosaurs are easily recognized by their large body size -- some species reach up to 45 feet in length.

"Think Loch Ness monster," said Dr. Dana Ehret, UA Museum paleontologist. "They have very large flippers for swimming and extremely long necks, consisting of up to about 70 neck vertebrae."

Plesiosaurs became extinct by the end of Cretaceous, or about 65.5 million years ago, and they are generally rare in the fossil record for Alabama. This is only the second elasmosaurid specimen containing more than one or two bones found in the state, Ehret said. The first, which consists of 22 vertebrae, was found in the late 1960s and is now part of UA Collections.

This discovery appears to be on par with the first one. To date, about 15 large vertebrae, a few paddle bones and many bone fragments have been collected, but an extensive excavation is still in progress, so Ehret is uncertain how complete this skeleton is.

"We find a lot of the more common fossils here, but this is a macropredator that is not normally found in Alabama," Ehret said. "It's really interesting because it gives us a bigger picture of what was happening in Alabama at that time."

The skeleton was also not found near water. Ehret said during the late Cretaceous period, temperatures were much warmer than they are today, resulting in higher sea levels. The specimen was found in a small quarry in rural Greene County, a region commonly called the "Black Belt."

The "Black Belt" represents the late Cretaceous shoreline in the Gulf Coast. The sediments found in this region are classified as chalk, are composed of extinct microscopic organisms and are extremely nutrient rich, making them the perfect place for farming.

The discovery was made during the Museum's Expedition 35, which was hosted by UA's Alabama Museum of Natural History and led by Randy Mecredy, director of the Museum. The expedition is an annual summer program that is open to middle and high-school students.

In addition to Ehret, others involved in the excavation include students from the expedition, Dr. Takehito "Ike" Ikejiri with UA's department of geological sciences, museum staff, Dr. Prescott Atkinson of the University of Alabama at Birmingham, the UA Museum's Board of Regents and a few UA geology students.

The bones were initially excavated in place from the chalk in the quarry. Once they were able to determine the size and extent of the individual bones, those working the excavation could take them out of the ground and transport them back to the museum. Some pieces came back loose, while others were wrapped to prevent them from falling apart.

In the paleontology lab, the bones are now being unwrapped and prepared. Specimens are washed and scrubbed to remove loose sediments, and, for those that are still embedded in the chalk sediment, Ehret said they will use different tools to remove the sediment.

It will take several weeks to prepare the bones properly and then harden them to ensure they will not later fall apart. Once finished, the specimen will be displayed in UA's Smith Hall.

"From a research standpoint, this is an important find. To have this many pieces, you can do an extensive comparative analysis," Mecredy said. "But, it's also having the ability to take high-school and middle-school students in the field where they find these things. It inspires them to pursue science-related fields."