Guantanamo Bay Fossils Fill Research Void

February 1st, 2009

By Bill Kanapaux

Roger Portell at Gitmo

Roger Portell, invertebrate paleontologist at the Florida Museum of Natural History, walks underneath a late Pleistocene coral terrace at Guantanamo Bay Naval Base, Cuba, during his July 2007 trip to search for invertebrate fossils. Photo by James Toomey

When most people hear the words Guantanamo Bay, they immediately think of the infamous prison built there in 2001. But for Roger Portell, an invertebrate paleontologist at the Florida Museum of Natural History, Guantanamo means the chance to collect marine fossils on an island that is otherwise largely off limits to U.S. researchers.

For the last two years, Portell and Florida Museum volunteer James Toomey have had access to a growing number of fossil sites on Guantanamo Bay Naval Base. The base, located on the eastern tip of Cuba, has been used by the U.S. Navy for more than 100 years. But until now, no formal paleontology work has occurred there. The rest of the island, under communist rule since 1959, is inaccessible to many paleontologists.

The Florida Museum’s invertebrate paleontology collections concentrate on the southeastern U.S., the Caribbean and parts of South America, but Cuba has remained a void.

“We just don’t have much in the line of invertebrate fossils,” Portell said. “We continually referred to fossils that had been described long ago from Cuba, but we didn’t have any comparative material. There are these big gaping holes in our knowledge. Cuba is a prominent island in the Caribbean. For us not to have a good picture of these faunas is rather unsettling.”

fossils in the rocks

125,000-year-old terraces at Guantanamo Bay yield numerous specimens for the invertebrate paleontology collection at the Florida Museum of Natural History, including these coral fossils. Photo by James Toomey

Portell, Toomey and other researchers have now visited the base three times and established 17 collecting sites.

Most of the fossil coral deposits near the base are about 125,000 years old. These terrace deposits formed as ocean levels receded. On the second visit, Portell and Toomey found a site dating back 20 to 25 million years. On their third visit, they and Florida Museum Director Douglas Jones found a site that is 45 million years old. These older sites, located farther inland and at higher elevations, resulted from geologic uplift.

“One of my roles is to find, collect, identify and describe the animals that are there,” Portell said.

His research is primarily alpha-level taxonomy, identifying which invertebrates lived in a place and when they lived there. Knowing the faunas helps flesh out the picture of an area’s paleoecology, which describes its ecosystems of the past, and its biogeography.

“We get some unique invertebrate occurrences here in Florida that we see nowhere else but on certain islands in the Caribbean,” said Portell, who also has conducted field work in Jamaica, Carriacou and CuraƧao.

Other researchers are also interested in using the Cuban fossil samples to help understand predator-prey relationships and determine faunal turnover and extinction.

“Once we get all these projects put together, we’ll have a much better idea of what was going on in Cuba at the various times that these fossils were deposited,” Portell said.

Access to Guantanamo

Portell with a Marine

Marine Col. Nathaniel “Turk” McCleskey, left, and Florida Museum invertebrate paleontologist Roger Portell take a break from digging in front of an Elkhorn coral, Acropora palmata, at one of the Florida Museum’s 17 collecting sites at Guantanamo Bay in 2007. Photo by James Toomey

 

Marine Col. Nathaniel “Turk” McCleskey first contacted Portell three years ago, in January 2006, looking for help identifying fossils he found at the base. Portell began identifying boxes of fossils for McCleskey and mentioned that he would like some of the fossils for the Florida Museum’s collection.

A year later, in February 2007, Portell and Toomey had clearance from the base’s commander and met McCleskey for the first week-long fossil-hunting trip.

Guantanamo Bay covers 45 square miles and is surrounded by a large fence that separates the base from the rest of Cuba. Portell’s first flight there arrived at night. The fence was completely lit, clearly marking the boundary.

“The sight made it worth the three-hour, 15-minute flight around Cuban airspace,” he said.

Each trip lasts a week and has resulted in thousands of fossils for the Museum, from microfossils to 1-foot-diameter coral heads. Portell measures sections of the terrace deposits to determine how they formed. Some sites contain massive thickets of broken coral, suggesting they formed from storm deposits. Other sites contain large upright corals, including some Elkhorn coral (Acropora palmata) that are 6 feet high. In these situations, the corals remained in place and were eventually surrounded by sediment.

Guantanamo Bay sits in a bowl, indicating geologic uplift in the area. Some of the older deposits look like they were washed in and concentrated from surrounding elevations, he said. The younger terrace fossils, on the other hand, look like they formed fairly close to their original position.

Many of the corals and mollusks found in the 125,000-year-old deposits are the same species one would see diving or snorkeling today, Portell said. But none of the 45-million-year-old fossil species are now alive.

For instance, in the Eocene deposit, Portell said he unexpectedly found pieces of one of the largest snails that ever lived, up to 3 feet long

“That’s pretty cool when you find those kinds of fossils because we don’t have anything like that living today.”

Ongoing relationship

McCleskey is no longer stationed at Guantanamo Bay, but Portell and Toomey’s work there continues. The base’s public works department now sponsors the Museum’s research efforts.

Portell said only a small portion of the base has been explored, and each of the three trips has resulted in new discoveries.

“We are hopeful future trips will help us complete the island’s paleontological story,” he said.

fossils 45 million years old

Florida Museum researchers discovered these 45-million-year-old trace fossils, which are impressions left by organisms, at Guantanamo Bay in September 2008. Photo by Roger Portell

 

 

 

 

 

 

 

 

 

 

 

 


Published on Science Stories: February 2009.