Whale fossils in the desert
Professor and doctoral student map more than 100 whale fossil remains in western Peru
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| Leonard R. Brand, PhD, professor of biology and paleontology, Graduate School, takes a closer look at one of more than 100 fossil whale remains found in an area less than two square kilometers in a desert area of western Peru. |
It all began with an invitation to guest lecture at Peruvian Union University (UPU), the Seventh-day Adventist University located in Lima, Peru, in June of 1998.
Leonard R. Brand, PhD, professor of biology and paleontology in the Graduate School at Loma Linda University; Arthur Chadwick, PhD, a biology professor and geoscience researcher at Southwestern Adventist University in Keene, Texas; and two staff members from the Geoscience Research Institute, a General Conference of Seventh-day Adventists facility located on the campus of Loma Linda University, had made a quick trip to UPU to deliver lectures and were about to return home.
"They asked us if we wanted to see some fossil whales," Dr. Brand remembers. "Since our hosts were not paleontologists, we had no idea what we might see."
Drs. Brand and Chadwick had a mere hour and a half to visit the site before beginning their trip home.
"When we saw 16 fossil whales in that short time, we knew it was a great find," Dr. Brand continues. "We tentatively agreed to return in 1999 for further study."
Back at Loma Linda, Dr. Brand immediately began the process of securing financial backing for the project. He was greatly encouraged when Raul Esperante-Caamano was accepted as a doctoral student in the natural sciences department beginning in the fall of 1998.
Mr. Esperante-Caamano taught biology and geology for 10 years at the Colegio Adventista de Sagunto (Sagunto Adventist College), located in Spain, before coming to Loma Linda.
"Raul's ability to speak Spanish was invaluable," explains Dr. Brand, "as well as his research expertise."
Mr. Esperante-Caamano has chosen the project in western Peru as the subject of his doctoral dissertation.
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| Back in his laboratory in Loma Linda, Dr. Brand displays a single vertebrae he removed for further study from the Pisco Formation site in western Peru. On the wall behind him to the left is a satellite photo of the area he studied. |
A master's student in the natural sciences department, Cristian Carvajal, has also chosen the project as the basis for his master's thesis. Mr. Carvajal is originally from Chile.
With a grant from the Geoscience Research Institute, Dr. Brand and his colleagues set out for the coast of western Peru in late May, 1999.
Collaboration with researchers and faculty at UPU also proved invaluable. The Peruvian members of the team were able to secure the necessary government research permits, as well as arrange for accommodations and transportation to and from the research site.
"We arrived in the wintertime," recalls Dr. Brand. "Though the Pisco Formation [Miocene/Pleocene] is in the tropics, the area is one of the driest deserts in the world, with an average of one millimeter of rainfall per year."
The negligible rainfall proved to be an advantage for the team. "No rain means virtually no plant life, leaving the area exposed and accessible," remarks Dr. Brand.
The research team stayed with the Bendezu family during the two-week project. On a typical day, they would arrive at the research site at about 8:00 a.m., work straight through the day, and head back around 4:30 p.m. to avoid being caught out after dark.
"In our survey of the area, we found the fossil remains of more than 100 whales in an area of less than two square kilometers," Dr. Brand recounts. "What was even more exciting was the well-preserved nature of the fossil remains."
Typically, when a whale dies at sea, the carcass falls to the bottom and becomes the source of a rich ecosystem. Many species of sea life benefit from the decaying remains at each stage of the process.
"Within four to six months, the whale carcass has been mostly stripped down to the bones," explains Dr. Brand. "At that point, other species of organisms burrow both into the bones and the surrounding sediment."
Within a year or two, the whale bones show much evidence of these burrowing animals.
As a paleontologist, Dr. Brand seeks to understand and explain what life was like during previous geologic periods. Not only is he interested in how organisms lived and interacted during a particular geologic period, but he also forms hypotheses about how various organisms died.
How did the whales in western Peru meet their end? "These whales were incredibly well-preserved," Dr. Brand observes, "suggesting that they were covered quickly."
Dr. Brand found that the whale remains were blanketed by a thick layer of diatomite (silica remains of diatoms). These tiny creatures, known collectively as plankton together with dinoflagellates, are part of the food source for whales.
In modern times, diatomite normally accumulates on the sea bottom at a rate of a few centimeters per thousand years.
"We also found beautifully preserved baleen," he adds. Baleen refers to the filtering teeth-like structures in the whale's mouth. "Whales feed by gulping in water and forcing it out through the baleen, trapping the tiny plankton."
Baleen is actually more akin to the human fingernail or toenail in its structure.
"The well-preserved baleen supports the theory of a quick burial to an even greater extent," he concludes.
But why did the whales die in the first place? "There is more and more evidence that red tides--blooms of diatoms and dinoflagellates--produce toxins which can kill large animals and fish," he says.
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| Orlando Poma, Lic., a member of the faculty at Peruvian Union University (left), and Arthur Chadwick, PhD, of Southwestern Adventist University, carefully remove the natural debris to expose the well-preserved skeleton of a whale in western Peru. |
Recently, it was discovered that several hundred sea lions off the coast of California were killed by toxins produced by diatoms. Other studies of these tiny organisms have found that increased levels of iron in the water greatly increase the rate of reproduction.
"Perhaps an increase of iron in the water, together with volcanic ash from the Andes--which provides silica--caused a bloom of diatoms to take place," Dr. Brand hypothesizes, "and the toxins produced by the diatoms killed the whales."
Falling to the bottom, he postulates, the whales were soon covered by the skeletal remains of the diatom bloom before decay and scavengers could damage and scatter the bones.
"We did not find evidence of the other animals which typically form the ecosystem around a decaying whale carcass," he details, "probably because whales were buried before those animals were able to colonize it."
Interestingly, sharks did leave their mark on the fossil whale remains studied in detail by the team, evidenced by both teeth marks on the bones and actual teeth left behind.
The research team presented their findings during the annual meetings of the Geological Society of America (GSA), which took place October 25 to 28, 1999, in Denver. The paper, titled "Taphonomy of Whales in the Miocene/Pliocene Pisco Formation, Western Peru," was co-authored by Mr. Esperante-Caamano, Dr. Brand, Dr. Chadwick, and Orlando Poma, Lic., a member of the UPU faculty in Peru
A brief description of their findings can be found in the GSA's Abstracts with Programs, volume 31, number 7, 1999.
The team returned to further study the fossil whale remains this summer. It began the next research phase on June 25.
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