CHICAGO, IL (December, 2007) – The only reason that most people ascend to 14,000 feet is to go skiing. For a group of U. S. and Chilean scientists, however, such altitudes are ideal fossil-hunting terrain. In fact, over the past 10 years their explorations have taken them to one of the highest elevation vertebrate fossil sites in the world. The localities near Salar de Surire in northern Chile have yielded several hundred fossil mammal specimens. A study led by Dr. Darin Croft of Case Western Reserve University has determined that one of these specimens, a partial skeleton collected in 2004, represents a new species of armored mammal known as a glyptodont, which they have named Parapropalaehoplophorus septentrionalis. As Dr. Croft says, “The name of this new species is a mouthful, but it does roll off the tongue nicely!” The discovery is reported in the December issue of the Journal of Vertebrate Paleontology.
Glyptodonts are a group of now-extinct armored mammals most closely related to modern armadillos. Unlike armadillos, glyptodonts had shells made of mostly immovable plates and reached much larger sizes; some of the largest likely weighed two tons – the size of a small car! The new species, P. septentrionalis, is much smaller, weighing a mere 200 pounds and it documents the early history of this interesting group, which went extinct at about the same time that humans arrived in the New World. “When we collected this fossil, we had no idea that it would turn out to be a new species,” said Croft. “We knew that it would be an important specimen, given its completeness, but it was only after careful comparison to other known species that we realized how unusual it was."
The new species of glyptodont is one of about 18 mammal species known from the Chucal Fauna, the collective name given to the fossils from the Salar de Surire region. Other Chucal mammals include armadillos, marsupials (opossum relatives), rodents, and a variety of extinct hoofed mammals. These mammals, along with plant fossils recovered from the same area, suggest that northern Chile had relatively few trees 18 million years ago. John Flynn, a co-author of the study said that " Our sites are now located more than 14,500 feet above sea level, but when these animals were alive the region was at much lower elevations. That means that the Chucal fossils give us a unique insight into the timing and rate of uplift of the high Andes.”
Croft said that “working in the Altiplano of Chile can be challenging; the air is thin, water is scarce, and the temperatures plummet as soon as night falls. On the other hand, there are hardly any bugs, you don't have to worry much about rain, and the stars are spectacular.”
ABOUT THE SOCIETY OF VERTEBRATE PALEONTOLOGY
Founded in 1940 by thirty-four paleontologists, the Society now has over 2,000 members representing professionals, students, artists, preparators and others interested in VP. It is organized exclusively for educational and scientific purposes, with the object of advancing the science of vertebrate paleontology.
The Journal of Vertebrate Paleontology
The Journal of Vertebrate Paleontology (JVP) is the leading journal of professional vertebrate paleontology and the flagship publication of the Society. It was founded in 1980 by Dr. Jiri Zidek and publishes contributions on all aspects of vertebrate paleontology.
Top: Reconstruction of the glyptodont Parapropalaehoplophorus septentrionalis, based on a partial skeleton from the early Miocene of northern Chile; artwork by Velizar Simeonovski. See Croft et al.
Middle: The team’s campsite near Salar de Surire. The site can only be reached by 4-wheel drive truck. Team members sleep in tents, and cook over a gas stove. Photo by D. Croft.
Bottom: Bill Simpson of the Field Museum brushes dirt away from the carapace (shell) of the new glyptodont specimen. It took five days to excavate the entire specimen and package it for transport back to the United States. Photo by D. Croft.
American Museum of Natural History
Case Western Reserve University