By Javier Castro Bugarin
Buenos Aires, Aug 13 (EFE).- Argentina’s Atlantic coast is a very different place today compared to 100,000 years ago, when it was home to four-meter-tall (13-foot-tall) giant ground sloths, herds of elephant-like gomphotheres, one-ton armadillos and a vampire bat that was significantly larger than its closest living relatives.
The presence there of Desmodus draculae, the largest fossil of which was recently found in that region, indicates a very distinct climate in that era.
“It’s the first (fossil) record in Argentina of this flying mammal,” Mariano Magnussen, a paleontology technician at the Miramar Museum of Natural Sciences, one of the institutions involved in this find along with the National University of Mar del Plata and the Azara Natural History Foundation, said in an interview with Efe.
Zoologists found the first fossil remains corresponding to that extinct species – called “Desmodus draculae” in honor of Irish author Bram Stoker’s iconic character – in 1988 in a cave in what is now northern Venezuela.
Since then, bones of that giant vampire bat, whose diet was solely based on the blood of other mammals, have been discovered over a territorial range stretching from Mexico to Argentina, including in Belize, Venezuela and Brazil,
Although those finds have been few and far between, a jaw fossil discovered recently near La Ballenera stream – roughly 450 kilometers (280 miles) south of Buenos Aires – clearly shows that now-extinct mammal was around 30 percent larger than Desmodus rotundus, one of the three extant vampire bat species.
“This jaw does provide information that it was bigger and weighed around 60 grams. According to studies, it had a wingspan of 60 to 80 centimeters (23-31 inches),” Mariano Magnussen said of the largest fossil remains discovered to date of Desmodus draculae, which can be traced back about 100,000 years to the Late Pleistocene age.
The find also is of note because of its location some 600 kilometers (370 miles) from the southernmost point of the territorial range of its modern-day cousins, a discovery that suggests a marked shift in the climatic conditions of Argentina’s Atlantic coast.
Magnussen said confirmation of the presence of that giant vampire bat in a Pampean cave 100,000 years ago indicates that the region’s climate, though not tropical, was considerably warmer.
“At that time, what is commonly known as the Ice Age was fully under way. During the Pleistocene, there were different periods of warmer temperatures in this region and times that were very cold. Surely at the time that vampire lived the climate was warmer,” the expert said.
Another discovery also lends weight to that same hypothesis. In 2000, a group of scientists found a Desmodus draculae fang in Centinela del Mar, a municipality located just 50 km from La Ballenera stream.
But an analysis surprisingly showed that those remains dated back only around three centuries, indicating that colder temperatures in that region are a relatively recent phenomenon.
“It’s presumed that this animal went extinct more or less in 1820” due to a period of regional cooling known as the Little Ice Age, Magnussen said.
“Obviously we hope to find new and even more complete remains, such as skulls or, why not, a skeleton. That would clear up a lot of the doubts we have about this animal’s dimensions” and biology, he added. EFE