Dinosaur Discovered in Boyacá
May. 10 de 2012
By: Hermann Sáenz, Unimedios
In 2005, a farmer in Villa de Leyva, who lived on a hillside in La Carolina, found what, at first glance, seemed to be two common ordinary rocks. His curiosity made him doubt this, however, and so despite their considerable weight, he took them to the Colombian Geobiology Foundation (Fundación Colombiana de Geobiología) in a rural area of the municipality, where experts confirmed his suspicions: those two objects found in the open air were actually fossils.
But there is nothing unusual about discovering prehistoric remains in Villa de Leyva, particularly when they come from marine reptiles, because numerous such findings have been recorded in that municipality. However, these nearly round remains were different because they proved to be femoral heads from a dinosaur.
The event became the first appearance of signs of a dinosaur in the region, and the third such discovery in Colombia.
Six years later, research confirms that the fosils are indeed from a land animal, and that its morphological characteristics correspond to those of a dinosaur. "The fossilized bones found in previous years in Villa de Leyva allow us to make comparisons. The femur from a marine animal is smaller, flattened and with a rounder volume. Bones from this recently–studied finding are different and may correspond to a sauropod", according to María Páramo, professor of paleontology at the Universidad Nacional de Colombia and at the Foundation.
Although species are defined by such characteristics as the cranium and vertebrae, it is difficult to conclude with precision the species to which these remains belong. Nonetheless, professor Páramo alludes to a particular characteristic of the sauropods: "They have a kind of lateral protuberance on the femur that could help us to approximate the identity of this individual. The size of this thighbone shows that the animal could have a length between 12 and 18 meters".
The pieces were found on the surface on top of rocks that are approximately 125,000,000 years old. Based on this data, on the form of preservation and on the geological characteristics of the region, it appears that the sauropod lived during the Cretaceous era between 125 and 110 million years ago.
The geologist explains that the fossils came to be there through a process of natural mechanical transport. After the muscles and organs decompose, the bones are dragged along by water currents, nearby waves, rising tides or rivers and thus fossilize in a place other than where the animal had actually died.
On the beaches of Villa de Leyva
During part of the Cretaceous era (between 145 and 65 million meters ago), half of Colombia’s territory was covered by the ocean, which is why marine species from that period are relatively easy to find there: plesiosaurs, ichthyosaurs and marine turtles dating from between 130 and 125 million years ago.
In Villa de Leyva, a number of geologists have associated the discovery of so many marine reptiles with its past proximity to the coast, while others have cited the rocks that were deposited in deeper sites away from the shores. "The fact that these dinosaur remains have been found here associated with those sediments is an additional indicator that the coast could not have been far away, because these animals were supremely continental", adds Páramo.
Another important aspect in the research is that the pieces found in this northwestern corner of the South American continent are of great scientific interest because they were discovered in an intermediate point between the large quantity of dinosaurs found in southern Argentina and Chile and those of North America and Europe. Thus, the few fossils that have been reported are of strategic importance in clarifying the relationship between the creatures from the two hemispheres.
Dinosaurs from the coast and from the Department of Tolima
While María Páramo and student David García continue to put together the jigsaw puzzle in search of further details on the dinosaur, it is known that in Colombia remains have been found from two other land–based giants.
The first was discovered during excavations carried out by the Tropical Oil Company in 1945. According to the book entitled Paleontological notes, by Langston and Durham, vertebrae from the middle part of the thorax belonging to a sauropod dinosaur was found in the municipality of La Paz, Magdalena.
The piece is at the Paleontology Museum of the University of California at Berkeley, and what is unusual is that, for a sauropod, the bone is of modest size: the centrum (center of the vertebrae in the form of a drum) is 180 mm long, 165 mm high and 154 mm wide. This specimen is important because it had hitherto been found more to the north of South America.
The remains of the second dinosaur were found at Ortega, Tolima, in 1949. They consist of three isolated teeth from theropods, according to research carried out by Spanish geologist Martín Ezcurra.
The continental sediments from the Cretaceous epoch as well as a bit before during the previous Jurassic epoch make it difficult to find additional dinosaurs in Colombia, because the fossils do not easily rise to the surface. "They are not found exposed to the surface but rather at depths, which is why there are not many such solid materials available for study", according to Professor Páramo.
Compared to the paleontology being carried out in Argentina or Chile, Colombia does not yet have much to contribute. "The advantage however is that we can learn from them", she concludes.