In March 2007, Mexican paleontologist Martha Carolina Aguillón made a unique discovery: amidst the rocks of Cerro del Pueblo, a geological formation south of Coahuila, the expert found the remains of a small skull, a “mysterious piece”. ” This did not correspond to the dinosaurs identified in the region up to that point. Sixteen years and dozens of analyzes later, the fossil reveals that the troodontids, a group of carnivorous dinosaurs with a larger brain capacity than any other species, lived in Mexico more than 74 million years ago. The discovery not only increases the diversity of dinosaurs discovered in Coahuila, a state that until three decades ago chose to excavate an unparalleled legacy and whose desert museum serves as the nation’s premier dinosaur research and dissemination center. It also represents a new piece in the geological puzzle that aims to reconstruct what the world looked like just before the extinction event that ended the age of dinosaurs.
“The dinosaur we found is small to medium-sized and therefore its bones must have been very fragile,” Aguillón explains to EL PAÍS about the improbability of the find. The remains of the skull, which include the troodontid’s frontal and parietal bones, fought a battle against time before they were found, dodging every possible obstacle to their preservation, from dismemberment by scavengers to destruction by land movement millions of years years. “Because they’re very small, it’s difficult to find them once they’re fossilized, and once you find them, it’s even more difficult to identify them.” That’s why this find is so significant,” says the author of the discovery, the latest in a line of extinct giants that have positioned Coahuila as the “Land of Dinosaurs” in recent decades and through a state government campaign.
The skull found in Coahuila. desert museum
About 74 million years ago, the landscape of southern Coahuila was very different than it is today. Instead of the arid climate and semi-desert landscapes that dominate the region today, dense subtropical vegetation made its way through swamps and lakes to the shore of the ancient Tethys Sea. This warm and humid environment, which the find’s authors liken to what is now southern Tabasco state, allowed for the emergence of large herbivores and with them carnivores of all sizes in search of prey. With a feather-covered body, the 1.3-meter-tall and just over eight-foot-long dinosaur didn’t reach the proportions of the large tyrannosaurids that also lived in northern Mexico; However, it did have a unique trait that has been a controversial subject for paleontologists for decades: a brain capacity larger than that of any dinosaur.
“Since the 1970s, people began to believe that this dinosaur was generally the most intelligent because of the size of the skull, which implies a fairly large brain capacity in relation to its dimensions, if we compare it, for example, with the Tyrannosaurus Rex, which is 12 meters long was, but had a brain about 30 centimeters. Intelligence is subjective, but it is the dinosaur that has the largest brain in relation to its body,” explains Héctor Rivera Sylva, head of the Paleontology Department at the Museo del Desierto. The remains of the skull show that he had highly developed eyesight, with large, forward-facing eyes, and a keen sense of smell—traits that have led experts to speculate about his possible nocturnal habits. “This dinosaur must have preyed on small prey such as snakes, mammals and lizards found in the same geological formation, as well as other baby dinosaurs. We knew it had a particular ecological role because it was the hunter that was missing,” says Aguillón.
Martha Carolina Aguillón works in the Paleontology Laboratory. desert museum
The dinosaur, which belonged to the Troodontid family and whose species has yet to be determined, is recreated with a scale model by a group of paleosculptors advised by Aguillón and Rivera and is on display in the Museo del Desierto, which has been in existence for 23 years. It houses the most important paleontological ones Discoveries of the country including the Velafrons coahuilensis, a six-ton, seven-meter-long herbivore that became famous for being the first dinosaur named in Coahuila and the most complete dinosaur found in Mexico. The discovery, made in April 1995 by a team led by Martha Carolina Aguillón, was key to the state’s paleontology boom, which brought unprecedented government investment and international scientific collaboration that took the first steps toward identifying dinosaurs in the state enabled country. “We could be so drastic and say we’re wearing diapers, or so enthusiastically say we’re at the forefront of this type of study.” We’re still taking stock to see what we have since Coahuila does book of life in the history of dinosaurs and other creatures,” concludes Aguillón.
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