2015-11-21 18:29:42
Thirty-eight years ago, in 1977, Marion Brandvold, owner of a fossil and mineral store in a small northwestern Montana town, discovered dinosaur bones with her son David Trexler in the nearby Two Medicine Formation, which stretches from that state to southern Alberta, in Canada. Every weekend, Marion returned to the same place, and she was recovering the remains of what seemed to be a single individual, which her son was joining in the back room.
One morning, in July 1978, a paleontologist happened to pass by. Jack Horner, from Princeton University, was on vacation and happened to come into the store. Horner helped the owner sort through some fossils she had for sale, and the owner gratefully showed him the dinosaur her son was putting back together. Horner immediately identified it as a baby hadrosaur, a duck-billed herbivorous dinosaur. An excavation led by Horner at the site where Marion Brandvold had found the fossils uncovered something never seen before: A dinosaur nesting colony in which young, young, and adults lived side by side. The deposit received the name of “Egg Mountain”, the mountain of the eggs.
“It was the first time that a nest had been found, not of eggs, but of baby dinosaurs, and it seemed to me that the evidence was incontrovertible: those babies had stayed in the nest while they were growing, and one or both parents had cared for them. This type of behavior, unheard of among dinosaurs, was probably the most surprising discovery to come out of that dig. It was undoubtedly the one that had the greatest impact on the public image of dinosaurs, since it contrasted sharply with the image of how dinosaurs were supposed to behave: laying eggs and abandoning them, like turtles or lizards or most of the reptiles. If dinosaurs, even just a few species, acted like birds and raised their young in nests, caring for them and bringing them food, this was information that would profoundly change our ideas about what kind of animals these ancient reptiles were. It was a revelation.”
After the appearance of the skull of an adult, discovered by Laurie Trexler, Marion Brandvold’s daughter-in-law, in 1979, Horner and Robert Makela described the new species, which they named Maiasaura, from Maya, the largest of the Pleiades according to Greek mythology. , and which also means “little mother”.
The discovery of Egg Mountain catapulted Horner to fame. A few years later, he became Steven Spielberg’s science advisor for the movie Jurassic Park.
Horner has continued excavating at Egg Mountain ever since, and has already unearthed more than two hundred Maiasaura specimens of all ages, with which he has been able to study the natural history of this species in detail unprecedented among humans. dinosaurs.
Maiasaura is a hadrosaur, a duck-billed dinosaur measuring about thirty feet in maximum length and weighing more than two tons. It has a short, broad, massive, pointed crest in front of the eyes, which is probably used in fighting between males during the mating season. It is a herbivorous dinosaur that can slide its jaws over each other to crush food and, at the same time, to keep its teeth sharp.
Maiasaura lived about 76 or 77 million years ago, at the end of the Cretaceous, in western North America, which at that time was separated from the rest of the continent by an inland sea, the so-called Niobrara Sea. This landmass is called Laramidia. The Laramidia region where Maiasaura lives has a semi-arid seasonal climate, with a long dry season and high temperatures. Probably, these animals undertake long migrations in search of food.
Maiasaura lives in the area with two other hadrosaur species: Gryposaurus, of the same size, which differs in the shape of its snout, and Hypacrosaurus, somewhat larger than Maiasaura, and with a semicircular crest. Other dinosaurs present include Troodon, an eight-foot-long running carnivorous dinosaur, Orodromeus, a similarly sized bipedal herbivore, Bambiraptor, a small meat-eating dinosaur less than four feet long, and Daspletosaurus, an eight to nine-foot tyrannosaurid. meters long. The only defenses of Maiasaura and the other hadrosaurs against predators are their long, muscular tail, and their gregarious way of life, in herds that can reach 10,000 individuals.
Maiasaura nests are mounds of mud three meters in diameter and one and a half meters high, with an interior depression two meters in diameter and 75 centimeters deep. The eggs, between 30 and 40, about the size of ostrich eggs, are arranged in circles or spirals and in layers, covered with earth or sand and with vegetation. The decomposition of this provides the necessary heat for incubation. The distance between nest and nest is about seven meters, less than the length of an adult animal. They must have been as crowded together as colonial seabirds are today. In addition to the predators we talked about earlier, nests have other enemies: lizards and egg-eating beetles.
When they hatch, the hatchlings are about 40 centimeters long, and their legs are so underdeveloped that they are unable to walk. They feed on food brought to the nest by their parents. They have larger eyes and a shorter snout than adults. During the first year they grow very quickly, up to a meter and a half in length. In this period, mortality is very high; only one in ten hatchlings survives. Between the first and second year, they leave the nest. These youngsters continue to grow until they are 8 years old. Its mortality rate during the growth period is much lower, less than 13%. At three years old they already reach sexual maturity. Up to four years, the young are bipedal, but thereafter they become quadrupedal, although they are still able to rise up on their hind legs to reach the leaves of high tree branches and to run when necessary. From the age of 8 they enter the third age, and their mortality rate increases again, up to 44% per year. They are animals that grow fast and die soon.
CONSTRUCTION OF GERMAN FERNÁNDEZ:
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Reticular Infiltrator is the first novel in the trilogy The Saga of the Borelians. Do you want to see how it starts? Here you can read the first two chapters.
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