Provided by Will Dunham
(Reuters) -Pachycephalosaurs, two -legged plant eaters known for their bone dome -shaped skull, are one of the weirdest known dinosaurs, as well as one of the least understandable. Fossil, found from a rock from the rock in the Mongolian desert – the oldest and most comprehensive of this group’s dinosaurs – now it is changing.
Investigators said the fossil is a minor of previously unknown species they called Zavacephale Rinpoche (alleged Zah-vah-sef-al-ay rin-poh-shaay), dated about 108 million years ago during the chalk. This individual was small and easily built, with long legs, short hands and small hands – similar to size compared to a German Shepherd.
About Pachycephalosaurus (Pak-Eee-Sef-Al-Oh-Sors), a group that lived in Asia and North America in the last age of dinosaur, with fossils, which are usually quite incomplete-sometimes with the skull.
However, the Zavacephale specimen is essentially complete, so the first detailed look at the anatomy of these dinosaures. Zavacephale is also the oldest of any known Pachycephalosaur for about 15 million years.
This Zavacephalee individual was at least two years old at the time of death. Although he was not completely grown – the equivalent of a person’s teenager – he had already had a well -developed skull dome consisting of a thickened bone above the skull. This feature of Zavacephale was a bit different from the pachycephalosaur, from later chalk. Zavacephale dome was mainly formed with one skull bone. In later Pachycephalosaurus, it consisted of two bones.
Zavacephale demonstrated an ornamentation that accompanies the dome in the form of small spikes and knots, which surrounds the skull dome and the posterior part.
Researchers found a person’s age of limb bone growth rings, similar to annual growth rings formed in trees. The study was the first to use growth rings to determine when the skull dome developed completely in the life of Pachycephalosaur.
The purpose of the dome remains the issue of discussion. Among other things, scientists have hypothesized that these dinosaurs beat their heads – in the face of a dome on the dome – like Bighorn sheep, perhaps to determine dominance and safe mating rights.
“The consensus is that these dinosaurs used a dome for social sexual behavior. Doma would not have helped predators or temperature regulation, so they were probably showing and competing for friends,” said the Paleontologist Lindsay Zann from North Carolina
“Was they been behind the headdress, grabbed or just showcased?” asked Zann. “At the end of the day you have to pass it on to pachycephalosaurs. When it comes to chic headgear, they didn’t say it.”
A fully formed dome on minors shows that Pachycephalosaurs, before they start completely overgrown, are engaged in social and likely mating behavior, Zann said.
The largest Pachycephalosauros, as well as subsequent Pachycephalosaurus from North America, could grow to about 14 feet long (4.3 meters), although Zavacephale could have been less than half of that length.
The environment in which Zavacephale lived was a valley marked with lakes and surrounded by rock. The remains of several other plants were found nearby, as well as various fish, turtles and krok relatives.
The name Zavacephale combines Tibett’s word “origin” with the Latin word “head” because this species is the earliest example of domes dinosaur.
“Before Zavacephale, our Pachycephalosaur’s record was almost limited to their indestructible domes. With such a small skeleton, we left holes known about their anatomy, including the main things like their hands,
Fossil are preserved for touring, stomach stones that helped the dinosaur crush the plants they ate.
Scientists are trying to find out the ancestors of the evolutionary evolution of Pachycephalosaurus.
“We lacked transitional forms that can explain how their strange skull domes evolved and resolved their relationship with other dinosaurs,” Zann said.
(Will Dunham’s message in Washington, edited by Rosalba O’Brien)