The 70-million-year-old fossilized remains of three juvenile oviraptorids from the Nemegt Formation of Southern Mongolia are the first evidence of ‘communal roosting’ in dinosaurs, according to University of Alberta paleontologist Gregory Funston and colleagues.
Photo and sketch of the confiscated specimen showing three different juveniles of the same species of dinosaur preserved in roosting posture, immediately next to each other. Image credit: Gregory Funston.
“The Nemegt Formation is one of the richest dinosaur-producing formations in the world. At least 30 genera are known from this formation, including ankylosaurs, hadrosaurs, sauropods, and theropods,” the researchers said.
“The abundance of these deposits has unfortunately attracted the attention of fossil poachers, and dozens of poached skeletons are suspected to hail from the Nemegt Formation.”
“In 2006, Mongolian customs officers confiscated two important poached specimens. One of the specimens is a spectacular block of three articulated skeletons of juvenile oviraptors.”
According to the team, the three young individuals belong to a whole new species, characterized by a domed cranial crest, a functionally didactyl hand, and a short tail.
“It’s a fantastic specimen. It’s rare to find a skeleton preserved in life position, so having two complete individuals and parts of a third is really incredible,” Funston said.
The three oviraptors were roughly the same age, preserved in a sleeping posture, so close to each other that they would have been touching in life.
Known as communal roosting, this behavior is seen in many birds today including chickens and pigeons.
“The evolutionary origins of communal roosting in modern birds are debated, and this specimen highlights the possibility that this behavior was inherited from their dinosaurian ancestors,” the paleontologists said.
In addition to the skeletons in the block, the second poached skeleton is an even younger individual of the same species.
“It further fleshes out the life history of these animals,” Funston and co-authors said.
“The notable head crest is present even at a young age, but the dinosaurs would have had gradually shorter tails as they aged, and some of their bones fused across their lifetime.”
“Their head crests and tails have been argued to represent sexual display features used in mating, somewhat similar to modern peacocks or turkeys.”
The scientists reported their findings August 25 at the 77th Annual Meeting of the Society of Vertebrate Paleontology in Alberta, Canada.
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Gregory F. Funston et al. 2017. A New Oviraptorid (Dinosauria: Theropoda) Provides a Rare Glimpse into Social Behaviour in Dinosaurs. SVP 77th Annual Meeting
