According to Sweden’s Uppsala University, new evidence points to polar dinosaurs who were feathered and “fluffy.” The feathers were collected from Australian fossils of dinosaurs that once lived near the South Pole. Dinosaur evolution is complex and nuanced.
The Uppsala University website made an announcement last week stating, “A cache of 118 million-year-old fossilized dinosaur and bird feathers has been recovered from an ancient lake deposit that once lay beyond the southern polar circle.” Feathered dinosaurs have rarely been evidenced, much less in consistently cold climates. In addition, in most incidents of feathers being found on dinosaurs, the feathers were sparse and sporadic like human body hair. The discovery implies that the dinosaurs would have evolved their full-body feathers for insulation in cold weather. Other physiological adaptations in the ancient creatures have captured the imaginations of children and adults for centuries.
From Death, Life
In the scope of the entire evolutionary scale of the planet, dinosaurs came along at an interesting time.
“It would take about 30 million years or so for complete ecological recovery after the Permo-Triassic extinction event,” said Dr. Stuart Sutherland, Professor in the Department of Earth, Ocean and Atmospheric Sciences at The University of British Columbia. “That sounds like a long time, but remember, removing the biosphere to around about 95 percent of the species, it’s not too surprising that the Earth took such a long time to get back on its feet.”
In this 30-million-year period throughout the Triassic, Dr. Sutherland said, several large amphibians thrived, having survived the extinction event at the end of the Permian period.
“But what of the other groups of reptiles from the Permian—what of the diapsids?” he asked. “They had diversified into a number of forms including a group called the archosaurs. And the archosasurs are important because they give us the crocodiles; the pterosaurs; the birds; and, of course, the dinosaurs.”
One early archosaur, called euparkeria, provides physiological clues of dinosaurs to come. While not a direct ancestor, euparkeria has unmistakable traits that flourished with dinosaurs.
“Euparkeria was possibly semi-bipedal, so it’s one of the first evidence that we have of a creature that had started to get up onto two legs,” Dr. Sutherland said. “It probably scurried about on four legs and then would occasionally move up onto two to perhaps grasp at insects with its two front legs.”
The Rise of the Dinosaurs
The earliest known dinosaur fossils, Dr. Sutherland said, date to the late Triassic period and were found in the Schigualasto Basin of Argentina. These fossils are of the eoraptor, a three-foot, bipedal carnivore or omnivore. Scientists have unearthed other early dinosaurs from around this same time; however, they are not the popularized dinosaurs we see being brought back to life, terrorizing theme parks, in Hollywood films. That diversity in dinosaurs eventuated after another extinction event, known as the Triassic-Jurassic event.
“After it, the dinosaurs would no longer be a part of the tetrapod fauna; they would dominate it,” Dr. Sutherland said. The exact reasons are unclear, but there are clues.
“Perhaps, it’s something to do with the way that dinosaurs moved,” continued Dr. Sutherland, “Dinosaurs generally have an upright stance—they brought their legs underneath their body, which makes them fairly stable. There’s a suggestion by [dinosaur paleontologist] Bob Bakker, as well. He believes that dinosaurs were endothermic, or warm-blooded, like us. They were active and dynamic, and it was this that gave them their edge.”
Poor records from the mid-Jurassic have kept scientists from firmly nailing down the causes of dinosaur proliferation, but with new discoveries like the full-body-feathered dinosaurs in Australia, that gap in archaeological records may one day be filled.
Dr. Stuart Sutherland contributed to this article. Dr. Sutherland is a Professor in the Department of Earth, Ocean and Atmospheric Sciences at The University of British Columbia (UBC). Raised in the United Kingdom, he earned an undergraduate degree in Geology from the University of Plymouth and a Ph.D. in Geological Sciences from the University of Leicester.