Maurilio Oliveira/Museu Nacional-UFRJ
A new species of flying reptile from the Cretaceous Era,
As paleontologists increasingly unearth evidence of feathers in prehistoric fossils, our conceptions of what dinosaurs looked like when they roamed the earth has gradually evolved.
Instead of the reptilian appearance we all recognize from childhood toys and films like Jurassic Park, many dinosaurs in fact more closely resembled birds, kind of like this recently discovered little guy, Eosinopteryx brevipenna, a flightless theropod dinosaur that roamed China during the Middle/Late Jurassic period.
Archaeopteryx, also known as Urvogel, the German word for "original bird" or "first bird," was first discovered in 1860 and later fossils of this species presented some of the earliest evidence of flight in these prehistoric animals.
An intermediate creature that was not quite dinosaur but not exactly a bird either when it lived 150 million years ago, Archaeopteryx had teeth, a long tail, and wings capable of flight with claws at the end for grabbing prey.
A century after the discovery of Archaeopteryx, paleobiologists increasingly found anatomical connections between birds and dinosaurs. In the 1970s, artists began to portray dinosaurs with feathers based on accumulating evidence.
Megapnosaurus, shown here, was another species with whom researchers began early to identify with feathers. A lightweight animal that could reach up to 10 feet in length and roamed Jurassic Zimbabwe, Megapnosaurus, also known as Syntarsus, traveled in packs and preyed on small reptiles and fish.
Many of the fossils unearthed that provided evidence of feathers had deteriotated over the eons they remained buried. It wasn't until 2010 that researchers identified color pigments in feathers from dinosaurs and early birds.
Sinosauropteryx, illustrated here, was a theropod dinosaur that had "simple bristles -- precursors of feathers -- in alternate orange and white rings down its tail," according to a description of the study's findings.
Given that so many feathered dinosaurs were in fact flightless, the purpose of the feathers has been a subject of debate. Some dinosaurs may have evolved feathers for social signaling; others had plumage to provide insulation.
In the cases of some dinosaurs, such as the two oviraptors, herbivores related to T. rex that lived during the Cretaceous period, researchers believe the feathers were used for mating displays, similar to modern-day peacocks and turkeys.
Jason Brougham/University of Texas
You might be fooled into thinking the animals in this illustration are something between a murder of crows and a band of blue jays. In fact they are Microraptors that lives more than 130 million years ago.
These four-winged, plumed dinosaurs were no larger than modern-day pigeons and sported iridescent tail feathers.
Researchers believe the shimmering plumage was likely used in mating and other social interactions.
Like the diversity among birds today, not all feathered dinosaurs were lightweight, agile animals. A massive tyrannosaur that lived in China until about 65 million years ago, Yutyrannus huali, meaning "beautiful feathered tyrant," grew up to 30 feet long and could weigh more than 3,000 pounds.
This titanic tyrannosaur, as it was described, significantly increases the size range for feathered dinosaurs.
In a stunning find published in the journal Science in 2011, paleontologists uncovered dinosaur feather preserved in amber that dated back some 79 million years ago.
This discovery provided scientists a new window into the evolution of feathers in terms of structure in the evolutionary timeline from dinosaurs to birds. Even shades of color remained well preserved in the amber.
An ancient flying reptile with a bizarre, butterflylike head has been unearthed in Brazil.
The newfound reptile species, Caiuajara dobruskii, lived about 80 million years ago in an ancient desert oasis. The beast sported a strange bony crest on its head that looked like the wings of a butterfly, and had the wingspan needed to take flight at a very young age.
Hundreds of fossils from the reptile were unearthed in a single bone bed, providing the strongest evidence yet that the flying reptiles were social animals, said study co-author Alexander Kellner, a paleontologist at the Museu Nacional/Universidade Federal do Rio de Janeiro in Brazil. [See Images of the Bizarre 'Butterfly Head' Reptile]
Though pterosaur fossils have been unearthed in northern Brazil, no one knew of pterosaurs fossils in the southern part of the country. In the 1970s, a farmer named Dobruski and his son discovered a massive Cretaceous Period bone bed in Cruzeiro do Oeste in southern Brazil, a region not known for any fossils, Kellner said. The find was forgotten for decades, and then rediscovered just two years ago. The team dubbed the reptile Caiuajara dobruskii, after the geologic formation, called the Caiuá Group, where it was found, as well as the farmer who discovered the species, Kellner said.
C. dobruskii belonged to a group of winged reptiles known as pterosaurs, which are more commonly known as pterodactyls.
Hundreds of bone fragments from the species were crammed in an area of just 215 square feet (20 square meters). At least 47 individuals — and possibly hundreds more — were buried at the site. All but a few were juveniles, though the researchers found everything from youngsters with wingspans of just 2.1 feet (0.65 m) long to adults with wingspans reaching 7.71 feet (2.35 m). The fossils weren't crushed, so the 3D structure of the animals was preserved, the authors wrote in a research article published today (Aug. 13) in the journal PLOS ONE.
The ancient reptiles' bony crests changed in size and orientation as the pterosaurs grew.
A new species of flying reptile from the Cretaceous Era, Caiuajara dobruskiii, has been unearthed in southern Brazil.Maurilio Oliveira/Museu Nacional-UFRJ
Because the adult skeletal size (other than the head) wasn't much different from the juveniles', the researchers hypothesized that C. dobruskii was fairly precocious and could fly at a young age, Kellner said.
Based on the sediments in which the bones were found, the area was once a vast desert with a central oasis nestled between the sand dunes, the authors wrote in the paper.
Ancient C. dobruskii colonies may have lived around the lake for long periods of time and died during periods of drought or during storms. As the creatures died, the occasional desert storm would wash their remains into the lake, where the watery burial preserved them indefinitely, the researchers said. Another possibility is that the pterosaurs stopped at this spot during ancient migrations, though the authors suspect that is less likely.
The bone bed, with its hundreds of individuals in well-dated geological layers, is some of the strongest evidence yet that the fruit-eating animals were social, Kellner said.
"This was a flock of pterosaurs," Kellner told Live Science.
This finding, in turn, strengthens evidence that other pterosaur species may have been social as well, the authors wrote in the paper.
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Photos of Pterosaurs: Flight in the Age of Dinosaurs
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Image Gallery: 25 Amazing Ancient Beasts