Call it the Jimmy Durante of dinosaurs — a newly discovered hadrosaur with a truly distinctive nasal profile. The new dinosaur, named Rhinorex condrupus by paleontologists from North Carolina State University and Brigham Young University, lived in what is now Utah approximately 75 million years ago during the Late Cretaceous period.

Rhinorex, which translates roughly into “King Nose,” was a plant-eater and a close relative of other Cretaceous hadrosaurs like Parasaurolophus and Edmontosaurus. Hadrosaurs are usually identified by bony crests that extended from the skull, although Edmontosaurus doesn’t have such a hard crest (paleontologists have discovered that it had a fleshy crest). Rhinorex also lacks a crest on the top of its head; instead, this new dinosaur has a huge nose.

Terry Gates, a joint postdoctoral researcher with NC State and the North Carolina Museum of Natural Sciences, and colleague Rodney Sheetz from the Brigham Young Museum of Paleontology, came across the fossil in storage at BYU. First excavated in the 1990s from Utah’s Neslen formation, Rhinorex had been studied primarily for its well-preserved skin impressions. When Gates and Sheetz reconstructed the skull, they realized that they had a new species.

“We had almost the entire skull, which was wonderful,” Gates says, “but the preparation was very difficult. It took two years to dig the fossil out of the sandstone it was embedded in — it was like digging a dinosaur skull out of a concrete driveway.”

Based on the recovered bones, Gates estimates that Rhinorex was about 30 feet long and weighed over 8,500 lbs. It lived in a swampy estuarial environment, about 50 miles from the coast. Rhinorex is the only complete hadrosaur fossil from the Neslen site, and it helps fill in some gaps about habitat segregation during the Late Cretaceous.

“We’ve found other hadrosaurs from the same time period but located about 200 miles farther south that are adapted to a different environment,” Gates says. “This discovery gives us a geographic snapshot of the Cretaceous, and helps us place contemporary species in their correct time and place. Rhinorex also helps us further fill in the hadrosaur family tree.”

When asked how Rhinorex may have benefitted from a large nose Gates said, “The purpose of such a big nose is still a mystery. If this dinosaur is anything like its relatives then it likely did not have a super sense of smell; but maybe the nose was used as a means of attracting mates, recognizing members of its species, or even as a large attachment for a plant-smashing beak. We are already sniffing out answers to these questions.”

Note : The above story is based on materials provided by North Carolina State University.

Some 66 million years ago, a 10-km diameter chunk of rock hit the Yukatan peninsula near the site of the small town of Chicxulub with the force of 100 teratons of TNT. It left a crater more than 150 km across, and the resulting megatsunami, wildfires, global earthquakes and volcanism are widely accepted to have wiped out the dinosaurs and made way for the rise of the mammals. But what happened to the plants on which the dinosaurs fed?

A new study led by researchers from the University of Arizona reveals that the impact that spelled doom for the dinosaurs also decimated the evergreen flowering plants to a much greater extent than their deciduous peers. They hypothesize that the properties of deciduous plants made them better able to respond rapidly to chaotically varying post-apocalyptic climate conditions. The results are publishing on September 16 in the open access journal PLOS Biology.

Applying biomechanical formulae to a treasure trove of thousands of fossilized leaves of angiosperms — flowering plants excluding conifers — the team was able to reconstruct the ecology of a diverse plant community thriving during a 2.2 million-year period spanning the cataclysmic impact event, believed to have wiped out more than half of plant species living at the time. The fossilized leaf samples span the last 1,400,000 years of the Cretaceous and the first 800,000 of the Paleogene.

The researchers found evidence that after the impact, fast-growing, deciduous angiosperms had replaced their slow-growing, evergreen peers to a large extent. Living examples of evergreen angiosperms, such as holly and ivy, tend to prefer shade, don’t grow very fast and sport dark-colored leaves.

“When you look at forests around the world today, you don’t see many forests dominated by evergreen flowering plants,” said the study’s lead author, Benjamin Blonder. “Instead, they are dominated by deciduous species, plants that lose their leaves at some point during the year.”

Blonder and his colleagues studied a total of about 1,000 fossilized plant leaves collected from a location in southern North Dakota, embedded in rock layers known as the Hell Creek Formation, which at the end of the Cretaceous was a lowland floodplain crisscrossed by river channels. The collection consists of more than 10,000 identified plant fossils and is housed primarily at the Denver Museum of Nature and Science. “When you hold one of those leaves that is so exquisitely preserved in your hand knowing it’s 66 million years old, it’s a humbling feeling,” said Blonder.

“If you think about a mass extinction caused by catastrophic event such as a meteorite impacting Earth, you might imagine all species are equally likely to die,” Blonder said. “Survival of the fittest doesn’t apply — the impact is like a reset button. The alternative hypothesis, however, is that some species had properties that enabled them to survive.

“Our study provides evidence of a dramatic shift from slow-growing plants to fast-growing species,” he said. “This tells us that the extinction was not random, and the way in which a plant acquires resources predicts how it can respond to a major disturbance. And potentially this also tells us why we find that modern forests are generally deciduous and not evergreen.”

Previously, other scientists found evidence of a dramatic drop in temperature caused by dust from the impact. “The hypothesis is that the impact winter introduced a very variable climate,” Blonder said. “That would have favored plants that grew quickly and could take advantage of changing conditions, such as deciduous plants.”

“We measured the mass of a given leaf in relation to its area, which tells us whether the leaf was a chunky, expensive one to make for the plant, or whether it was a more flimsy, cheap one,” Blonder explained. “In other words, how much carbon the plant had invested in the leaf.” In addition the researchers measured the density of the leaves’ vein networks, a measure of the amount of water a plant can transpire and the rate at which it can acquire carbon.

“There is a spectrum between fast- and slow-growing species,” said Blonder. “There is the ‘live fast, die young’ strategy and there is the ‘slow but steady’ strategy. You could compare it to financial strategies investing in stocks versus bonds.” The analyses revealed that while slow-growing evergreens dominated the plant assemblages before the extinction event, fast-growing flowering species had taken their places afterward.

Note : The above story is based on materials provided by PLOS.