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Prehistoric crocodiles ran like dogs

Prehistoric crocodiles survived by running around like dogs in a dinosaur-dominated world, some 235 to 65 million years ago, a new study has found.

While most modern crocodiles live in freshwater habitats and feed on mammals and fish, their ancient relatives were extremely diverse.

Some were built for running around like dogs on land and others adapted to life in the open ocean, imitating the feeding behaviour of today’s killer whales.

For the first time, the study has found how the jaws of ancient crocodiles evolved to enable these animals to survive in vastly different environments, all whilst living alongside the dinosaurs 235 to 65 million years ago.

“The ancestors of today’s crocodiles have a fascinating history that is relatively unknown compared to their dinosaur counterparts. They were very different creatures to the ones we are familiar with today, much more diverse and, as this research shows, their ability to adapt was quite remarkable,” Tom Stubbs, who led the study at the University of Bristol, said.

“Their evolution and anatomical variation during the Mesozoic Era was exceptional. They evolved lifestyles and feeding ecologies unlike anything seen today,” Stubbs said.

The team examined variation in the morphology (shape) and biomechanics (function) of the lower jaws in over 100 ancient crocodiles, using a unique combination of numerical methods.

“We were curious how extinction events and adaptations to extreme environments during the Mesozoic - a period covering over 170 million years - impacted the feeding systems of ancient crocodiles and to do this we focused our efforts on the main food processing bone, the lower jaw,” Dr Stephanie Pierce, from The Royal Veterinary College, said.

By analysing variation in the lower jaw, the researchers provide novel insights into how the feeding systems of ancient crocodiles evolved as the group recovered from the devastating end-Triassic extinction event and subsequently responded to the distribution of ecological resources, such as habitat and foodstuff.

For the first time, the research has shown that, following the end-Triassic extinction, ancient crocodiles invaded the Jurassic seas and evolved jaws built primarily for hydrodynamic efficiency to capture agile prey, such as fish.

However, only a small range of elongate lower jaw shapes were suitable in Jurassic marine environments.

“Our results show that the ability to exploit a variety of different food resources and habitats, by evolving many different jaw shapes, was crucial to recovering from the end-Triassic extinction and most likely contributed to the success of Mesozoic crocodiles living in the shadow of the dinosaurs,” Pierce added.


Obesity linked to body’s sugar production

 Researchers have suggested that the cause of obesity and insulin resistance may be linked to the fructose a person’s body makes in addition to the fructose they eat.

The team led by researchers at the University of Colorado School of Medicine claimed that fatty liver and insulin resistance may also result from fructose produced in the liver from non-fructose containing carbohydrates.

First authors are Miguel Lanaspa, PhD, and Takuji Ishimoto, MD, reported that mice can convert glucose to fructose in the liver, and that this conversion was critical for driving the development of obesity and insulin resistance in mice fed glucose.

Senior author Richard Johnson, MD, professor of medicine and chief of the division of renal diseases and hypertension at the School of Medicine, said that their study shows that much of the risk from ingesting high glycemic foods is actually due to the generation of fructose, which is a low glycemic sugar.

Colourless coatings to keep  fruits and veggies fresh

Scientists have now described advances in keeping other foods fresh, flavourful and safe for longer periods of time through the use of invisible, colourless, odourless, tasteless coatings.

Attila E. Pavlath, Ph.D., pointed out that the use of edible films has grown dramatically since the mid-1980s, when only 10 companies were in the business, to more than 1,000 companies with annual sales exceeding $100 million today.

Pavlath said that fruits and vegetables have skins that provide natural protection against drying out, discoloration and other forms of spoilage, asserting that cutting and peeling remove that natural protection, allowing deterioration and spoilage to begin.

Pavlath and his group invented the technology that enabled schoolchildren and other consumers to enjoy a new apple treat — refrigerated, packaged apple slices that last 2-3 weeks without turning brown or losing crispness.

Apples ordinarily begin to turn brown within 30 minutes after cutting or peeling. Pavlath’s process involves treating freshly cut apple slices with a form of vitamin C, resulting in the first commercial product that retains the desirable characteristics of fresh apples without leaving a detectable residue.

Today’s edible films, however, allow that exchange of gases and have other features that maintain freshness, flavor, aroma, texture and nutritional value. They generally provide the same protection against bacteria as the natural skin if the foods are handled under sterile conditions when they are cut in the factory, Pavlath said.

Workers either spray on the films or immerse the foods in the liquid coating after cutting. The finished fruits and vegetables then go to consumers in sealed containers.

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