The megaherbivores of the Mesozoic era — gigantic sauropods such as the famous Diplodocus, Brachiosaurus, and Apatosaurus — were the largest creatures to ever walk the Earth.
And, judging by their gargantuan size, scientists have long assumed that these dinosaurs needed large amounts of plant food in order to produce enough energy for their daily requirements.
But a new study uncovered that the largest land animals of all time didn’t actually need as much food as previously believed, Science Daily reports.
The research, led by Dr. Fiona Gill of the University of Leeds in the U.K., focused on sauropod diet during the Late Jurassic and made some important discoveries regarding the nutrition of these giant reptiles — one of the most long-lived groups of dinosaurs, according to the University of California Museum of Paleontology in Berkeley, California.
These giant sauropods endured through all the three geological periods of the Mesozoic era, roaming the planet’s ancient plains for some 100 or so million years, from the Triassic to the Cretaceous. But they were most widespread toward the end of the Jurassic (the middle period), a time when the atmosphere had high levels of carbon dioxide (CO2).
This made plants grow faster and bigger, which scientists have always associated with a decrease in their nutritional value. But, as it turns out, that wasn’t necessarily the case.
In an unusual experiment, Gill’s team decided to grow some of the plants that giant sauropods frequently grazed on, such as horsetail and ginkgo, but with a twist. For their gardening exercise, the researchers replicated the same high-CO2 atmospheric conditions that dinosaur plant food would have grown in 150 million years ago during the Late Jurassic.
Once this part of the experiment was completed, the scientists set about to determine the plants’ nutritional value by using an artificial fermentation system that simulated the digestion process of the plant leaves like it would have occurred in the stomach of a sauropod.
The results revealed that Late Jurassic plants had a much higher nutritional value than previously believed and thereby provided a lot more energy than anticipated.
This suggests that giant sauropods didn’t actually need to gorge on plants and ate much less per day than we imagined.
“Our research doesn’t give the whole picture of dinosaur diet or cover the breadth of the plants that existed at this time, but a clearer understanding of how the dinosaurs ate can help scientists understand how they lived,” notes Gill, who is a paleontologist and geochemist at the university’s School of Earth and Environment.
Growing a dinosaur’s dinner | #Geology #GeologyPage— Geology Page (@GeologyPage) July 14, 2018
Scientists have measured the nutritional value of herbivore dinosaurs’ diet by growing their food in atmospheric conditions similar to those found roughly 150 million years ago.
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The results, published this week in the journal Palaeontology, indicate that there could have been more giant sauropods on Earth than science had estimated — maybe even 20 percent more, since using up fewer resources per individual meant the ecosystem could have supported a higher number of dinosaurs.
“The large body size of sauropods at that time would suggest they needed huge quantities of energy to sustain them. When the available food source has higher nutrient and energy levels it means less food needs to be consumed to provide sufficient energy, which in turn can affect population size and density,” explains Gill.
As she points out, her team’s method of growing plants in prehistoric atmospheric conditions could be applied to other ecosystems as well and used to learn more about “the diets of other ancient megaherbivores, such as Miocene mammals — the ancestors of many modern mammals.”