Scientists have analyzed the stomach contents of a 110-million-year-old dinosaur, according to a recently-published paper. Most of the partially digested food is multiple species of plant matter, though small amounts of wood and charcoal were also detected. The dino world is due for some mythbusting.
According to the study published in The Royal Society, a team of scientists found a mass in the abdominal region of a fossilized dinosaur and have studied it for its contents. “Fourteen independent criteria […] support the interpretation of this mass as ingested stomach contents—a cololite,” the study said. “Analysis of the cololite documents well-preserved plant material dominated by leaf tissue (88%), including intact sporangia, leaf cross-sections, and cuticle, but also including stems, wood, and charcoal.” The plant portion of the mass included ferns and conifer foliage.
Dinosaurs didn’t spring out of the Earth and start eating. They evolved from smaller “diapsid” reptiles and their world was far different from what science believed just a few decades ago.
The Long, Long, Long Haul
Contrary to popular belief, dinosaurs roamed the Earth for a considerable span of our planet’s life.
“Dinosaurs first evolved from their diapsid predecessors in the late Triassic Period about 230 million years ago,” said Dr. Anthony Martin, Professor of Practice in the Department of Environmental Studies at Emory University. “They made it to the end of the Cretaceous Period, which ended 65 million years ago. That means dinosaurs were living and evolving for a minimum of 165 million years.”
Dr. Martin added that this claim is backed by the evidence of more than 500 genera of dinosaurs, with new genera being discovered every year. This makes them about as diverse as the types of birds on Earth today.
“A major revelation in our study of dinosaur evolution was that dinosaurs did not really go extinct,” Dr. Martin said. “They’re still here as birds. Birds evolved from small, feathered dinosaurs during the latter half of the Mesozoic era. And of course they’re still very much a part of life today, which means dinosaurs beat the bum rap of being extinct too.”
Walk Like a Man
A frequent point of skepticism about our knowledge of dinosaurs revolves around how we can infer so much about them simply from fossil evidence. One such example is, how do we know that many dinosaurs were bipedal? Even today, animals that walk on all fours sometimes feature shorter front limbs.
“One way, which ties in directly with body fossils, is looking at limb proportions and modifications of the hands for grasping,” Dr. Martin said. “This is an example of how natural selection favors one trait at the expense of another. In ancestors of dinosaurs, this inverse proportion shows up as a lengthening of the femur, tibia, and fibula, and foot bones, which corresponded with a shortening of the forelimb bones.”
Dr. Martin said that a shortened femur meant that each leg was able to cycle more quickly through a sprint, and the tibia and fibula bones were able to reach longer distances with each step.
Technological developments are forever updating and changing the way we think about the world that the dinosaurs inhabited. Humanity has debunked some earlier myths about dinos and we will continue to do so, one meal at a time.
Dr. Anthony Martin is Professor of Practice in the Department of Environmental Studies at Emory University. He earned his BS in Geobiology from St. Joseph’s College (Indiana), MS in Geology from Miami University (Ohio), and PhD in Geology from the University of Georgia.