Baby dinosaurs were born into a world of danger – scientific american blog network
In 1985, three years before Littlefoot and gang would set off for The Great Valley, paleontologist Jack Horner, writer James Gorman, and artist Doug Henderson told the story of a different baby dinosaur on a perilous journey. Diet plan maker Her name was Maia – short for Maiasaura – and while her adventure was fiction, it was informed by the science of what Horner and his colleagues were digging up at Egg Mountain in Montana.
Maia was not a miniature version of her parents. Losing weight in menopause She hatched as a big-eyed, wobbly-legged infant, and spent her early days in the warmth of the nest as she grew and her limbs became stronger.
Special k weight loss But her salad days quickly ended when hungry Troodon raided the nesting ground, and as Maia matured she encountered even bigger, toothier dangers in the surrounding forests. Paleo appetizers Ultimately, though, Maia survived long enough to become a mother herself, and this, according to a 2015 study by paleohistologist Holly Woodward and colleagues, would have made Maia a very exceptional member of her species.
The site that inspired the story of Maia isn’t just a horizon of tiny bones and eggshells. Benefits of weight loss Over the past three decades paleontologists from Montana’s Museum of the Rockies have dug up hundreds of Maiasaura bones from a second horizon just above the nesting grounds. Pregnancy and exercise first trimester So man y bones have been found here, in fact, that Woodward and her collaborators have been able to assemble the first good picture of what Maiasaura population biology was like.
Of all the dinosaurs that ever lived, only a fraction of a fraction of a fraction are preserved in the fossil record. Paleo diet and diabetes And of the dinosaurs that have come down to us as petrified versions of their former selves, many are only known from fragments or partial skeletons. Lose belly fat menopause This makes studying dinosaur biology incredibly difficult. Exercise definition While a biologist working on living animals might have hundreds of specimens to study for demographic information – and can often go observe their chosen species in life – paleontologists are lucky if they have a small smattering of beat-up bones to work with. Weight calculator lbs to kg And even well-known dinosaurs can be hard to study. Healthy diet to lose weight indian While 50 or so partial Tyrannosaurus rex skeletons are known, for example, they don’t represent a single population but are from different places and slices of time from a window of about two million years. Lose water weight fast 2 days So if you’re a paleobiologist wanting to study variation between individuals, population structure, and other details, more often than not there just aren’t enough dinosaurs to get at those puzzles.
But the Egg Mountain bonebed is another story. Paleo italian dressing Even though the bones were strewn into a jumble when buried, paleontologists have been able to recover elements from animals of different sizes and ages that died very close to each other in time. Paleo chili verde Within that sample the researchers have extracted at least 50 tibiae – the larger of the two lower hindlimb bones – and, as Woodward and colleagues demonstrate, this is a very useful bone to have.
Histology, or the study of bone structure, is one of the most important subfields within paleontology right now. Paleo apple crisp By cutting into bones and looking at them under the microscope paleontologists can see how fast a dinosaur was growing, estimate its age, and get other biological information otherwise invisible to us. 3 month diet plan The most useful for studying dinosaurs have been leg bones – the femur and the tibia – as they often record a great deal of detail about an individual animal’s life in a way that’s relatively easy to see. Paleo diet potatoes To that end, Woodward and coauthors cut into and scrutinized the 50 leg bones – representing at least 32 distinct individual Maiasaura ranging from about 10 to over 23 feet in length – to investigate what the osteological details would reveal about this dinosaur population.
As it turns out, the fictional Maia was even luckier than even Horner initially understood. Paleomg Within the sample, 31 of the bones lacked any lines of arrested growth (or LAGs) that are usually taken as markers of each passing year. Healthy diet foods for breakfast This means that the majority of the dead dinosaurs were yearlings that were still growing extremely quickly. Losing weight after pregnancy From this Woodward and her colleagues calculated that baby Maiasaura faced an 89.9% mortality rate in their very first year. Paleo honey If baby dinosaurs even survived to the moment they pushed out of their eggs, the odds were set against most of them surviving to adulthood.
Old dinosaurs didn’t fare so well, either. Paleo diet rules and foods Woodward and colleagues counted 11 tibiae from Maiasaura that were seven years old or more, and five of these had a special growth marker – the external fundamental system (EFS) – which signaled that these were old dinosaurs whose skeletons had stopped growing. 7 day protein diet plan for weight loss These fully mature dinosaurs had a mortality rate of 44.4%, Woodward and coauthors concluded, and probably represent the attrition that comes with old age.
There were a few dinosaurs in the middle of these two extremes, but, for the most part, young, vigorous Maiasaura were absent from the sample. Healthy diet for weight loss and muscle gain And this seems to fit with the general picture of how the bonebed formed. 3 day weight loss The profile seems to suggest some kind of local catastrophe, like a drought or disease. Weight loss meal prep recipes Yearlings and old individuals were hit hardest, as is the case with many large animals alive today, while the young dinosaurs in their years of “peak performance” were better able to withstand the stress. Exercise and anxiety and depression Not that being a young, vigorous dinosaur was without its challenges, though. Exercise and blood pressure The few prime-aged Maiasaura in the sample might have been undergoing some unique growing pains that made them more susceptible, Woodward and colleagues write, which might be related to the onset of sexual maturity at around three years of age.
This sort of life history wasn’t unique to dinosaurs. The best diet foods Maiasaura grew at rates comparable to their living avian cousins, and the survivorship estimates Woodward and colleagues were able to calculate compare well with those biologists have recorded for red deer and Dall sheep. Best diet to lose 10 pounds And the fact that such conclusions are possible at all is not only owed to the fortuitous discovery of so many dinosaurs in one place, but to the decades of work Museum of the Rockies researchers and volunteers have put into the site.
Best of all, all that hard work raises the possibility that paleontologists can apply the same lessons to other places where dinosaurs died en masse. Diet plan to lose belly fat meal plans The disarticulated remains of at least 48 individual Allosaurus have been found at the Cleveland Lloyd Dinosaur Quarry in Utah, for example, and New Mexico’s Ghost Ranch quarry is famous for producing hundreds of Coelophysis skeletons. Exercise and depression study These collections of bones, as well as others scattered around the world, offer additional opportunities to gain new insights into dinosaur life if we can grit our teeth and comes to terms with this simple fact – we won’t really be able to understand dinosaurs without slicing up a few bones.
Woodward, H., Freedman Fowler, E., Farlow, J., Horner, J. Exercise room ideas 2015. Exercise moves names Maiasaura, a model organism for extinct vertebrate population biology: a large sample statistical assessment of growth dynamics and survivorship. Weight loss yoga for beginners tara stiles Paleobiology. Exercise list to lose weight doi: 10.1017/pab.2015.19
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