A new study found that dinosaur fossils of Maiasaura peeblesorum from Montana indicate how the said species lived and died. The findings may also serve as a comparative model in the study of other dinosaurs.
The study of fossils may expose historical details of how extinct animals lived, grew and evolved, but without enough fossil data, researches often fail to provide a complete picture of an animal's growth and life cycle. The said limitation prompted researchers from Montana State University, Purdue University and Oklahoma State University to conduct a study using not just one, but 50 Maiasaura shinbones excavated from a bone bed in Montana.
With the number of fossils used, the researchers were able to come up with enough data to determine the growth and life cycle of the Maiasaura.
The researchers, led by Holly Woodward, an anatomy professor from the Oklahoma State University, studied the histology of the fossils. The histology or fossil bone microstructure reveals areas of growth such as growth rate, sexual and skeletal maturity, metabolism and death age, which cannot be determined by merely inspecting the bone shape.
The findings of the study, published in the journal Paleobiology, showed that the growth rate of the Maiasaura was similar to that of birds and that its bone tissues were almost the same as present-day warm-blooded species like elk.
The fossils also emphasized the degree of variation that each dinosaur species exhibited. Previous small-scale dinosaur histology investigations assigned a corresponding dinosaur age based on the length of the bones. According to Woodward, it was like giving an age to a person based on the general height of people with the same age.
"Our results suggest you can't just measure the length of a dinosaur bone and assume it represents an animal of a certain age," said Woodward. She added that histology is the sole technique to quantify dinosaur age.
By examining what lies inside the fossil bones and integrating the findings of previous researches, the authors were able to reveal more facts about the life history and growth dynamics of the Maiasaura than any other dinosaur species.
"Our study makes Maiasaura a model organism to which other dinosaur population biology studies will be compared," Woodward closed.