The actual naming of Maiasaura dates back to 1979. It was described scientifically by renowned Montana State University paleontologist and Museum of the Rockies curator Jack Horner. At the time, a number of eggs, embryos, juveniles and adults were unearthed from a location in the Two Medicine Formation, known as Egg Mountain. Dinosaur nests had been discovered already in Mongolia but the degree of care was not really known back then.
About two hundred specimens were uncovered from this site. It is thought that in life these herbivores lived in herds up to 10,000 strong or more. We also know that the adults took care of their young for an extended period of time, and that the hatchlings were ‘cute’, with large eyes and big, short faces. This has been shown to be true for most other duckbill genera.
A recent study involved fifty individuals, which may seem like nothing much but considering the sparseness of the fossil records this is a huge number. The scientists participating in the study add that their methodology involved treating their samples just like a population of modern animals. The study is now known as the Maiasaura Life History Project, and aims to uncover as much data as possible, in order to properly reconstruct the animal’s family life and its world as an entirety.
The new study was published in the journal Paleobiology. It was led by Holly Woodward from the Oklahoma State University, Elizabeth Freedman Fowler, adjunct professor at MSU, and Horner himself. James Farlow, professor emeritus of Geology at Indiana Purdue University also contributed to the paper. It involved the use of bone histology, using the microstructure of fifty leg bones to properly calculate the growth of the animals. Not only did the young Maiasaura grow at exceptional speeds when young, they were almost like mammals or even fast-growing avian theropods. The Maiasaura started life as a helpless little creature of 45 centimeters in length but grew to almost four times this length by the end of their first year.