Today, it is Mothering Sunday here in the UK. The fourth Sunday in Lent following the Christian calendar, a day dedicated to celebrating motherhood. Mother’s Day is celebrated on different days in many parts of the world, most commonly in the Northern Hemisphere spring months of March through to May.

Maiasaura

As we consider mums, maternal bonds and the contribution of mothers to society, our thoughts turn to the ornithischian dinosaur Maiasaura. Named and described in 1979 (Horner and Makela), this hadrosaurid dinosaur (Maiasaura peeblesorum) is synonymous with motherhood and maternal behaviours.

The first fossils of this dinosaur were discovered in the Badlands of Montana (USA), by a team of American scientists led by palaeontologist Jack Horner. The site the team uncovered consisted of a number of dinosaur nests, eggs, baby Maiasaura, juveniles and adults. The fossil site was renamed “Egg Mountain” and represents the fossilised remains of a Maiasaura colonial nesting area.

Happy Mother’s Day

Studies of Maiasaura provided unequivocal proof that dinosaurs raised their young and fed them at the nest (altricial behaviour). Maiasaura translates from the Greek meaning “Good Mother Lizard”, an appropriate epithet for a dinosaur that demonstrated that these reptiles, looked after their offspring.

The extensive fossil remains of this hadrosaur have enabled palaeontologists to undertake large scale studies of dinosaur ontogeny (growth rate studies). In addition, scientists have been able to determine the mortality rate of Maiasaura based on the Montana “Egg Mountain” fossils. A study of fifty Maiasaura peeblesorum tibia revealed that 90% of all Maiasaura hatchlings died within their first twelve months. If the dinosaurs survived into their second year, the mortality rate would fall to around 13%.

To view models and figures of ornithischian dinosaurs: Safari Ltd – Wild Safari Prehistoric World Models.

Maiasaura remains one of our favourite dinosaurs. Happy Mother’s Day from Everything Dinosaur.