A tiger-sized saber-toothed creature called Inostrancevia has previously only been found in Russia. But scientists have discovered its fossils in South Africa, suggesting that it migrated 7,000 miles across the supercontinent Pangaea during the world s worst mass extinction 252 million years ago. Heading to South Africa allowed it to fill a gap in a faraway ecosystem that had lost its top predators.
Credit: Dorling Kindersley
Anyone who s raised a child or a pet will know just how fast and how steady their growth seems to be. You leave for a few days on a work trip and when you come home the child seems to have grown 10cm! That s all well and good for the modern household, but how did dinosaurs grow up? Did they, too, surprise their parents with their non-stop growth?
A new study lead by Dr Kimberley Chapelle of the American Museum of Natural History in New York City and Honorary Research Fellow at the University of the Witwatersrand suggests NOT. At least for one iconic southern African dinosaur species. By looking at the fossil thigh bones under a microscope, researchers can count growth lines, like those of a tree. This allows them to study how much the individuals grew each year. By looking at growth rings in the bones of Massospondylus carinatus, Dr Chapelle was able to show that its growth varied season-to-season, more like a tree than a puppy or a baby human.
Massospondylus carinatus was a plant-eating dinosaur from the early
Jurassic
They counted growth rings in the bones to determine how it grew with time
Like trees, the researchers found its growth varied significantly over its life
This strategy likely allowed it to adapt to changing environmental conditions
M. carinatus adults could reach up to 1,100 lbs in weight and 13–20 feet long