Weekend Argus (Saturday Edition)
SA expert played role in dinosaur find
THE remains of the oldest Tyrannosaurus species, Moros intrepidus, have been discovered in North America.
According to the North Carolina Museum of Natural Sciences (NCMH), it is the oldest Cretaceous tyrannosaur species discovered in North America. It is believed the Moros intrepidus bridges the 70-million-year gap between the early tyrannosaurs and the T-Rex.
The team of palaeontologists, led by Dr Lindsay Zanno of the NCMH, dug on the site for almost a decade. In 2015, Ryan Tucker in the earth sciences department at Stellenbosch University, joined the team to give a geological context.
“These bones are way too old for carbon-dating, so we look for minerals, such as zircons, in the sediments and rocks in which the fossil bones have been entombed. Because they contain uranium, lead and thorium, we use the ratio of these particular isotopes preserved within the zircon to determine the possible age of the rock.”
This was done at Stellenbosch University’s Central Analytical Facility, one of a handful of institutions in the world to house the required equipment.
“It’s like searching for buried treasure. When you finally find that zircon in the rocks entombing a fossil, you know you have in your hands a time-capsule from the prehistoric past,” Tucker said
The specimens discovered were a femur, tibia and parts of a foot. Analysis of the femur revealed the
Moros intrepidus had been more than 7 years old and weighed about 78kg. It was a small specimen that lived about 96-million years ago during the Cretaceous period in modern-day Utah.