November 22, 2024

Paleontology Plot Twist: New Research Shows Nanotyrannus Is Separate Species, Not “Juvenile T. rex”

Artist illustration of Nanotyrannus attacking a juvenile T. rex. Credit: Raul MartinNanotyrannus was a smaller sized, longer-armed relative of T. rex, with a narrower snout.A brand-new analysis of fossils believed to be juveniles of T. rex now reveals they were grownups of a small tyrannosaur, with narrower jaws, longer legs, and larger arms than T. rex. The species, Nanotyrannus lancensis, was initially named decades ago but later reinterpreted as a young T. rex.The first skull of Nanotyrannus was found in Montana in 1942, but for years, paleontologists have gone back and forth on whether it was a separate species, or just a juvenile of the much larger T. rex.Fossil Analysis by ExpertsDr. It recommends these animals were nearly full-size; not fast-growing juveniles.Modeling the development of the fossils revealed the animals would have reached a maximum of around 900-1500 kgs (~ 2,000-3,300 pounds) and 5 meters (~ 16 feet)– about 15 percent of the size of the giant T. rex, which grew to 8,000 kilograms (~ 18,000 pounds) and nine meters (~ 30 feet) or more.The researchers have released their findings in the journal Fossil Studies.Comparison of T. rex and Nanotyrannus skulls.” The other features and long arms recommend it was just distantly associated to T. rex– and might have sat outside the family Tyrannosauridae, which T. rex is part of, in its own household of predatory dinosaurs.The brand-new study is the latest in a series of publications on the problem, going back decades.Longrich stated: “Nanotyrannus is extremely questionable in paleontology.

Credit: Raul MartinNanotyrannus was a smaller, longer-armed relative of T. rex, with a narrower snout.A new analysis of fossils thought to be juveniles of T. rex now shows they were adults of a little tyrannosaur, with narrower jaws, longer legs, and larger arms than T. rex. It recommends these animals were nearly full-size; not fast-growing juveniles.Modeling the development of the fossils revealed the animals would have reached a maximum of around 900-1500 kilograms (~ 2,000-3,300 pounds) and five meters (~ 16 feet)– about 15 percent of the size of the giant T. rex, which grew to 8,000 kilograms (~ 18,000 pounds) and nine meters (~ 30 feet) or more.The scientists have released their findings in the journal Fossil Studies.Comparison of T. rex and Nanotyrannus skulls.” The long arms and other functions recommend it was only distantly associated to T. rex– and might have sat outside the family Tyrannosauridae, which T. rex is part of, in its own family of predatory dinosaurs.The new study is the most current in a series of publications on the issue, going back decades.Longrich said: “Nanotyrannus is highly controversial in paleontology.