![]() ![]() ![]() "It's an ancestral condition for all mammal groups. "It's very interesting really because many of these early mammal groups had teeth," Dr Long said. The scientists also discovered that this ancient platypus had teeth. "But the recent discoveries made in the last week have shown with the high resolution CT scanner in Texas that some of these jaws that they found, they're actually in the same family, ornithorhynchidae, as the modern platypus and this is absolutely outstanding," he said. Museum Victoria's head of sciences, Dr John Long, says at first the paleontologists thought the jaw was from an ancestor of the platypus. Palaeontologists Dr Tom Rich from Museum Victoria and Professor Pat Vickers-Rich from Monash University have been searching the southern coastline of Victoria for the remains of early mammals for more than two decades.Īround 10 years ago they found a fossil jaw which was thought to be around 120 million years old. Now Australian scientists have discovered that the platypus is significantly older than previously thought: it may have been around since 120 million years ago, meaning it lived alongside the dinosaurs. On the other hand, sexual selection drove the evolution of more complex crest shapes, and this is reflected by multiple evolutionary bursts.Just about everyone loves the platypus, but for years the strange little monotreme has keep its secrets to itself. Hadrosaurs apparently fixed on a feeding apparatus that was successful and did not require massive modification to process their food. On the other hand, the bones that form the display crests showed multiple fast rate branches."ĭr Albert Prieto-Márquez, co-author and world-leading expert on hadrosaurs from the Catalan Institute of Paleontology in Barcelona, added: "Our results suggest that evolution can be driven in different ways by natural selection and sexual selection. "When we looked at the jaws and teeth, we only saw fast evolution on a single branch at the base of the group. "Our methods allowed us to identify branches on the hadrosaur evolutionary tree that showed rapid evolution in different parts of the skeleton," said co-author Dr Armin Elsler. New numerical methods allow us to test these kinds of complex evolutionary hypotheses." We wanted to compare the two famous hadrosaur innovations, and by doing so, provide new insights into the evolution of this important dinosaur group. ![]() Professor Mike Benton, the study's co-author from Bristol's School of Earth Sciences, added, "Variation in anatomy can arise in many ways. In comparison, the elaborate display crests kept diversifying in several bursts of evolution, giving rise to the many weird and wonderful shapes." Researchers from the Universities of Bristol and the Catalan Institute of Paleontology in Barcelona used a large database describing morphological variety in hadrosaur fossils and computational methods that quantify morphological variety and the pace of evolution.ĭr Tom Stubbs, lead author of the study and a researcher from Bristol's School of Earth Sciences, said: "Our study shows that the unique hadrosaur feeding apparatus evolved fast in a single burst, and once established, showed very little change. Some even trumpeted and tooted their special call, using nasal passages through the head crests. They also had hugely varied head display crests that signalled which species each belonged to and were used to attract mates. Called the 'sheep of the Mesozoic'as they filled the landscape in the Late Cretaceous period, hadrosaurs walked on their hind legs and were known for their powerful jaws with multiple rows of extremely effective teeth. ![]()
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