We can learn about the future of the modern platypus by studying its ancestors. It would have eaten crayfish and other freshwater crustaceans, like the modern platypus does, but its large size and robust dentition would have let it feed also on small vertebrates including the lungfish, frogs, and small turtles that are preserved with it. So what information can we gather about the life of this giant platypus? Basing the whole picture on one tooth makes it difficult, but the bumps and ridges indicate that it may have fed on wide range of aquatic organisms. The Two Tree site, where the tooth was found, is not actually dated, but the authors estimate the age at between 15 and 5 million years old. The well-preserved fossils from this area have already rewritten the book on marsupial evolution, and now they are doing the same for Australia’s egg-laying mammals (monotremes). Like the skull of Obdurodon dicksoni, this skull was recovered from the limestone formations of the Riversleigh World Heritage Site, where Archer and his colleagues have been working for over 20 years. This species was double the size of the typical mainland platypus. Compare this to the modern platypus, where a large male from Tasmania is lucky to reach 60cm. It is the largest species of platypus ever described the authors estimate it was almost a metre long.
What is spectacular about the new discovery, named Obdurodon tharalkooschild, is its size. Everett Kennedy Brown A big platypus with a broad diet The tubes are a continuous conduit to the plate surface and may serve a sensory function or result from the ever-growing nature of the epithelial plate.Not quite THAT big.
PLATYPUS EVOLUTION HISTORY SERIES
New images of the epithelial plates offer insight into a series of tubes concentrated under the juvenile teeth. Structures in the epithelial plates are broadly similar to those found in the keratin plates. New imagery highlights potential phylogenetically informative morphology in the pulp cavity and roots.Īs the roots of the juvenile teeth degenerate, the epithelium below the teeth thickens into epithelial plates. These differences reinforce the need for caution when applying dental terminology that originally was produced for therian mammals. Transverse lophs on monotreme teeth contain complexity not reflected in cusps alone, unlike therian mammals. The teeth of the juveniles are highly variable, but early-forming features (major cusps and transverse valleys) are stable enough for comparison. New imagery of those teeth and plates from high-resolution x-ray computed tomography and scanning electron microscopy contribute to the understanding of mammal evolution and the unique morphology of platypus teeth. Deciduous teeth and thickened epithelial plates of the extant platypus, Ornithorhynchus anatinus, are sparsely figured in the literature. Although adult monotremes are edentulous, juvenile platypuses have teeth that can be compared with extinct monotremes, but terminology can be a barrier to efficient comparison to non-monotreme mammals. The evolutionary history of mammals, when including extinct taxa, is mainly reconstructed using tooth morphology and employs terminology based on non-monotreme mammals.