Monotremes are different from other mammals because they have no teats and lay eggs like birds even though they raise their young like mammals. The platypus is smaller than most people think, males are about 50 cm long and weigh about 1. The first thing most people notice about the platypus is its bill.
Very sensitive, the bill is like soft, wet rubber and is used to find food. The platypus's body is covered in thick, dark brown fur and is flat and streamlined.
It has a broad, flat tail with short, stout legs and webbed front feet well suited to its life in the water. The tail acts as a stabiliser when the platypus swims, and is also used for burrowing. Fat is stored in the tail for when food is scarce or when the female returns to her burrow to breed. If the water is cold, platypus can increase their body's heat-production to keep their temperature at around 32 degrees.
Awkward on the ground, the platypus waddles with the webs of its front feet turned back so it can use its claws for digging. The male platypus has a sharp spur on each ankle. These spurs are connected to a venom gland in each thigh. The venom glands are most active during the spring breeding season, so competing males probably use the spurs in territorial fights.
Platypus are found in eastern Australia from the steamy tropics of far north Queensland to the freezing snows of Tasmania. In Queensland, platypus live in rivers east of the Great Dividing Range, and are also found in some western-flowing streams. In north Queensland, the range of the platypus is close to the coast. The animals aren't found in Cape York Peninsula. But even he had his doubts. So much about it seemed wrong. The more closely the platypus was studied, the deeper the mystery grew.
In the German naturalist Johann Friedrich Blumenbach conducted the most detailed study to date. But he could not ignore the fact that they still had a number of other characteristics that did seem reminiscent of mammals. Two years later Sir Everard Home took a rather different view. He reported that the male platypus had internal testes like reptiles and a cloaca a single orifice for the digestive, urinary and reproductive tracts.
At the time it was believed that cloacae belonged only to reptiles, amphibians and birds, and was indicative of egg-laying. Exactly where it belonged, however, was unclear. Lamarck argued that, rather than being static, all living things were in a constant state of change.
But it clearly suggested that, over time, one variety of animal could transform into another. The implications for taxonomy were immense.
But rather than settling matters, this only seemed to make things worse. What he found came as a surprise. While he established that male platypuses had a poison gland — usually associated with reptiles and amphibians — he also discovered that the females did have mammary glands after all.
Clearly, the picture was too confused for any definite conclusions to be reached; but suddenly, the platypus was looking a lot more like a mammal than a short time before. In Lauderdale Maule, a young Scottish soldier, published two papers which bolstered this idea further. Although he acknowledged that platypuses had some reptilian characteristics, and even identified certain bones in the pelvic girdle that were found only in mammal-like reptiles, he drew attention to several features that were distinctively mammalian.
True, the mammary glands were atypical, but he left no doubt that the females had nipples capable of expressing milk; and he confirmed that both sexes had warm blood and true diaphragms. Ornithorhynchus anatinus.
But most naturalists quickly realised that they actually made classification more difficult. The lead-in words never come easy to me. Now, make room for the Lord and have a great week. Now, that would be a great ending. Or is it snow-laden platypi? Ten percent stopped when they read the words Doug Bursch. If my math is correct, 55 percent of my initial readers remain.
By the way, I just lost two more readers who are upset with my subpar math skills. And 2 percent of my readership just baled because all this math is reminding them of how much they hate word problems. So where was I? Or more importantly, where am I? I begin to panic that I have too much or too little left to say. The platypus genome contains both reptilian and mammalian genes involved in the fertilization of eggs.
Unlike most mammals, which have a pretty good sense of smell, the platypus doesn't—and its genome has about half as many odor receptors as the mouse and other mammals. Just one request, please. In the PR avalanche preceding this announcement, one talked about the medical benefits that would surely come from this feat. The very real potential for advances in human disease prevention and a better understanding of mammalian evolution. There have been virtually no medical benefits from sequencing the human genome yet , for goodness sake; can't we, just occasionally, celebrate a feat of pure science without raising hopes that it will, you know, cure cancer or something?
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