Paula C. Dentzien-Dias
as lifestyle, parasitism obviously works. Long before human ancestors crawled down trees, profiteer leeches were already are at home in the guts and veins of primitive vertebrates. These tough little pests have arrived on the scene there-140 at least 270 million years ago million years earlier than previous records intestinal parasites, according to new evidence discovered by chance in the fossil record. When examining fossilized feces sharks (main photo) collected in southern Brazil, the researchers noticed a strange group of oval objects. Let's look closer, they realized they had found a case tapeworm eggs bearing an uncanny resemblance to those produced by modern parasites today. Eggs lids (indicated by the blue arrows in inset) feature, or small teapot lid flaps of such characteristics tapeworm eggs, which have helped researchers identify conclusions. These findings, they wrote in PLOS ONE , are exceptionally rare; old fossil, the less chance of finding signs of tiny parasites, which can have fragile once colonized. The "amazing" new specimen contains 93 tiny eggs, they write, each measuring about the same width of a human hair. Some eggs appear swollen, suggesting that they still contain the fabric former tapeworms babies. A eggs same holds what appears to be a developing larva. If the egg is ranked as the first known evidence of tapeworm parasites in vertebrates, indicating that this particular parasite has been afflicting other animals since the days of the supercontinent Pangaea solid. And more than likely, it will remain for millennia to come.
See Science Shots .
0 Komentar