Saturday, February 2, 2013

Newsflash: Tapeworm Eggs Found In Prehistoric Sharks.

Although it's easy to focus on giant mammals for an entire week, here's a small reprieve: parasites have been around even longer. (Actually, I couldn't find too many newsworthy things related to ancient mammals.) Tapeworms have been found in the body of a shark from the Permian, a time when mammal-like reptiles were a thing. That was before the dinosaurs, in case you aren't up to snuff with your periods of Earth's history.

The tapeworm cysts were found in the gut of  a 270-million-year-old fossil shark. Given the presence of Brazilian journals, we can safely assume that it was found somewhere in South America.

"Remains of such parasites in vertebrates from this era are rare- of 500 samples examined, only one revealed the tapeworm eggs. This particular discovery helps establish a timeline for the evolution of present-day parasitic tapeworms that occur in foods like pork, fish and beef.

The fossilized eggs were found in a cluster very similar to those laid by modern tapeworms. Some of them are un-hatched and one contains what appears to be a developing larva. According to the study, "This discovery shows that the fossil record of vertebrate intestinal parasites is much older than was previously known and occurred at least 270-300 million years ago."

The fossil described in this study is from Middle-Late Permian times, a period followed by the largest mass extinction known, when nearly 90% of marine species and 70% of terrestrial species died out."- source.

It's kind of humbling to know that tapeworms have lived so long. If you know absolutely nothing about parasites, you know that some parasites have super-specific life cycles. Tapeworms have survived so long precisely because they are simple. Humans can get fish tapeworms, pork tapeworms, beef name it. The tapeworm is not picky, which explains its amazing endurance over eons.Versatility tends to win out in the long run.

Parasite fanaticism over. Back to your regularly-scheduled mammals. Speaking of, happy Groundhog Day!

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