It turns out that Intestinal parasites have been around for far longer
than anyone had guessed. The discovery of a cluster of tapeworm eggs in
fossilized shark feces from 270 million years ago was ground-breaking in
Tapeworm (Public Domain Image)Tapeworm (Public Domain Image)understanding the history of parasites. Back then they were still
fairly rare. Out of the 500 samples studied only this one turned up the
tapeworm evidence.

This new information was published last month in the open access journal PLOS ONE.

The fossilized eggs were formed together in a cluster that appears very similar to those laid by modern parasites. The discovery is a major step forward in the understanding of the history of the parasites that can infect regular present-day foods like pork and beef. It also shows that intestinal parasites are much older than previously thought.

The fossil is from the Middle to Late Permian period, a time just before the largest mass extinction on the planet when 90% of marine animals and 70% of land animals died out. The tapeworm not only survived, but thrived.

Source: Underwater Times