sciencehabit writes: While examining fossilized shark feces collected from southern Brazil, researchers noticed a strange cluster of oval-shaped objects. Taking a closer look, they realized they had found a tapeworm egg case bearing an uncanny resemblance to those produced by modern pests today. Such discoveries are exceptionally rare. The "amazing" new specimen contains 93 tiny eggs, they write, each measuring about the same width as a human hair. Some of the eggs appear swollen, suggesting that they still contain the makings of ancient tapeworm babies. One of the eggs even holds what appears to be a developing larva. The egg case ranks as the earliest known evidence of tapeworm parasitism in vertebrates, indicating that this particular parasite has been plaguing fellow animals since the days of the massive supercontinent Pangaea.