160-Million-Year-Old Flesh-Eating Lampreys Discovered in China, Provide Insight on the Evolutionary History of Jawless Fish

Lampreys are known for feeding on the flesh and blood of other organisms using their suctioning discs lined with teeth. Also called the "vampires of the ocean and lakes," modern parasitic lampreys tend to be adapted to consume blood or flesh.

Giant Water Vampire

Lampreys are eel-like, jawless, aquatic vertebrates which possess sucker-like mouths. Since they live in oceans and fresh-water environments, they are often considered a threat to other fish, killing about 40-60% of their prey.

Prior studies reveal that these animals evolved 360 million years ago; the oldest fossil from the Late Devonian period was found in South Africa. Since then, only seven species have been discovered, five of which are Paleozoic.

During the early stage of their development, they were small and measured only a few centimeters long. Over time, the lampreys have grown much larger, with some modern species measuring more than a meter long. Paleontologists believe that modern-day lampreys probably evolved in the Southern Hemisphere due to the remarkable resemblance of lampreys found in water today.

Experts are particularly interested in discovering how these jawless fish evolved their complex teeth. They rely on fossils to gather information about their life cycle and geographical origin. Living jawless fish have become a highly studied group of animals for their contribution to studying vertebrate evolutionary biology. However, fossil records of their extinct ancient ancestors are rare, and an evolutionary gap exists between the old and modern lampreys.

Jawless Bite From the Past

In northeast China, a team of scientists from the Chinese Academy of Sciences and Muséum National d'Histoire Naturelle, UMR, has discovered the fossils of two large lamprey species from the Jurassic era. Paleontologists Feixiang Wu, Philippe Janvier, and Chi Zhang unearthed the features of the ancient lampreys and believe that the discovered species help fill in some of the gaps in the evolutionary history of jawless fish.

The two fossilized remains were discovered in the Yanliao Biota, a rock formation that has yielded multiple fossils of ancient creatures. Previous studies suggest that the rock formation where the new species were unearthed was formed around 160 million years ago, revealing the age of the fossilized lampreys.

Since both specimens were in excellent condition, they allowed the researchers to study the creatures from head to tail. The longer specimen was named Yanliaomyzon occasion, which means 'sucker killer from Yanliao Biota.' It measures 23 inches (58 centimeters) long and is the largest fossil lamprey ever found in the world, with a superbly preserved set of teeth. The shorter one was called Yanliaomyzon ingensdentes and measured approximately 11 inches (28 centimeters).

Both species have many teeth; the longer specimen has 16, while the shorter one has 23. The scientists believe that the mouth structures and teeth of the lampreys, along with the structure that held their tongue, are indications that both specimens latched onto prey. Their anatomy also suggests that the lampreys sucked out blood and removed tissue from their prey for consumption.

Analysis of the fossils suggests that these animals had already developed a three-stage life cycle. The result of the study indicates that the blood-sucking lampreys used to be predators before the Jurassic period.