December 5, 2023

Scientists have been stunned by the discovery of two gigantic fossils of a 160-million-year-old blood-sucking creature in northern China.

The “unusually large” fossils, which were described in a new paper published in Nature Communications, belonged to the lamprey species—an ancient species of jawless fish that can still be found in the Atlantic today. The parasitic fish has a funnel-like mouth full of teeth, used to latch onto other creatures.

Once a lamprey is attached to another fish it uses its tongue to remove its flesh. It then begins to suck its blood and other bodily fluids.

These new fossils—discovered in the Jurassic terrestrial fossil Lagerstätte Yanliao Biota of North China—are ten times larger than the earliest lampreys ever found. One was over 23 inches long.

“One of the two Jurassic species, Yanliaomyzon occisor, meaning ‘sucker killer from Yanliao Biota,’ is the largest fossil lamprey ever found in the world with superbly preserved teeth,” Feixiang Wu, corresponding author of the study and researcher at Chinese Academy of Sciences, told Newsweek.

An artist’s impression of a Jurassic lamprey. Its sucking mouth closely resembles that of the modern pouched lamprey.
Heming Zhang

Lampreys as a species date back 360 million years ago. The first examples were found in the Paleozoic and were only a few inches long.

However, only a few ancient lamprey fossils have ever been discovered, meaning there are still many questions about their evolution. These new fossils will help fill a gap in knowledge of the evolution of lampreys and their feeding.

Scientists are particularly interested in finding out how lampreys evolved their complex teeth. These fossils may help scientists gather more information about their life cycle, as well as their geographical origin.

“Before our report, the oldest fossil lamprey was from the Late Devonian, around 360 million years ago, and found in South Africa. Since then only seven species have been found, of which five are Paleozoic,” Wu said. “Now we add two Jurassic ones which represent an important stage of the evolutionary history of lampreys (regarding the feeding mode and life history pattern).”

The mouths of these lamprey fossils, and biting structures, are very well preserved, the study reported, providing evidence that this evolved by the Jurassic period. From this, scientists already know that the blood-sucking creatures were predatory before this period.

Analysis of these fossils also indicates that they had already developed a three-stage life cycle, which gives more insight into the peculiar species.

The scientists conclude that modern-day lampreys likely evolved in the Southern Hemisphere, rather than the Northern Hemisphere. This is because the fossil greatly resemble the lampreys found in water today.

Today, one lamprey can kill around 40 pounds of fish every year. They can be greatly destructive to the wrong environment. In the 1830s, they were invasive to the Great Lakes, and killed many important fish including trout, whitefish, perch, and sturgeon. This led to a huge collapse of fisheries in the area.

Wu said that more fieldwork will continue in order to find more lamprey fossils from Jurassic and Cretaceous periods, “to think deeper about the origin of the life history pattern of lampreys.”

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