The Predator - the controversial figure of a half-billion-year-old biological terrorist

Anomlocaris was unlike any other known creature that lived in its time. In fact, many believed that it was also unlike any creature that exists in the present

Fossils found in western China shed new light on the nature and modus operandi of one of the earliest super predators on Earth. A top predator is an animal that stands at the top of the food chain in a given environment. That is, it feeds - directly or indirectly - on almost all other animals, and no other animal feeds on it. This is an extinct animal called Anomalucaris, which about half a billion years ago, probably ruled the water bodies of the earth, like a fox in a chicken coop.

The first fossils of Anomlocaris were discovered more than a hundred years ago, in 1866. Unfortunately, these were parts of an external skeleton, from which it was very difficult to reconstruct the body structure of the entire animal. Since then, more fossilized exoskeleton parts of the Anomlocaris have been found in various parts of the world, but no complete exoskeleton has ever been found. This is how the paleontologists tried, for years, to put together the different known parts of the animal, like trying to put together the pieces of a puzzle game.

It seems that during these assembly attempts quite a few researchers made mistakes in their diagnosis of most of the known organs of the animal. The errors resulted from an over-reliance on the animal species that were known to the researchers. But as it turned out later, the Anomlocaris did not resemble any other known creature that lived in its time. In fact, many believed that it was also unlike any creature that exists in the present. The name of the animal - Anomlocaris - which means "strange snail", was given to it based on a wrong assumption that it is some relative of the snails - shrimp. The discoverer of the first fossilized exoskeletons of Anomlocaris, the Canadian paleontologist Jay Whitebbs, actually found only the frontal appendages of the animal, and due to their shape he believed that he had an exoskeleton of a strange exoskeleton.

Some paleontologists who came across the fossilized remains of the Anomlocaris body believed that they were facing a sea cucumber. In other cases, the researchers tried to assemble separate organs of Anomlocaris on the skeletons of other animals. The fearsome round jaws of the ancient predator were diagnosed as the remains of a jellyfish "with a hole in the middle".

Only about 100 years after its first remains were discovered, the skeleton of Anomalucaris was assembled for the first time by Harry Whittington and Dark Bridges of the University of Cambridge, England. They recognized for the first time, together, the connection between the round jaws, the protrusions that bring the food to the mouth and the whole body, which is made up of eleven parts.

From the work of Whitington and Bridges, a creature 60 centimeters long was depicted, which moved through the water using horizontal wing-like fins. The frontal appendages, which appeared to Waitives like parts of a shrimp, were in fact organs exquisitely adapted for capturing prey, cracking shells and bringing the prey to the jaws. According to this description, Anomlocaris was able to easily crack the rigid shell of the trilobites that inhabited the world's water bodies at that time. The predator's eyes were carried on short stalks and gave him good spatial vision. In its strange round mouth, the like of which was not known in the animal kingdom, there was a round ring containing 32 teeth. This ring was unable to close, but it could crush the prey and pass it inside, to another ring of teeth, and it is possible that after the second ring, deep in the creature's mouth, a third ring of teeth was waiting to complete the job.

The skeleton assembled by Whitington and Briggs looked "correct" and "logical", but it did not fit into any known group of animals. Parts of him corresponded to one group, while other parts indicate, so to speak, his belonging to another group. Because of this, it was difficult to find the evolutionary position of Anomlocaris, which raised doubts or at least discomfort as to the correctness of Whittington and Bridges' conception.

Fossils found in western China, by paleontologist Chun Yan Shen from the Institute of Geology and Paleontology in Nanjing, China, helped here. Shen found that Anomlocaris, after all, was not lonely. He was a member of a small group of animals similar to him, which Shen called "Anomlucaridids". The group was assembled on the basis of fossil finds found in western China. Since then, the findings have been studied by Shen and his colleague, Lars Ramskold, from Uppsala University, Sweden.

In their research report, Shen and Ramskold describe three different species of anomalucaridids. At first they added to Whitington and Briggs' Anomlucaris, a sort of broad tail from which two stingers extend. The second species is characterized by a wider body than the original Anomlocaris, and by shorter and thicker front extensions, which are equipped with a kind of pincers like a pair of daggers. The third species was diagnosed only based on its fossilized jaws 25 centimeters in diameter. According to the diameter of the jaws, Shen and his colleagues claim that this third species from the Anomlucaridid ​​group reached a length of two meters. Shen and his colleagues also believe that anomlucaridids moved through the water using body movements and vertical fins, similar to fish, rather than using horizontal wing-like fins, as suggested by Whitington and Bridges.

Shen and his colleagues even suggest associating other animals from the Cambrian period, to a broader group of association, together with the Anomlucaridids. The first of these distant relatives, according to Shen, is the animal from Greenland called Krigmachela, which also has two flexible front appendages, an 11-part body structure, similar limbs and two tail spines. Shen believes that another distant relative of the anomalucariids is the animal called Opbinia. This animal feeds with tube-like frontal appendages, which it uses to suck up food. It has eyes borne on short stalks and organs of movement similar to those of the anomalucariids.

Shen and his colleagues believe that the group of animals that includes the Anomlucaridids, along with the Crigamchela and the Opbinia, is a relatively close group to the group of arthropods that includes the insects and crustaceans. If this theory is correct, this means that at least a small part of the "genetic heritage" of these ancient sea monsters survived many ages and reached the animals that exist today. In fact, if this theory is correct, because then the original name given to Anomalucaris by mistake - "Strange Hasilon", is not so wrong as it might have been thought until now.