As the name indicates, Anomalocaris is undoubtedly an anomaly– its an animale thats not quite like any other. Its name stems from the Greek words for “anomalous” and “shrimp”, due to the fact that although its not technically a shrimp, it bears some resemblances to one.
Regardless of its shrimp-like appearance, Anomalocaris was a fierce predator that preyed on other marine animals using its powerful jaws and sharp spines. At about one meter (3 feet) long and formed like a flat oval, Anomalocaris would have been the king of the seas– couple of animals might complete with it in size.
Maybe its most striking function was its eyes.
Despite its shrimp-like look, Anomalocaris was a strong predator that preyed on other marine animals utilizing its powerful jaws and sharp spines. At about one meter (3 feet) long and formed like a flat oval, Anomalocaris would have been the king of the seas– few animals could contend with it in size. Some research studies suggest that Anomalocaris may have had a dichromatic vision, much like numerous of todays mammals. For hundreds of millions of years, Anomalocaris was likely the animal with the most eyes. You can make an argument that the lenses in compound eyes arent technically eyes, and by that meaning, the animal with the most eyes is most likely the scallop, which has 50-100 true eyes.
For hundreds of millions of years, Anomalocaris was most likely the animal with the most eyes. You can make an argument that the lenses in compound eyes arent technically eyes, and by that definition, the animal with the most eyes is most likely the scallop, which has 50-100 real eyes. The lenses inside compound eyes (technically called ommatidia) function as independent photoreception units with an optical system. If we accept them as eyes, the animal with the most eyes that we understand of is the dragonfly: each eye has around 30,000 telescope-shaped ommatidia.
It had big, bulging eyes, which might have been its most evolved feature. Some incredible, 515 million-year-old fossils from Australia revealed that they were in reality compound eyes formed like little lenses, much in line with what we see in todays arthropods and pests.
The eyes of Anomalocaris featured 16,000 lenses and used a resolution measuring up to the very best we see in todays world in the dragonfly (which has 28,000 lenses), however bear in mind were speaking about an animal half a billion years ago. Some studies suggest that Anomalocaris may have had a dichromatic vision, much like numerous of todays mammals. Its vision should have been an order of magnitude better than that of the trilobites, long believed to have had the very best vision of their age.
Reconstruction of an Anomalocaris types. Image credits: Muse Museum Trento/ Wikipedia.
It was at first misidentified and misclassified for decades, and theres still dispute as to whether some of the fossil parts associated with it in fact belong to it at all. Its understanding arms were very first found in 1892, and believed to be tails of shrimp-like animal; its ring-shaped mouth was believed to belong to a jellyfish; its body was thought to belong to a sponge. It was just in the 1980s that paleontologists convincingly shown that all the body parts belong to the very same animal, and the animal is a stunning one.
Paleontologists have long suggested that Anomalocarids were the peak predators of the Cambrian seas, pushing many smaller animals into their jaws. This claim is supported by the reality that some trilobites appear to bear scratch marks from Anomalocaris, and Anomalocaris coprolites were found to include trilobite parts. This makes a lot of sense: with its very well-developed visual system, it might have easily tracked down victim and then used its appendages to hunt it. This likewise fits in with another popular, but controversial theory about the Cambrian: that life exploded in the Cambrian partly since the very first large predators drove an evolutionary arms race that resulted in new forms of security, fitting in perfectly with the concept of an extremely competitive environment.
The problem with this idea is that its not clear how Anomalocaris could have broken through the trilobites thick protective shell. There are some theories that try to discuss this (like how they would have broken the victims skeleton at the cuticles or simply fed upon trilobites that had just molted), but the evidence in the meantime is not definitive.
Because the fossils are so old (nearly 8 times older than the Tyrannosaurus Rex), theyre often broken down and less clear, that makes interpretation even more hard. This being stated, however, some Anomalocaris fossils are absolutely stunning. Its exceptional to see simply well preserved and incredible the eyes– so well preserved in some fossils that if you look with a microscopic lense, you can even see the eye structure.
A fossil preserves proof of its amazing eyes. Image credits: Nature.
Eventually, were stuck to what appears to be an apex predator that still conceals lots of mysteries– a predator with incredibly developed eyes however otherwise, quite different from modern-day arthropods. It was only after scientists found another ancient arthropod, a “missing link” in arthropod evolutionary history, that researchers began comprehending how Anomalocaris relate to the rest of its evolutionary tree.
Well no, theyre not actually pointed at you, and really, theyre not actually pointed at anybody. This creature called Anomalocaris lived throughout the Cambrian, some 500 million years back. But this amazing fossil can teach us a lot about evolution and what life resembled in those times.
A painting of Anomalocaris. Image credits: Katrina Kenny & & University of Adelaide.