Giant Cambrian Predator Had Excellent Vision

Recent analysis of fossils of an ancient predator reveal that the creature had excellent vision. The predator, Anomalocaris, had a worldwide distribution and is though to have been the top predator in the Cambrian seas. The existence of the predator was postulated before the creature was known. In 1979, a paleontologist studying trilobites explained that wounds on the bodies of certain trilobites might be caused by a large predator. At the same time, another paleontologist realized that what had previously been identified as a shrimp body was actually an appendage on a larger creature, which might be responsible for trilobite injuries. When the full body of the creature was described in 1985, it was characterized as “a formidable predator.”

Now we know that vision was an essential tool for this predator. 515 million year old fossils attributed to the creature show extremely complicated compound eyes. The eyes are speculated to have had as many as 16,0000 individual lenses, which is comparable to modern dragonflies, which may have as many as 30,000 lenses per eye. By contrast, triDragonflies use their excellent vision for hunting prey in a three-dimensional space, much like the Anomalocaris, which, with its newly-discovered vision could locate prey more effectively than competitors. In response, it is likely that prey developed anti-vision defenses, such as camouflage.

But what did Anomalocaris eat? Some researcher claim its teeth were too soft to eat trilobites, but fossil feces too large to be from any other known animal contain trilobite pieces. So, until another candidate is discovered, Anomalocaris is the prime culprit.

Because the fossils in question are not directly attached to Anomalocaris, some dispute that the eyes actually belonged to the predator. However, it is unknown what other creature they might belong to. Again, Anomalocaris is the only creature large enough to have owned them. However, because preservation of lenses is rare in fossils of this age, there may be many creatures with similarly sharp eyesight, which had been unknown before this discovery. It also likely means that arthropods likely developed eyes before they developed their characteristic jointed skeletons. For more information on this predator and its vision, see the Discover blog Not Exactly Rocket Science.

This type of eye is very different from human eyes. Instead of having a pair of lenses (the cornea and the crystalline lens) that focuses light onto a bank of nerve endings (the retina), compound eyes have many separate lenses that each focus light onto a separate photoreceptor. Thus, each separate lens represents a pixel in the creature’s vision, creating an arrangement that is ideally suited for capturing movement, but less well suited to capturing detail. An evolutionary arms race between camouflage and vision would drive increasing numbers of pixels that could resolve detail to allow predators to spot hiding prey, even when static.

As with these early predators, your vision is a great tool, and visual acuity can make the difference in facing your competition. To make sure your vision is at its peak, please contact a local ophthalmologist today.