We have long known about many of the ancient monsters that used to inhabit our lovely world so far in the past. Some of the better known are the visually disturbing “many-limbed worms” and the ancestors of today’s crabs, but were six feet long. But just recently we were introduced to an anus-eye creature that used to haunt our ancient oceans.
BEND OVER AND KISS YOUR- OH, HELLO ANUS-EYE!
Scientists have published a paper giving us the “nod” and “wink” to one Capinatator praetermissus, ae 500-million year old bristled-jawed worm. But there’s no “way around it,” it looks like an anus-eye. While both our increasing understanding and knowledge of the ancient world still seems to be coupled with unceasing modern oceanic discoveries, with all the phallic designs evolution has provided us in the myriad, we’ve never known anything like the anus-eye.
ANUS-EYES FOSSILS HARD TO FIND, FEW SAMPLES EXISTED TILL NOW
Chaetognaths, also known as arrow worms, are a diverse phyla of tiny predators that swim about eating smaller zooplankton in the open ocean. They evolved hundreds of millions of years ago, possibly during the early Cambrian, but where exactly they fit among other animals on the evolutionary tree isn’t totally clear. As one of the most striking chaetognaths ever discovered, Capinatator praetermissus could shed light on how these critters, their lifestyle, and their ecological roles have evolved over time.
Also, as a reminder, this one looks like an anus-eye.
DESIGN IS AKIN TO LITTLE SHOP OF HORRORS, BUT AN ANUS-EYE WORM THAT SHOVES PREY INTO ITS ANUS-EYE MOUTH
As detailed in this week’s Current Biology, researchers at the Yale Peabody Museum of Natural History and the Royal Ontario Museum drew on roughly 50 fossils specimens, collected from the Burgess Shale fossil bed in British Columbia, in order to identify Capinatator praetermissus as a new genus and species of arrow worm. Fossilized chaetognaths that include evidence of soft tissue are incredibly rare—the researchers say only two other unequivocal specimens have been reported, and both from fossil beds in China. Many of the specimens in the new paper feature evidence of soft tissue, which allowed scientists to piece together the anatomy of the animal’s gut and musculature.
According to the researchers, the animal’s head configuration is “unique,” with roughly 25 grasping spines per side. It probably captured its prey by flapping its graspy bits toward one another, forcing its helpless victims into its anus-shaped mouth. Capinatator may have only been four inches long, but it still would have been a “terrifying sight” to small marine critters alive at the time, according to study co-author Jean-Bernard Caron.
“The large body size and high number of grasping spines in C. praetermissus may indicate that miniaturization and migration to a planktonic lifestyle,” the lifestyle most chaetognaths enjoy today, “were secondary,” the researchers write. Earlier forms like this one might have prowled closer to the seafloor, and been larger than their contemporaries. Obviously, more fossil specimens from the same time period could help confirm or refute that idea.
But more importantly—dang, look at that anus-eye.