Kylinxia zhangi is a newly described euarthropod with five-eyes. It is was discovered in a Cambrian aged deposit in Chengjiang, China, and was recently described in the journal Nature.
Kylinxia looks remarkably like a cross between two Burgess Shale animals, Opabinia regalis and Anomalocaris canadensis. The Burgess Shale is currently dated to 506 million years ago, while the Chengjiang biota is dated to 518 million years ago. The two sites are separated by 12 million years but have animals that look remarkably similar. During the Cambrian, the sites were also separated geographically, but are both interpreted to have been at low latitudes, most likely in the tropics.
Kylinxia, has five eyes like Opabinia, and they are arranged in a similar pattern with two on the bottom row and three on the top row. While having more than two eyes is not unusual in the animal kingdom, having specifically five-eyes, and in this arrangement is. To the best of the author’s knowledge, Kylinxia and Opabinia are the only two animals in the fossil record that currently share this anatomy. As an aside, box jellyfish, have 24 eyes, and perhaps more interestingly, no brain to process the information that those eyes are collecting.
Kylinxia, also looks a lot like Anomalocaris, with two large grasping appendages at the front of its head and a circular mouth with teeth in it. This mouth looks similar, in shape and design, to a pineapple ring. Click here for an image of Anomalocaris canadensis‘ mouth
It may come as a surprise to some readers that pineapple ring mouths and frontal grasping appendages are quite common to many different species in the Cambrian. These traits have also shown up in the fossil record in the two proceeding geological time periods, the Ordivician and the Silurian. Animals possessing this anatomy are assigned to the Class Radiodonta (Greek for pineapple-mouth… just joking. It’s Latin radius for ‘spoke of a wheel’ and Greek odous for ‘tooth’). To make the naming convention a little more confusing radiodonta used to be known as anomalocaridids. The radiodonts were significantly bigger than most of the other animals of the Cambrian.
For more information please read the academic paper published in Nature.
H. Zeng et al. An early Cambrian euarthropod with radiodont-like raptorial appendages. Nature, published online November 4, 2020; doi: 10.1038/s41586-020-2883-7.