|1st Species||Opabinia regalis|
|Time Range||508-505 mya|
|Name Meaning||Animal from Opabin Pass|
|Physical Dimensions||7 centimeters long|
Opabinia is an opabiniid radiodont dinocaridid arthropod from the Cambrian Stage 3 of Canada. It was named in 1912 by Charles D. Walcott. Like most animals from Cambrian Canada, it was a unique arthopod, and it had held middle ground in the food chain.
Opabinia looked similar to another fellow dinocaridid, Anomalocaris, as it also had a long body, long, fin-like lobes running down the sides of its body, and a rounded head with big eyes and a disk-like mouth. However, it also had some physical traits very different from those of Anomalocaris, as it had 5 eyes instead of just 2, and it had a long proboscis ending in a claw. Its body would have been covered in a semi-hard, chitinous exoskeleton.
Opabinia was a predator, feeding on small invertebrates by picking them up with its claw and passing them down to its mouth. However, it would also sometimes settle for detritus suspended on the seafloor.
It is unknown if Opabinia's 5 eyes were complex eyes or not; however, all 5 eyes used together would achieve the effect of a single complex eye. As well as this, it had a swimming style similar to Anomalocaris, undulating its fin-like lobes on its body to propel itself through the water. Instead of directly facing down, Opabinia's mouth slightly slanted backwards, so its long, flexible proboscis would be used to pass food into it without any problems. Another interesting thing to note is that Opabinia's proboscis made up 1/3 of its body length.