Discovered in 1986, Sacabambaspis was a jawless fish that inhabited coastal areas of a shallow sea that once extended across parts of North America. The fish had a broad head-shield and a body that narrowed to end in a small fin. It was a bottom-feeder, and would suck in scraps of food through its ever-open mouth. Sacabambaspis had sense organs that helped it to feel movement in the water, allowing it to judge the distance to its prey and predators. Scientist believe it was a poor swimmer because it lacked paired fins.