Based on a study of stable isotope signatures found in its teeth and bones, which can help tell us what an animal ate, it looks like Castoroides mostly ate freshwater plants, like water lilies, pondweeds, and sedges.

根据对其牙齿和骨骼中发现的稳定同位素特征的研究，这可以帮助我们了解动物吃什么，Castoroides 看起来主要吃淡水植物，如睡莲、池塘草和莎草。