What’s this fern?

I was rearranging my daughter’s frog vivarium to make it easier to clean the water bowl and unburied a fern. I bought the fern around August, I thought it died off but turns out it was buried under the dirt and the branch she put in her tank. Does anyone know what kind of fern this is? Thank you. I don’t really have any better pictures as it was squished and buried. But its roots are very strong and the plant seems healthy besides not being in light for a couple months.