I'm very, very new to Blender, and for an assignment, I've used the Trnio app to create a 3D image of a stuffed animal that I then imported into Blender. This is the result (as you can see, Trnio also scanned in the floor that the animal was sitting on):
The scanned bit of the floor aside, my problem is that the bottom of the animal wasn't scanned, as it was on the floor, and so I get this opening below:
My task is to both close the bottom of my design while also cleaning up a bit of the extra floor. But I can't seem to close my gap. I've tried selecting vertices, but this took a very long time and turned out to be quite a mess. I'm not really sure what the solution is, and would greatly appreciate some help.