An Exact Match
Anticipation grew as I hurried through the winding hallway towards the front desk. It was another identification request from a visitor, and I never know what sort of natural object to expect. Is it a poor songbird who had hit a window? A photo of a plant off someone's phone? A mushroom? Something for which I'll provide a totally useless diagnosis?
The talkative young blond wanted it to be a bird, which I quickly learned while her mom was setting down the worn skull and explaining that the kids loved birds. The investigation started from that point. I was quick to point out the remaining teeth in the skull and redirect the insistent child to a mammalian source. But from there I wasn't exactly sure how I would narrow the identity down further.
So I kept on working with the basics. Size. The skull was certainly small enough, but prior experience extracting and cleaning off flying squirrel skulls told me that the animal was probably a bit larger than our local squirrel species.
And from there, what I lacked in expertise I made up for with resources. I pulled out a thick book titled "Animal Skulls: A Guide to North American Species," and soon had an answer. I placed the skull right over a life-size illustration of a common muskrat, and what remained of its structure fit perfectly with the image below. An exact match!