One of the great recent controversies was how to define the word Shafan in the Torah.
Rabbi Slifkin argues for the Hyrax. Dr. Betech argues for the Rabbit. Rabbi Lubin argues for the Llama.
Much of Rabbi Slifkin's view rides on the fact that there are "no alternative candidates". Well, that theory is not air-tight if in the year 2013 we are still finding new species.