Talmud Yerushalmi, Kilayim Reader

Mishnah: The wild mules are forbidden, but the ramakh is permitted. And the adnei ha-sadeh (lords of the field) are a wild beast. Rabbi Yose says: they convey impurity by overshadowing, like a human. The hedgehog and the wildcat of the briars are a wild beast. The wild ox is a category of domesticated animal; Rabbi Yose says: it is a category of wild beast. The dog is a category of wild beast; Rabbi Meir says: it is a category of domesticated animal. The pig is a category of domesticated animal. The wild ass is a category of wild beast. The elephant and the monkey are a category of wild beast. And a human may work together with all of them, to plow and to draw a load. The adnei ha-sadeh (lords of the field) are a wild beast. They flee. It is a man of the mountain, and it lives by means of its navel. If its navel is severed, it cannot live. Rabbi Hama bar Ukba said in the name of Rabbi Yose ben Hanina: the reason of Rabbi Yose is the verse, "and whatever shall touch them when they are dead shall be unclean" (Leviticus 11:31), since it grows upon the surface of the field.