Religious restrictions on the consumption of pork Torah (Pentateuch) contains passages in Leviticus that lists the animals people are permitted to consume. It first notes what qualifies an animal that is absolutely permitted: Animals that have cloven hooves and chew their cud are ruminants such as cows, sheep, and deer. This text does not specify every possible animal by name, only their behaviors. The text goes on to describe specific animals that are known and meet one, but not both, of those qualifications, thereby prohibiting their consumption. It does not elaborate on the exact reason for prohibition other than physical characteristics. Pigs are described in this section
Chewing Ornithopods, a group of dinosaurs including the Hadrosaurids ("duck-bills"), developed teeth analogous to mammalian molars and incisors during the Cretaceous period; this advanced, cow-like dentition allowed the creatures to obtain more nutrients from the tough plant life. This may have given them the advantage needed to usurp the formidable sauropods, who depended on gastroliths for grinding food, from their ecological niches. They eventually became some of the most successful animals on the planet until the Cretaceous–Paleogene extinction event wiped them out. The process of chewing has, by analogy, been applied to machinery. The U.S. Forest Service uses a machine called