Regarding Kosher at least, I think it had more to do with health than taxonomy. The birds that were forbidden tended to be scavengers (such as vultures). These

Regarding Kosher at least, I think it had more to do with health than taxonomy. The birds that were forbidden tended to be scavengers (such as vultures). These could carry diseases. Likewise, the main livestock they were forbidden from eating were pigs, which could present a health hazard at that time. They were also forbidden from eating most insects except locusts, probably for similar reasons. I would disagree with the taxonomic interpretation mainly because there are a couple examples where I don't think it makes sense. For instance, pigs were "beasts of the field". They weren't in any way challenging to the Jewish taxonomy. Catfish also weren't challenging. They were fish (that is, basically, they lived in water). But they don't have scales, so they're not kosher (they're also bottom-feeders, so again could carry diseases if prepared incorrectly). The health interpretation also extends to preparation rules. Animals must be slaughtered and bled out. This was likely to reduce risk of blood-borne diseases. Animals found dead also cannot be eaten, reducing risk of eating diseased meat. Of course, these interpretations aren't mutually exclusive. I just don't see much support for the taxonomic interpretation aside from the fact that of course the regulations classify animals as fit to eat based on certain characteristics. I'm also only familiar with Kosher rules, so can't comment about how the taxonomic interpretation might apply to other dietary rules.