The authors of Mediaeval bestiaries were not merely concerned with providing a description of creatures. No, for them, everything in Creation had a purpose - nothing had been made without an ulterior aim: the edification and instruction of sinful man. So, each creature described is not merely an animal but a living parable, imbued with moral or religious symbolism.
When the great ice-sheets covered the north, life retreated before them, but some species stayed and endured. Whilst man huddled around fires in his caves, mighty beasts roamed the tundra: the Woolly Mammoth, the Woolly Rhinoceros…and the Woolly Wyvern.
Small red flower, originally sprouted from the blood where St. Senren fell but now found widely over all Laurentia. Occasionally, a rare white flower will be found, with powerful magic properties. It is particularly prized by the religious order, the Senrenites.
In some regions, various occupations might be exclusively staffed by members of a particular race or ethnic group. As examples, a city's butchers might tradtionally have orcish blood, or all the dwarves in an area could be expected to join the miners' guild (even if they personally have nothing to do with mining). Those who violate these stereotypes may find themselves in conflict with local customs or idiosyncratic laws.