There are hundreds of different styles of Chinese martial arts, each with their own sets of techniques and ideas. The concept of martial arts styles appeared from around the Ming dynasty (1368–1644). Before the Ming period, martial skills were commonly differentiated mainly by their lineage. There are common themes among these styles which allow them to be grouped according to generalized "families" (Chinese: 家; pinyin: jiā), "fractions" (Chinese: 派; pinyin: pài), "class" (simplified Chinese: 门; traditional Chinese: 門; pinyin: mén), or "schools" (教; jiào) of martial art styles. There are styles that mimic movements from animals, or otherwise refer or allude to animals or mythical beings such as dragons, and others that gather inspiration from various Chinese philosophies or mythologies. So