Hieroglyphics Maya priests not only excelled in mathematics, they also invented the hemisphere’s most complex writing system. Most of the Maya writing dates from the Classic Period, traditionally defined as the period covering the era of dated stone inscriptions. The Maya had a complete writing system and they wrote on stone, bone, stucco, wood, shell, clay vessels, and paper (though thousands of Classic codices have disappeared). Maya writing consists of block-like hieroglyphs, consisting of individual glyphic elements gathered into compounds that are to be read in double columns, from left to right and top to bottom. Individual glyphs sometimes clearly depict animals, plants, parts of the body, and other objects of the Maya world; others are largely symbolic, and what they were meant to depict is not always known. Most of the Maya inscriptions appear to be events pertaining to the ruler, along with a large amount of astronomical and astrological information considered pertinent to these events by the ancient Maya. Colonial observers noted that there were books at that time that treated of other matters-such as botany, medicine, maps-but we have no such texts now.