Most illuminated manuscripts were created as codices, which had superseded scrolls. The Madrid Codex is the longest of the surviving Maya codices. The other two Greek codices written in that way are Uncial 048 and Uncial 053. All the Gnostic codices found in Nag Hammadi used the Coptic alphabet. Then hand-bound, expensive, and elaborate manuscripts known as codices appeared. Three of the four extant Maya codices are based on Yucatec. The black vulture appears in a variety of Maya hieroglyphics in Mayan codices. The technical term for this physical arrangement is "codex" (plural, "codices"). It is one of the four Great uncial codices. Early forms are also found in medieval Byzantine codices which preserve ancient horoscopes. Mars is also mentioned in preserved astronomical codices and early mythology. The contents of the codices were written in the Coptic language. Sheets of parchment were folded to form quires from which book-form codices were fashioned. Early intact codices were discovered at Nag Hammadi in Egypt. Such histories were produced as well in pictorial codices.