Please answer the following question: Given the following passage "In Latin, papyri from Herculaneum dating before 79 AD (when it was destroyed) have been found that have been written in old Roman cursive, where the early forms of minuscule letters "d", "h" and "r", for example, can already be recognised. According to papyrologist Knut Kleve, "The theory, then, that the lower-case letters have been developed from the fifth century uncials and the ninth century Carolingian minuscules seems to be wrong." Both majuscule and minuscule letters existed, but the difference between the two variants was initially stylistic rather than orthographic and the writing system was still basically unicameral: a given handwritten document could use either one style or the other but these were not mixed. European languages, except for Ancient Greek and Latin, did not make the case distinction before about 1300.[citation needed]", answer the following question. Note that the answer is present within the text. Question: Written in old Roman cursive, early forms of the "r" letter have been found on what?
A:
papyri from Herculaneum