Proto-writing consists of visible marks communicating limited information. Such systems emerged from earlier traditions of symbol systems in the early Neolithic, as early as the 7th millennium BC in Eastern Europe and China. They used ideographic or early mnemonic symbols or both to represent a limited number of concepts, in contrast to true writing systems, which record the language of the writer. Paleolithic Analysis in 2022, led by Bennet Bacon, an amateur archaeologist, showed that lines and dots on Upper Palaeolithic cave paintings were used to indicate the mating cycle of animals in a lunar calendar, the markings found in over 400 caves across Europe were compared to the mating cycles of the animals with which they were associated, showing a correlation with the month of the year in which the animals depicted in the cave paintings would typically give birth. Neolithic Neolithic China In 2003, tortoise shells were found in 24 Neolithic graves excavated at Jiahu, Henan province, northern China, with radiocarbon dates from the 7th millennium BC. According to some archaeologists, the symbols carved on the shells had similarities to the late 2nd millennium BC oracle bone script. Others have dismissed this claim as insufficiently substantiated, claiming that simple geometric designs such as those found on the Jiahu shells cannot be linked to early writing. Neolithic Europe The Dispilio tablet is a wooden tablet bearing inscribed markings, unearthed during George Hourmouziadis's excavations of Dispilio in Greece, and carbon 14-dated to 5202 (± 123) BC. It was discovered in 1993 in a Neolithic lakeshore settlement that occupied an artificial island near the modern village of Dispilio on Lake Kastoria in Kastoria, Western Macedonia, Greece. The Vinča symbols (6th to 5th millennia BC, present-day Serbia) are an evolution of simple symbols beginning in the 7th millennium BC, gradually increasing in complexity throughout the 6th millennium and culminating in the Tărtăria tablets of c. 5300 BC. Chalcolithic and Early Bronze Age The transition from proto-writing to the earliest fully developed writing systems took place in the late 4th to early 3rd millennia BC in the Fertile Crescent. Prehistoric Mesopotamia The Kish tablet, dated to 3500 BC, reflects the stage of Proto-Cuneiform, when what would become the cuneiform script of Sumer was still in the proto-writing stage. By the end of the 4th millennium BC, this symbol system had evolved into a method of keeping accounts, using a round-shaped stylus impressed into