Not the oldest, because beginning was in paleolithic, as tally marks. But some attested ones were:
From Early Numeration – Tally Sticks, Counting Boards, and Sumerian Proto-Writing John Alan Halloran
http://www.sumerian.org/
<<Proto-Writing and Tally Marks
2.1. The tally stick conventions described by Menninger appear also to have inspired the
early script of Old Europe, which developed in the middle and lower Danube basin
starting around 5.300 BCE, calibrated. Although different theories have been proposed
about the signs found on 940 inscribed objects excavated from the Vinča-Tordos region
of Transylvania, Eric Lewin Altschuler and Nicholas Christenfeld have shown that nearly
one-third of the inscribed pottery objects bear numerical inscriptions. They suggest that
the script of Old Europe may have been used for economic purposes, The Number
System of the Old European Script, 9 Sep 2003, [math.HO] at
http://arxiv.org/html/math/0309157v1. A literature search fails to find any student of this
ancient script who references the tally marks chapter of Menninger’s book, probably
because nothing about the title, Number Words and Number Symbols, indicates that it is
about the history of writing, However, if one goes back far enough, economic tally
marks are very relevant to the origins of writing. Altschuler and Christenfeld describe
how to read the number signs on the Old European Script (‘OES’) inscriptions – the score
marks, the ‘comb’ motif, and the ‘telephone pole’ motif. They suggest that the common
OES signs V and X or + should be read as 10 and 20. …………………………………….
2.3. Nissen, Damerow, and Englund describe and illustrate on page 20 of Archaic
Bookkeeping, Uruk IV-period “tags consisting of small, transversely perforated tablets,
usually containing but few ideographic signs and no numerical notations. These signs do
not belong to the well-known repertoire of symbols representing goods such as plants,
animals, textiles, and metals. The tags therefore may carry personal names and were
probably attached with a string to containers or other items, stating the proprietor or
receiver of such goods.” The idiosyncratic identifying signs on these Mesoptamian clay
tags may be compared to other undeciphered short sequences of signs, such as the ‘Vinca
script’ found in Old Europe or the ‘Jiahu script’ found on tortoise shells in China, both
dated to about 6,000 BCE. ………….
- Sumerian Goat and Sheep Pictograms from Tally Stick Conventions
3.1. The Sumerian MAŠ sign with the word-meaning of ‘(male) goat’ was a simple cross.
The Sumerian LU or UDU sign with the word-meanings of ‘many’ and ‘(male) sheep’ was
a cross inside a circle. The symbol of a cross inside a circle having the abstract meaning
‘sheep’ may already be present among the complex tokens found at Uruk in the fourth
millenium, according to their primary investigator, Denise Schmandt-Besserat (Beyond
Writing, vol. 1, 1992, p. 152). Following Jöran Friberg, she says that, at least in Elam
and Uruk, a cylinder token represented one herd animal and a lenticular disk represented
10 herd animals. But, during the fourth millenium Uruk period, tokens with complex
markings replaced the plain tokens that had functioned for millenia, driven by the need
for greater precision and accuracy in large production centers. Disks were marked
differently to count lambs, ewes, and sheep. The mystery why such an abstract symbol as
a cross came to represent goats and sheep in the Near Eastern clay token system and
Sumerian pictograms is solved when one realizes that, outside the urban centers where
complex tokens and writing arose, shepherds traditionally counted goats and sheep by
making notches on tally sticks – and shepherds used the cross convention to record groups
of goats and sheep. ……….
3.2. The simple cross does not have a numerical meaning in written Sumerian, but the
tally mark symbolism of the cross in a circle meaning ‘many’ is preserved in an alternate
reading for the Sumerian sign of the circled cross. When the sign is read udu, it means
‘sheep’, but sometimes it must be read lu, meaning ‘many, much; to be/make numerous,
abundant’.>>
Later, the meaning of cross diverged, from UDU:”sheep,many” to UTU:”Sun”, cause of close phonetics: udu-utu.
https://cdli.ucla.edu/tools/SignLists/protocuneiform/archsigns.html “UDU”
Very interesting, another cross-sign was used, for “MASZ/MAS” :”twin”
Sumerian Lexicon – Sumerian Language Pagewww.sumerian.org › sumerianPDFAug 11, 1999 — M. Civil, unpublished Sumerian glossary for students. … maš: one-half; twin
This one was also used for sun, because sun was aprehended as “twin”, day-sun and night-sun wich travel under earth.
https://en.wikipedia.org/wiki/Nergal << Nergal seems to be, in part, a solar deity, sometimes identified with Shamash, but only representative of a certain phase of the sun. Portrayed in hymns and myths as a god of war and pestilence, Nergal seems to represent the sun of noontime and of the summer solstice that brings destruction, high summer being the dead season in the Mesopotamian annual cycle. He has also been called “the king of sunset”.[7] Over time Nergal developed from a war god to a god of the underworld.[8] In the mythology, this occurred when Enlil and Ninlil gave him the underworld.>>
Nergal was also the deity who presides over the netherworld, and who stands at the head of the special pantheon assigned to the government of the dead (supposed to be gathered in a large cave known as Aralu or Irkalla).
https://medium.com/@modernplatonist/divine-twins-indo-european-religion-myth-dioscuri-ashvins-greek-roman-vedic-f7567a922a2f << One of the central figures in the Indo-European pantheon is the Sky Father. He is also known by his reconstructed Proto-Indo-European term, *Dyeus. The patriarch of the gods has an intricate web of family relatives — as it is well evinced, for example, through both Vedic and Greek mythologies. Among these relatives, the sons of *Dyeus are probably the most relevant ones. They are the divine Twins. ….. Moving on to the Baltic myth, we find the Lithuanian Diẽvo sunẽliai and the Latvian Dieva dēli. Also called the Ašvieniai in Lithuanian, they are the Sons of God. Like their other Indo-European cognates, the Ašvieniai also appear with horses and a chariot, which they use every morning to go to see the Sun. This is a clear reference to the Dawn, also known as the Daughter of the Sun. In the Baltic folklore, the Ašvieniai rescue the Dawn from sinking into the sea. The Vedic Ashvins are associated with the Dawn as well, and she appears as their sister.>>
So, cross become the sign of twin-suns, sun: https://en.wikipedia.org/wiki/Utu
Tartaria tablets 
Leave a Reply