A linguist at Indiana University has tied such farflung languages as Sumerian, Sa'ami, a written Chinese language, and a spoken American Indian language ~ to the group that first developed writing.
These hieroglyphic/pictographic techniques are not to be confused with alphabets or syllabries invented thousands of years later.
Sioux or Plains Indian sign language is essentially the same as these earliest hieroglyphic/pictographic languages ~ with my little sign language guidebook I was able to read a display of Shang Dynasty written materials at the Smithsonian several years back.
Some believe that the Sumerians were not native to that area and were from places in the east. Refugees from Sundaland?