The oldest Hebrew Cairo Geniza fragment in Cambridge?

GENIZA FRAGMENT OF THE MONTH (NOVEMBER 2010): The oldest Hebrew fragment in the Collection? T-S NS 3.21.

... The scroll, of which two parts have been found in the T-S Collection, T-S NS 3.21 and a small piece T-S NS 4.3, contains only the book of Genesis, so it may have been a Genesis scroll rather than the whole Torah. Colette Sirat estimated that if it had contained the whole Torah, then it would have measured 40m long. The script is highly distinctive, when compared with that of most Bible fragments in the Collection, with an acutely-angled serif and what Ada Yardeni believes are some of the earliest regular examples of tagin, the ornamental 'crowns' that appear only in Torah scrolls (with a few exceptions). The hand is similar to that of the (very few) Hebrew and Aramaic papyri of the Byzantine period (300–700 CE).

Sirat also detects differences from the Masoretic Text (MT) in the division of paragraphs (paraša petuḥa and paraša setuma), though these are minor, and one consonantal difference from the MT at Genesis 17:1, where the scroll has שנה for the MT's plural שנים.
Genesis 17:1, showing the singular where MT has the plural

According to Sirat, the scroll is early, pre-Islamic, and dates from the fifth or sixth century. Although this is centuries earlier than the great majority of Genizah fragments, it would make it contemporaneous with some of the underscripts of the palimpsests in the Collection and its survival in the Genizah is therefore not at all impossible. Nothing is straightforward in dealing with undated manuscripts, however, and Ada Yardeni prefers to date it later, to the eighth or ninth century, still early, but not as spectacularly so. There appear to be sufficient grounds, however, to believe that an earlier dating is more likely, given the clear differences in hand, in particular, from most other Bible manuscripts found in the Genizah, and it is thrilling to think that this scroll may have been in use in synagogue services hundreds of years before being consigned to the Ben Ezra Genizah.