washed off to make the parchment reusable again—a practice which was common in ancient times due to the scarcity of writing material. However, the faint washed-off underlying text () is still barely visible and believed to be "pre-Uthmanic" Quranic content, while the text written on top () is believed to belong to Uthmanic times. Studies using radiocarbon dating indicate that the parchments are dated to the period before 671 CE with a 99 percent probability. The German scholar Gerd R. Puin has been investigating these Quran fragments for years. His research team made 35,000 microfilm photographs of the manuscripts, which he dated to the early part of the 8th century. Puin has not published the entirety of his work, but noted unconventional verse orderings, minor textual variations, and rare styles of orthography. He also suggested that some of the parchments were palimpsests which had been reused. Puin believed that this implied an evolving text as opposed to a fixed one. In 2015, fragments of a very early Quran, dating back to 1370 years earlier, were discovered in the library of the University of Birmingham, England. According to the tests carried out by the Oxford University Radiocarbon Accelerator Unit, "with a probability of more than 95%, the parchment was from between 568 and 645". The manuscript is written in Hijazi script, an early form of written Arabic. This is possibly the earliest extant exemplar of the Quran, but as the tests allow a range of possible dates, it cannot be said with certainty which of the existing versions is the oldest. Saudi scholar Saud al-Sarhan has expressed doubt over the age of the fragments as they contain dots and chapter separators that are believed to have originated later. However Joseph E. B. Lumbard of Brandeis University has written in the Huffington Post in support of the dates proposed by the Birmingham scholars. Lumbard notes that the discovery of a Quranic text that may be confirmed by radiocarbon dating as having been written in the first decades of the Islamic era, while presenting a text substantially in conformity with that traditionally accepted, reinforces a growing academic consensus that many Western skeptical and 'revisionist' theories of Quranic origins are now untenable in the light of empirical findings—whereas, on the other hand, counterpart accounts of Quranic origins within classical Islamic traditions stand up well in the light of ongoing scientific discoveries. Significance in Islam