Where did the Gospel of Mark originally end?

The King James version has Mark ending at chapter 16 verse 20. Detractors to the traditional King James version point to the work done by Brooke Foss Wescott and Fenton John Anthony Hort's work that began in 1853 and argue that the disputed passages were added later as scribal errors or amendments . Both men were strongly influenced by Origen and others who denied the deity of Jesus and embraced the prevalent Gnostic heresies of the period. There are over 3,000 contradictions in their four gospels compared to earlier Greek (Alexandrian) manuscripts. They deviated from the original Greek text in 8,413 places.

Defenders of the Textus Receptus (used heavily by the King James version translators) say Wescott and Hort expurgated these passages, noting that these disputed passages underscore the deity of Christ, His atonement, and His resurrection. These disputed passages would have been an embarrassment to the Gnostics, and why Wescott and Hort would advocate their exclusion and insist that they were "added later." However, it seems that Irenaeus In 150 A.D., and also Hypolytus in the 2nd century, each quote from these disputed verses, so the documentary evidence is that they were deleted later in the Alexandrian texts, not added subsequently.