Crux simplex in the context of "Instrument of Jesus' crucifixion"

The instrument of Jesus's crucifixion (known in Latin as crux, in Greek as stauros) is generally taken to have been composed of an upright wooden beam to which was added a transom, thus forming a "cruciform" or T-shaped structure.

Most Christian denominations present the Christian cross in this form, and the tradition of the T-shape can be traced to early Christianity and the Church Fathers. Nonetheless, some late-19th century scholars maintained that it was a simple stake (crux simplex). In 2011 Gunnar Samuelsson concluded that there is not enough evidence in pre-Christian ancient texts or in the New Testament writings themselves to resolve the ambiguity of the terms referring to the instrument on which Jesus was executed. On the other hand, David W. Chapman argues that to take one single Greek word and conclude that it has one universal and unchanging meaning like the word stauros "is a common word study fallacy in some populist literature. In fact, such terminology often referred in antiquity to cross-shaped crucifixion devices. For example, Lucian, in a brief dialogue that employs most Greek crucifixion vocabulary, refers to the "crucifixion" of Prometheus, whose arms are pinned while stretched from one rock to another. Such a cross-shaped crucifixion position in the Roman era may actually have been the norm."