One of the perplexing realities for archaeologists is a lack of residual wood from the massive record of Roman crucifixion. Despite the fact the Romans killed tens of thousands of people through crucifixion — and as many as 500 a day during the siege of Jerusalem from 66-70 CE — the only piece of evidence connected to this terrible punishment was discovered in 1968, when archaeologists found the heel bone of a crucified man with the nail still intact.From the CNN wire (via Fox News) article "What’s ‘true’ about Jesus’ cross? Duke professor weighs in." The Duke professor is Mark Goodacre, who makes a brief appearance at the end with commentary on the "True Cross" phenomenon.
In the Israel Museum in Jerusalem, Israel Hershkovitz, who teaches anatomy and archaeology at Tel Aviv University, said that the heel bone of the crucified man was found in a Jewish burial tomb in a northern suburb of Jerusalem, near Golgotha — the hill where the Romans crucified people.
The man, whose ossuary, or burial box, identified him as Yehohanan, was in his mid 20s when he died on the cross. His good teeth and lack of heavy musculature meant that he most likely came from a wealthy family, for most crucifixion victims were far too humble to wind up in tombs –save for Jesus, who was put in one by the wealthy Joseph of Arimathea. Others buried in the same tomb as Yehohanan had connections to the Temple, so it’s possible that he was killed by the Romans for some political transgression.
Yehohanan was cut down from the cross with a 4.5-inch nail still in his right heel bone, and with part of a board still attached to the head of the nail. Hershkovitz believes that the relative shortness of the length of the nail reveals much about Roman crucifixion methods. “The nail was too short (to go through) two heel bones, so sure enough each foot was hammered separately to the cross.”
Hershkovitz is convinced that crosses were not made from olive trees because the people depended on the olive tree for food and wouldn’t be slashing them down to make crosses.
More importantly, for the purpose at hand, they wouldn’t be suitable because of the structure of the tree itself.
Regarding the quoted passage, it seems the ancient remains of two crucified men have been found in Jerusalem, not just one. See here and links for posts on both, as well as related matters regarding ancient crucifixion.