He said: “After I found some blackened patches in the ground I decided to trowel back at that level and to my astonishment the ghostly outlines of a skeleton started to appear.
“I was able to identify the spinal column with individual vertebrae, and then moving up the body I uncovered the upper arms and shoulders, all of which were just black stains in the ground.
“Moving carefully higher up, I was able to locate the skull, which is better preserved – although it had partly collapsed in on itself.”
Mr Birch also found legs and feet, which appear to have been bound together before burial, and eventually almost the whole outline of the skeleton could be seen, surrounded by the “faint shadow” of a coffin”.
Prof Gordon Noble, of the University of Aberdeen and an advisor on the excavation, said Tarradale was one of the largest recorded Pictish barrow cemeteries.
He said: “The Tarradale Through Time project has done a fantastic job of revealing and excavating part of the cemetery.
“The discovery of human remains within one of the barrows is a particularly exciting result for it may help date one monument of the cemetery and tell us more about the individual buried within the grave.
“Very few of these cemeteries have been excavated so projects like this have much to tell us about the ways in which the Picts buried their dead.”