Harry Groener, who plays Dr. Henry Atlas, also played the evil mayor, Richard Wilkins, in season 3 of Buffy, la cazavampiros (1997). The show also featured David Boreanaz , who plays agent Booth, as the vampire Angel.
The gang is examining remains from the "Iron Age" in Southern Britain dated about 1500 years old. However the real Iron Age in Britain dates from about 800 BCE - early 1st century AD, about 400 years before the specimen in the show.
Dr. Goodman asks how long ago the Cretaceous Era was and Zack replies 65 million years. The Cretaceous period spanned 79 million years; it began 145.5 million years ago and ended 65.5 million years ago.
While looking at the victim's remains, Zack says that a normal person would say "Oh my God", but just a few episodes previously, in A Boy in a Bush (2005) Zack utters this exact phrase himself.