Curiously, one of the beliefs associated with Griffins is that they hoarded gold, and Mayor has a map on page 28 showing the juxtapositions of gold digs and protoceratops\dinosaur bones found lying on the ground, along ancient trade routes, so "purest rubbish" seems to be supported by some actual evidence. The area in question covers from the hindu kush into kazakhstan, mongolia and china.
I'm curious... what does the author mean by "gold digs?"
Does he/she mention the type of rocks?
And what is the connection between these digs/bone deposits and the trade routes? I'd actually like to see the dataset, that would be really interesting. But I'm always skeptical of these sorts of associations until I can see the raw dataset and make my own maps.
Dinosaur fossils are often found in sedimentary rocks and gold can occur as placer deposits, typically as a result of fluvial processes. That's the sort of connection that could make sense, particularly if these protoceratops were excavated from fluvial deposits. The same sorts of processes that concentrate gold, could possibly localize dino bodies during a rainy/wet season.
Okay, I'm heading to the bookstore NOW!