The problem was that while they were well documented at some sites, usually the ones with the very nice animals, there was also a large number of them where it was very vague -- there wasn't a lot of description or detail.
Problemet var att vissa fyndplatser var väldokumenterade, typiskt de som bestod av fina djur, medan väldigt många andra var ytligt dokumenterade - knappt några beskrivningar eller detaljer alls.