If you click on Mass Dials to the left of this page http://www.sundialsoc.org.uk/
and find Figure 2, there's a picture that's worth discussing in the context of Rock Art. Quite simply, could the "tail" on some cup and rings be an event marker – the position of a shadow cast by a wooden gnomon inserted into the central hole at a particular time of day and time of year?
I've never seen any rock art in the flesh so please accept this as a humble suggestion, not the Answer to everything (which is how it ought to be!).
I guess, for this to be a possibility, tails on horizontal panels shouldn't point South and ones on vertical panels shouldn't point upwards, mostly. Do any of you who know about these things know if there's a statistical tendency for the tails to point in a particular way?
Quite separately, here's my further musing about rock art, which I've wondered about for years. Could it be a funerary marker? Since bold claims without back up are irritating, here's my possible circumstantial evidence –
The markings span millennia. For a belief or practice to last so long shouldn't it have something concrete or practical to sustain it? What more enduring and unchanging than the fact that people die?
The earliest markings date from nomadic times AND tend to be on prominent outcrops, with good views and near trackways. If you're on a journey, far from home, and uncle Albert dies… what nicer and more practical than to bury him there and then, and commemorate him at the next rocky necropolis you come to (very few burials are found round rock art panels).
Later panels tend to be down in the valleys – could this be a continuation of the tradition but connected with settled village lifestyles?
From what I've seen, cup and rings of similar age tend to have an etiquette about them, whereby you don't encroach on other marks, whereas there seems no such reticence about encroaching upon marks that are clearly far older. This seems to be much as we act in churchyards, where very old graves are no longer so sacrosanct.
Could the grouped patterns and connecting lines between individual motifs be expressions of family connections? Does such grouping tend to occur in the later, settled period panels, when whole families are more likely to be commemorated, and is it rarer in the nomadic period panels?
Could this analysis of funerary markers explain why panels were used – sometimes in "edited" form and usually facing down, to cover graves? If the tradition was ending, and you'd opted to have a marked grave, might it be appropriate to have your family tree, that was no longer going to be added to, buried with you? What date are the graves that show this feature? Late?
Back to the initial speculation about the tails being gnomon shadows. Could the tails be permanent marks of the day and time when uncle Albert's essence passed into the rock? Some even show ladders…
Well there yer go. Hypothesis and possible evidence, the TMA way.