First I want to say that trying to establish a direct relationship between cultural phenomena (archaeology) and ethonlinguistic groups (linguistics) results very simplistic: different groups can participate from the same cultural innovations.
The problem with Urnfield culture in Iberia consists in its influential area: from its arrival to the historical development of the iberian complex there's a cultural continuity. In other words, if we act avoiding my first paragraph this culture should be linked to non IE groups. In adition, I'd like to comment that there's no trace of iberian language outside its influencial area (except SE Spain, but this could be explained as a natural expansion from the Ebro valley towards the whole mediterranean coast).
I see your point. It doesn't change the fact that Celtic languages (specifically Gaulish and Lepontic) emerge out of the former Urnfield area.
Then the historic linguistic picture (I won't put toponymic issues that could make the question more complex or detailed) of Iberia is this:
-Ibero-aquitanian complex in the middle and low Ebro valley, the mediterranean coast and possibly in northern Aragon and Navarre, with penetrations in the basque country.
-Tartessian in SW Iberia.
-IE in the rest of the peninsula.
Well, the last studies on prerroman toponyms (Francisco Villar) mantain that IE names are widespread along the whole peninsula, while iberian and others are more or less circumscribed in their historical zones.
Well, I see your point there. I have a problem however with the Celtic languages spreading from Iberia towards the east, because there is no such pattern visible.
Tartessian isn't iberian for sure and we don't already know exactly what was, but it would fit better in the IE spectrum. We don't have written records in central Europe to solve or give more light to the problem, but we know of nearby non IE groups such as etruscan and rhaetian and others whose linguistic adscription is dubious.
Well, I cannot rule out Tartessian is quite possibly an Indo-European language, but definitely not based on the Koch paper. First off, Koch has the
ad hoc hypothesis that Tartessian is a Celtic language (he doesn't try to prove that it's Indo-Eurpean, but that it's outright
Celtic), and I thoroughly mentioned the bewildering problems in his methodology in my previous posts.
With these data I'd bet for a pre-urnfield kultur indoeuropeanation of the Iberian Peninsula and, therefore, for the rest of western Europe. Bell beakers, perhaps? I don't know.
Well, the idea that the Bell-Beaker culture spoke an Indo-European language (or rather, introduced the Indo-European languages in Western Europe) is a firm possibility, however bears a number of consequences which I will elaborate below:
Many scholars suggest that Celticity developed with Bell Beaker culture. Through carbon dating, the earliest confirmed Bell Beaker sites have been identified as existing in Southern Portugal (Algarve and S. Alentejo).
What do you exactly mean with "Celticity"? It is a quite nebulous term. If you mean self-identification as "Celts", that is a modern fabrication, anyways. I would are talking about the Celtic languages, I must say that I find it quite presumptuous to say that the
Celtic languages started in Southern Portugal in 2900 BC. That's a bit like saying that the
French or
Spanish language started in Rome in the 8th century BC. In my opinion, given the vast scope of the Bell-Beaker culture it is far more plausible to assume that if the Bell-Beaker people already spoke an early Indo-European language, far more than
just the Celtic languages alone are descended from their language. In my opinion, not only the Celtic languages (including "dubiously" Celtic languages such as Lusitanian and Lepontic), as well as the Italic languages, and a number of poorly attested languages such as Ligurian and Venetic. If you consider that Beaker influence extended all the way to
Denmark, it's also conceivable that the Proto-Germanic language was influenced by a hypothetical Beaker language (which would explain some similarities of the Celtic and Germanic languages). Also, I must add though that the site in southern Portugal is
not necessarily the oldest. The Beaker sites in southern France and northern Italy are almost exactly the same age.
Hmm... well and I have also considered the possibility that there never was one common "Proto-Celtic" language to begin with. At least, not
exclusively Proto-Celtic.