Duccius[?] - inscriptions, notably a tombstone of Lucius Duccius Rufinus at York[2] (http://museums.ncl.ac.uk/archive/arma/contents/iconog/tombston/cent1/uk/york/duccius.htm)
... r + uu, depending on the region
l^i = l + r^i
(Sanskrit recognizes vocalic r (errr) and l (ulll), unlike, say, English)
Diphthongs (Combinations of Simple Vowels) ...