the back vowel axis short ŭ [ʊ] merged with long ū [u(ː)], while short ŏ [ɔ] merged with long ō [o(ː)] as /o/ (similar to in Sardinian.) Due to the vast size of Roman territory in Africa, it is indeed plausible (if not likely) based on the analysis above that multiple distinct Romance languages had evolved there from Latin, perhaps separating along provincial lines between a Mauretanian Romance variety spoken in the western regions and an "Afro-Sardinian" or "Afro-Insular" Romance group spoken in central North Africa and the Mediterranean islands. Some scholars also theorise that many of the North African invaders of Hispania in the Early Middle Ages spoke some form of African Romance, with "phonetic, morphosyntactic, lexical and semantic data" from African Romance appearing to have contributed in the development of Ibero-Romance." It is suggested that African Latin betacism may have pushed the phonological development of Ibero-Romance varieties in favor of the now characteristic Spanish b/v merger as well as influencing the lengthening of stressed short vowels (after the loss of vowel length distinction) evidenced in lack of diphthongization of short e/o in certain words (such as teneo > tengo ("I have"), pectus > pecho ("chest"), mons > monte ("mountain".) In the area of vocabulary, it is possible that the meaning of rostrum (originally "bird beak") may have changed to mean "face" (of humans or animals), as in Spanish rostro, under the influence of African usage, and the African Latin-exclusive word centenarium ("granary") may have yielded the names of two towns in Huesca called Centenero. Adamik also finds evidence for dialectological similarity between Hispania and Africa based on rates of errors in the case system, a relation which could have increased from the 4th-6th centuries AD but was disrupted by the Islamic invasion. Berber and Maghrebi Arabic Scholars including Brugnatelli and Kossmann have identified at least 40 words in various Berber dialects which are certain to have been loans from Latin or African Romance. For example, in Ghadames the word "äng'alus" (, ) refers to a spiritual entity, clearly using a word from the Latin "angel". A complete list of Latin/Romance loanwords is provided below under the section on Berber vocabulary. Some impacts of African Romance on Maghrebi Arabic are also theorised. For example, in calendar month names, the word furar "February" is only found in the Maghreb and in the Maltese language – proving the word's ancient origins.