147 © Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 2022 DOI 10.7546/PhB.28.2.2022.1 PHYTOLOGIA BALCANICA, 28(2): 147-156, Sofa, 2022 Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, Acad. G. Bonchev Str, bl. 23, 1113 Sofa, Bulgaria, e-mail: vladimir_bozukov@yahoo.com (corresponding author); dimiter@gbg.bg Received: May 10, 2022 ▷ Accepted: June 10, 2022 New data on the Middle Miocene fora of Northwest Bulgaria Vladimir S. Bozukov & Dimiter A. Ivanov Key words: Bulgaria, Macclintockia basinervis, Melaleuca, Middle Miocene, Myrtaceae, paleofora, Tristaniopsis Abstract. Two leaf imprints have been studied of the Middle Miocene fora from Ruzhintsi village, Northwest Bul- garia. One was determined as Macclintockia basinervis and the second as Tristaniopsis af. laurina. New evidence has been obtained that Macclintockia is afliated to the Myrtaceae family. In that context, the Australian species Melaleuca quinquenervia has been acknowledged as the nearest living relative to the frst fossil species. In the course of determination of the second leaf imprint, a considerable morphological iden- tity has been found with another representative of the family Myrtaceae, again from the Australian fora, namely, Tristaniopsis laurina. Tat recent species has been acknowledged as the nearest rlative to the fossil material, for the taxonomic determination of which the combination Tristaniopsis af. laurina was applied. Bozukov, V.S. & Ivanov, D.A. 2022. New data on the Middle Miocene fora of Northwest Bulgaria. --Phytologia Balcanica, 28 (2): 147-156 -- ISSN 1310-7771 (print), 1314-0027 (online). Citation: Introduction Tere are 32 studied locations of the Sarmatian s.l. macrofora in Northwest Bulgaria (Palamarev & Petkova 1987), most of them dated to the Middle Miocene (Volhynian = Late Serravalian) and only few to the Late Miocene (Bessarabian = Early Tor- tonian (see Ivanov & al. 2019). Te local palaeofora in the area of Ruzhintsi Vilage, Vidin District, is the richest among the other Middle Miocene foras. It comprises 102 fossil species. In spite of the fact that macrofossils from that location, stored in the paleo- botanical collection of the Institute of Biodiversity and Ecosystem Research (IBER) with the Bulgarian Academy of Sciences, have been thoroughly studied, two imprints of so far indetermined leaf laminas have been found there. Te present study deals with the elucidation of their taxonomy. Te two studied imprints have been acknowledged as being afliated to the family Myrtaceae. Presently, representatives of this family are extremely rare in the European fo- ra. Only the species Myrtus communis L. occurs in the European part of the Mediterranean. Tat is why, new data about taxa from this family are extremely important for revealing its distribution, both geohis-