Szabó János szerk.: Fragmenta Mineralogica Et Palaentologica 20. 2002. (Budapest, 2002)

proportion range between 1.00-1.05 in Pacbyptila, Daption, Oceanodroma genera, while it is bigger (1.071.28 in Fulmarus, Pagodroma, Oceanites, Puffinus and Pelecanoides genera's. The grebes present 1.08-1.14. - in the case of ulna/carpometacarpus proportion, this value is less than 1.50 in Pelecanoides and Oceanites, it ranges between 1.50-2.00 in Pacbyptila, Puffinus, Frigadafons, Pagodroma and Oceanodroma genera and reaches 2.23 in Pterodroma, Procellaria, Fulmarus, Daption, Calonectis and Bulweria. This proportion is 1.86-2.15 within grebes, while the fossil specimen presents 2.12. - the ratio of carpometacarpus/phalanx alae 1 digiti 2 give the same arrangements as the ulna/carpometacarpus for all the studied genera excepting the grebes, where it ranges between 2.25-2.57. This proportion in the fossil specimen is only 2.18. The fossil specimen osteometrically also differs from the recent species: the shaft of humerus is stouter but the ratio of carpometacarpus/phalanx alae 1 digiti 2 shows smaller values. Summarising the morphological characteristics of the bones, the comparisons of the sizes and the proportions of the bones with other genera, we may conclude that there is no doubt that the fossil wing belongs to a new fossil genus and thus, a new species of grebe. Table 1 — Measurements (mm) of humeri, ulnae, radii, carpometacarpi and phalangaes alae of the compared recent and fossil Podicipediformes species. — Abbreviations: 1 = total length, 2 = width of the shaft, 3 = width of the distal epiphysis, Cmcp = carpometacarpus, Ph. alae = phalanga alae 1 digiti 2, ::

" = bibliographical data. Species Humerus Ulna Radius Cmcp Ph. alae Ulna/ Cmcp/ 1 2 3 1 1 1 1 Cmcp Ph. alae Aechmophorus clarkii Male: n = 2 (USNM 560534, 560535) 115.8-119.6 4.1-4.5 10.3-10.9 104.1-107.3 103.9-107.3 51.3-51.5 20.7-21.9 2.03-2.08 2.35-2.48 Female: n = 3 (USNM 560531, 560537, 560542) 103.5-107.5 3.4-4.4 9.7-9.9 89.6-96.4 87.8-93.7 44.7-46.1 19.4-19.6 1.96-2.09 2.30-2.35 Aechmophorus occidentalis Male: n = 4 (USNM 560546, 560548, 114.1-122.3 4.5-6.0 10.9-11.7 102.4-110.1 99.7-106.7 50.6-55.2 21.5-23.0 1.98-2.00 2.35-2.57 561115, 561116) Female: n = 3 (USNM 560550, 561113, 109.1-114.7 4.6-4.9 9.6-9.8 97.1-103.3 94.8-101.0 46.6-49.8 20.1-21.5 2.07-2.08 2.31-2.32 561117) Podiceps cristatus Male: n= 34 (BBU + ») 103.6-114.9 5.4 10.1-11.6 94.7-1C9.2 90.9-106.3 44.6-50.9 18.8-21.5 2.12-2.15 2.32-2.37 Female: 11=37* 100.2-117.5 9.9-11.6 91.5-106.6 89.5-104.0 42.6-50.3 18.4-21.9 2.13-2.15 2.29-2.32 Podiceps griseigena n = 48 (BBU + *) 84.9-1C4.9 4.0 9.1-11.4 77.0-99.0 74.8-94.9 36.1-48.3 16.0-21.2 2.05-2.13 2.25-2.27 Podiceps auritus Q-13 (BBU + *) 67.2-78.4 4.16 7.1-8.3 59.6-69.6 57.4-67.5 30.1-34.8 13.0-14.6 1.86- 2.00 2.38-2.56 Podiceps nigricollis n = 28 (BBU+*) 61.5-75.3 3.4 6.8-8.2 60.3-69.2 58.6-67.0 29.0-33.6 12.5-14.8 2.06-2.08 2.27-2.32 Tachybaptus ruficollis n = 47 (BBU + *) 48.8-57.5 2.9 5.2-6.2 43.6-51.3 42.7-49.8 21.6-25.5 9.3-11.3 2.01-2.C2 2.25-2.40 Podiceps pisanus (PORTIS) ap. 73.0 7.9 Podiceps sociatus (NAVAS) 70.0 73.0 73.0 Podiceps miocenicus KESSLER ap. 113.0 6.0 11.2 Miodytes serbicus sp. nov. ap. 62.0-65.0 4.60 7.31 56.27 53.42 26.52 12.19 2.12 2.18 Conclusions The number of Tertiary grebes is very few in Europe. Two genera, Podiceps and Miobaptus, belong to the Podicipedidae. According to MLIKOVSKY (1995) and BOCHENSKI (1997), recent genus Podiceps includes the following fossil species: Podiceps pisanus (PORTIS), 1889 from the Middle Pliocene of Italy, Podiceps sociatus (NAVAS), 1922 from the Upper Miocene of Spain and Podiceps miocenicus KESSLER, 1984 from the Upper Miocene of Moldavia Miobaptus waited SVEC, 1982 from the Lower Miocene Czech Republic belong to the fossil genus Miobaptus. Miobaptus walteri description is based on the proximal part of humerus, a nearly complete coracoideum and three fragments of tarsometatarsus (two proximal and one distal) (SVEC, 1982). Podiceps pisanus was described on a humerus (REGALIA, 1902), while P. sociatus is based on a nearly complete skeleton (humerus, ulna, radius, femur, tibiotarsus and tarsometatarsus) in a slab (LAMBRECHT, 1933). A humerus of Podiceps miocenicus was described by KESSLER (1984, 1992). Miodytes serbicus differs morphologically and by its dimensions from all the mentioned species. Fossil grebes are also known from the Miocene, Pliocene and Pleistocene of North America: Podiceps parvus (Sl-LUFELDT), 1913, Podiceps oligoceanus (SHUFELDT), 1915, Podiceps subparvus (L. MLLLER & BOWMANN), 1958, Podiceps dixi BRODKORB, 1963 and Pliodytes languisti BRODKORB, 1953 (BRODKORB 1963, LAMBRECHT 1933). As majority of the species were described from other type of bones then presented in Suseoke specimen, their comparison was more difficult. Podiceps parvus description is based on tarsometatarsus, a distal part of femur is described of P. oligocaenus and P. subparvus. P. dixi was described from the proximal part of carpometacarpus, but it's sizes differ from our species', while Pliodytes languisti description is based on coracoideum. All these birds were much larger than Miodytes serbicus. Modern grebes live almost exclusively on the water. They are found on the backwaters, lakes and reeds, and avoid the vicinity of ice or snow or intensely cold water. All species are vulnerable to habitat changes and water pollution. As the ecological conditions of Suseoke in Miocene seem to have been convenient for our species, its presence is not considered surprising. We may