New Fossil Record of the Late Pliocene Kestrel (Falco Bakalovi Boev, 1999) from the Type Locality in Bulgaria

GEOLOGICA BALCANICA, 40. 1–3, Sofia, Dec. 2011, p. 13–30.

New fossil record of the Late Pliocene kestrel (Falco bakalovi Boev, 1999) from the type locality in Bulgaria

Zlatozar Boev

National Museum of Natural History, Bulgarian Academy of Sciences, 1, Tsar Osvoboditel Blv., 1000 Sofia, Bulgaria; e-mail: [email protected]; [email protected] (Accepted in revised form: 10.03.2011)

Abstract. Twenty six new bone finds of 4 individuals (2 adult and 2 juvenile) have been described and referred to the Late Pliocene kestrel Falco bakalovi Boev, 1999. They came from the species type locality near the town of Varshets (northwest Bulgaria) and demonstrate specific distinguishing from all known falcons of the “tinnunculus” group. They enrich the bone morphology of that falcon covering a large variety of 16 different skeletal elements.

Boev, Z. N. 2011. New fossil record of the Late Pliocene kestrel (Falco bakalovi Boev, 1999) from the type locality in Bulgaria. Geologica Balcanica 40(1–3), 13–30. Key words: Falco bakalovi, Falcons, fossil birds, Late Pliocene, Villafranchian Bulgaria.

Introduction The finds come from the type locality near the town of Varshets in northwest Bulgaria and are associated with Until now a total of 11 fossil species were described in F. bakalovi, the only known falcon of the site until now. the genus Falco Linnaeus, 1758. Only two of them were They are the first confirmation of the existing of this spe- considered valid species from Europe (Mlíkovský, 2002). cies and enlarge its morphological characteristics. Until recently, F. medius Umanskaya, 1981 from the Late Miocene (MN 11-13) in south Ukraine was the only known falcon of the Miocene of both Eurasia and Africa and the Material and method oldest record of the genus. Recently, F. bulgaricus , anoth- er and older Miocene falcon of “tinnunculus” group has Abbreviations: Anatomical: c. – cotyla; cond. – condylus; been described from SW Bulgaria (Late Miocene; Boev, dex. – dextra; dig. – digitus, digiti; dist. – distalis; f. a. – 2011). The second species is the present F. bakalovi Boev, facies a.; max. – maximum; min. – minimum; pr. – proc- 1999. Falco umanskajae Sobolev 2003 (Late Pliocene, essus, processi; prox. – proximalis; sin – sinistra; s. a. – MN 16) from the vicinities of Odessa in Ukraine, is con- sulcus articularis; tbt – tibiotarsus; tmt – tarsometatarsus. sidered “nomen nudum” (Wikipedia, 2011). Outside Institutional: BMNH – Natural History Museum, former- Europe only one Neogene species, F. oregonus Brodkorb, ly British Museum (Natural History), Tring; NMNHS – 1946 (Early/Middle Pliocene of Oregon, USA), has been National Museum of Natural History, Bulgarian Academy described. of Sciences, Sofia; UCBL – University Claude Bernard, The Pliocene falcon F. bakalovi has been designat- Lyon 1, France. ed through a synsacral fragment (holotype) collected in The material was collected through screening and 1990. Since that time additional excavations for collect- washing of the sediments. It consists of 26 bones and ing of fossil material have been undertaken which lasted bone fragments, representing 16 skeletal elements of several years. both fore limbs and the pectoral girdle, and the hind Part of the collected rich material, still unexamined limbs and the pelvis girdle: No NMNHS 122-124; 131- completely, belongs to a small falcon. Boev (1999 a, b; 132, 134-136, 143-145, 181, 189, 223, 294, 304-306, 2002) listed a total of sixteen new finds identified as 317-321, 364, 14 952 and 14964. The finds belong to 2 Falco ex gr. tinnunculus. In addition, some finds col- adult and 2 juvenile individuals from MNI 4. They have lected in the last two years were also referred to this fal- been collected by the author in a 12-year period (1991- con. All this material is the subject of the present paper. 2001) from the type locality near the town of Varshets,

13 NW Bulgaria. The material was identified by comparison and Livezey and Zusi (2006). The chronostratigraphy with the holotype in the reference avian skeleton collec- follows Mein (1990) and Guerin (1990). tion of the NMNHS, as well as the osteological collec- All measurements (Tables 1–16, Fig. 1) have been tions of the Centre des Sciences de la Tèrre, Université taken using calipers to 0.05 mm accuracy, but read to Claude Bernard – Lyon (UCBL) in 1994–1995 and the the 1st digit after decimal point. Description of the meas- Natural History Museum, Tring, a part of the Natural uring manner of some bones in fossil and recent Falco: History Museum, London, former British Museum of humerus dex. dist.: a – thickness of condylus dorsalis; Natural History (BMNH) in 1999 and 2003. It is kept in b – thickness of condylus ventralis; c – total width of c. the Vertebrate Animal Department of the NMNHS. dorsalis and c. ventralis (Table 4); ulna sin. prox.: a – lon- The taxonomy follows White et al. (1994). The osteo- gitudinal diameter of cotyla ventralis; b – transversal di- logical terminology is after Baumel and Witmer (1993) ameter (length) of cotyla dorsalis; c – maximum width of

Fig. 1. Manner of measurings of the pelvis in Falconidae (Drawings Vera Hristova)

14 proximal diaphysis; d – length of depressio m. brachialis; Genus Falco Linnaeus, 1758 e – width of diaphysis at the middle of depressio m. bra- Falco bakalovi Boev, 1999 chialis (Table 5); femur sin. dist.: a – width of distal epiphysis; b – diameter of condylus lateralis; c – diameter Holotype: Postacetabular part of the left half of pelvis, of condylus medialis; d – diameter (thickness) in sulcus NMNHS 1642. Collected on July 25th, 1990 by Z. Boev. intercondylaris; e – cranio-caudal thickness of the dia- Paratypes: humerus dex. dist. NMNHS 135; ulna sin. physis above distal epiphysis (Table 10); tibiotarsus dex. prox. NMNHS 131; ulna dex. dist. NMNHS 14 964; fe- dist.: a – width of distal epiphysis; b – diameter of the mur sin. dist. NMNHS 223; tbt dex. dist. NMNHS 136. condylus medialis; c – diameter of the condylus lateralis; Comparison: See Tables 1–16; Fig. 1 and “Description d – thickness in the incissura intercondylaris; e – width and comparison” section. of diaphysis in the proximal end of sulcus supratendineus Measurements of the paratypes: Tables 1–16; Fig. 1. (Table 11). The manner of other measuring is given on Neodiagnosis: A small-sized (between F. tinnunculus and Fig. 1. All generic names of the binominals are given ab- F. subbuteo) fossil species of genus Falco, differing by breviated in the text and are in full in the Appendix 1. the sharp transition (turn) of crista iliaca dorsolateralis “Smaller”, “much smaller”, “larger” or “much larger” over the ala ischii and the rounded (oval), but not angular in the “Comparison and discussion” section mean that shape of the caudal edge of foramen ilioischiadicum. the fossil specimen differs considerably in size from the Distinguishing differences from: (A) the modern F. tin- specimens of the compared species, and thus their taxo- nunculus: (1) distal humerus: blunter (rounder) epicondy- nomic identity is excluded. lus ventralis; (2) рroximal ulna: shallower fossa under c. dorsalis, and almost twice narrower depressio m. brachialis; (3) distal ulna: thicker cond. ventralis ulnae in caudal Systematic Palaeontology view; (4) distal femur: much higher crista tibiofibularis in caudal view; (5) distal tbt: much thicker wall of the medial The general morphology of all 26 finds indicates that tendineal fossa above c. medialis; from (B) the Miocene they belong to the group of the small falcons (Falco F. bulgaricus : (1) proximal ulna, (2) distal humerus and sp. ex gr. tinnunculus). As F. bakalovi is the only known (3) distal tibiotarsus much stouter and robust. representative of that group in the Varshets locality, we Locality: A ponor in a rocky hill, 6 km NNE of the town refer all these finds to the same species. of Varshets (43.13° N, 23.17° E). Unconsolidated, un- stratified sediments accumulated as terra-rossa clay. The Order FALCONIFORMES (Sharpe, 1874) fossil bones are broken, locally forming a bone breccia. Family FALCONIDAE (Vigors, 1824) Chronology: Villafranchian. The associated mammal Subfamily Falconinae (Vigors, 1824) fauna (Spassov 1997 a, b, 2000; Popov, 2001) gave

Table 1 The measurements of coracoid sin. in some fossil and recent Falco (ref. to Fig. 1 A) Taxa a b c d e Fossil – Varshets Falco bakalovi NMNHS 304 2.4 2.8 2.1 10.2 4.6 Recent Falco chicquera BMNH 1965.18.1 3.5 3.5 2.0 11.7 ca. 7.1 Falco chicquera BMNH 1993.2.5 2.6 2.8 1.7 10.0 6.1 Falco columbarius BMNH 1930.3.24.264 2.4 2.8 1.9 10.0 5.8 Falco columbarius BMNH 1930.3.24.267 2.7 2.6 1.8 10.5 6.6 Falco columbarius BMNH 1988.61.1 2.7 3.1 1.7 10.6 7.0 Falco naumanni BMNH 1955.15.2 2.6 2.9 1.6 8.9 6.2 Falco naumanni BMNH 1961.13.4 2.2 2.8 1.6 3.8 5.5 Falco newtoni BMNH 1897.5.10.29 2.2 2.6 1.5 7.4 ca. 4.7 Falco sparverius BMNH 1954.3.2 2.0 2.4 1.7 7.2 5.2 Falco subbuteo BMNH 1985.76.1 2.8 3.2 2.3 11.1 7.3 Falco subbuteo BMNH 1994.39.1 3.0 3.3 1.8 11.5 7.3 Falco subbuteo UCBL 111/2 2.9 2.7 1.8 11.4 5.2 Falco tinnunculus BMNH 1930.3.24.275 2.9 3.1 1.8 10.3 6.9 Falco tinnunculus UCBL 119/2 2.6 2.4 1.6 9.2 4.6 Falco tinnunculus UCBL 119/3 2.8 2.6 1.7 9.3 4.6 Falco vespertinus BMNH 1855.4.4.9 2.3 2.9 2.0 9.4 6.0 Falco vespertinus BMNH 1869.10.19.12 2.3 2.4 1.8 8.7 5.2 Falco vespertinus BMNH 1952.3.122 2.5 3.2 1.8 9.7 6.3

15 16 ← Fig. 2. Falco bakalovi Boev (Photographs: Assen Ignatov) a, b, coracoid sin. NMNHS 304 c, coracoid sin. NMNHS 305 d, e, clavicula sin. prox. NMNHS 306 f, humerus dex. dist. NMNHS 14 952 g, h, humerus dex. dist. NMNHS 134 i, j, k, humerus dex. dist. NMNHS 135 l, ulna sin. prox. NMNHS 132

the site a MN17/MNQ17 zone attribution (Mein, 1990; f. a. humeralis; F. newtoni: the same way as F. sparverius; Guerin, 1990). Spassov (2000, 2003) attributed the site F. sparverius: by the larger size, and the thicker shaft in the St. Vallier unit between the levels of the localities in c. scapularis; F. subbuteo: morphologically similar, Roccaneyra and St. Vallier. but smaller and differs by the narrower f. a. humeralis, and narrower pr. acrocoracoideus; F. tinnunculus: high similarity in size, general shape and proportions, Description and comparison but differs by the almost twice narrower f. a. humeralis; F. vespertinus: sharper pr. acrocoracoideus, narrower Skeletal elements of the fore limbs f. a. humeralis. and the pectoral girdle Coracoid sin. NMNHS 305 (Fig. 2 c, Table 2). The specimen lacks caudal part of the sternal end and all Coracoid sin. NMNHS 304 (Figs 2 a, b, Table 1). The humeral end. Its preserved part (mainly the bone shaft) specimen belongs to a juvenile/subadult individual. It completely fits to No 304 in both morphology and size. differs from: F. chicquera: similar in size and general Clavicula sin. prox. NMNHS 306 (Figs 2 d, e, Table 3). morphology, but differs by the thinner shaft of coracoid; The specimen preserves the distal (humeral) half of the bone F. columbarius: sharper pr. acrocoracoideus; F. nau- and differs from: F. chicquera: by the less rounded pr. manni: by the larger size, and the relatively narrower acromialis; F. columbarius: shallower relief of f. a. ac-

Table 2 The measurements of coracoid sin. in some fossil and recent Falco (ref. to Fig. 1 B)

Taxa a b c d e Fossil – Varshets Falco bakalovi NMNHS 305 7.7 15.9 2.9 2.1 5.2 Recent Falco chicquera BMNH 1965.18.1 – – 3.2 – – Falco chicquera BMNH 1993.2.5 ca. 9.2 ca. 18.9 2.9 – 6.1 Falco columbarius 1930.3.24.267 9.6 20.2 2.8 2.3 5.3 Falco columbarius BMNH 1930.3.24.264 8.2 17.8 2.7 2.3 5.5 Falco columbarius BMNH 1988.61.1 8.7 20.0 3.1 2.3 6.3 Falco naumanni BMNH 1955.15.2 6.9 14.8 2.9 2.2 5.4 Falco naumanni BMNH 1961.13.4 6.3 14.0 2.8 2.0 5.3 Falco newtoni BMNH 1897.5.10.29 7.5 13.7 2.7 2.2 5.0 Falco sparverius BMNH 1954.3.2 8.1 15.4 2.3 1.9 4.8 Falco subbuteo BMNH 1985.76.1 9.0 18.0 3.0 2.4 6.2 Falco subbuteo BMNH 1994.39.1 8.5 18.1 3.2 2.5 6.5 Falco subbuteo UCBL 111/2 10.2 17.6 3.1 2.4 6.6 Falco tinnunculus BMNH 1930.3.24.275 9.3 17.9 3.3 2.4 5.7 Falco tinnunculus UCBL 119/2 9.0 16.4 2.8 2.1 5.2 Falco tinnunculus UCBL 119/3 8.2 16.0 3.4 2.2 5.2 Falco vespertinus BMNH 1855.4.4.9 7.6 16.1 2.2 1.7 5.7 Falco vespertinus BMNH 1869.10.19.12 8.7 16.4 2.5 2.3 5.1 Falco vespertinus UCBL 117/1 10.0 18.9 3.1 2.0 5.8

17 Table 3 The measurements of clavicula sin. prox. in some fossil and recent Falco (ref. to Fig. 1 C, D, E)

Taxa a b c d e Fossil – Varshets Falco bakalovi NMNHS 306 1.8 3.4 1.1 6.1 5.3 Recent Falco chicquera BMNH 1965.18.1 – 3.5 1.5 7.2 – Falco chicquera BMNH 1993.2.5 6.6 2.9 1.1 6.6 3.9 Falco columbarius BMNH 1930.3.24.264 1.7 2.1 0.9 5.0 3.8 Falco columbarius BMNH 1930.3.24.267 1.8 3.2 0.7 5.5 6.0 Falco columbarius BMNH 1988.61.1 1.7 3.0 0.8 6.1 4.9 Falco naumanni BMNH 1955.15.2 1.5 2.8 0.9 4.9 4.4 Falco newtoni BMNH 1897.5.10.29 1.4 2.6 0.9 4.0 3.0 Falco sparverius BMNH 1954.3.2 1.7 2.4 1.0 3.9 3.4 Falco subbuteo BMNH 1994.39.1 1.9 3.8 1.3 6.5 4.2 Falco subbuteo UCBL 111/3 1.8 3.4 1.0 6.8 5.5 Falco subbuteo UCBL 111/4 1.5 2.8 1.1 6.0 5.3 Falco tinnunculus BMNH 1930.3.24.275 1.5 2.8 1.8 4.7 5.2 Falco tinnunculus BMNH 1930.3.24.278 1.2 2.8 1.7 5.2 4.4 Falco tinnunculus UCBL 119/7 1.5 2.7 1.0 5.1 5.0 Falco tinnunculus UCBL 119/8 1.2 2.6 0.9 5.1 4.1 Falco vespertinus BMNH 1855.4.4.9 1.8 2.8 1.1 5.2 4.2 Falco vespertinus BMNH 1869.10.19.12 1.8 2.8 0.9 4.3 3.6 Falco vespertinus BMNH 1952.3.122 1.7 2.8 0.9 4.3 3.8

Table 4 The measurements of humerus dex. dist. in some fossil and recent Falco

Taxa a b c Fossil – Varshets Falco bakalovi NMNHS 134 4.7 2.2 ca. 7.4 Falco bakalovi NMNHS 135 4.8 2.4 ca. 7.6 Falco bakalovi NMNHS 14 952 5.8 ca. 2.8 ca. 8.5 Recent Falco chicquera BMNH 1965.18.1 6.3 3.2 7.8 Falco chicquera BMNH 1993.2.5 5.0 2.7 6.5 Falco columbarius BMNH 1930.3.24.264 5.3 2.6 6.9 Falco columbarius BMNH 1930.3.24.267 5.6 2.7 7.4 Falco columbarius BMNH 1988.61.1 5.7 2.9 7.4 Falco naumanni BMNH 1955.15.2 5.5 2.6 6.9 Falco naumanni BMNH 1961.13.4 4.9 2.7 5.8 Falco newtoni BMNH 1897.5.10.29 4.6 2.3 5.1 Falco sparverius BMNH 1954.3.2 4.8 2.2 5.7 Falco subbuteo BMNH 1974.16.1 6.3 3.0 7.9 Falco subbuteo BMNH 1985.76.1 6.2 3.0 8.4 Falco subbuteo BMNH 1994.39.1 6.5 3.0 8.5 Falco tinnunculus BMNH 1930.3.24.275 4.2 2.9 7.8 Falco tinnunculus BMNH 1930.3.24.276 6.1 2.9 8.2 Falco tinnunculus BMNH 1930.3.24.278 5.3 2.7 6.8 Falco vespertinus BMNH 1855.4.4.9 5.2 2.7 6.7 Falco vespertinus BMNH 1869.10.19.12 5.1 2.7 6.7 Falco vespertinus BMNH 1952.3.122 5.2 2.6 7.4

18 rocoracoidea, larger distance between the f. a. acrocora- shallower sulcus m. humerotricipitis, shorter pr. flexo- coidea; F. naumanni: by the wider f. a. acrocoracoidea; rius in medial view; F. tinnunculus: blunter (rounder) F. newtoni: by the larger size, and the deeper relief of the epicondylus ventralis; F. vespertinus: the same way as acrocoracoidal articular end; F. sparverius: by the larger F. tinnunculus. size; F. subbuteo: by the shorter f. a. acrocoracoidea; Ulna sin. prox. NMNHS 131 (Table 5). The speci- F. subbuteo: smaller, in cranio-lateral view the vow-like men differs from: F. chicquera: by the more straight, profile between the f. a. acrocoracoidaea is narrower instead slightly curved shaft of the proximal part of dia- and round than open and elliptic; F. tinnunculus: wider physis; F. chicquera: by the relatively slightly narrower f. a. acrocoracoidea and sharper pr. acrocoracoideus; c. dorsalis; F. columbarius: by the wider diaphysis, and F. vespertinus: larger size and the wider humeral part the wider depressio m. brachialis; F. naumanni: by the in lateral view. larger size, and the less oval, instead angular, in dorsal Humerus dex. dist. NMNHS 14 952 (Fig. 2 f, Table 4). edge, c. dorsalis; F. subbuteo: smaller, c. ventralis is The specimen preserves only fragment of dorsal (lateral) more angular, instead round; F. tinnunculus: similar, part of the distal epiphysis. It differs from: F. chicquera: but differs by the thicker diaphysis, shallower fossa by the deeper relief on the dorsal side of distal epiphysis. under c. dorsalis, and almost twice narrower depressio F. columbarius: less developed pr. supracondylaris dor- m. brachialis; F. vespertinus: more robust, longer ole- salis, smaller diameter of cond. dorsalis; F. naumanni: cranon, c. dorsalis more angular than round. mainly by the larger size. F. newtoni: the same way as Ulna sin. prox. NMNHS 132 (Fig. 2 l, Table 5). The F. sparverius; F. sparveriusi: by the larger size. F. sub- specimen differs the same way as No 131. buteo: smaller, in caudal view cond. dorsalis more short- Ulna dex. dist. NMNHS 294 (Fig. 3 a, Table 6). ened; F. tinnunculus: similar, but slightly larger, differs The specimen belongs to a juvenile/subadult individual, by the wider facies a. acrocoracoidea, and narrower cond. reached its definitive size. The dorsal part of c. dorsalis ventralis humeralis; F. vespertinus: similar, but cond. ulnaris had been broken. Beside the incompletely de- dorsalis slightly bigger in caudal view. veloped articular surfaces, the distal epiphysis bears the Humerus dex. dist. NMNHS 134 (Figs 2 g, h, Table 4). characteristic features of Falconiformes and Falconidae, The specimen belongs to a juvenile/subadult individual. F. especially the widely open depressio radialis, the wider tinnunculus: dimensionally completely fits. (in comparison to Accipitridae) s. intercondylicus, and Humerus dex. dist. NMNHS 135 (Figs 2 i, j, k, the more protuberant in ventral direction tuber carpale. Table 4). F. columbarius: more straight distal diaphysis, Metrically and morphologically completely fits to small- shorter epicondylus dorsalis; F. subbuteo: smaller size; er Palearctic falcons of genus Falco. It differs from:

Table 5 The measurements of ulna sin. prox. in some fossil and recent Falco

Taxa a b c d e Fossil – Varshets Falco bakalovi NMNHS 131 4.4 4.0 8.3 13.5 4.7 Falco bakalovi NMNHS 132 4.5 4.0 7.9 10.6 4.9 Recent Falco chicquera BMNH 1965.18.1 5.1 4.8 8.9 11.2 5.1 Falco chicquera BMNH 1993.2.5 4.5 3.8 7.8 ca. 9.4 4.1 Falco columbarius BMNH 1930.3.24.264 4.0 4.2 7.4 ca. 10.2 ca. 4.2 Falco columbarius BMNH 1930.3.24.267 4.3 3.4 8.0 9.5 4.3 Falco columbarius BMNH 1988.61.1 4.5 3.9 8.1 9.7 4.4 Falco naumanni BMNH 1955.15.2 4.2 3.7 7.7 12.3 4.1 Falco naumanni BMNH 1961.13.4 3.9 3.5 6.9 10.5 3.9 Falco newtoni BMNH 1897.5.10.29 3.7 3.0 6.2 7.6 3.6 Falco sparverius BMNH 1954.3.2 3.6 2.8 6.5 8.2 4.1 Falco subbuteo BMNH 1974.16.1 4.7 4.0 9.3 11.0 5.2 Falco subbuteo BMNH 1985.76.1 4.4 4.3 8.5 ca. 10.9 4.9 Falco subbuteo BMNH 1994.39.1 4.9 3.9 8.9 11.2 4.7 Falco tinnunculus BMNH 1930.3.24.275 4.1 3.8 8.0 11.4 4.5 Falco tinnunculus BMNH 1930.3.24.276 4.8 3.9 8.3 11.3 4.9 Falco tinnunculus BMNH 1930.3.24.278 4.4 3.6 7.8 10.8 4.3 Falco vespertinus BMNH 1855.4.4.9 4.8 3.8 7.8 11.7 4.0 Falco vespertinus BMNH 1869.10.19.12 3.9 3.2 7.3 11.7 4.1 Falco vespertinus BMNH 1952.3.122 4.2 3.3 7.4 9.0 4.6

19 20 ← Fig. 3. Falco bakalovi Boev (Photographs: Assen Ignatov) a, ulna dex. dist. NMNHS 294 b, ulna dex. dist. NMNHS 14 964 c, ulna sin. dist. NMNHS 364 d, e, carpometacarpus dex. prox. NMNHS 124 f, g, h, carpometacarpus sin. prox. NMNHS 189 i, carpometacarpus sin. dist. NMNHS 122 j, k, l, femur sin. dist. NMNHS 223

F. columbarius: larger and more robust, more angular cond. ventralis ulnae in caudal view; F. vespertinus: c. ventralis and c. dorsalis; F. subbuteo: smaller size, thicker diaphysis, deeper s. radialis. shallower s. radialis; F. tinnunculus: shallower s. tend- Ulna sin. dist. NMNHS 364 (Fig. 3 c, Table 6). The ineus; F. vespertinus: lower cond. dorsalis. specimen differs the same way as No 294. Ulna dex. dist. NMNHS 14 964 (Fig. 3 b, Table 6). Carpometacarpus dex. prox. NMNHS 124 (Figs 3 d, e, The specimen differs from: F. chicquera: by the absence Table 7). The specimen belongs to a juvenile/subadult in- of clear constriction between the diaphysis and cond. dividual. It differs from: F. columbarius: of similar size; ventralis in lateral view; F. columbarius: slightly bigger, F. subbuteo: smaller, less steep caudal profile of tr. car- wider s. radialis, higher c. ventralis; F. naumanni: by the palis; F. tinnunculus: by the narrower f. a. radiocarpalis; larger size, and the shallower s. radialis; F. newtoni: by F. vespertinus: more angular cranial edge of the dorsal the larger size, and by the straight, instead slightly curved condyle of trochlea carpalis. distal fourth of diaphysis in lateral view; F. sparverius: Carpometacarpus sin. prox. NMNHS 189 (Figs 3 f, by the larger size; F. subbuteo: by the deeper s. radialis; g, h, Table 8). The specimen differs from: F. chicquera: F. tinnunculus: very similar, but slightly larger; thicker by the larger size and the slightly concaved caudal pro-

Table 6 The measurements of ulna dex. dist. in some fossil and recent Falco (ref. to Fig. 1 F)

Taxa a b c d Fossil – Varshets Falco bakalovi NMNHS 294 4.5 6.3 4.1 3.8 Falco bakalovi NMNHS 14 964 4.7 6.8 4.2 3.7 Recent Falco chicquera BMNH 1965.18.1 – 7.0 4.9 4.4 Falco chicquera BMNH 1993.2.5 4.2 6.0 3.5 3.3 Falco columbarius BMNH 1930.3.24.264 4.1 6.2 3.8 3.4 Falco columbarius BMNH 1930.3.24.267 4.5 6.7 3.5 3.5 Falco columbarius BMNH 1988.61.1 4.6 6.6 3.5 3.6 Falco naumanni BMNH 1955.15.2 4.5 6.0 4.0 3.4 Falco naumanni BMNH 1961.13.4 4.1 5.9 3.4 3.1 Falco newtoni BMNH 1897.5.10.29 3.6 5.1 3.1 2.9 Falco sparverius BMNH 1954.3.2 3.6 5.4 3.4 3.0 Falco subboteo UCBL 111/4 5.4 7.4 4.2 3.8 Falco subbuteo UCBL 111/2 4.8 7.2 4.3 3.7 Falco subbuteo UCBL 111/3 4.8 6.9 4.4 3.7 Falco tinnunculus UCBL 119/1 4.6 7.1 4.6 3.8 Falco tinnunculus UCBL 119/2 4.2 5.9 3.7 3.3 Falco tinnunculus UCBL 119/3 4.4 6.2 4.0 3.4 Falco tinnunculus UCBL 119/7 4.6 6.7 4.2 3.9 Falco vespertinus BMNH 1855.4.4.9 4.2 6.3 4.2 3.8 Falco vespertinus UCBL 117/1 4.4 6.1 3.8 3.4 Falco vespertinus UCBL 117/2 4.2 5.7 3.6 3.0

21 Table 7 The measurements of carpometacarpus dex. prox. in some fossil and recent Falco (ref. to Fig. 1 G)

Taxa a b c Fossil – Varshets Falco bakalovi NMNHS 124 4.8 5.1 2.6 Recent Falco chicquera BMNH 1965.18.1 5.2 5.9 3.1 Falco chicquera BMNH 1993.2.5 3.7 5.3 2.8 Falco columbarius BMNH 1930.3.24.264 4.5 5.4 2.7 Falco columbarius BMNH 1930.3.24.267 5.2 6.8 2.7 Falco columbarius BMNH 1988.61.1 4.4 5.7 2.9 Falco naumanni BMNH 1955.15.2 4.5 4.8 2.6 Falco naumanni BMNH 1961.13.4 4.3 5.0 2.4 Falco newtoni BMNH 1897.5.10.29 4.0 5.1 2.6 Falco sparverius BMNH 1954.3.2 3.8 4.5 2.5 Falco subbuteo BMNH 1974.16.1 5.6 6.6 3.6 Falco subbuteo BMNH 1985.76.1 5.0 6.5 4.3 Falco subbuteo BMNH 1994.39.1 5.5 7.2 3.6 Falco tinnunculus UCBL 119/2 4.5 5.6 2.7 Falco tinnunculus UCBL 119/3 4.2 5.6 2.6 Falco tinnunculus UCBL 119/4 4.4 5.7 2.7 Falco vespertinus BMNH 1855.4.4.9 4.6 5.2 2.9 Falco vespertinus BMNH 1869.10.19.12 4.3 5.3 2.8 Falco vespertinus BMNH 1952.3.122 4.9 5.4 2.6

Table 8 The measurements of carpometacarpus sin. prox. in some fossil and recent Falco (ref. to Fig. 1 H)

Taxa a b c d e Fossil – Varshets Falco bakalovi NMNHS 189 6.0 10.1 3.7 11.4 4.3 Recent Falco chicquera BMNH 1965.18.1 6.5 – 3.3 12.0 – Falco chicquera BMNH 1993.2.5 5.5 7.2 3.1 10.2 3.9 Falco columbarius BMNH 1930.3.24.264 5.5 8.8 2.0 9.8 3.5 Falco columbarius BMNH 1930.3.24.267 6.8 9.3 2.6 11.8 3.7 Falco columbarius BMNH 1988.61.1 6.1 9.2 3.0 11.7 3.8 Falco naumanni BMNH 1955.15.2 5.2 8.8 3.8 10.4 3.6 Falco naumanni BMNH 1961.13.4 5.2 8.4 2.7 10.4 3.5 Falco newtoni BMNH 1897.5.10.29 5.1 6.3 2.7 ca. 8.6 3.2 Falco sparverius BMNH 1954.3.2 4.8 6.3 2.6 8.8 3.3 Falco subbuteo BMNH 1974.16.1 6.8 8.8 3.8 12.4 4.6 Falco subbuteo BMNH 1985.76.1 6.3 10.7 3.6 12.0 4.1 Falco subbuteo BMNH 1994.39.1 6.5 9.0 3.7 11.2 4.4 Falco tinnunculus BMNH 1930.3.24.275 5.8 8.4 3.0 10.7 4.0 Falco tinnunculus BMNH 1930.3.24.278 6.1 9.0 3.0 10.3 3.6 Falco tinnunculus UCBL 119/7 5.5 9.4 3.2 10.2 3.8 Falco vespertinus BMNH 1855.4.4.9 5.5 9.2 3.0 11.6 4.0 Falco vespertinus BMNH 1869.10.19.12 5.2 7.2 3.0 10.8 3.4 Falco vespertinus BMNH 1952.3.122 5.7 9.1 3.1 9.2 3.2

22 Table 9 The measurements of carpometacarpus sin. dist. in some fossil and recent Falco (ref. to Fig. 1 I) Taxa a b c d Fossil – Varshets Falco bakalovi NMNHS 122 ca. 3.3 6.5 3.1 4.4 Recent Falco chicquera BMNH 1965.18.1 3.0 6.8 3.1 4.6 Falco chicquera BMNH 1993.2.5 3.0 6.3 2.2 3.7 Falco columbarius BMNH 1930.3.24.264 3.9 6.0 2.7 3.7 Falco columbarius BMNH 1930.3.24.267 4.2 6.2 2.4 3.8 Falco columbarius BMNH 1988.61.1 4.1 5.6 2.5 4.2 Falco naumanni BMNH 1955.15.2 3.7 6.2 2.5 4.0 Falco naumanni BMNH 1961.13.4 3.2 5.4 2.3 3.6 Falco newtoni BMNH 1897.5.10.29 2.7 5.0 2.2 3.3 Falco sparverius BMNH 1954.3.2 3.3 4.8 2.2 3.0 Falco subbuteo BMNH 1985.76.1 4.5 6.8 2.7 4.3 Falco subbuteo BMNH 1994.39.1 4.6 6.8 2.8 4.4 Falco subbuteo UCBL 111/3 3.8 7.0 3.2 4.0 Falco tinnunculus UCBL 119/1 3.8 7.3 2.9 4.2 Falco tinnunculus UCBL 119/2 3.7 6.7 2.8 4.0 Falco tinnunculus UCBL 119/6 3.6 7.0 2.9 4.0 Falco vespertinus BMNH 1855.4.4.9 4.4 5.9 2.5 3.9 Falco vespertinus UCBL 117/2 3.5 6.1 2.6 3.6 Falco vespertinus UCBL 117/4 3.8 6.4 2.6 3.7

file of trochlea carpalis; F. columbarius: slightly larger in wider cond. lateralis in ventral view; F. columbarius: size, deeper s. between pr. extesorius and the lateral con- wider impressio ansae m. iliofibularis, shorter crista su- dyle of dorso-lateral view, longer pr. extensorius; F. nau- pracondylaris medialis, wider cond. medialis in cranial manni: by the larger size and the bigger pr. pisiformis; view; F. naumanni: by the larger size, and the relatively F. newtoni: the same way as F. sparverius; F. sparverius: larger crista supracondylaris medialis; F. newtoni: by the by the larger size, and the much deeper constriction be- larger size; F. sparverius: by the larger size, and the more tween pr. extensorius and the lateral condyle of the troch- asymmetrical s. patellaris in ventral view; F. subbuteo: lea carpalis in lateral view; F. subbuteo: more proximal smaller, more developed and sharper tuberculum muscu- position of the synostosis metacarpalis proximalis, more li gastrocnemialis lateralis; F. tinnunculus: much higher reversed (upright) inception of the os metacarpale minus; crista tibiofibularis in caudal view, by the wider crista F. tinnunculus: by the slightly larger size, shorter incis- supracondylaris medialis; F. vespertinus: bigger in size, sura tendineus on the os metacarpalis majoris, and the and the smaller tuberculum m. gastrocnemialis lateralis. shorter and rounder pr. pisiformis; F. vespertinus: larger Tbt dex. dist. NMNHS 136 (Fig. 4 a, Table 11). The size, and by the bigger pr. pisisformis. specimen differs from: F. chicquera: the same way as Carpometacarpus sin. dist. NMNHS 122 (Fig. 3 i, F. subbuteo; F. columbarius: slightly larger general size, Table 9). The specimen differs from: F. columbarius: larger distal part of diaphysis, wider pons supratendineus; slightly bigger; F. subbuteo: smaller, by the round, in- F. naumanni: the same way as F. vespertinus; F. new- stead of pear-shaped protuberance of the middle part toni: the same way as F. sparverius; F. subbuteo: more of f. a. digitalis major, by its stronger protruding, by its robust and larger distal part of diaphysis, deeper depres- vertical orientation towards the joint axis, by its more sio epicondylaris lateralis; F. sparverius and F. newtoni: ventral position (reaching the edge), by the shallower s. by the larger size, and the relatively wider distal part of tendineus in its distal end; F. tinnunculus: f. a. digiti mi- diaphysis; F. tinnunculus: by the much thicker wall of the noris narrower and all differences listen for F. subbuteo; medial tendineal fossa above c. medialis, by the thinner F. vespertinus: bigger, thicker f. a. digiti majoris. cond. medialis in ventral view and by the wider (more robust) distal third of diaphysis; F. vespertinus: larger size, Skeletal elements of the hind limbs and the relatively wider distal part of diaphysis. and the pelvis girdle Tbt dex. dist. NMNHS 145 (Fig. 4 b, Table 11). The specimen differs the same way as No 136. Femur sin. dist. NMNHS 223 (Figs 3 j, k, l, Table 10). Tmt dex. prox. NMNHS 123 (Figs 4 c, d, Table 13). The specimen differs from: F. chicquera: by the clearly The specimen differs from: F. columbarius: bigger in

23 Table 10 The measurements of femur sin. dist. in some fossil and recent Falco

Taxa a b c d e Fossil – Varshets Falco bakalovi NMNHS 223 7.6 6.2 6.2 4.5 4.7 Recent Falco chicquera BMNH 1965.18.1 ca. 7.3 6.9 7.5 – 5.6 Falco chicquera BMNH 1993.2.5 7.4 6.9 6.5 4.4 4.6 Falco columbarius BMNH 1930.3.24.264 7.0 6.2 6.0 4.4 4.0 Falco columbarius BMNH 1930.3.24.267 7.5 6.5 6.3 4.3 4.4 Falco columbarius BMNH 1988.61.1 7.9 6.9 6.8 4.4 4.3 Falco naumanni BMNH 1955.15.2 6.6 5.8 5.3 4.0 3.8 Falco naumanni BMNH 1961.13.4 6.1 5.8 5.2 4.0 3.5 Falco newtoni BMNH 1897.5.10.29 6.4 5.0 5.0 ca. 2.6 3.7 Falco sparverius BMNH 1954.3.2 6.3 5.7 5.5 3.7 4.4 Falco subbuteo BMNH 1974.16.1 8.3 7.4 7.0 5.0 4.8 Falco subbuteo BMNH 1985.76.1 7.7 6.6 6.6 4.1 4.0 Falco subbuteo BMNH 1994.39.1 8.5 7.2 6.8 4.6 4.7 Falco tinnunculus BMNH 1930.3.24.275 8.2 7.1 6.2 5.6 4.5 Falco tinnunculus BMNH 1930.3.24.276 8.2 7.2 6.5 4.6 5.0 Falco tinnunculus BMNH 1930.3.24.278 7.7 6.8 6.0 4.1 4.0 Falco vespertinus BMNH 1855.4.4.9 6.4 5.9 5.8 4.6 4.2 Falco vespertinus BMNH 1869.10.19.12 6.2 5.5 5.4 4.5 4.9 Falco vespertinus BMNH 1952.3.122 6.8 5.9 6.0 4.2 4.2

size, less prominent lateral edge of c. lateralis; F. sub- Tmt sin. NMNHS 144 (Fig. 4 f; Table 12). The speci- buteo: smaller size, probably lower crista medialis hy- men belongs to a juvenile individual of almost definite potarsi (partly broken); F. tinnunculus: by the shallower size. The specimen differs the same way as No 123. c. medialis in cranial view; F. vespertinus: bigger in size. Phalanx 1 dig. I pedis dex. NMNHS 319 (Fig. 4 g, Tmt dex. prox. NMNHS 143 (Fig. 4 e, Table 12). Table 14). The specimen differs from: F. columbarius: The specimen differs from: F. columbarius: more angu- thicker phalangeal body; F. subbuteo: smaller, slight- lar instead round, c. medialis; F. subbuteo: higher facies ly more asymmetrical trochlea a. in cranial view; F. subcutanea medialis and facies subcutanea lateralis; F. tinnunculus: by the smaller dimensions, and particu- tinnunculus: lower eminentia intercondylaris; F. colum- larly lesser diameter of the condyles of the trochlea; barius: bigger, wider proximal third of diaphysis. F. ves- F. vespertinus: bigger, both condyles more parallel in pertinus: bigger in size. dorsal view. ←

Fig. 4. Falco bakalovi Boev (Photographs: Assen Ignatov) a, tbt dex. dist. NMNHS 136 b, tbt dex. dist. NMNHS 145 c, d, tmt dex. prox. NMNHS 123 e, tmt dex. prox. NMNHS 143 f, tmt sin. NMNHS 144 g, phalanx 1 dig. I pedis dex. NMNHS 319 h, phalanx 1 dig. I pedis dex. NMNHS 320 i, phalanx 1 dig. I pedis dex. NMNHS 321 j, phalanx 2 dig. II pedis dex. NMNHS 317 k, phalanx 2 dig. II pedis sin. NMNHS 318 l, phalanx dist. dig. 1 pedis dex. NMNHS 181 – lateral view (above) and caudal view (bellow)

24 25 Table 11 The measurements of tibiotarsus dex. dist. in some fossil and recent Falco

Taxa a b c d e Fossil – Varshets Falco bakalovi NMNHS 136 6.8 5.5 ca. 5.1 4.3 6.0 Falco bakalovi NMNHS 145 ca. 7.2 5.5 – 4.0 5.0 Recent Falco chicquera BMNH 1965.18.1 7.8 6.0 6.3 4.6 5.4 Falco chicquera BMNH 1993.2.5 6.7 5.0 5.4 3.9 4.3 Falco columbarius BMNH 1930.3.24.264 6.0 5.0 4.7 3.6 4.0 Falco columbarius BMNH 1930.3.24.267 6.7 5.3 5.0 3.5 4.3 Falco columbarius BMNH 1988.61.1 6.9 5.4 5.0 3.8 4.4 Falco naumanni BMNH 1955.15.2 6.0 4.6 4.8 3.2 4.0 Falco naumanni BMNH 1961.13.4 5.6 4.7 4.6 3.3 3.5 Falco newtoni BMNH 1897.5.10.29 5.6 4.5 4.5 3.1 4.3 Falco sparverius BMNH 1954.3.2 5.6 4.5 4.4 3.5 4.0 Falco subbuteo BMNH 1974.16.1 7.1 5.3 5.8 3.7 4.4 Falco subbuteo BMNH 1985.76.1 6.7 5.1 5.2 3.3 4.1 Falco subbuteo BMNH 1994.39.1 7.2 5.6 5.9 4.2 4.3 Falco tinnunculus BMNH 1930.3.24.275 7.1 5.6 5.7 4.4 4.8 Falco tinnunculus BMNH 1930.3.24.276 6.8 5.7 5.6 4.1 4.6 Falco tinnunculus BMNH 1930.3.24.278 6.6 5.4 5.3 3.7 4.2 Falco vespertinus BMNH 1855.4.4.9 5.7 4.6 4.7 3.4 4.1 Falco vespertinus BMNH 1869.10.19.12 5.2 4.7 4.5 3.3 3.5 Falco vespertinus BMNH 1952.3.122 6.2 4.9 4.6 3.6 4.4

Table 12 The measurements of tarsometatarsus sin. in some fossil and recent Falco (ref. to Fig. 1 J, K)

Taxa a b c d e Fossil – Varshets Falco bakalovi NMNHS 143 7.1 – – 2.9 – Falco bakalovi NMNHS 144 7.6 39.5 ca. 2.2 2.8 3.5 Recent Falco columbarius NMNHS 1/1997 6.9 35.5 2.5 3.3 4.6 Falco columbarius NMNHS 2/2002 6.5 36.3 2.2 2.8 4.3 Falco subbuteo NMNHS 1/1989 8.4 35.7 3.4 3.4 5.1 Falco subbuteo NMNHS 3/1993 6.9 35.4 3.2 3.1 4.6 Falco tinnunculus UCBL 119/7 7.4 40.7 2.6 3.2 4.3 Falco tinnunculus NMNHS 10/1991 7.4 41.4 2.7 3.0 4.4 Falco vespertinus NMNHS 1/1991 6.2 29.3 2.3 2.7 3.6

Phalanx 1 dig. I pedis dex. NMNHS 320 (Fig. 4 h, “parallelity” of the surfaces of both condyles of the Table 14). The specimen differs the same way as No 319. trochlea; F. vespertinus: biger, both condyles more Phalanx 1 dig. I pedis dex. NMNHS 321 (Fig. 4 i, parallel in dorsal view. Table 14). The specimen belongs to a juvenile/sub- Phalanx 2 dig. II pedis dex. NMNHS 317 (Fig. 4 j, adult individual of almost definite size. It differs Table 15). The specimen differs from: F. columbarius: from: F. columbarius: more concave ventral side in bigger and more robust; F. subbuteo: smaller, by the wid- the proximal end; F. subbuteo: smaller; F. tinnun- er f. a. (measurement “c”); F. tinnunculus: by the smaller culus: by the smaller dimensions, and by the higher diameter of the phalangeal trochlea, narrower trochlea

26 Table 13 The measurements of tarsometatarsus dex. prox. in some fossil and recent Falco (ref. to Fig. 1 L)

Taxa a b c d e Fossil – Varshets Falco bakalovi NMNHS 123 3.7 3.1 4.4 7.7 7.2 Recent Falco chicquera BMNH 1965.18.1 4.2 3.6 5.4 8.9 7.2 Falco chicquera BMNH 1993.2.5 3.3 3.2 4.7 7.8 7.0 Falco columbarius BMNH 1930.3.24.264 2.9 2.8 4.0 6.5 6.4 Falco columbarius BMNH 1930.3.24.267 3.9 2.9 4.5 7.6 7.0 Falco columbarius BMNH 1988.61.1 3.4 3.1 4.4 7.5 6.9 Falco naumanni BMNH 1955.15.2 3.0 2.7 3.8 6.5 6.2 Falco naumanni BMNH 1961.13.4 3.1 2.7 3.7 6.3 5.7 Falco newtoni BMNH 1897.5.10.29 3.0 2.6 3.7 5.2 5.8 Falco sparverius BMNH 1954.3.2 3.1 2.7 3.6 6.2 5.7 Falco subbuteo BMNH 1974.16.1 3.6 3.2 4.8 7.9 7.4 Falco subbuteo BMNH 1985.76.1 3.6 3.4 4.8 7.6 7.0 Falco subbuteo BMNH 1994.39.1 3.6 3.4 5.2 8.3 7.2 Falco tinnunculus BMNH 1930.3.24.275 3.7 3.3 4.5 7.7 7.0 Falco tinnunculus BMNH 1930.3.24.278 3.6 2.8 4.5 7.3 6.9 Falco tinnunculus UCBL 119/7 3.4 2.8 3.8 7.7 7.0 Falco vespertinus BMNH 1855.4.4.9 3.1 3.0 3.7 6.5 6.2 Falco vespertinus BMNH 1869.10.19.12 2.8 2.7 3.6 6.0 5.4 Falco vespertinus BMNH 1952.3.122 3.0 2.6 3.9 6.9 6.7

Table 14 The measurements of phalanx 1 dig. I pedis in some fossil and recent Falco (ref. to Fig. 1 M)

Taxa a b c d e f Fossil – Varshets Falco bakalovi NMNHS 319 2.4 2.2 3.2 2.2 9.9 1.4 Falco bakalovi NMNHS 320 2.6 2.6 3.3 2.3 10.3 1.3 Falco bakalovi NMNHS 321 2.2 2.0 3.3 2.2 10.4 1.3 Recent Falco columbarius NMNHS 2/2002 2.2 2.4 3.3 2.2 9.7 1.2 Falco subbuteo NMNHS 1/1989 2.6 2.5 4.1 2.9 12.6 1.6 Falco subbuteo NMNHS 3/1993 2.2 2.0 3.2 2.2 10.3 1.2 Falco tinnunculus NMNHS 10/1991 2.6 2.3 3.8 2.6 11.0 1.4 Falco tinnunculus UCBL 119/1 2.5 2.4 3.9 2.5 11.4 1.5 Falco tinnunculus UCBL 119/2 2.4 2.2 3.6 2.5 10.3 1.4 Falco tinnunculus UCBL 119/3 2.2 2.1 3.3 2.3 9.8 1.3 Falco tinnunculus UCBL 119/7 2.4 2.2 3.7 2.3 10.7 1.4 Falco vespertinus NMNHS 1/1991 2.0 2.0 3.0 2.0 8.5 1.1

(measurement “a”), possibly indication of more primitive er; F. tinnunculus: The same way as No 317; F. vesperti- raptority, i. e. narrower and less strong claws; F. vesper- nus: bigger and more robust. tinus: bigger and more robust. Phalanx dist. dig. 1 pedis dex. NMNHS 181 (Fig.4 l, Phalanx 2 dig. II pedis sin. NMNHS 318 (Fig. 4 k, Table 16). The specimen differs from: F. columbarius: Table 15). The specimen belongs to a juvenile/subadult more robust; F. subbuteo: wider articular surfaces (meas- individual of almost definite size. The specimen differs urement “d”); F. vespertinus: bigger in size and wider from: F. columbarius: narrower distal end; F. subbuteo: f. a.; F. vespertinus: bigger; Falco tinnunculus: by the by the wider f. a. (measurement “c”); F. subbuteo: small- shorter base of the attachment of the muscle.

27 Table 15 The measurements of phalanx 2 dig. II pedis in some fossil and recent Falco (ref. to Fig. 1 M) Taxa a b c d e f Fossil – Varshets Falco bakalovi NMNHS 317 1.9 1.8 2.6 2.2 9.7 1.4 Falco bakalovi NMNHS 318 1.9 1.9 2.6 2.2 9.8 1.3 Recent Falco columbarius NMNHS 2/2002 2.0 1.9 2.5 2.5 9.3 1.1 Falco subbuteo NMNHS 1/1989 2.5 2.6 3.1 2.9 12.5 1.6 Falco subbuteo NMNHS 3/1993 1.8 1.8 2.0 1.9 9.8 1.0 Falco subbuteo UCBL 111/1 1.6 1.7 1.9 1.8 9.0 1.2 Falco tinnunculus NMNHS 10/1991 2.1 2.0 2.4 2.4 9.8 1.3 Falco tinnunculus UCBL 119/2 1.9 1.9 2.2 2.2 9.1 1.2 Falco tinnunculus UCBL 119/3 2.0 2.0 2.5 2.4 9.7 1.3 Falco tinnunculus UCBL 119/7 2.1 2.1 2.4 2.3 9.9 1.2 Falco vespertinus NMNHS 1/1991 1.7 1.8 2.2 2.0 8.7 1.1

Table 16 The measurements of phalanx dist. dig.I pedis in some fossil and recent Falco (ref. to Fig. 1 N)

Taxa a b c d Fossil – Varshets Falco bakalovi NMNHS 181 3.2 2.8 ca. 10.2 2.6 Recent Falco columbarius NMNHS 2/2002 2.8 3.1 9.5 2.4 Falco subbuteo NMNHS 1/1989 3.2 3.2 10.1 2.7 Falco subbuteo NMNHS 3/1993 3.4 4.7 9.5 2.1 Falco subbuteo UCBL 111/1 3.0 2.7 9.1 2.0 Falco tinnunculus NMNHS 10/1991 3.8 2.9 10.5 2.6 Falco tinnunculus UCBL 119/1 3.2 3.0 10.1 2.6 Falco tinnunculus UCBL 119/2 3.1 2.7 10.2 2.4 Falco tinnunculus UCBL 119/3 3.0 2.9 9.5 2.4 Falco tinnunculus UCBL 119/7 3.5 2.9 10.2 2.8 Falco vespertinus NMNHS 1/1991 4.0 2.8 8.0 1.8

DISCUSSION other paper (Boev, 1999a), describing the fossil species Falco bakalovi. The abundant excavated avian material The comparative analysis of the examined finds un- (1589 finds, Boev, 2002; over 1700 finds, Boev, inpubl. equivocally shows that they could only be referred to data) collected so far, and its examination shows that no the so-called “tinnunculus” group (Falco sp. ex gr. tin- taxa are represented by now by a single find, and most nunculus) of the smaller falcons in the genus Falco, well of them are represented by several (even several dozens separated from the “cherrug” group of the larger falcons. of bones). Some finds, however, because of the worse degree of The smallest Old World falcons (Microhierax Sharpe, their preservation, or being specimens of immature indi- 1874 and Polihierax Kaup, 1847) are excluded from our viduals, could not be accepted as reliable proofs for the comparison, because of their evident strong metrical dif- former existing of a concrete definite species of Falco ferences. Their skeletal elements are more than twice sp. ex gr. tinnunculus. Having in mind the common col- smaller compared to specimens of these genera. lecting of all material (common sample and horizon), and The sexual dimorphism in size should also be taken their dimensional characteristics, we refer all finds to a into account. Hill (1944) examining Falconiformes in single species. Its skeletal elements clearly differ from general, stated that falcons of genus Falco constitute a all compared species of the recent fauna. They could group of species demonstrating the most expressed sexual not be referred also to the hitherto known fossil taxa of dimorphism (concerning length of the wing, tail, tarsus, genus Falco. Considerations for that have been given in and bill), reaching up to 37.8 % (male to female meas-

28 urements). The only feature (tarsus length) where the for their hospitality and help during the research visits at bone structure determines much the size varies between their institutions. Special thanks to Dr. Nikolay Spassov 2.0 and 20.5 %. On the other hand, Cramp and Simmons (NMNHS) and an anonymous reviewer who improved (1980) noted that in F. t. tinnunculus, for example, the the former version of the manuscript. “sex differences [are] significant for adult and juvenile, except for tarsus”. According to them these differences in the wing length reach 6.30 to 8.48 %. Obviously the APPENDIX 1 skeletal elements differ less. Two measurements of the proximal ulna show that Examined specimens belonging the length of depressio m. brachialis in F. bulgaricus to recent species of Falconiformes is 12.3 mm, while in F. bakalovi it is 7.9 to 8.3. On the other hand, the longitudinal diameter of cotyla ventralis Accipiter nisus (Linnaeus, 1758); UCBL 96/6; UCBL in F. bulgaricus is ca. 4.9 mm while in F. bakalovi it is 96/10; 4.4 to 4.5 mm (Boev, 2011; Table 4). The general ap- Falco chicquera Daudin, 1800: BMNH 1965.18.1, pearance of the proximal ulna, distal humerus and dis- BMNH 1993.2.5; tal tibiotarsus of F. bakalovi considerably differs from Falco columbarius Linnaeus, 1758: BMNH 1930.3.24. F. bulgaricus. All these skeletal elements are much 264, 1930.3.24.267, BMNH 1988.61.1; stouter and robust. Falco naumanni Fleischer, 1818: BMNH 1955.15.2, The morphology and size of F. bakalovi show that BMNH 1961.13.4; it was a close late Pliocene relative to recent F. tinnun- Falco newtoni Gurney, 1863: BMNH 1897.5.10.29; culus, having similar ecological features and biology. Falco sparverius Linnaeus, 1758: BMNH 1954.3.2; Until now it is the most abundant raptorial bird, found Falco subboteo Linnaeus, 1758: BMNH 1974.16.1, BMNH in the Varshets locality and in Bulgaria at all (26 finds; 1994.39.1, UCBL 111/1, UCBL 111/2, UCBL 111/3, 4 individuals). UCBL 111/4; Falco tinnunculus Linnaeus, 1758: BMNH 1930.3.24.275, Acknowledgments BMNH 1930.3.24.276, BMNH 1930.3.24.278, UCBL 119/1, UCBL 119/2, UCBL 119/3, UCBL 119/4, UCBL The Foundation Scientifique de Lyon et du Sud-Est 119/6, UCBL 119/7, UCBL 119/8; (Lyon), the Short-term Visits Program of the Royal Falco vespertinus Linnaeus, 1766: BMNH 1855.4.4.9, Society (London), the National Science Fund, Sofia, grant BMNH 1869.10.19.12, BMNH 1952.3.122, UCBL No B-202/1992), and the National Museum of Natural 117/1, UCBL 117/2, UCBL 117/4; History (Sofia) have supported the study. The author is Microhierax caerulescens (Linnaeus, 1758): BMNH very grateful to Dr. Cécile Mourer-Chauviré (UCBL), 2002.41.2; Dr. Robert Prys-Jones and Dr. Joanne Cooper (BMNH) Polihierax semitorqutus (Smith, 1846): BMNH 2002.41.1.

References

Baumel, J. J., Witmer, L. M. 1993. 4. Osteologia. In: Baumel, Birds of Western Palearctic, Vol. II. Hawks to Bustards. J., King, A., Breazile, J., Evans, H., Van den Berge, J., Oxford University Press, 695 pp. (Eds.). Handbook of Avian Anatomy, Nomina Anatomica Guerin, C. 1990. Biozones or Mammal Units? Methods and Avium 23, 45–132. Nutall Ornithological Club. limits in Biochronology. In: Linday, E.H., Fahlbusch, V., Boev, Z. 1999a. Falco bakalovi sp. n. – a Late Pliocene falcon Mein, P. (Eds.). European Neogene mammal Chronology. (Falconidae, Aves) from Varshets (W Bulgaria). Geologica Plenum Press, New York, 116–130. Balcanica 29(1–2), 131–135. Hill, N. P. 1944. Sexual dimorphism in the Falconiformes. The Boev, Z. 1999b. Neogenski i kvaternerni ptitsi (Aves) ot Auk, 61, 228–234. Balgariya. [Neogene and Quaternary birds (Aves) from Livezey, B. C., Zusi, R. L. 2006. Higher-order phylogeny of Bulgaria]. DSci. Thesis, National Museum of Natural modern birds (Theropoda, Aves: Neornithes) based on History, Bulgarian Academy of Sciences, Sofia, 243 pp. comparative anatomy: I. Methods and Characters. Bulletin supplements (in Bulgarian, unpublished). of Carnegie Museum of Natural History, Pittsburgh, 37, Boev, Z. 2002. Neogene avifauna of Bulgaria. In: Zhou, Z., 502–544. Zhang, F. (Eds.) Proceedings of the 5th Symposium of Mein, P. 1990. Updating of MN zones. In: Lindsay, E.H., the Society of Avian Paleontology and Evolution, Beijing, Fahlbusch, V., Mein, P. (Eds.) European Neogene mammal 29–40. chronology. Plenum Press, New York, 73-90. Boev, Z. 2011. Falco bulgaricus sp. n. (Aves, Falconiformes) Mlíkovský, J., 2002. Cenozoic Birds of the World. Part 1, from the Middle Miocene of Hadzhidimovo (SW Bulgaria). Europe. Praha, Ninox Press. 406 pp. Acta zoologica bulgarica 63(1), 17–35. Popov, V. 2001. Late Pliocene voles (Mammalia, Arvicolidae) Cramp, S., K., Simmons, E. L. (Eds.). 1980. Handbook of the from Varshets (North Bulgaria). Acta zoologica cracovien- Birds of Europe the Middle East and North Africa. The sia 44(2), 143–172.

29 Spassov, N. 1997a. Varshets and Slivnitsa – new localities of Spassov, N. 2003. The Plio-Pleistocene vertebrate fauna in Villafranchian vertebrate fauna from Bulgaria (taxonomic South-Eastern Europe and the megafaunal migratory waves composition, biostratigraphy and climatochronology). from the east to Europe. Revue de Paléobiologie. 22(1), Geologica Balcanica 27(1–2), 83–90. 197–229. Spassov, N., 1997b. Villafranchian succession of mammalian Umanskaya, A. S. 1981. The Miocene birds of the western megafaunas from Bulgaria and the biozonation of South- Black Sea coasts of the Ukrainian SSR. Vestnik Zoologii East Europe. In: Aguilar, J.-P., Legendre, S., Michaux, 17(3), 17–21 (in Russian with English abstract). J. (Eds.), Actes du Congres Biochrom’97. Mémoires et White, C. M., Olsen, P. F., Kiff, L. F. 1994. Family Falconidae travaux de l’Institut de Montpellier de l’École Pratique des (Falcons and Caracaras). In: del Hoyo, J., Elliot, A., Hautes Études 21, 669–676. Sargatal, J. (Eds.). Handbook of the Birds of the World. Spassov, N. 2000. Biochronology and zoogeographic affinities Vol. 2. New World Vultures to Guineafowl. Lynx Edicions, of the Villafranchian faunas of Bulgaria and South Europe. Barcelona, 216–275. Historia naturalis bulgarica 12, 89–128. Wikipedia 2011. Falcon. At: http://en.wikipedia.org/wiki/Falcon.