Submitted : July 9th , 2020 – Accepted : December 30 th , 2020 – Posted online : January 29 th , 202 1 To link and cite this article: doi: 10.5710/AMGH.30.12.2020.3379 1 NEW RECORD OF THE VAMPIRE DESMODUS DRACULAE (CHIROPTERA) FROM 2 THE LATE PLEISTOCENE OF ARGENTINA 3 NUEVO REGISTRO DE DESMODUS DRACULAE (CHIROPTERA) DEL PLEISTOCENO 4 TARDÍO DE ARGENTINA 5 6 SANTIAGO BRIZUELA*,1 and DANIEL A. TASSARA2 7 1Universidad Nacional de Mar del Plata, CONICET, Departamento de Biología, Facultad de 8 Ciencias Exactas y Naturales, Mar del Plata, Argentina. Funes 3250, B7602AYJ Mar del Plata, 9 Argentina. [email protected] 10 2 Museo Municipal de Ciencias Naturales Pachamama, Niza 1065, B7609LNC Santa Clara del Mar, 11 Partido de Mar Chiquita, provincia de Buenos Aires, Argentina. 12 13 16 pag. (text + references); 3 figs.; 2 tables 14 15 Running Header: BRIZUELA AND TASSARA: LATE PLEISTOCENE VAMPIRE FROM 16 MIRAMAR 17 Short Description: The presence of Desmodus draculae, an extinct giant vampire bat, from the 18 Pleistocene of Buenos Aires is confirmed. 19 Corresponding author: Santiago Brizuela, [email protected] 20 21 22 Keywords. Vampire. Bat. Desmodontinae. Dentary. Miramar. 23 Palabras clave. Vampiro. Murciélago. Desmodontinae. Dentario. Miramar 1 24 25 BATS (Chiroptera) are one of the most diverse groups of extant mammals (Amador et al., 2018), but 26 this diversity is not represented in their fossil record (Teeling et al., 2005). In Argentina there are 27 presently four bat families represented, all Yangochiroptera, with more than 60 species (Díaz et al., 28 2016). In contrast with this diversity, the fossil record of bats in Argentina is scarce and patchy 29 (Czaplewski, 2010), mostly accounting for very few, isolated, partial elements (Table 1). 30 One interesting record of fossil bats of Argentina is that of an isolated upper canine from the 31 late Holocene of southeast Buenos Aires referred to Desmodus cf. D. draculae (Pardiñas & Tonni, 32 2000), a large, extinct vampire. This species had a large late Pleistocene–late Holocene distribution 33 from Mexico to Argentina (see Ubilla et al., 2019). However there is some taxonomic uncertainty 34 (cf., aff.) regarding the specific assignation of the fossils of D. draculae at its latitudinal limits. Here 35 new fossil material from Late Pleistocene sediments outcropping near the city of Miramar 36 (Argentina) (Fig. 1) is described and discussed. 37 Institutional Abbreviations. CML, Colección Mastozoológica, Fundación Miguel Lillo, 38 Univerdidad Nacional de Tucumán, Tucumán, Argentina; LIEB-PV, Laboratorio de 39 Investigaciones en Evolución y Biodiversidad, Universidad Nacional de la Patagonia “San Juan 40 Bosco”, Esquel, Argentina; MLP, Museo de La Plata, Universidad Nacional de La Plata, La Plata, 41 Argentina. MPH-P, Museo Municipal Punta Hermengo, Collección Paleontológica, Miramar, 42 Argentina. 43 MATERIALS AND METHODS 44 The fossil here described is housed in the Colección Paleontológica of the Museo Municipal 45 Punta Hermengo (MPH-P). It was studied under stereoscope microscope, and compared to available 46 reference materials (Diaemus youngi CML 1343; Desmodus rotundus CML 8664), specimens 47 available in MorphoSource (https://www.morphosource.org), and bibliography. Images were 48 obtained by Scanning Electron Microscope (SEM) at the Laboratorio de Microscopía Electrónica of 2 49 the Universidad Nacional de Mar del Plata. Osteology follows Giannini et al. (2006) with 50 comments from Rädulet (2006). Systematics follows that of Cirranello et al. (2016). Dentary 51 measurements from Morgan et al. (1988), Barquez et al. (1999), and Davis et al. (2010) were used 52 for comparison. 53 Stratigraphical provenance. The fossil site is located 700 m north of the mouth of the La 54 Ballenera stream (38° 19' 25.60" S; 57° 56' 6.74" W), 9 km south of Punta Hermengo (Miramar 55 city) (Fig. 1). The fossil was located in situ within a cave section (1.2 m diameter) which is 56 attributed to a Mylodontidae. The cave section is situated near the top of a 5 m sea cliff in which six 57 stratigraphic units can be recognized (Fig. 2). The lower deposits, units A–C, which are topped by 58 calcrete levels (C 1–3), correlated to units A–D of Tonni & Fidalgo (1982), units I–III of Alberdi et 59 al. (2006), and units A–E of Soibelzon et al. (2010). The faunistic content of these units 60 corresponds to Ensenadan Age/stage. The top units D–E, and the calcrete level atop (C 4) are 61 considered as Lujanian sensu lato, and could correlate to units E and F of Tonni & Fidalgo (1982). 62 Unit F is where the cave develops, this unit is transgressive to units D–E, and the surface form 63 where MPH-P 302 was recovered is at the level of unit E, close to C4. Unite F is assigned to the 64 Lujanian sensu stricto Stage/Age given that it correlates to unit G of Tonni & Fidalgo (1982) and 65 unit IV of Alberdi et al. (2006), which correspond to the Equus (Amerhippus) neogeus biozone 66 (Cione & Tonni, 2005). This is consistent with Glyptodon reticulatus shield fragments (MPH-P 034) 67 recovered in the superior part of unit F, above the cave. 68 69 SYSTEMATIC PALEONTOLOGY 70 71 Order CHIROPTERA Blumenbach, 1779 72 Family PHYLLOSTOMIDAE Gray, 1825 73 Subfamily DESMODONTINAE Wagner, 1840 3 74 Tribe DESMODONTINI Wagner, 1840 75 Genus Desmodus Wied-Neuwied, 1826 76 Type species. Desmodus rotundus (Geoffroy, 1810) 77 Desmodus draculae Morgan et al., 1988 78 Figure 3 79 Geographic occurrence. Mexico, Belize, Venezuela, Brazil, Uruguay, and Argentina. 20° N–38° S. 80 Stratigraphic occurrence. late Pleistocene–late Holocene. 81 Referred material. MPH-P 302, right dentary with no preserved teeth. 82 DESCRIPTION 83 A robust right dentary with the corpus mandibulae half the total length of the mandible (LM 84 = 18.79 mm). The margo alveolaris (length of mandible tooth row = 8.63 mm) presents six alveoli 85 (i2, c1, 3 postcanine), the three anterior (i1, i2, c) are circular–subcircular while the following are 86 oval, labiolingually compressed (pm1, pm2, m1). All alveoli have only one root. Posterior to the 87 last one there is a shallow depression. 88 In lateral view (Fig. 3.1) the dentary is excavated (not the coronoid process), with a strong 89 ventral ridge that extends posteriorly from the anterior premolar. In this same view, the most 90 posteromedial part of the symphysis is exposed, projecting posteroventrally a very short distance 91 from the ventral border of the dentary. Two foramina are observed, the anterior (below i2) and the 92 posterior (below pm1) mental foramina. The ramus mandibulae is close to quadrangular in outline. 93 The linea obliqua mandibulae of the coronoid process (= processus coronoideus) raises vertically 94 (close to 20° from the vertical), the coronoid process is of the same height of the condyloid process 95 (processus condylaris/condyloideus). Between these processes the incisura mandibulae is straight, 96 horizontal. The dorsal posterior border of the ramus mandibulae is vertical up to the small non 97 nominatus processus (see Rädulet, 2006 for synonyms) which is located at mid height (above the 4 98 margo alveolarias plane). Ventral to the non nominatus processus the posterior border of the ramus 99 mandibulae is inclined for a short distance. 100 Medially (Fig. 3.2) the symphysis is irregular, interdigitating with its counterpart. There is a 101 diastema from the symphysial articulation to the first incisive. Above the symphysis, lingual to both 102 incisors there is no evident pocket/depression for the upper incisors. In this view two foramina are 103 exposed. An anterior one, very small, on the symphysis below the canine. A second larger one, the 104 mandibular foramen, at the end of a groove in the center of the ramus mandibulae. In this view the 105 coronoid process is excavated. At mid height on the posterior part of the ramus mandibulae is a 106 short, horizontal crest that precedes the non nominatus processus. Ventral to the non nominatus 107 processus the posterior border of the dentary curves medially. 108 DISCUSSION 109 The general morphology of MPH-P 302 resembles that of vampire bats (Desmodontinae). 110 Among extant vampire bats the fossil shares with the Desmodontini (Desmodus and Diaemus) the 111 dentary dental formula (2121), the diastema between incisors, and an unfused symphysis, unlike 112 Diphylla (Allen, 1896; Burns, 1972; Davis et al., 2010; Scheffer et al., 2015). The fossil and 113 Desmodus present the coronoid process as tall as the condyloid process, with a straight, horizontal 114 incisura mandibulae, unlike Diaemus in which the coronoid process is taller than the condyloid 115 process. Furthermore, the diastema between left and right incisors is inferred large, more like that of 116 Desmodus (Scheffer et al., 2015). Desmodus is the only genus of Desmodontinae with known fossil 117 species (D. archaeodaptes, D. draculae, and D. stocki) (see Orihuela (2011) for discussion on D. 118 puntajudensis). Among all Desmodus spp. the fossil shares the large size (Table 2) and, more 119 significantly (autapomorphies), the straight ventral border and absence of pocket/depression behind 120 incisors (to accommodate the upper incisors), with Desmodus draculae (Morgan et al., 1988). 121 Therefore, from the aforementioned, MPH-P 302 is referred to D. draculae. 5 122 Unlike MPH-P 302, previous mid latitude records were assigned to D. draculae with caution 123 (cf. and aff.). This dentary removes the reasonable doubts and confirms the presence of this species 124 at mid latitudes (≈38 °S, Argentina) during the Late Pleistocene. At present the Desmontini have the 125 southernmost distribution of the Desmodontinae, where both Diaemus youngi and Desmodus 126 rotundus reach Argentina (Fig. 1). The southernmost present distribution of the Desmodontinae (D.