Bollettino della Società Paleontologica Italiana, 50 (2), 2011, 135-143. Modena, 31 ottobre 2011135 New remains of Paralutra garganensis Willemsen, 1983 (Mustelidae, Lutrinae) from the Late Miocene “Terre Rosse” of Gargano (Apulia, Italy) Boris VILLIER, Marco PAVIA & Lorenzo ROOK B. Villier, Università degli Studi di Torino, Dipartimento di Scienze della Terra, via Valperga Caluso 35, I-10125, Torino, Italy; [email protected] M. Pavia, Università degli Studi di Torino, Dipartimento di Scienze della Terra, via Valperga Caluso 35, I-10125, Torino, Italy; [email protected] L. Rook, Università degli Studi di Firenze, Dipartimento di Scienze della Terra, via G. La Pira 4, I-50121, Firenze, Italy; [email protected] KEY WORDS - Paralutra garganensis, Mikrotia fauna, Late Miocene, Gargano, Italy. ABSTRACT - A short account is presented here of the discovery of new material attributable to Paralutra garganensis Willemsen, 1983, the only carnivore species documented from the Late Miocene endemic “Terre Rosse” faunal complex (also referred to as the “Mikrotia fauna”). Although thousands of fossil remains of the “Mikrotia fauna” have been collected during extensive sampling campaigns carried out since the 1970’s, Paralutra garganensis was to date only represented by the type specimens. The recent revision of material belonging to the “Mikrotia fauna” housed in Museum collections in Firenze and Torino (Italy) and Leiden (Netherlands) has allowed the identification of the specimens described herein and, furthermore, has highlighted new evidence regarding the ecology of the species. The latter findings in turn broaden our understanding to date of the ecological structure of the “Mikrotia fauna”. RIASSUNTO - [Nuovi resti di Paralutra garganensis Willemsen, 1983 (Mustelidae, Lutrinae) dai depositi a “Terre Rosse” del Miocene Superiore del Gargano (Puglia, Italia)] - In questa breve nota vengono descritti nuovi resti attribuibili a Paralutra garganensis Willemsen, 1983, l’unica specie di mammifero carnivoro conosciuta all’interno del complesso faunistico del Miocene Superiore delle “Terre Rosse” del Gargano (noto anche come “Fauna a Mikrotia”). Tra le molte migliaia di resti attribuiti alla “Fauna a Mikrotia” raccolti a partire dalla fine degli anni 1970, Paralutra garganensis era rappresentato solo dalla serie-tipo. La recente revisione dei materiali conservati a Firenze, Torino e Leiden ha permesso l’identificazione del nuovo materiale descritto nel presente lavoro, con ulteriori indicazioni sull’ecologia della specie. Questi nuovi dati permettono anche di aumentare le conoscenze sulla struttura ecologica della “Fauna a Mikrotia”. INTRODUCTION the area between Apricena and Poggio Imperiale in the western part of the Gargano, are well known in the Fossil insular faunas are generally referred to in the literature since the late 1970’s (Freudenthal, 1971; Abbazzi paleontological literature as unbalanced impoverished et al., 1996; Masini et al., 2010). The vertebrate fossil- faunas (MacArthur & Wilson, 1963; Sondaar, 1977). bearing infillings of the extensive karst system network Even through insular faunas may contain relatively (Abbazzi et al., 1996; Pavia et al., 2010) document two large numbers of endemic taxa, the term “impoverished” different population phases, a Late Miocene endemic indicates that taxonomic diversity is poor at the higher faunal association (the so called “Mikrotia fauna”) and a levels with many major groups absent. In addition, insular late Villafranchian continental faunal assemblage, a fauna faunas are usually referred to as “unbalanced” because of in literature referred to as “Pirro”, or “Dell’Erba”, from the absence of large terrestrial carnivores. As a matter of the family names of different quarry owners, or “Pirro fact, otters form by far the majority of the fossil insular Nord” (Abbazzi et al., 1996; Arzarello et al., 2007, 2009; carnivores, while other carnivores are generally lacking Pavia et al., 2011). from endemic insular faunas (Van der Geer et al., 2010). For the purpose of the present note, we limit our As an exception to this general rule, mustelids, hyaenids attention to the Late Miocene population phase. The and canids are among the taxa sporadically occurring in “Mikrotia fauna” is named after one of the most insular endemic fossil assemblages (Rook et al., 2004; representative elements, the endemic stephanodont murid Theodorou et al., 2007; Lyras et al., 2010). The aim of the of the genus Mikrotia. Faunal elements belonging to this present note is to report on new carnivore specimens from faunal assemblage display highly developed endemic the endemic insular Late Miocene “Terre Rosse” faunal characteristics and record evolutionary radiations complex (also known as “Mikrotia fauna”) in the Gargano indicating that there were only sporadic communications area, southern Italy (Masini et al., 2010). (testified by new immigrants) with the continental mainland (De Giuli et al., 1985, 1990; Rook et al., 2006; Van den Hoek-Ostende et al., 2009; Freudenthal & Martín- CARNIVORE RECORD IN THE GARGANO Suárez, 2010). “TERRE ROSSE” FAUNAL COMPLEX Practically all mammals of the “Mikrotia fauna” show marked endemic features and most of the genera Rich vertebrate bearing karst fissure infillings, are restricted to this endemic paleo-bioprovince (like the outcropping thanks to an intense quarrying activity in galericine Deinogalerix, the murid Mikrotia, the glirid ISSN 0375-7633 doi:10.4435/BSPI.2011.13 136 Bollettino della Società Paleontologica Italiana, 50 (2), 2011 was till now represented by a left maxillary fragment with M1 and P4 (Figs 1, 2a) and a right calcaneum (Fig. 4a), constituting the type series of the species described by Willemsen (1983) as Paralutra garganensis. The revision of the collections stored at the Università di Firenze allowed the identification of a new specimen of Paralutra garganensis. Moreover, the revision of the Leiden collections, and the recent (2000) field work by a team from the Università di Torino, allowed us to identify the occurrence of more fossils representing additional carnivore material. Despite the lack of comparative material of European Miocene Lutrinae for most of these Fig. 1 - The holotype (left maxillary fragment bearing P4 and M1) of remains, we attributed these new specimens to Paralutra Paralutra garganensis (RGM 261151): a) occlusal view. b) buccal garganensis, the only carnivore present in the “Mikrotia view. From Willemsen (1983). fauna” assemblage. Stertomys, the hamster Hattomys, and the five-horned MATERIALS AND METHODS ruminant Hoplitomeryx) (Freudenthal, 1976, 1985; Butler, 1980; Leinders, 1984; Daams & Freudenthal, Abbreviations 1985), while a number of endemic species belongs to TRF - “Terre Rosse” collection of the Dipartimento genera with a wider distribution (e.g. several species di Scienze della Terra, Università di Firenze (collections of the ochotonids Prolagus, the glirid Dryomys and the of 1980’s field work by the team directed by the late otter Paralutra) (Freudenthal, 1971; Willemsen, 1983; Claudio De Giuli). RGM - Rijksmuseum van Geologie Mazza, 1987; Freudenthal & Martín-Suárez, 2006; en Mineralogie of Leiden (now Netherlands Centre of Masini et al., 2010), finally a very limited number of Biodiversity, Naturalis; collections of 1970’s field work species are not endemic (e.g. Apodemus present in all by Mathijs Freudenthal team). PU - Museo di Geologia e sampled localities, and Cricetulodon restricted to the Paleontologia, Università di Torino (2000-2010 field work oldest fissure fillings) (Freudenthal, 1976, 1985). Among by Giulio Pavia team). CCC - Centre de Conservation thousands of fossil remains from the extensive sampling du Musée des Confluences, Lyon. LGR -“La Grive carried out since the 1970’s by different research groups, Saint-Alban” collection of the CCC. FSL - Collection of the only known carnivore within the ”Mikrotia fauna” Université Claude Bernard, Lyon 1. Fig. 2 - Paralutra garganensis dentition. a) Holotype left maxillary fragment with M1 and P4 RGM 261151, in buccal (a1) and occlusal (a2) views. b) Left maxillary bone with P4 TRF001F9, tooth extracted from alveoli in lingual view (b1) and inserted in its maxillary bone in occlusal view (b2). Note the relative position of P3 and M1 alveoli, respectively. c) Left upper canine RGM 178193, in distal (c1) and buccal (c2) views. B. Villier et alii - New lutrine remains from the Late Miocene of Gargano 137 Comparative Material We compared our material with the holotype of Paralutra garganensis (RGM 261151). According to Willemsen (1983), Paralutra jaegeri (Fraas, 1862), a species described from Steinheim (Germany; Helbing, 1936) and reported from La Grive Saint-Alban (France; Roman & Viret, 1934) is the nearest continental relative to Gargano lutrines, thus why we extended the comparisons to fossils from “La Grive Saint-Alban”(CCC collections) and “Steinheim crater” (FSL collections). Unfortunately all the dental material (but the lower canines CCC LGR 4186 and CCC LGR4187) from “La Grive Saint-Alban” disappears from the collections after various relocations, at this regard we are therefore forced to compare TRF001F9 only with the available illustrations and descriptions (Viret, 1951; Willemsen, 1983, 1992). We also compare our dental material with the Italian Late Miocene lutrines from Monte Bamboli and Baccinello (Paludolutra campanii, P. maremmana and Tyrrhenolutra helbingi; Hürzeler, 1987) and with Paludolutra lluecai from the “Cuenca de Turel” in Spain