ANNALS OF CARNEGIE MUSEUM VOL . 77, NU M BER 1, PP. 211–227 30 JUNE 2008 DESCRIPTION AND PHYLOGENETIC RELATIONSHIPS OF TWO NEW SPECIES OF BARIPUS (COLEOPTERA: CARABIDAE: BROSCINI) AND CONSIDERATIONS REGARDING PATTERNS OF SPECIATION SERGIO A. ROIG -JUÑENT Laboratorio de Entomología. Instituto Argentino de Investigaciones de las Zonas Áridas (IADIZA). Avenida Ruiz Leal s/n – Pq. Gral. San Martín, 5500 – Mendoza, Argentina [email protected] FEDERICO AGR A IN * [email protected] RODOL F O CA RR A R A * [email protected] EIDER RUIZ -MA NZ A NO S * [email protected] MA RCELO F. TOGNELLI * [email protected] ABSTRACT Baripus Dejean is a genus of the family Carabidae restricted to southern South America. Three subgenera are recognized within the genus; one of them, Cardiophthalmus Curtis, is endemic to the Patagonian Steppe. Together with the members of the genus Cnemalobus Guérin-Ménéville, these beetles are the largest Carabidae of the Patagonian Steppe. New studies in the northern region of Patagonia, the Payunia, reveal the presence of two new species, Baripus (Cardiophthalmus) nevado, new species, and Baripus (Cardiophthalmus) precordillera, new species, restricted to isolated montane habitats. In this paper, we provide morphological descriptions of the new taxa with illustrations of male and female genitalia. We also conducted a phylogenetic analysis including all known species of Baripus. The cladistic analysis showed that B. (C.) mendozensis, B. (C.) nevado and B. (C) precordillera constitutes a monophyletic group of species. These three species are allopatric, but B. (C.) mendozensis and B. (C.) nevado ranges are in close proximity. The distribution pattern, together with the phylogenetic pattern, suggests a possible peripatric pattern of speciation. We used a predictive model of species distribution to establish the present, past, and future distribution of B. (C.) mendozensis which is the most widely distributed species. Based on these analyses, we speculate that the current pattern of speciation may be a result of climatic changes during the Pleistocene. KEY WORD S : Baripus, Broscini, Carabidae, Cardiophthalmus, Coleoptera, new species, pattern of speciation, phylogeny, vicariance. RESUMEN Baripus Dejean es un género de la familia Carabidae del Sur de Sudamérica. Se reconocen tres subgéneros dentro del género; uno de ellos, Cardiophthalmus Curtis, es endémico de la estepa de Patagonica. Junto con los miembros de Cnemalobus Guérin Ménéville, son los géneros de Carabidae de mayor tamaño de la estepa patagónica. Nuevos estudios en la región norte de Patagonia, Payunia, revelan la presencia de dos nuevas especies Baripus (C.) nevado, n. sp., y B. (C.) precordillera, n. sp., restringidas a ambientes montanos aislados. Se suministran descripciones morfológicas con ilustraciones, incluyendo genitalia femenina y masculina, para los nuevos taxa. Los análisis filogenéticos fueron desarrollados utilizando todas las especies conocidas de Baripus. El análisis cladístico muestra que B. (C.) mendozensis, B. (C.) nevado and B. (C) precordillera constituyen un grupo monofiletico. Estas tres especies son alopátricas, pero en B. (C.) mendozensis y B. (C.) nevado los límites de sus áreas de dis- tribución son muy cercanos. El patrón de distribución, junto con el filogenético, muestra un posible patrón de especiación peripátrica. Se utilizó un modelo predictivo de distribución de especies para establecer la distribución presente, pasada y futura de B. (C.) mendozensis, la cual es la especie mas ampliamente distribuida. Sobre la base de estos análisis, especulamos que los cambios climáticos durante el Pleistoceno podrían haber causado el patrón de especiación actual. PA L A BR as CL A VE : Baripus, Broscini, Carabidae, Cardiophthalmus, Coleoptera, filogenia, nueva especie, patrones de especiación, vicariancia. *Same address as senior author. 212 ANN A L S O F CA RNEGIE MU S EU M VOL . 77 INTRODUCTION anatomical structures. To study the male genitalia, the ae- deagus was removed through the pygidium and cleared in Baripus Dejean is a South American genus of the tribe boiling 10% KOH for ten minutes. The internal sac was Broscini, comprising a monophyletic group comprised of everted by injecting 1:1 glycerin with a hypodermic sy- species classified in three subgenera (Roig-Juñent 1992b, ringe. To study the female genitalia, membranes and mus- 2000). The systematics of the genus were recently stud- cles were removed. All the illustrations were made using a ied by Roig-Juñent and Cicchino (1989) and Roig-Juñent camera lucida attached to a Nikon stereomicroscope. Pic- (1992a, 1992b). The phylogenetic and biogeographical tures of male protarsomeres were taken with a Power Shot hypotheses were analyzed by Roig-Juñent (1995, 2000) S50 digital camera adapted to a Leica MS5 stereoscopic to investigate vicariant events in the history of Baripus. microscope. These pictures were taken at different focal The three subgenera exhibit an allopatric distribution and lengths, and then a single image was obtained by using inhabit different types of grassland. The most diverse sub- Helicon Focus v3.20 software, available at www.helicon- genus, Cardiophthalmus Curtis (1839), occurs exclusively focus.com. The terms used for the aedeagus follow Jeannel in the Patagonian Steppe, a lowland habitat that extends (1955), and the terms used for the female genitalia follow from the Atlantic Coast to the western slope of the Andes Deuve (1993) and Liebherr and Will (1998). Mountains. After the systematic revisions (Roig-Juñent and Cicchino 1989; Roig-Juñent 1992a, 1992b), we col- lected new specimens of the known species of the subge- CLADISTIC Analysis nus Cardiophthalmus and obtained new distributional data. Characters.—The 55 characters and their states used for We also discovered two new species of Cardiophthalmus, the analysis are shown in Table I. The distribution of the one in the northern region of Patagonia, and the other in states among the terminal taxa are in the data matrix (Table the southern region of the Precordillera Formation. These 2), and the apomorphic states are shown in the obtained new records allowed us to analyze accurately the distribu- cladograms (Fig. 8). When a character had more than two tion pattern of Cardiophthalmus species. We then used the states, the states were organized in the matrix with most phylogenetic relationships of the species to determine their similar states adjacent, and most divergent states at op- geographical pattern of speciation. posing ends of the series (i.e., characters 8, 17, 36, and The objectives of this study were to describe two new 53). Character 53 was analyzed as an ordered multistate species of Baripus, to develop a hypothesis of the phyloge- character; all others were analyzed as unordered. Polymor- netic relationships of the new taxa, to describe the habitats, phic characters are represented by letters in the data matrix and to analyze the possible biogeographic hypotheses that (Table 2). led to the current distribution pattern of the genus. We in- ferred a phylogeny for the lineage, and used it to establish Taxa.—All species of the genus Baripus were included in possible patterns of speciation by comparing pairs of sister the analysis, 24 known species and the new taxa Baripus species and sister clades. We also used predictive models (C.) nevado, new species, and Baripus (C.) precordillera, with an exemplar species to determine likely events influ- new species. The cladograms obtained were rooted follow- encing past and future distributions. ing the Parsimonius Outgroup Analysis Method proposed by Farris (1982) and suggested by Nixon and Carpenter MATERIALS AND METHODS (1993). This method involves adding an external group to the matrix, analyzing it without forcing any type of rela- Specimens and Taxonomic Material.—Most of the spec- tionship, and rooting between the external and the internal imens we examined belong to the Instituto Argentino de group. As external groups, we chose the genera Nothobro- Investigaciones de las Zonas Áridas (IADIZA), Mendoza, scus Roig-Juñent and Ball (Nothobroscus chilensis Roig- Argentina. We also used specimens from Museo Argentino Juñent and Ball), Creobius Guérin Ménéville (Creobius de Ciencias Naturales “Bernardino Rivadavia” (MACN), eydouxii (Guérin Ménéville)), Cascellius Curtis (Cascel- Museo de La Plata (MLP), American Museum of Natural lius gravesii Curtis), and Bembidiomorphum Champion History (AMNH), and Smithsonian Institution, National (Bembidiomorphum convexum Champion). These four Museum of Natural History (USNM). We studied a total of genera belong to different subtribes of the tribe Broscini 374 specimens of Baripus (Cardiophthalmus) mendozensis (Roig-Juñent 2000): Nothobroscus to Nothobroscina, Cre- Roig-Juñent and the new species to analyze their morphol- obius and Cascellius to Creobiina, and Bembidiomorphum ogy. We also studied a series of 237 specimens of other (=Microbarypus Roig-Juñent) to Barypina. species of Cardiophthalmus held at different museums and institutions to establish geographical distribution patterns. Data Analyses.—The data matrix was analyzed with the program TNT (Goloboff et al. 2003) using the implicit enu- Dissection Methods.—The comparisons among the dif- meration search option, which finds the most parsimonious ferent species were based on characteristics of the exter- trees by means of an exact solution. Branch support was nal morphology and male and female genitalia. Speci-