Luis Norberto Piacentini

• Doctor in Biological Sciences
• PhD posdoc and now Researcher at Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"

Two new genera in the family Lycosidae Sundevall, 1833 from Argentina are proposed. Lobizon gen. nov. comprises five species: Lobizon corondaensis (Mello-Leitão, 1941) comb. nov. (type species), L. minor (Mello Leitão, 1941) comb. nov., and L. humilis (Mello-Leitão, 1944) comb. nov., all these with a wide distribution in Argentina, and two new spec...

The study of many museum specimens of goblin spiders from the Himalayan range and neighboring countries allows for the description of new taxa of the family Oonopidae. The genus Dysderoides Fage is taxonomically reviewed. It comprises small, blind, loricate troglobitic spiders: the type species (D. typhlos Fage, from India) and at least five new sp...

The wolf spider genus Birabenia Mello-Leitão, 1941 is revalidated, comprising B. birabenae Mello-Leitão (type species) and B. vittata (Mello-Leitão) comb. n. The monotypic genus Melloicosa Roewer is synonymised with Birabenia by the transfer of its type species Gnatholycosa vittata Mello-Leitão. Three species, Hogna taeniata (Mello-Leitão), Geolyco...

The lycosid genus Agalenocosa Mello-Leitão, 1944 comprises at least eight species from northern and eastern Argentina and neighbouring countries: Agalenocosa velox (Keyserling, 1891) comb. nov. (from southern Brazil and Argentina), transferred here from Pirata Sundevall, 1833, A. tricuspidata (Tullgren, 1905) comb. nov. (from northwestern Argentina...

The recently described cribellate gradungulid Progradungula otwayensis Milledge, 1997 is endemic to the Great Otway National Park (Victoria, Australia) and known from only one male and a few juvenile specimens. In a recent survey we recorded 47 specimens at several localities across the western part of the Great Otway National park. Our field data...

During evolution, the morphology of animal organs can vary drastically, such as the reduction or loss of structures. This phenomenon is recurrent in the male copulatory organs of many spiders, where structures that are usually well-developed, are missing or vestigial in some taxa. One example is the retrolateral tibial apophysis (RTA) of the male p...

Pisauridae are a global and heterogeneous assemblage of spider genera with diverse morphologies and lifestyles. So far, the monophyly of Pisauridae and the inclusion of fishing spiders ( Dolomedes ) in this family have not been thoroughly tested. Here, we amend the systematics and classification of these lineages within a UCE phylogenomic framework...

An annotated checklist and taxonomic review of the spiders of Saint Helena is presented. A total of 88 genera and 114 species are known; of these, 12 genera and 45 species are endemic. Two new genera and two new species are described: Anapistula martinae Sherwood, Harvey, Fowler, Joshua, Stevens, Scipio O’Dean & Ellick sp. nov., Helenidion Sherwood...

Pisauridae Simon, 1890 or "nursery web spiders" are a global and heterogenous assemblage of spider genera with diverse lifestyles, containing web builders and webless species, as well as terrestrial and semi-aquatic species, notably "fishing spiders", genus Dolomedes Latreille, 1804. Incomplete, unresolved, or conflicting phylogenies have so far ha...

The Caatinga is a nucleus of seasonally dry tropical forest (SDTF) known as a hotspot of diversification and endemism. Despite its importance, this biome is still insufficiently sampled, resulting in extensive knowledge gaps regarding its species richness and composition. In this study we report two species of Xenoctenidae that are endemic to, and...

Spiders evolved a distinctive sperm transfer system, with the male copulatory organs located on the tarsus of the pedipalps. In entelegyne spiders, these organs are usually very complex and consist of various sclerites that not only allow the transfer of the sperm themselves but also provide a mechanical interlock between the male and female genita...

Typically, females and males are expected to have characteristic sexual strategies and patterns of size dimorphism, but these generalizations are subject to exceptions. The occurrence of atypical cases has been related to species or populations from environments under strong physical, ecological and/or social constraints. Allocosa marindia and Allo...

Sperm transfer in spiders is achieved by copulatory organs on the male pedipalps (i.e., copulatory bulbs), which can be simple or a complex set of sclerites and membranes. During copulation, these sclerites can be used to anchor in corresponding structures in the female genitalia by means of hydraulic pressure. In the most diverse group of Entelegy...

Species are the fundamental category and the key to formulate conservation efforts. DNA and ecological niche modeling have become valuable tools for species delimitation. Wolf spiders include few web-living species, such as Aglaoctenus lagotis (Holmberg, 1876), a priority species for conservation in Uruguay. Behavioral and body coloration patterns...

The taxonomy and systematics of the subfamily Allocosinae are poorly known, especially in South America. In the last century, several species have been described in genera from other subfamilies or transferred to them creating great confusion in the knowledge of Allocosinae. In this study we propose the new genus, Abaycosa gen. nov. to contain two...

1. Major floods of riparian and grassland habitats may lead to a shift in the availability of resources (e.g., food, space) that produces cascading effects on the organisms that rely on it. After flooding occurs, particularly in natural grasslands or agricultural fields, massive aggregative spider webs are occasionally observed. However, given it i...

The male of the wolf spider Paratrochosina amica Mello-Leitão (1941) is redescribed, and the female of this species is described for the first time. Additionally, we evaluate the phylogenetic position of P. amica using the mitochondrial genes cytochrome c oxidase subunit I (cox1), the 12S rRNA (12S) and 16S rRNA (16S), NADH deshydrogenase subunit I...

Genital traits are among the fastest to evolve, and the processes that drive their evolution are intensively studied. Spiders are characterized by complex genitalia, but the functional role of the different structures during genital coupling is largely unknown. Members of one of the largest spider groups, the retrolateral tibial apophysis (RTA) cla...

Along many decades, protected environments were targeted by the scientific community for ecological research and for the collection of scientific information related to environmental aspects and biodiversity. However, most of the territory in hotspot regions with weak or even non legal protection has been left aside. These non-protected areas (NPA)...

Along many decades, protected environments were targeted by the scientific community for ecological research and for the collection of scientific information related to environmental aspects and biodiversity. However, most of the territory in hotspot regions with weak or even non legal protection has been left aside. These non-protected areas (NPA)...

Resumen. Aglaoctenus Tullgren, 1905 es un género de arañas sudamericanas perteneciente a la familia Lycosidae, del cual se conocen cinco especies. Se reporta por primera vez su presencia en Chile, donde en febrero de 2018 se registraron ejemplares de la especie Aglaoctenus puyen Piacentini, 2011 en un ambiente altoandino. Se observaron y fotografia...

Pavocosa sp. (Lycosidae) burrows found in an open sparsely vegetated area on the edge of the Gran Salitral saline lake, in central Argentina, are described. Burrows were studied by capturing the occupant and casting them with dental plaster. The hosting sediments and vegetation were also characterized. Inhabited Pavocosa sp. burrows display distinc...

Cast GHUNLPam-4779 Length = 130 mm; Minimum Diameter = 12 mm; Maximum Diameter = 100 mm; Angle = 85º. 3D model credit: Fatima Mendoza-Belmontes.

Cast GHUNLPam-4771 Length = 131 mm; Neck Length = 8 mm; Minimum Diameter = 15 mm; Maximum Diameter = 22 mm; Angle = 84º. Dweller captured (Pavocosa sp GHUNLPam-4770). 3D model credit: Fatima Mendoza-Belmontes.

Cast GHUNLPam-4772 Length = 115 mm; Neck Length = 5 mm; Minimum Diameter = 15 mm; Maximum Diameter = 18 mm; Angle = 88º. 3D model credit: Fatima Mendoza-Belmontes.

Cast GHUNLPam-4774 Length = 106 mm; Neck Length = 6 mm; Minimum Diameter = 13 mm; Maximum Diameter = 23 mm; Angle = 72º. Sac of eggs found on the bottom. 3D model credit: Fatima Mendoza-Belmontes.

Cast GHUNLPam-4775 Length = 118 mm; Neck Length = 7 mm; Minimum Diameter = 13 mm; Maximum Diameter = 25 mm; Angle = 85º. 3D model credit: Fatima Mendoza-Belmontes.

Cast GHUNLPam-4778 Cast GHUNLPam-4778. Length = 116 mm; Minimum Diameter = 15 mm; Maximum Diameter = 22 mm; Angle = 87º. Smaller burrows with around 33 mm length and 8 mm of diameter. 3D model credit: Fatima Mendoza-Belmontes.

Cast GHUNLPam-4773 Length = 130 mm; Neck Length = 6 mm; Minimum Diameter = 16 mm; Maximum Diameter = 27 mm; Angle = 75º. Dweller captured (Pavocosa sp GHUNLPam-4770). Eggs sac found on the bottom. 3D model credit: Fatima Mendoza-Belmontes.

Cast GHUNLPam-4776 Length = 111 mm; Minimum Diameter = 15 mm; Maximum Diameter = 15 mm; Angle = 86º; ”Umbrella” Structure: Diameter = 47 × 59 mm. 3D model credit: Fatima Mendoza-Belmontes.

Cast GHUNLPam-4777 Length = 106 mm; Minimum Diameter = 15 mm; Maximum Diameter = 22 mm; Angle = 78º.”Umbrella” Structure Diameter = 54 × 66 mm. 3D model credit: Fatima Mendoza-Belmontes.

Environmental distribution of the specimens from the MACN collection compared with Pavocosa sp

Pavocosa sp. (Lycosidae) burrows found in an open sparsely vegetated area on the edge of the saline lake the “Gran Salitral”, in central Argentina, are described. Burrows were studied by capturing the occupant and casting them with dental plaster. The hosting sediments and vegetation were also characterized. Inhabited Pavocosa sp. burrows display d...

Pavocosa sp. (Lycosidae) burrows found in an open sparsely vegetated area on the edge of the saline lake the “Gran Salitral”, in central Argentina, are described. Burrows were studied by capturing the occupant and casting them with dental plaster. The hosting sediments and vegetation were also characterized. Inhabited Pavocosa sp. burrows display d...

The South American genus Diapontia is revised to include nine species: Diapontia uruguayensis Keyserling, 1877 (= Diapontia senescens Mello-Leitão, 1944 syn.n.; D. infausta Mello-Leitão, 1941 syn.n.; D. pourtaleensis Mello-Leitão, 1944 syn.n.; D. albopunctata Mello-Leitão, 1941 syn.n.) from northern Paraguay, southeastern Brazil, southern Uruguay,...

The taxonomy of the poorly known South American goblin spider genus Birabenella Grismado (Araneae: Oonopidae) is updated in light of recently collected material. Three new species are described: B. kamanchaca, from northern Chile, B. portai, from northwestern Argentina, and B. chincha, from southern Peru, where the genus is reported for the first t...

We present a phylogenetic analysis of spiders using a dataset of 932 spider species, representing 115 families (only the family Synaphridae is unrepresented), 700 known genera, and additional representatives of 26 unidentified or undescribed genera. Eleven genera of the orders Amblypygi, Palpigradi, Schizomida and Uropygi are included as outgroups....

Two new genera in the family Lycosidae Sundevall, 1833 from Argentina are proposed. Lobizon gen. nov. comprises five species: Lobizon corondaensis (Mello-Leitão, 1941) comb. nov. (type species), L. minor (Mello Leitão, 1941) comb. nov., and L. humilis (Mello-Leitão, 1944) comb. nov., all these with a wide distribution in Argentina, and two new spec...

A new genus of the spider family Zoropsidae, Cauquenia, gen. nov., is proposed for Cauquenia maule, sp. nov., from the Maule region in central Chile. The familial placement is tested through the inclusion of Cauquenia in the latest major published morphological analyses of the superfamily Lycosoidea, and the subfamily placement of the South America...

A new species of the orb-weaving spider genus Aculepeira Chamberling & Ivie 1942, A. morenoae new species, is de-scribed and illustrated based on male and female specimens from the Argentinean natural flooding pampas grasses.

The araneomorph spider family Palpimanidae is reported from Bolivia for the first time. Two new species: Otiothops kathiae and O. naokii are described and illustrated based on specimens recently collected in Santa Cruz Department. Additionally, Fernandezina pulchra Birabén, 1951 previously known only from Formosa, in northern Argentina, is newly re...

Three new species of Sosippinae from Argentina are described; one new species of Hippasella Mello-Leitão, 1944, H. alhue sp. nov., from temperate Andean forests in the Argentinean provinces of Neuquén and Río Negro and two new species of Aglaoctenus Tullgren, 1905, A. yacytata sp. nov., from the rainforests in Misiones province, and A. puyen sp. no...

Two new genera in the family Lycosidae Sundevall, 1833 from Argentina are proposed. Lobizon gen. nov. comprises five species: Lobizon corondaensis (Mello-Leitão, 1941) comb. nov. (type species), L. minor (Mello Leitão, 1941) comb. nov., and L. humilis (Mello-Leitão, 1944) comb. nov., all these with a wide distribution in Argentina, and two new spec...

FIGURES 1 – 2. Lobizon gen. nov., photographs of life specimens. 1, Lobizon ojangureni sp. nov., female from Parque Nacional Calilegua; 2, Lobizon corondaensis (Mello-Leitão), male from San Rafael.

FIGURES 39 – 44. Genitalia of Lobizon humilis (Mello-Leitão). 39 – 40, female from Reserva Natural Otamendi (MACN-Ar 16239); 41, male from Don Torcuato (MACN-Ar 16277); 42, female from Las Gamas (MACN-Ar 16275); 43 – 44, male from Don Torcuato (MACN-Ar 16268); 39, epigyne, ventral; 40, 42, vulvae, cleared, dorsal; 41, dissected embolic division (as...

FIGURES 49 – 54. Lobizon ojangureni sp. nov., habitus of preserved specimens from Parque Nacional Calilegua. 49, 51, 53, female paratype (MACN-Ar 18318); 50, 52, 54, male holotype (MACN-Ar 18319); 49 – 50, dorsal; 51 – 52, lateral; 53 – 54, ventral.

FIGURES 65 – 68. Lobizon otamendi sp. nov. 65, female paratype (MACN-Ar 16307), epigyne, ventral; 66, female from Caseros (MACN-Ar 16308), vulva, cleared, dorsal; 67 – 68, male holotype (MACN-Ar 16309); 67, left palp, retrolateral, 68, same, ventral.

FIGURES 83, 84. Geographic distribution of Lobizon gen. nov. 83, Lobizon corondaensis (Mello-Leitão), 84, Lobizon minor (Mello-Leitão).

FIGURES 85, 86. Geographic distribution of Navira gen. nov. and Lobizon gen. nov. 85, Lobizon humilis (Mello- Leitão), 86, Lobizon ojangureni sp. nov. (triangles), L. otamendi sp. nov. (squares) and Navira naguan gen. nov. sp. nov. (circles).

FIGURES 9 – 14. Female genitalia of Lobizon gen. nov. and Navira gen. nov .. 9 – 10, L. corondaensis (Mello-Leitão) from Parque Nacional Chaco, Laguna Carpincho (MACN-Ar 13618); 11 – 12, L. humilis (Mello-Leitão) from Reserva Natural Otamendi (MACN-Ar 16240); 13 – 14, Navira naguan sp. nov. from Bosque Alegre, 20 km de Carlos Paz (MACN-Ar 16282); 9...

FIGURES 27 – 32. Lobizon corondaensis (Mello-Leitão), variability. 27 – 31, epigynes of five specimens collected together in Parque Nacional Chaco (MACN-Ar 13618); 32, male from Suipacha (MACN-Ar 16220), showing the whitish setae on cephalic area.

FIGURES 33 – 38. Lobizon humilis (Mello-Leitão), habitus of preserved specimens from Reserva Natural Otamendi. 33, 35, 37, female (MACN-Ar 16239); 34, 36, 38, male (MACN-Ar 16257); 33 – 34, dorsal; 35 – 36, lateral; 37 – 38, ventral.

FIGURES 59 – 64. Lobizon otamendi sp. nov., habitus of preserved specimens from Reserva Natural Otamendi. 59, 61, 63, female paratype (MACN-Ar 16307); 60, 62, 64, male holotype (MACN-Ar 16309); 59 – 60, dorsal; 61 – 62, lateral; 63 – 64, ventral.

FIGURES 69 – 74. Navira naguan sp. nov., habitus of preserved specimens from Merlo. 69, 71, female paratype (MACN-Ar 16280); 70, 72 – 74, male holotype (MACN-Ar 16281); 69 – 70, dorsal; 71 – 72, ventral; 74, lateral; 73, detail of the ocular area and the clypeal condyle.

FIGURES 55 – 58. Lobizon ojangureni sp. nov. 55 – 56, female from Tucumán, Ruta Prov. 307 (MACN-Ar 16320); 57 – 58, male from Parque Nacional Calilegua (MACN-Ar 16313); 55, epigyne, ventral; 56, vulva, cleared, dorsal; 57, left palp, retrolateral, 58, same, ventral.

FIGURES 75 – 78. Navira naguan sp. nov. 75, female paratype, epigyne, ventral (MACN-Ar 16280); 76, female paratype Merlo (MACN-Ar 16280), vulva, cleared, dorsal; 77 – 78, male holotype (MACN-Ar 16281); 77, left palp, retrolateral, 78, same, ventral.

FIGURES 3 – 8. Expanded left male palp of Lobizon gen. nov.. 3 – 5, L. corondaensis (Mello-Leitão) from Parque Nacional Chaco, Laguna Carpincho (MACN-Ar 13618); 6 – 8, L. humilis (Mello-Leitão) from Don Torcuato (MACN-Ar 16277); 3, 6 ventral view; 4, 7, detail of terminal apophysis and embolus; 5, 8, retrolateral view. Asterisk: lateral outgrowth o...

FIGURES 15 – 20. Lobizon corondaensis (Mello-Leitão), habitus of preserved specimens from Parque Nacional Chaco (MACN-Ar 13618). 15, 17, 19, female; 16, 18, 20, male; 15 – 16, dorsal; 17 – 18, lateral; 19 – 20, ventral.

FIGURES 21 – 26. Genitalia of Lobizon corondaensis (Mello-Leitão). 21 – 22, female holotype of Pardosa corondaensis; 24, female from Parque Nacional Chaco (MACN-Ar 13618); 23, 25 – 26, male from Parque Nacional Chaco (MACN-Ar 13618); 21, epigyne, ventral; 22, 24, vulva, cleared, dorsal; 23, dissected embolic division (asterisk: lateral outgrowgth o...

FIGURES 45 – 48. Lobizon minor (Mello-Leitão), female holotype. 45, habitus dorsal; 46, same, ventral; 47, epigyne, ventral; 48, vulva, cleared, dorsal.

FIGURES 79 – 82. 79, 81, Lobizon humilis (Mello-Leitão) male from Reserva Natural Otamendi (MACN-Ar 12514), 80, 82, Navira naguan sp. nov., 80, male without locality (MACN-Ar 16286), 82, female without locality (MACN-Ar 16283). 79, 80, left palpal femur, ventral view. 81, 82, cheliceral retromargin, posterior view.

Two environments of Mburucuyá National Park (hygrophilous woodland and savannah-park) were considered to analyze patterns of abundance of the Trochosippa anomala, Alopecosa humilis, Lycosa thorelli, Hogna bivittata and Trochosa sp. The spiders were collected by pitfall trappings and sieve of dead leaves using seasonal samplings (2003-2004). Tempora...