Dolichognatha, O.Pickard-Cambridge, 1869

Dimitrov, Dimitar, Álvarez-Padilla, Fernando & Hormiga, Gustavo, 2010, On the Phylogenetic Placement of the Spider Genus Atimiosa Simon, 1895, and the Circumscription of Dolichognatha O. P. - Cambridge, 1869 (Tetragnathidae, Araneae), American Museum Novitates 3683, pp. 1-19 : 5-10

Dolichognatha O. P.- Cambridge, 1869

TYPE SPECIES: Dolichognatha nietneri O. P.-

Cambridge, 1869.

Landana Simon, 1884 , transferred from Archaeidae to Araneidae by Lehtinen, 1967: 289, here by Levi, 1981: 277.

Paraebius Thorell, 1894 , Prolochus Thorell, 1895 , Nicholasia Bryant and Archer, 1940 , type Araneus pentagonus (Hentz, 1850) and Afiamalu Marples, 1955 , type Afiamalu richardi Marples, 1955 , transferred here by Levi, 1981: 277.

Homalopoltys Simon, 1895 , transferred here by Smith, 2008: 10.

(A), retrolateral (B), ventral (C), schematic (ventral) (D). Habitus: dorsal (E).

Atimiosa Simon, 1895 , new synonymy, type species Atimiosa quinquemucronata Simon, 1895 .

JUSTIFICATION FOR THE SYNONYMY: The holotype of Atimiosa quinquemucronata is a subadult female. Describing new taxa based on juvenile specimens was common before the early 20th century. The validity of taxa based on such specimens is often difficult to assess because genital morphology cannot be examined and they are subsequently neglected or treated as nomina dubia. Fortunately, A. quinquemucronata shares some easily recognizable somatic features with the genus Dolichognatha , such as the separated lateral eyes, PME smaller than the lateral eyes, and the absence of fourth femur trichobothria in females. The size and distribution of the eyes are particularly relevant, as those are among the most important diagnostic characters of Dolichognatha . The pointed tip of the abdomen and the shape of the labium and sternum are also as in Dolichognatha . Based on these observations and the results from our cladistic analyses (figs. 9; 10), we transfer all Atimiosa species to Dolichognatha , which renders the former genus into a junior synonym of Dolichognatha .

DIAGNOSIS: The genus Dolichognatha can be most easily distinguished from close relatives ( Meta and Metellina ) by the very long male chelicerae and the characteristic shape and coloration of the prosoma. In Dolichognatha the cephalic region is rectangular in shape and elongated with dark sides (e.g., fig. 6A). In addition, the following combination of characters differentiates Dolichognatha from other tetragnathids: aggregate spigots not embracing the flagelliform spigot, PME and PLE without canoe tapetum, PME smaller than PLE, abdomen with anterior tubercles, and horizontal orb web with closed web hub close to the substrate.

PHYLOGENETICS: The monophyly of Dolichognatha is supported by all analyses and it is placed in a Metainae lineage together with the genera Meta and Metellina (figs. 9; 10), which includes also Mollemeta , Chrysometa , and Allende when k 5 4–7 (fig. 11). All analyses, except when k # 3, found Dolichognatha sister to Metellina . Three unambiguous synapomorphies support the monophyly of Dolichognatha (fig. 12A): PLE larger than PME, lateral eyes separated, and anterior abdominal tubercles present. When A. quinquemucronata is excluded form the analyses the number of synapomorphies supporting Dolichognatha increases to 17 (fig. 12B) due to the reduction of data missing from the matrix. These synapomorphies include: aggregate spigots not embracing the flagelliform spigot; apically distended conductor path; short clypeus; PME close to each other (less than one PME diameter); PME without canoe tapetum; PLE without canoe tapetum; PME smaller than PLE; lateral eyes separated; male paturon with a basal tubercle; male chelicerae larger than in female; intermediate length of copulatory ducts; short fertilization ducts; abdomen with anterior tubercles; male palpal patella without macrosetae; horizontal orb web; and closed web hub.

COMPOSITION: Dolichognatha comprises 29 described species ( Platnick, 2010), including the two new combinations proposed here: D. aethiopica Tullgren, 1910 ; D. albida (Simon, 1895) ; D. baforti (Legendre, 1967) ; D. cygnea (Simon, 1893) ; D. deelemanae Smith, 2008 ; D. ducke Lise, 1993 ; D. erwini Brescovit and Cunha, 2001; D. incanescens ; D. kampa Brescovit and Cunha, 2001; D. kratochvili (Lessert, 1938) ; D. lodiculafaciens (Hingston, 1932) ; D. longiceps ; D. mandibularis (Thorell, 1894) ; D. mapia Brescovit and Cunha, 2001; D. maturaca Lise, 1993 ; D. minuscula (Mello- Leitão, 1940); D. nietneri ; D. pentagona ; D. petiti (Simon, 1884) ; D. pinheira l Brescovit and Cunha, 2001; D. proserpina (Mello-Leitão, 1943) ; D. quadrituberculata (Keyserling, 1883) ; D. raveni Smith, 2008 ; D. richardi (Marples, 1955) ; D. spinosa (Petrunkevitch, 1939) ; D. tigrina Simon, 1893 ; D. umbrophila Tanikawa, 1991 ; D. quinquemucronata (Simon, 1895) , new combination; and D. comorensis ( Schmidt and Krause, 1993) , new combination.

DISTRIBUTION: Dolichognatha has a circumtropical distribution with the highest species diversity in South America and Southeast Asia.

NATURAL HISTORY: The majority of Dolichognatha species live near the ground where they build nearly horizontal orb webs ( Levi, 1981; Smith, 2008 and observations reported herein). However, there are at lest some species, such as D. albida , that were reported to build vertical orb webs ( Simon, 1894). Smith (2008) confirms that Dolichognatha species may live in the canopy, as specimens for her study were collected using canopyfogging techniques. Unfortunately, she did not observe the webs of these specimens. Our observations of D. longiceps webs are consistent with the descriptions of Levi (1981) and represent the most common web architecture in Dolichognatha (horizontal orbs close to the substrate).