Cyrtognatha petila, Dimitrov & Hormiga, 2009

Dimitrov, Dimitar & Hormiga, Gustavo, 2009, Revision And Cladistic Analysis Of The Orbweaving Spider Genus Cyrtognatha Keyserling, 1881 (Araneae, Tetragnathidae), Bulletin of the American Museum of Natural History 2009 (317), pp. 1-140 : 47-50

Cyrtognatha petila , new species Figures 3E, 18, 19

TYPE: Male holotype from Mexico, Chiapas, Ocosingo, Ejido Nueva Argentina, Laguna Miramar, Reserva de la Biosfera Montes Azules, 16 ° 23 9 36.2 0 N, 91 ° 14 9 29.6 0 W, MAP 150 m. 23–25.x.2005. F. Álvarez, L. Lopardo, and J. Castelo ( CNAN).

ETYMOLOGY: The species epithet is an adjective taken from the Latin word petilus (‘‘thin, slender’’), in reference to the body size and shape of this species.

DIAGNOSIS: This species can be easily distinguished from similar relatives ( C. insolita and C. orphana ) by the presence of a well-developed membrane on the tip of the basal apophysis of the conductor (fig. 18C). In C. insolita this membrane is missing (fig. 37C) and in C. orphana the basal apophysis of the conductor is much wider distally (fig. 22C). C. petila can be further distinguished from C. orphana by the triangular shape of the metine embolic apophysis (fig. 18A, B) and from C. insolita by the lack of a serrated membrane of the embolus in prolateral view. Here the serrated membrane is seen in retrolateral view (fig. 18B).

An important diagnostic feature of this species is the morphology of the male chelicerae. In C. orphana and C. insolita the male chelicerae are much more divergent and with a very strong dorsal tooth (fig. 38B, E, F), while in C. petila the dorsal tooth is just slightly larger than the rest of the cheliceral teeth (fig. 19D).

DESCRIPTION: Male (holotype). Habitus as in figures 3E, 19A–D. Carapace yellowish with a well-marked fovea; with darker band in the center and darker margins. Dorsally some remains of greenish coloration still can be observed. Abdomen brown-grayish, cylindrical with guanine spots concentrated dorsolaterally. Ventrally and ventrolaterally with darker bands and with four darker spots on the distal edge dorsally. Abdominal tubercles strongly reduced. Total length 4.74. Cepha- lothorax 1.74 long, 1.10 wide, 0.80 high. Abdomen 3.00 long, 0.80 wide, 0.70 high. Sternum yellowish with darker margins; 0.80 long, 0.78 wide. Clypeus height equal to an AME diameter. AME diameter 0.09. Distance between AME half of their diameter; ALE–PME distance 1.5 AME diameters and between them and PLE equal to one AME diameter. Distance between PME equal to their diameter. All eyes surrounded by dark pigmentation. Chelicerae (fig. 19D) moderately divergent with dark brown-grayish color. Dorsal cheliceral tooth well developed, outlying the fang joint and with sharp tip. Cheliceral fang with very strongly reduced outgrowth and practically straight except for the both edges. Femur I 4.03, 2.3 times the length of the cephalothorax. Pedipalp as in figure 18A–C. Palpal tibia length 0.2; cymbium length 0.54.

Female (paratype from the type locality). Habitus and coloration as in male. Chelicerae lack the dorsal tooth and are much less divergent. Sternum 0.90 long, 0.84 wide. Total length 7.39. Cephalothorax 2.12 long, 1.55 wide, 0.99 high. Abdomen 5.27 long, 1.67 wide, 2.17 high. Clypeus height half of one AME diameter. AME diameter 0.08. Femur I 5.33, 2.5 times the length of the cephalothorax. Vulva as in figures 18D, E.

Variation. Male cephalothorax ranges in length from 1.74 to 1.86 (n 5 3). Female cephalothorax ranges in length from 1.96 to 2.12 (n 5 9). Male total body length ranges from 4.74 to 5.38 (n 5 3). Female total body length ranges from 6.16 to 7.39 (n 5 9).

DISTRIBUTION: This species is known only from southern Mexico (Chiapas) (fig. 5).

ADDITIONAL MATERIAL EXAMINED: Paratypes: MEXICO: Chiapas, Ocosingo, Ejido Nueva Argentina, Laguna Miramar , Reserva de la Biosfera Montes Azules, 16 ° 23 9 36.2 0 N, 91 ° 14 9 29.6 0 W, MAP 150 m. 23–25.x.2005, F. Álvarez, L. Lopardo, and J. Castelo, 1 female ( CNAN) ; Chiapas, Ocosingo, Sierra de la Cojolita, Arroyo Nayte. 16 ° 47 9 36.2 0 N, 91 ° 02 9 35.3 0 W, EPE 06 202 m. 1–27.x.2005, L. Lopardo, J. Castelo, and F. Álvarez, 2 female ( CNAN) ; Chiapas, Ocosingo, Hidalgo Cortés orillas de la Reserva Montes Azules. N 16 ° 42 9 19.1 0 N, 90 ° 53 9 08.2 0 W, EPE 07 145 m. 31.x.2005, L. Lopardo, J. Castelo, and F. Álvarez, 1 male and 5 females ( CNAN) ; Chiapas, Ocosingo, Monumento Natural Bonampak , 16 ° 43 9 32.5 0 N, 91 ° 04 9 43.4 0 W, EPE07 207 m. 26.x–2.xi.2005, F. Álvarez, L. Lopardo, and J. Castelo, 1 female ( CNAN) .

Other material: MEXICO: Chiapas, Palenque ruins area. 92 ° 01 9 W, 17 ° 29 9 N. 2– 11.vii.1983, W. Maddison and R.S. Anderson, 83-0995 tropical rain forest edge. 1 male (MCZ 67459).