searchable PDF - Association for Mexican Cave Studies

the south and includes the endemic pholcid spiderMetagonia candela Gertsch, the phalangodid harvestmanPellobunus mexicanus Goodnight and Goodnight,and the gryllid cricket Paracophus subapterus Chopard.Potrero Redondo, Nuevo Leon.-This ill-definedregion occurs to the west and southwest of Villa deSantiago. The two caves which have been studied areformed in Cretaceous limestone. Sotano de la Anticlinais a large single-room pit, while Sotano de PotreroRedondo is a vertical cave with some horizontaldevelopment at the bottom.The only troglobite among the six species recordedfrom the region is the nesticid spider Nesticus nahuanusGertsch, which is also known from caves to thenorth. The troglophile fauna includes the endemicoctochaetid earthworm Trigaster albida Gates andmillipeds of the rhachodesmid genus Strongylodesmusand sphaeriodesmid genus Sphaeriodesmus.Sierra del Fraile, Nuevo Leon.-The Sierra delFraile is formed almost entirely of vertical-beddedCupido Limestone of lower Cretaceous age (Russelland Raines, 1967). The only cave which has beenstudied is the spectacular commercial cave, Grutas deVilla de Garcia. It has been much modified by commercialization,and recent attempts at collection havebeen largely unproductive. It is located at an elevationof 1,060 meters. A second cave, Cueva del Rinconde la Virgen, houses a large colony of Mexicanfreetail bats, Tadarida brasiliensis mexicana (Saussure),but has not been studied for its invertebratefauna.Of the 13 species of invertebrate known fromGrutas de Villa de Garcia, six are troglobites: theleptonetid spider Leptoneta isolata Gertsch, theopilionid Hoplobunus osorioi (Goodnight and Goodnight),an undetermined rhagidiid mite, the lithobiidcentipede Garcibius osorioi Chamberlin, and thecampodeid diplurans Parallocampa (Parallocampa)cavemicola Wygodzinsky and Paratachycampa bonetiWygodzinsky. Of these species, L. isolata is clearlymost closely related to species known from the SierraMadre Oriental to the south. Hoplobunus osorioioccurs also in Grutas del Palmito and Gruta del Carrizalto the north. The other species are of uncertainaffinities. The troglophile fauna includes the pholcidspiders Metagonia serena Gertsch, Modisimus pusillusGertsch, and Physocyclus hoogstraali Gertsch andDavis; the scytodid spider Loxosceles bolivari Gertsch;and the carabid beetle Platynus pelaezi (Bolivar andHendrichs).Sierra de Garia, Nuevo Leon.-This range is locatedin western Nuevo Leon near the town of Espinazo.The only cave which has been investigated is Cuevade Constantin, a single-room cave which is heavilydecorated with speleothems. The fauna recordedfrom the cave includes undetermined reduviid hemipteransand crane flies.Sierra de Gomas, Nuevo Leon.-The Sierra deGomas is a north-south range located south of thetown of Bustamante. It is composed to a large extentof the massive Cupido Limestone of Cretaceous age(Fuentes, 1964; Russell and Raines, 1967). Althoughcollections have been made in four caves in the area,the only cave which has been well studied is Grutasdel Palmito. This cave, now commercialized, isamong the larger and more beautiful in Mexico. Thesmall entrance is located about 500 meters above thefloor of the plain. From the large entrance chambera steep breakdown-floored slope descends into achamber about 100 meters wide, 600 meters long,and up to 30 meters high. Total depth of the cave isabout 220 meters, making it one of the deeper cavesin northern Mexico.The fauna of the cave is very rich, with 10 troglobitesbeing represented. The troglobite fauna, withone possible exception, is closely related to the faunaof the Sierra Madre Oriental. Troglobites include thetrichoniscid isopods Brackenridgia palmitensis (Mulaik)and Cylindroniscus cavicolus (Mulaik); the hyidpseudoscorpion Leucohya heteropoda Chamberlin;the opilionid lloplobunus osorioi (Goodnight andGoodnight); the rhachodesmid milliped Ceuthauxuspalmitonus Chamberlin; the trichopolydesmid millipedSpeodesmus sp.; the collembolans Oncopoduraprietoi Bonet and Pararrhopalites anops Bonet andTellez; and the trechine beetle Mexaphaenops prietoiBolivar. This is the northern limit of the range for thegenera Cylindroniscus, Ceuthauxus, Pararrhopalites,and Mexaphaenops. Hoplobunus reaches its northernlimit in Texas, where it is represented only by tworelict troglobites. Brackenridgia and Oncopodurarange from southern Mexico well into the UnitedStates. Speodesmus is apparently a relict of a morenorthern distribution. It is well represented in thecaves of Texas and New Mexico, but only S. peckiShear in the Sierra de El Abra occurs south of Grutasdel Palmito.The troglophile fauna includes widespread species,such as the nesticid spider Gaucelmus augustinusKeyserling which ranges from the United States intosouthern Mexico. A few species are typical of thecave fauna of the Sierra Madre Oriental, such as themysmenid spider Maymena chica Gertsch; the pholcidspider Me tagonia candela Gertsch; the opilionid Pellobunusmexicanus Goodnight and Goodnight; thescolopendrid centipede Newportia pelaezi Chamberlin;the collembolan Acherontiella sabina Bonet; and28