Page 37 - Land Snails of New Mexico

Mountains, Socorro Co. Habitat—Theareasmentionedaboveareverydifferentwith
respecttohabitat.TheOgallalascarpislowandarid,supporting mainlyforbs,shrubs,andafewsmalltreessuchasjunipersand oaks. The habitat of G. procera in the Sacramento Mountains, on the other hand, is montane forest of the Transition Zone. Specimens have been taken along several canyons in the range. W i t h t o l e r a n c e o f s u c h d i v e r s e h a b i t a t s , it i s s u r p r i s i n g t h a t t h e speciesisnotmorecommon atpresent.
In New Mexico, G. procera is more widespread as a Pleistocene fossil than as a living species. There are fossil o c c u r r e n c e s i n t h e R i o G r a n d e V a l l e y w e s t o f its p r e s e n t r a n g e and, as mentioned above, at one time the species probably occurred entirely across N e w Mexico and into Arizona.
Gastrocopta cristata (H. A. Pilsbry and E. G. Vanatta, 1900, as Bifidaria procera cristata). Proceedings of the AcademyofNaturalSciencesofPhiladelphia,52:595,Pl. 22,Figs.4,5,T.L.:Camp Verde,YavapaiCo.,Arizona.
(crestedsnaggletooth)
General Distribution--Most records are from the Great
PlainsandsouthwesternUnitedStates,fromKansastoTexas,
and west to Arizona, where Bequaert and Miller (1973:169) foundittobecommoninthesouthernhalfofthestate.
New Mexico Distribution--This is a species of lower elevations, usually found along stream valleys. In the Rio Grande Valley,itoccursatleastasfarnorthasSierraCo.(excluding urbanrecords)andfossilshavebeentakenasfarnorthasSan Juan Pueblo, Rio Arriba Co. It occurs in southeastern N e w Mexico in the Pecos River Valley and along Pecos River tributaries such as the Rio Felix. The species was collected in a “cienegaatbaseofCapitanMountains”byE. H.Ashmun (USNM 152373). Thespecieshasbeentakenatscattered localitiesinnortheasternNew Mexico,asalongTramperosand Perico Creeks in Union Co. and along a tributary of Cimarron Creek south of Springer. Italso has been taken as a fossil along tributaries of the Canadian River system in San Miguel Co. In s o u t h w e s t e r n N e w M e x i c o it o c c u r s a l o n g t h e l o w e r G i l a R i v e r Valley of the state.
General Distribution-Gastrocopta procera isfound in
mostoftheeasternUnitedStates.Itisrareinthesoutheastern speciesintheNewMexicomalacofauna.Itoccursunderstones
near Swartz and Deming, and along the Rio Grande near Mesilla.The villageofSwartzisinthesouthernfoothillsofthe BlackRange,whereG prototypusmayoccur,althoughwehave not collected itthere. Fossils have been found atca. 5,250-ft elevation along Trujillo Canyon, 4 mi, south of Hillsboro in the
southeastern foothills of the Black Range. W e have taken it, living, only in the Mogollon Mountains, along Rain Canyon in t h e s o u t h w e s t e r n p a r t a n d a l o n g t h e W e s t F o r k o f t h e G i l a R i v e r inthecentralpartoftherange.However,itseemslikelythatthe speciesoccursinotherrangesinsouthwesternNew Mexico.
Habitat—The locality in Rain Canyon is at 5,800-ft e l e v a t i o n . T h e c o l l e c t i o n w a s m a d e i n a r i p a r i a n f r i n g e f o r e s t along the creek and at the base of the canyon walls. Specimens occurred in litter, predominantly of oak leaves, from among angular igneous stones. Along the West Fork, Gila River the s p e c i e s a l s o o c c u r r e d i n r i p a r i a n w o o d s a t c a . 5 , 6 0 0 ft.
Gastrocopta dalliana dalliana (V. Sterki, 1898, as Bifidaria).TheNautilus,12:91.T.L.:EphraimCanyonin Nogales, Santa Cruz Co., Arizona. (shortneck snaggletooth)
General Distribution--Gastrocopta dalliana comprises two subspecies, dalliana and bilamellata, as recognized by Bequaert and Miller (1973:165-169). The species ranges widely in southern Arizona and adjacent Sonora, México, and ithas been reported from Chihuahua and Baja California Territorio Sur inMéxico.
New Mexico Distribution and Habitat--In New Mexico,
this species has been taken only in Indian Creek Canyon, at 5,900-ft elevation on the northern flank of Animas Peak in HidalgoCo.Two specimensweretakeninleaflittercollected along the wooded canyon.
Subgenus Gastrocopta
Gastrocopta procera (A. A. Gould, 1840, as Pupa). Boston Journal of Natural History, 3:401; 4:359. T.L.: Baltimore, Maryland. (wing snaggletooth)
states, but widespread in Texas and Oklahoma to the east of New Mexico.AccordingtoBequaertandMiller(1973:170 171), the species probably does not occur as a native, living
species in Arizona at this time, although populations of introduced snailshave been found. Bequaert and Miller failed to find itas a fossil in Arizona, in situ. However, specimens found inriverdriftinvariouspartsofthestatearepresumably offossil provenience, indicating that the species once ranged west to A r i z o n a . G a s t r o c o p t a p r o c e r a is, t h e n , o n e o f s e v e r a l s p e c i e s thatonceextendedwestwardacrossNew MexicointoArizona, butnow extendno fartherthancentraloreasternNew Mexico.
NewMexicoDistribution--MostrecordsofG.proceraare
from alongscarpsoftheOgallalaFormationineasternNew
Mexico,fromEddyCo.northwardtoUnionCo.An isolated
population occurs in the Sacramento Mountains, and there is a
specimen(UMMZ67950)indicatedasbeingfromtheOscura ThespeciesGastrocoptapellucidawasdescribedfrom
Habitat--Thisis,perhaps,thebestexample ofafloodplain
or branches in leaf litter in timbered areas. The species often
occurs in association with cottonwood groves along the
floodplains, but strictly avoids habitats dominated by Tamarix,
which likelyindicatesthatitshabitathasbeenreducedgreatly since introduction of salt cedar.
Perhaps G. cristata finds urban habitats in cities along the Rio Grande and Pecos River Valleys similar, or even superior, to its natural habitat. Itis c o m m o n in regularly watered parks a n d l a w n s , w h e r e t h e r e a r e s h r u b s t o p r o v i d e s h e l t e r a n d l e a f litter.
Gastrocopta pellucida (L. Pfeiffer, 1841, as Pupa). SymbolaeadHistoriuimHeliciorum,i,p.46.T.L.:Cuba, withoutmorepreciselocality.(slimsnaggletooth)
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