{"elementGlobalId":111599,"circumscripConfidence":null,"classificationLevel":{"id":7,"classificationLevelNameEn":"Species","classificationLevelNameEs":"Especies","classificationLevelNameFr":"Espèce"},"classificationStatus":{"id":1,"classificationStatusDescEn":"Standard","classificationStatusDescEs":"Estándar","classificationStatusDescFr":"Standard"},"iucn":{"id":11,"iucnDescEn":"Least concern","iucnDescEs":"Menos preocupante","iucnDescFr":"Moins préoccupante","iucnCode":"LC"},"nameCategory":{"id":2,"nameCategoryDescEn":"Invertebrate Animal","nameCategoryDescEs":"Animal invertebrado","nameCategoryDescFr":"Animal invertébré","nameTypeCd":"A","nameTypeDesc":"Zoological"},"rankMethodUsed":null,"formattedScientificName":"<i>Discus macclintocki</i>","scientificName":"Discus macclintocki","scientificNameAuthor":"(F.C Baker, 1928)","primaryCommonName":"Pleistocene Disc","relatedItisNames":"<i>Discus macclintocki</i> (F. C. Baker, 1928) (TSN 77400)","uniqueId":"ELEMENT_GLOBAL.2.111599","elcode":"IMGAS54060","conceptRefFullCitation":"Turgeon, D. D., J. F. Quinn, Jr., A. E. Bogan, E. V. Coan, F. G. Hochberg, W. G. Lyons, P. M. Mikkelsen, R. J. Neves, C. F. E. Roper, G. Rosenberg, B. Roth, A. Scheltema, F. G. Thompson, M. Vecchione, and J. D. Williams. 1998. Common and scientific names of aquatic invertebrates from the United States and Canada: Mollusks. 2nd Edition. American Fisheries Society Special Publication 26, Bethesda, Maryland. 526 pp.","conceptName":"<i>Discus macclintocki</i>","taxonomicComments":null,"roundedGRank":"G1","conservationStatusFactorsEditionDate":"2009-01-29","conservationStatusFactorsEditionAuthors":"Cordeiro, J.","primaryCommonNameLanguage":"EN","recordType":"SPECIES","elementNationals":[{"elementNationalId":183476,"classifConfidence":null,"nation":{"id":225,"nameEn":"United States","nameEs":"Estados Unidos","nameFr":"États-Unis","isoCode":"US","region":"United States"},"roundedNRank":"N1","elementSubnationals":[{"elementSubnationalId":388916,"subnation":{"id":19,"nameEn":"Illinois","nameEs":"Illinois","nameFr":"Illinois","subnationCode":"IL","dnationId":225},"roundedSRank":"S1","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"S1","speciesSubnational":{"elementSubnationalId":388916,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":282495,"subnation":{"id":17,"nameEn":"Iowa","nameEs":"Iowa","nameFr":"Iowa","subnationCode":"IA","dnationId":225},"roundedSRank":"S1","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"S1","speciesSubnational":{"elementSubnationalId":282495,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":739350,"subnation":{"id":30,"nameEn":"Missouri","nameEs":"Missouri","nameFr":"Missouri","subnationCode":"MO","dnationId":225},"roundedSRank":"SH","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"SH","speciesSubnational":{"elementSubnationalId":739350,"hybrid":false,"exotic":false,"native":true}}],"nrankReviewYear":2009,"nrank":"N1N2","speciesNational":{"elementNationalId":183476,"exotic":false,"native":true}}],"lastModified":"2026-10-02T22:01:27.723006Z","lastPublished":"2026-10-02T21:32:08.892226Z","promotionalDescription":null,"conceptLineageSummary":null,"nsxUrl":"/Taxon/ELEMENT_GLOBAL.2.111599/Discus_macclintocki","grankAdjustmentReasons":null,"grankChangeDate":"2009-01-29","grankReviewDate":"2009-01-29","grankReasons":"Presently in only about 22 (updated to 37 recently but lump to about half for population delineation purposes) small areas in northeast Iowa and northwest Illinois, and 50% of the individuals are in 4 colonies. Only about 40,000 individuals remain and this density varies from year to year.","grank":"G1G2","rankInfo":{"elementGlobalId":111599,"aooPercentGood":null,"enviromentalSpecificity":{"id":1,"enviromentalSpecificityDescEn":"Very narrow.  Specialist or community with key requirements scarce.","enviromentalSpecificityDescEs":"Muy estrecho.  Especialista o comunidad con requisitos claves escasos.","enviromentalSpecificityDescFr":"Très étroit. Spécialistes ou communautés répondant aux critères clés sont rares."},"intrinsicVulnerability":{"id":6,"intrinsicVulnerabilityDescEn":"Not intrinsically vulnerable","intrinsicVulnerabilityDescEs":"No intrínsecamente vulnerable","intrinsicVulnerabilityDescFr":"Non intrinsèquement vulnérable"},"longTermTrend":{"id":28,"longTermTrendDescEn":"Decline of <70% to Relatively Stable","longTermTrendDescEs":"Disminución de <70% a relativamente estable","longTermTrendDescFr":"Diminution de <70 % à relativement stable"},"numberEos":{"id":6,"numberEosDescEn":"6 - 20","numberEosDescEs":"De 6 a 20","numberEosDescFr":"De 6 à 20"},"numberGoodEos":{"id":12,"numberGoodEosDescEn":"Few (4-12)","numberGoodEosDescEs":"Pocos (4-12)","numberGoodEosDescFr":"Peu (de 4 à 12)"},"numberProtEos":{"id":13,"numberProtEosDescEn":"Many (13-40) occurrences appropriately protected and managed","numberProtEosDescEs":"Varias ocurrencias (13 a 40) adecuadamente protegidas y controladas","numberProtEosDescFr":"Plusieurs occurrences (de 13 à 40) protégées et contrôlées convenablement"},"popSize":{"id":31,"popSizeDescEn":"10,000 - 100,000 individuals","popSizeDescEs":"De 10.000 a 100.000 individuos","popSizeDescFr":"De 10 000 à 100 000 individus"},"rangeExtent":{"id":2,"rangeExtentDescEn":"<100-250 square km (less than about 40-100 square miles)","rangeExtentDescEs":"De <100 a 250 kilómetros cuadrados (menos de 40 a 100 millas cuadradas aproximadamente)","rangeExtentDescFr":"De <100 à 250 km carrés (moins de 40 à 100 miles carrés approximativement)"},"shortTermTrend":{"id":33,"shortTermTrendDescEn":"Decline of <50% to Relatively Stable","shortTermTrendDescEs":"Disminución de <50% a relativamente estable","shortTermTrendDescFr":"Diminution de <50 % à relativement stable"},"threatImpactAssigned":{"id":2,"threatImpactAssignedDescEn":"Very high - high","threatImpactAssignedDescEs":"Muy alto - alto","threatImpactAssignedDescFr":"Très élevé — élevé"},"rangeExtentComments":"Presently in only about 22 (updated to 37 talus slopes in Henry, 2003) small areas in northeast Iowa and northwest Illinois, and 50% of the individuals are in 4 colonies. Only about 40,000 individuals remain and this density varies from year to year.  Fossil occurrences in northeast Iowa, northwest Illinois, southeast Minnesota, and southwest Wisconsin (Henry, 2003).  See also Frest (1987).","areaOfOccupancy":null,"areaOfOccupancyComments":null,"numberEosComments":"Hubricht (1972) cites only around the mouth of a cave in Bixby Park, Clayton Co., Iowa.  Presently in only about 22 small areas in northeast Iowa and northwest Illinois, and 50% of the individuals are in 4 colonies.  Henry (2003) updated to 37 talus slopes (probably lump to about half for population delineation purposes) although these are highly subdivided and only a few have decent viable populations and population numbers vary from year to year (Clark et al., 2008).","popSizeComments":"Frest (1987) conducted extensive studies during the 1980s and these form the basis for the species recovery plan (USFWS, 1994).  In a mark recapture study over six years at eight algific slope sites in Clayton, Dubuque, Fayette and Jackson counties, Iowa , Clark et al. (2008) found average density among years at the recapture sample locations was 26 snails per square meter on one site, 51 snails per square meter  on another site, and 583 snails per square meter on another site.  Most populations were represented by a high percentage (average 86%) of mature individuals.  The demographic analyses of Clark et al. (2008) support the previously expressed view that genetic diversity remains relatively high in these snail populations.","viabilityComments":"Of the 8 sites surveyed by Clark et al. (2008) in Iowa, about half had good viability with somewhat decent numbers and recruitment.","threatImpactComments":"The threats outlined in the recovery plan (USFWS, 1984) still apply (see USFWS, 2009):<br>Increased development (primarily rural house building) in northeast Iowa since the issuance of the 1984 recovery plan and 1991 5-year review could threaten some sites as there tend to be scenic ridges above the algific slopes. Most grazing threats have been alleviated by working with landowners to fence their sites. Deer populations have greatly increased since the recovery plan was written and may impact some algific slopes with increased trails and trampling. Sinkhole filling is still a concern when they occur in crop fields or pastures. Sinkhole searches and mapping have been completed for all snail locations and several of the sinkhole sites occur in forested areas where they likely will not be disturbed. Landowners have been educated about the need to leave the sinkholes open. Climate change including warming trends is a potential threat and the snail is a glacial relict that lived in a cold climate historically. This snail has a narrow temperature tolerance of 35-45F which is provided on algific talus slopes. Underground ice is critical to maintaining this habitat. Algific slope systems are relatively shallow systems with an annual freeze/thaw cycle, so presumably, if the freezing cycle is shorter and the thaw cycle is longer because of global warming, the system will be unable to perpetuate ice throughout the entire summer and the snail loss could be catastrophic. Increased rain events could also impact the habitat and since sinkholes are a direct conduit for runoff , increased water may increase melting, or conversely may provide water for more ice formation. In addition, most snail sites are located directly above streams that are subject to flash flooding causing erosion of the algific slopes. Invasive species, primarily garlic mustard are overtaking some algific slopes, however, it is not known whether the dominance of this species would affect the snail's food resources or other habitat characteristics in any way.<br><br>The algific slopes where these snails live are fragile because of their steepness and loose rock covering. Activity on a site can dislodge rocks and soil, compact surface vents and crush snails. Therefore, monitoring methods need to be minimally intrusive and yet be able to reliably detect snails (Clark et al., 2008).  Fluctuations in recruitment might be a function of immediate threats to local habitat conditions, such as grazing or trampling on the sites, that would reduce plant cover and litter that is important as both food and cover. In contrast, factors such as global climate change that has been predicted to cause shifts in distribution and abundance in biological communities (Parmesan and Yohe, 2003), could affect the unique microclimate of the sites and have long-term effects on adult survival and population persistence. Damage from flooding that removes much of the talus layer, leaves sites that are steep and unstable, and directly removes individuals is a catastrophic loss of habitat and snails from which populations cannot demographically recover (Clark et al., 2008).  Thus far, monitoring indicates that recruitment will be more responsible than survival for fluctuations in growth rate (Henry 2008). Fluctuations in recruitment might be a function of immediate threats to local habitat conditions, such as grazing or trampling on the sites, that would reduce plant cover and litter that is important as both food and cover. In contrast, factors such as global warming that could influence the subterranean ice, cold air drainage, and the unique microclimate of the sites might have long-term effects on adult survival and population persistence (USFWS, 2009). Although in the short term, fluctuations in recruitment may influence local dynamics most substantially, long-term threats of habitat loss or climatic change will ultimately affect survival and adaptation of adults and persistence of the populations.","shortTermTrendComments":"Clark et al. (2008) used mark-recapture methods applied over 6 y to estimate vital demographic parameters of Iowa Pleistocene snails and to estimate population size, and to directly estimate finite population growth rate.  Although these populations of snails exhibited a relatively high survival for small terrestrial gastropods, the analyses indicate that variable recruitment accounts for much of the variation in population growth rates. Although a monitoring program has been developed, data to this point does not indicate whether populations are stable. It will be difficult to extrapolate population trends from one site to the entire snail population because of the extreme variation between sites and the highly divided nature of snail populations within sites (USFWS, 2009).<br>","longTermTrendComments":"The number of known colonies has increased from 19 to 37 since issuance of the recovery plan in 1984 (USFWS, 1984; 2009). Although a monitoring program has been developed, data to this point does not indicate whether populations are stable. It will be difficult to extrapolate population trends from one site to the entire snail population because of the extreme variation between sites and the highly divided nature of snail populations within sites (USFWS, 2009).<br>","inventoryNeeds":"The algific slopes where these snails live are fragile because of their steepness and loose rock covering. Activity on a site can dislodge rocks and soil, compact surface vents and crush snails. Therefore, monitoring methods need to be minimally intrusive and yet be able to reliably detect snails (Clark et al., 2008).","numberProtEosComments":"Currently 24 of 37 sites in Iowa and Illinois where the Iowa Pleistocene snail occurs are protected by some form of conservation protection (Clark et al., 2008). As of 2007, there are 24 colonies in some form of protected ownership (USFWS, 2009).","protectionNeeds":null,"otherConsiderations":null,"intrinsicVulnerabilityComments":"One study (Ross, 1999) was completed by Iowa State University on the genetics and Clark et al. (2008) state that the demographic analyses completed in their report support Ross' (1999) view that genetic diversity remains relatively high in these snail populations because they exist in numerous local demes with relatively low migration rates, even within sites and especially among sites.","enviromentalSpecificityComments":"The algific slopes where these snails live are fragile because of their steepness and loose rock covering. Activity on a site can dislodge rocks and soil, compact surface vents and crush snails. Therefore, monitoring methods need to be minimally intrusive and yet be able to reliably detect snails (Clark et al., 2008)."},"animalCharacteristics":{"elementGlobalId":111599,"majorHabitat":{"id":3,"majorHabitatDescEn":"Terrestrial","majorHabitatDescEs":"Terrestre","majorHabitatDescFr":"Terrestre"},"nonMigrant":true,"localMigrant":false,"longDistanceMigrant":false,"mobilityMigrationComments":"Clark et al. (2008) found horizontal movement was minimal within the algific site habitat over a six year study (about 16.7 meters in one year).","foodHabitsComments":"Birch and maple leaves (Henry, 2003).","animalPhenologyComments":"Combining Clarke et al. (2008) observations with those of Frest (1987) implies that many captured individuals in 8 populations studied in Iowa were alive for at least four years (with one captive specimen living six years); not 2-2.5 years as was previously reported (Frest, 1987).  From the mark-recapture surveys Clark et al. (2008) estimated that once captured, the expectancy of further life averaged an additional 1 to 1.25 y. This rough estimate of life span would still place the Iowa Pleistocene snail among those considered to have a comparatively short life span among terrestrial gastropods (Heller, 2001).","colonialBreeder":false,"length":null,"width":null,"weight":null,"animalPhenologies":[],"animalFoodHabits":[{"animalCagFoodHabitsId":106199,"foodHabits":{"id":4,"foodHabitsDescEn":"Herbivore","foodHabitsDescEs":"Herbívoro","foodHabitsDescFr":"Herbivore","displayOrder":4},"adult":true,"immature":false}]},"occurrenceDelineations":[{"eoSpecsDetailId":1235,"locationUseClass":{"id":1,"locationUseClassDescEn":"Not applicable","locationUseClassDescEs":"No se aplica","locationUseClassDescFr":"Sans objet","displayOrder":1},"eoSpecGroupName":"Terrestrial Snails","subtypes":null,"inferredExtentDistance":null,"inferredExtentNotes":null,"minimumEoCriteria":"Occurrences are based on some evidence of historical or current presence of single or multiple specimens, including live specimens or recently dead shells (i.e., soft tissue still attached without signs of external weathering or staining), at a given location with potentially recurring existence.  Weathered shells constitute a historic occurrence.  Evidence is derived from reliable published observation or collection data; unpublished, though documented (i.e. government or agency reports, web sites, etc.) observation or collection data; or museum specimen information.","mappingGuidance":null,"separationBarriers":"Barriers include barriers to dispersal such as the presence of permanent water bodies greater than 30 m in width, permanently frozen areas (e.g. mountaintop glaciers) which generally lack land snails (Frest and Johannes, 1995), or dry, xeric areas with less than six inches precipitation annually, as moisture is required for respiration and often hatching of eggs.  For the various slugs and slug-like species (families Arionidae, Philomycidae, Limacidae, Milacidae, Testacellidae, Veronicellidae), absence of suitable moisture, except for the most ubiquitous of species such as <i>Deroceras reticulatum</i> (Müller, 1774), can serve as a barrier to movement (Frest and Johannes, 1995).  Members of these groups tend to have greater difficulty crossing areas of little moisture than other pulmonates.  For tree snails (family Bulimulidae [= Orthalicidae]), lack of appropriate arboreal habitat (e.g. distance of greater than 500 m) also serves as a separation barrier.</b>","separationDistanceUnsuitableHabitatat":1.0,"separationDistanceSuitableHabitatat":1.0,"altSeparationProcedure":"None","separationJustification":"Burch and Pearce (1990) suggest refuges may be the most important factor limiting terrestrial snail abundance, although the greatest richness of species among carbonate cliff habitats (one of the most diverse in North America) is associated with calcareous, as opposed to acidic, substrates (Nekola, 1999; Nekola and Smith, 1999).  The panmictic unit (a local population in which matings are random) is small relative to those of other animal groups because terrestrial snails tend to be more sedentary.  Baker (1958) claimed, \"long-distance dispersal of terrestrial gastropods is undoubtedly passive\" although short distance dispersal is active involving slow, short distance migration under favorable conditions.  Long-distance passive migration is not considered when assigning separation distances, as otherwise separation distances for many animals and plants would be made impracticably large.  Passive migration of snails on terrestrial mammals, birds, or insects may occur over longer distances may occur across barriers.  Passive migration also may occur by wind or by rafting on floating objects (Vagvolgyi, 1975).  A third form of passive migration may occur through human activity such as transport as food, with consumed goods, or for biological control of other organisms.  <br><br>Terrestrial gastropods do not move much usually only to find food or reproduce.  Olfaction is the primary sensory behavior utilized to find and move toward a food item (on the scale of cm to m) although Atkinson (2003) found that <i>Anguispira alternata</i> was capable of switching foraging behavior when snails encountered a physical barrier to movement.  Fisher et al (1980) reported maximum movement rate of <i>Rumina decollata</i> (Linnaeus, 1758), an introduced pest species in California spreading relatively rapidly (for a snail), to be 20 m in three months (= 6.67 m/month) in an irrigated orchard.  Tupen and Roth (2001) reported the movement rate for the same species in an un-irrigated native scrub on San Nicolas Island to be 0.4 km in 12 years (= 33.33 m/month).  South (1965) found in dispersal studies of the slug, <i>Deroceras reticulatum</i>, that slugs traveled a mean distance of 1.13 m in seven days indicating this species disperses little throughout its life.  Giokas and Mylonas (2004) found mean dispersal and minimal movement distances were very small (16.2 and 5.4 m, respectively) for <i>Albinaria coerulea</i>, with few individuals dispersing longer distances.  Even the most extreme dispersal distances, such as 500 m for the giant African land snail <i>Achatina fulica</i> (Tomiyama and Nakane, 1993), do not approach the scale of km.  Viable land snail populations generally occupy small areas.  Frest and Johannes (1995) report the largest <i>Oreohelix</i> colony they observed was one mile (1.67 km) long and 0.25 miles (0.41 km) wide while the smallest was six feet (183 cm) long and two feet (61 cm) wide.  <br><br>As a whole, pulmonates (previously Subclass Pulmonata) are better dispersers than prosobranchs (previously Subclass Prosobranchia) possibly due to their hermaphroditic reproduction increasing the chance of new colonization (Pilsbry, 1948).  When compared with prosobranch families, pulmonates generally reproduce at smaller sizes and sooner, produce greater numbers of eggs/young, have larger clutch sizes, greater growth rates, and shorter life cycles (Brown, 1991).  Further, prosobranchs' requirement of constant moisture for oxygen exchange limits their ability to colonize drier habitats.  Suitable habitat for pulmonate groups tends to be more varied and less restrictive than for prosobranch groups.  All of these factors contribute to pulmonates greater dispersal capability over prosobranchs, as evidenced by the wider and more varied distribution of pulmonates over prosobranchs.  Despite this, separation distance for both groups is set at the minimum one km as most movements are well within this suggested minimum separation distance.","versionDate":"2004-05-26","versionAuthor":"Cordeiro, J.","versionNotes":null,"lastModified":"2020-04-30T02:29:11.104336Z"}],"plantCharacteristics":null,"elementManagement":{"elementGlobalId":111599,"eoManagementGroupName":null,"stewardshipOverview":null,"impacts":null,"restorationPotential":null,"siteConservationPlansConsidered":null,"managementMethods":null,"monitoringMethods":null,"managementProgramContacts":null,"monitoringProgramContacts":null,"managementResearchPrograms":null,"managementResearchNeeds":null,"biologicalResearchNeeds":null,"additionalTopics":null},"occurrenceViabilities":[{"eoRankSpecsDetailId":112837,"eoRankSpecsGroupName":null,"locationUseClass":{"id":1,"locationUseClassDescEn":"Not applicable","locationUseClassDescEs":"No se aplica","locationUseClassDescFr":"Sans objet","displayOrder":1},"excellentViability":null,"goodViability":null,"fairViability":null,"poorViability":null,"viabilityJustification":"Use the Generic Guidelines for the Application of Occurrence Ranks (2008).<br>The Key for Ranking Species Occurrences Using the Generic Approach provides a step-wise process for implementing this method.","versionDate":null,"versionAuthor":null,"versionNotes":null,"lastModified":"2020-05-14T02:45:42.652158Z"}],"references":[{"id":642057,"citation":"Clark, W.R., C.J. Henry, and C.L. Dettman. 2008. Demographic processes influencing population viability of the Iowa Pleistocene snail (<i>Discus macclintocki</i>). American Midland Naturalist, 160: 129-139.","shortCitationAuthor":"Clark et al.","shortCitationYear":2008,"referenceCode":"A08CLA01EHUS","lastModified":"2020-02-25T18:42:09.877926Z"},{"id":102722,"citation":"Frest, Terrence J. 1984. National Recovery Plan for Iowa Pleistocene Snail (Discus macclintocki). U.S. Fish and Wild- life Service, Washington, D.C. 33 p.","shortCitationAuthor":"Frest","shortCitationYear":1984,"referenceCode":"N84FRE01HQUS","lastModified":"2020-02-25T18:42:09.877926Z"},{"id":444170,"citation":"Frest, T.J. 1987. Iowa Pleistocene snail project 1987. Final report submitted to the Minnesota Department of Natural Resources, St. Paul, Minnesota, 14 November 1987. 28 pp. + app.","shortCitationAuthor":"Frest","shortCitationYear":1987,"referenceCode":"N87FRE01EHUS","lastModified":"2020-02-25T18:37:37.155045Z"},{"id":642274,"citation":"Heller, J. 2001. Life history strategies. Pages 413445 in G.M. Barker (ed.). The Biology of Terrestrial Molluscs. CAB International, London, England.","shortCitationAuthor":"Heller","shortCitationYear":2001,"referenceCode":"B01HEL01EHUS","lastModified":"2020-02-25T18:42:09.877926Z"},{"id":374806,"citation":"Henry, C. 2003. Refuge for an Ice Age survivor. Endangered Species Bulletin, 28(1): 1-3.","shortCitationAuthor":"Henry","shortCitationYear":2003,"referenceCode":"A03HEN01EHUS","lastModified":"2020-02-25T18:42:09.877926Z"},{"id":142096,"citation":"Hubricht, L. 1982. Endangered land snails of the eastern United States. Bulletin of the American Malacological Union, 1981: 45: 53-54.","shortCitationAuthor":"Hubricht","shortCitationYear":1982,"referenceCode":"A82HUB02HQUS","lastModified":"2020-02-25T18:31:29.430736Z"},{"id":116116,"citation":"Turgeon, D. D., J. F. Quinn, Jr., A. E. Bogan, E. V. Coan, F. G. Hochberg, W. G. Lyons, P. M. Mikkelsen, R. J. Neves, C. F. E. Roper, G. Rosenberg, B. Roth, A. Scheltema, F. G. Thompson, M. Vecchione, and J. D. Williams. 1998. Common and scientific names of aquatic invertebrates from the United States and Canada: Mollusks. 2nd Edition. American Fisheries Society Special Publication 26, Bethesda, Maryland. 526 pp.","shortCitationAuthor":"Turgeon et al.","shortCitationYear":1998,"referenceCode":"B98TUR01EHUS","lastModified":"2023-08-05T01:08:17.193393Z"},{"id":667676,"citation":"U.S. Fish and Wildlife Service (USFWS). 2009. Iowa Pleistocene snail (<i>Discus macclintocki</i>) 5-year review: Summary and evaluation. U.S. Fish and Wildlife Service: Moline, Illinois. 17 pp.","shortCitationAuthor":"USFWS","shortCitationYear":2009,"referenceCode":"N09FWS12EHUS","lastModified":"2020-02-25T18:42:09.877926Z"}],"otherCommonNames":[{"id":131314,"name":"Iowa Pleistocene Snail","language":"EN"},{"id":144531,"name":"pleistocene disc","language":"EN"}],"speciesGlobal":{"elementGlobalId":111599,"cites":null,"cosewic":null,"fwsRegion":{"id":3,"fwsRegionDescEn":"North Central","fwsRegionDescEs":"Norte Central","fwsRegionDescFr":"Centre-Nord"},"genusSize":null,"jurisEndem":{"id":3,"jurisEndemDescEn":"endemic to a single nation","jurisEndemDescEs":"Endémico de una nación","jurisEndemDescFr":"Endémique à une nation"},"nomenclaturallyEst":null,"usesa":{"id":1,"usesaDescEn":"Endangered","usesaDescEs":"Catalogado como en peligro de extinción","usesaDescFr":"En voie de disparition","usesaCode":"E"},"informalTaxonomy":{"informalTaxonomyId":14,"level1":"Animals","level2":"Mussels, Snails, & Other Molluscs","level3":"Terrestrial Snails","level":3,"hasChildren":false,"parentId":11,"distributionStatus":"complete","displayOrder":2030},"parentSpecies":null,"infraspecies":false,"kingdom":"Animalia","phylum":"Mollusca","taxclass":"Gastropoda","taxorder":"Stylommatophora","family":"Discidae","genus":"Discus","americanFisheriesStatus":null,"americanFisheriesStatusDate":null,"saraStatus":null,"saraStatusDate":null,"cosewicDate":null,"interpretedCosewic":null,"cosewicComments":null,"usesaDate":"1978-07-03","interpretedUsesa":null,"usesaComments":"In 2017, USFWS initiated 5-year status reviews of eight endangered animal species.","completeDistribution":true,"synonyms":[],"infraspeciesList":[],"ebarId":null,"ebarCanadianScope":false,"ebarGlobalScope":false,"ebarKbaGroup":"Invertebrates","caGeneralStatusId":null},"speciesCharacteristics":{"elementGlobalId":111599,"reproductionComments":"Although the reproductive mode of <i>Discus macclintocki </i>is unknown, some stylommatophorans have developed the ability to self-fertilize (Heller, 2001), a life-history trait that would be highly adaptive when populations decline and the chances for cross-fertilization decrease.","ecologyComments":null,"habitatComments":"This species lives on algific talus slopes, usually north facing, covered with a talus layer and upland sinkholes; lives in leaf litter (Henry, 2003).  Algific slopes, usually north facing, occur where air circulates over underground ice producing a constant stream of cold moist air through vents on to the slope. These vents are typically covered with a loose talus layer and thin plant and litter cover. Many rare plant and animal species that are considered glacial relicts persist only on these small areas of suitable habitat.","generalDescription":null,"diagnosticCharacteristics":null,"speciesMarineHabitats":[],"speciesTerrestrialHabitats":[{"cagTerrHabId":-111913,"terrestrialHabitat":{"id":17,"terrestrialHabitatDescEn":"Bare rock/talus/scree","terrestrialHabitatDescEs":"Roca viva/pendiente de roca/piedras sueltas","terrestrialHabitatDescFr":"Éboulis","displayOrder":20}}],"speciesRiverineHabitats":[],"speciesPalustrineHabitats":[],"speciesLacustrineHabitats":[],"speciesSubterraneanHabitats":[],"speciesEstuarineHabitats":[]},"primaryReference":{"id":116116,"citation":"Turgeon, D. D., J. F. Quinn, Jr., A. E. Bogan, E. V. Coan, F. G. 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