Life beneath the surface of the central Texan Balcones Escarpment: genus Anillinus Casey, 1918 (Coleoptera, Carabidae, Bembidiini): new species, a key to the Texas species, and notes about their way of life and evolution

Abstract The Texas fauna of the genus Anillinus Casey, 1918 includes three previously described species (A. affabilis (Brues), 1902, A. depressus (Jeannel), 1963 and A. sinuatus (Jeannel), 1963) and four new species here described: A. acutipennis Sokolov & Reddell, sp. n. (type locality: Fort Hood area, Bell County, Texas); A. comalensis Sokolov & Kavanaugh, sp. n. (type locality: 7 miles W of New Braunfels, Comal County, Texas); A. forthoodensis Sokolov & Reddell, sp. n. (type locality: Fort Hood area, Bell County, Texas); A. wisemanensis Sokolov & Kavanaugh, sp. n. (type locality: Wiseman Sink, Hays County, Texas). A key for identification of adults of these species is provided. The fauna includes both soil- and cave-inhabiting species restricted to the Balcones Fault Zone and Lampasas Cut Plain and adjacent areas underlain by the Edwards-Trinity Aquifer. Based on morphological and distributional data, we hypothesize that four lineages of endogean Anillinus species extended their geographical ranges from a source area in the Ouachita-Ozark Mountains to the Balconian region in central Texas. There the cavernous Edwards-Trinity aquifer system provided an excellent refugium as the regional climate in the late Tertiary and early Quaternary became increasingly drier, rendering life at the surface nearly impossible for small, litter-inhabiting arthropods. Isolated within the Edwards-Trinity aquifer system, these anilline lineages subsequently differentiated, accounting for the currently known diversity. The paucity of specimens and difficulty in collecting them suggest that additional undiscovered species remain to be found in the region.

[1]  I. Sokolov.  A new genus and eight new species of the subtribe Anillina (Carabidae, Trechinae, Bembidiini) from Mexico, with a cladistic analysis and some notes on the evolution of the genus , 2013, ZooKeys.

[2]  I. Sokolov.  Five New Species of Anillinus Casey from Alabama with a Key to the Alabama Species (Carabidae: Trechinae: Bembidiini) , 2012 .

[3]  Y. Bousquet.  Catalogue of Geadephaga (Coleoptera, Adephaga) of America, north of Mexico , 2012, ZooKeys.

[4]  C. Carlton,et al.  Species of Anillinus Casey (Coleoptera: Carabidae: Trechinae) Described from Brazil and their Relation to North American Representatives of the Genus , 2012 .

[5]  K. Miller,et al.  Description of a New Genus and Species of Stygobiontic Diving Beetle, Psychopomporus felipi Jean, Telles, and Miller (Coleoptera: Dytiscidae: Hydroporinae), from the Edwards-Trinity Aquifer System of Texas, USA , 2012, The Coleopterists' bulletin.

[6]  C. Griswold,et al.  Systematics, conservation and morphology of the spider genus Tayshaneta (Araneae, Leptonetidae) in Central Texas Caves , 2012, ZooKeys.

[7]  Mundi.  Five new species of Anillinus Casey from the Southern Appalachian Mountains and the Piedmont Plateau of eastern U.S.A. (Coleoptera: Carabidae: Trechinae: Bembidiini) , 2011 .

[8]  J. Cokendolpher.  A NEW SPECIES OF TROGLOBITIC RHADZNE ( COLEOPTERA : CARABIDAE ) FROM TEXAS , 2010 .

[9]  G. Ball,et al.  A Taxonomic Review of the Genus Apenes Leconte (Coleoptera: Carabidae: Lebiini) in the West Indies, with Descriptions of New Species and Notes About Classification and Biogeography , 2009 .

[10]  Y. Alarie,et al.  North American Stygobiontic Diving Beetles (Coleoptera: Dytiscidae: Hydroporinae) with Description of Ereboporus naturaconservatus Miller, Gibson and Alarie, New Genus and Species, from Texas, U.S.A , 2009 .

[11]  A. Nelson,et al.  First records of 13 mammalian species within the southwestern Cross Timbers region of Texas , 2009 .

[12]  I. Sokolov,et al.  A New Species and the First Record of the Genus Anillinus (Carabidae: Trechinae: Bembidiini) from the Ozark Region , 2008 .

[13]  C. Carlton,et al.  Two new species of blind, forest litter-inhabiting ground beetles from the subtribe Anillina (Carabidae: Trechinae: Bembidiini) from eastern U.S.A. , 2008 .

[14]  B. Šket,et al.  The mid-latitude biodiversity ridge in terrestrial cave fauna , 2006 .

[15]  G. Ball,et al.  Taxonomic review of the Tribe Melaenini (Coleoptera: Carabidae), with observations on morphological, ecological and chorological evolution , 2005 .

[16]  M. Hedin,et al.  The power and perils of ‘molecular taxonomy’: a case study of eyeless and endangered Cicurina (Araneae: Dictynidae) from Texas caves , 2004, Molecular ecology.

[17]  C. Carlton,et al.  Review of Anillinus, with Descriptions of 17 New Species and a Key to Soil and Litter Species (Coleoptera: Carabidae: Trechinae: Bembidiini) , 2004 .

[18]  M. Christman,et al.  The North American obligate cave fauna: regional patterns , 2003, Biodiversity & Conservation.

[19]  R. Cranfill,et al.  Late Cretaceous and Cenozoic History of North American Vegetation: North of Mexico , 1999 .

[20]  P. Ryder.  Ground Water Atlas of the United States: Segment 4, Oklahoma, Texas , 1996 .

[21]  C. Barr,et al.  A new genus and species of stygobiontic dytiscid beetle, Comaldessus stygius (Coleoptera: Dytiscidae: Bidessini) from Comal Springs, Texas , 1995 .

[22]  J. Reddell.  THE CAVE FAUNA OF TEXAS WITH SPECIAL REFERENCE TO THE WESTERN EDWARDS PLATEAU , 1994 .

[23]  C. Barr,et al.  A new genus and species of stygobiontic dryopid beetle, Stygoparnus comalensis (Coleoptera : Dryopidae), from Comal Springs, Texas , 1992 .

[24]  C. Carlton.  Symposium: Origins of Arthropod Fauna of the Southeastern United States: Biogeographic Affinities of Pselaphid Beetles of the Eastern United States , 1990 .

[25]  S. Hatch,et al.  Checklist of the vascular plants of Texas , 1990 .

[26]  T. Erwin,et al.  A catalogue of the primary types of Carabidae (incl. Cicindelinae) in the collections of the United States National Museum of Natural History (USNM) (Coleoptera) , 1978 .

[27]  G. Longley,et al.  A New Subterranean Aquatic Beetle from Texas (Coleoptera: Dytiscidae-Hydroporinae) , 1976 .

[28]  T. Barr.  Revision of Rhadine Le Conte (Coleoptera, Carabidae). l. The subterranea group , 1974 .

[29]  J. R. Holsinger.  Systematics, speciation, and distribution of the subterranean amphipod genus Stygonectes (Gammaridae) , 1967 .

[30]  R. Jeannel.  Monographie des "Anillini", Bembidiides endogés ("Coleoptera trechidae") , 1963 .

[31]  F. W. Gould,et al.  Texas plants: a check list and ecological summary. , 1962 .

[32]  C. Hubbs.  Distributional patterns of Texas fresh-water fishes. , 1957 .

[33]  C. Leng.  Catalogue of the Coleoptera of America, north of Mexico , 1920 .

[34]  T. L. Casey.  A review of the North American Bembidiinae , 1918 .

[35]  C. T. Brues.  New and Little-Known Guests of the Texan Legionary Ants , 1902, The American Naturalist.

[36]  J. L. Conte.  Notes on the Classification of the Carabidae of the United States , 1853 .