title: Discovery of living Potamolepidae (Porifera: Spongillina) from Nearctic freshwater with description of a new genus.
abstract: We report here the first record of a living Potamolepidae (Cherokeesia n. gen.) from the Nearctic Region and from the northern hemisphere. The new species Cherokeesia armata from southern Appalachians diverges at generic and specific level from all the other known taxa of the family Potamolepidae in its unique combination of diagnostic traits: gemmular theca armed by gemmuloscleres ranging from small strongyle-like spicules to stout, large oxeas; absence of pneumatic layer; spiny oxeas as main skeleton megascleres; irregular, slender pauci- to uni-spicular skeletal network. The most similar species belong to the genera Potamophloios and Oncosclera. The circumtropical biogeographic pattern of extant Potamolepidae, previously considered of Gondwanian to Gondwanian-like origin, is enlarged to the Nearctic. The present Tennessee discovery confirms a wider range of the family. An updated species inventory of Nearctic Spongillina, a checklist of the family Potamolepidae at the global level together with a key to the genera of Potamolepidae are also provided.
authors.affiliation: Department of Biology, Lincoln Memorial University, Cumberland Gap Parkway, Harrogate, Tennessee 37752, USA.; Email: john.copeland@lmunet.edu.
authors.forename: John
authors.initials: J
authors.lastname: Copeland
authors.affiliation: Dipartimento di Scienze della Terra, dell'Ambiente e della Vita, Università di Genova, Corso Europa 26, 16132 Genova, Italy.; Email: pronzato@dipteris.unige.it.
authors.forename: Roberto
authors.initials: R
authors.lastname: Pronzato
authors.affiliation: Dipartimento di Scienze della Natura e del Territorio, Università di Sassari, Via Muroni 25, 07100 Sassari, Italy.; Email: r.manconi@uniss.it.
authors.forename: Renata
authors.initials: R
authors.lastname: Manconi
mesh_terms: D063147:Animal Distribution; D000825:Animal Structures / Q000033:anatomy & histology / Q000254:growth & development; D000818:Animals; D049628:Body Size; D017753:Ecosystem; D009929:Organ Size; D010802:Phylogeny; D011161:Porifera / Q000033:anatomy & histology / Q000145:classification* / Q000254:growth & development; D045483:Rivers / Q000737:chemistry