Hexactinellid and associated sponges from the upper Reef Trail Member of the Bell Canyon Formation, southern Guadalupe Mountains National Park, Texas

Abstract

A small faunule of silicified hexactinellid sponges and root tufts has been recovered from the upper Guadalupian Reef Trail Member of the Bell Canyon Formation, from the Patterson Hills, in the southwestern part of the Guadalupe Mountains National Park in western Texas. Some demosponges from the type section of the Reef Trail Member, near the mouth of McKittrick Canyon on the front of the Guadalupe Mountains in the park, have also been documented. Included in the faunule from the Patterson Hills localities are the new amphidiscosid hexactinellid pelicasponge Trailospongia reischi n. gen. and sp., the questionable pelicaspongiid Hexirregularia nana n. gen. and sp., and the dictyospongiid hexactinellids Microstaura doliolum Finks, 1960, and Microstaurella minima n. gen. and sp., and Microstaurella parva n. gen. and sp. They are associated with specimens of the lyssacinosid brachiosponges Toomeyospongiella gigantia Rigby and Bell, 2005, Toomeyospongia modica n. sp., and Toomeyospongia minuta n. gen. and sp., and fragments of three different types of root tufts, termed Tufts 1, 3, and 4. Two specimens of the new cylindrical demosponge Mckittrickella pratti n. gen. and sp. are associated with Tuft 2 in the collection from the type section of the Reef Trail Member, and a third specimen was collected from the member in the Patterson Hills. These sponges from Localities 1-7 are the youngest Permian sponges known from the region, and possibly from North America.

Ordovician sponge spicules from Spitsbergen, Nevada and Newfoundland: new evidence for hexactinellid and demosponge early diversification

“…Finks & Rigby (2004) included several families of Palaeozoic hexactinellids, including Ordovician forms, in the Amphidiscophora, based on the presence of lyssacine skeletons which have no fusion of spicules in any part of the body. Although the presence of amphidics or hemidisc microscleres was included in the diagnoses of the Palaeozoic Amphidiscophora, only in the Carboniferous (Kling & Reif 1969) and Permian (Rigby et al 2007) were true amphidiscs and hemidiscs found associated with megascleres.…”

Molecular paleobiology of early-branching animals: integrating DNA and fossils elucidates the evolutionary history of hexactinellid sponges

“…Following a high Paleozoic diversity, most groups dominant in that era had disappeared by the end of the Permian (Mostler 1990;Mehl 1996;Mehl-Janussen 1999;Krautter 2002). Because the taxonomically important microscleres are rarely preserved in situ (but see, e.g., Kling andReif 1969 andRigby et al 2007 for notable exceptions), and Paleozoic skeletal architectures differ greatly from Mesozoic and modern forms (Mehl and Mostler 1993;Mehl 1996), relationships of these taxa to extant hexactinellids remain largely elusive. Thus, fossils assigned to modern families are mostly confined to the Mesozoic-Cenozoic.…”

Occurrence and paleoecological significance of lyssacinosid sponges in the Upper Cretaceous deposits of southern Poland

“…Quite often, only the root tufts that were buried in the sediment during the sponges' lifetime have been preserved (Leys et al 2007). The isolated root tufts of lyssacinosids and other non-rigid hexactinellid sponges were often described from other assemblages of fossil sponges, e.g., from Eocene of Catalonia (Pisera and Busquets 2002) or Permian of Texas (Rigby et al 2007). The lack of well-preserved specimens and occurrence of dispersed spicules in the Campanian deposits result most likely from a slow rate of sedimentation and periodic weak bottom currents, which prevented the accumulation of the sediment and favored destruction of skeletons of dead sponges.…”