N. Gary Lane

A nearshore sponge spicule mat from the Pennsylvanian of West-central Indiana

ABSTRACT A thin (3-6) cm) interval in the Perth Limestone Member of the Staunton Formation (Pennsylvanian, Desmoinesian) in Warren County, Indiana, contains abundant small siliceous sponge spicules that form a spicule mat. The limestone is a grain-supported packstone with a micritic matrix, the predominant grains being small sponge spicules that range down to a few micrometers in size. The intermeshed spicules helped support a wide variety of vagile and sessile benthonic marine invertebrates on a lime mud bottom. In contrast to other spiculites that are basinal deposits, the spiculite reported here developed in shallow water, probably no more than 90 feet deep, as part of a cyclothemic sequence that includes coals and fluviatile channel sandstones above and below the Perth.

A camerate-rich late carboniferous (Moscovian) crinoid fauna from volcanic conglomerate, Xinjiang, People's Republic of China

A new trace fossil from the Lower Triassic of northern Italy is described. It is a sinuous resting trace of a bilaterally symmetrical worm-like animal. The anterior end is characterised by a pair of lateral projections. It most closely resembles an acorn- worm (class Enteropneusta) in morphology. As such, it is the only known resting trace of an acorn-worm from the fossil record. . Paleont., 70( ), 1996, pp. 128-131 pyright ? 1996, Th Pale ntological Society ENTEROPNEUSTS, OR acorn-worms, are deposit-feeding, ma- rine hemichordates that can be found anywhere from in- tertidal areas to deep abyssal plains (Barrington, 1965). In shal- lower environments they tend to live in U-shaped burrows, whereas in the abyssal plains they have been photographed mov- ing freely on the substrate surface (Bourne and Heezen, 1965; Gaillard, 1991). Their fossil record is extremely poor (Benton 1993). The only known example is from the Lower Jurassic of Lombardy, Italy (Arduini et al., 1981). Bulman (1970) also lists several instances where trace fossils have been assigned to enteropneust activity. The similarity no- ticed between the spiral traces photographed by Bourne and Heezen (1965) and the trace fossil Taphrhelminthopsis is one example. However, this sort of trace could be made by any organism moving efficiently over the substrate, without crossing its own track. For example, Gaillard (1991) photographed deep- sea echinoids producing an identical trail. Enteropneust burrows have also been reported from the Muschelkalk of Poland (Kaz- mie czak and Pszczolkowski, 1969) and Upper Cretaceous of Germany (Wetzel, 1972). They consist of U-shaped burrows with funnel-shaped outlets, and usually have side branches off the head shaft (Kazmierczak and Pszczolkowski, 1969). This is ve y milar to modem day acorn-worm burrows (Barrington, 1965). However, the burrows also have horizontal connecting tubes w th short, blind-ended side branches and lack evidence of fecal castings. This morphology is very similar to the burrows f modern day shrimps figured in Bromley (1990). The inter- pretati of the Muschelkalk structures as enteropneust in origin is therefore equivocal. In c ntrast, the specimen described here is identified as being 128 This content downloaded from 157.55.39.27 on Wed, 07 Sep 2016 05:17:37 UTC All use subject to http://about.jstor.org/terms

NEW PERMIAN CRINOIDS FROM THE BATTLESHIP WASH PATCH REEF IN SOUTHERN NEVADA

Abstract The small crinoidal patch reef in the Bird Spring Formation near the mouth of Battleship Wash, Clark County, Nevada, has yielded the largest Early Permian crinoid fauna known in North America. Earlier studies of the fauna were based on 535 specimens. Additional collecting has yielded another 239 specimens. These new specimens provide new information about some of the earlier described species and include three new genera and seven new species, bringing the total recognized in the Battleship Wash fauna to 37 genera and 62 species. Representatives of the camerates, disparids, primitive cladids (cyathocrinitids and dendrocrinids), advanced cladids (formerly poteriocriniids), flexibles, and articulates are recognized in the Battleship Wash fauna. Of particular significance among these new specimens is the presence of an actinocrinid. A specimen formerly identified from the fauna is here recognized as an articulate. This is the first report of an actinocrinid and an articulate from the Permian of North America. Based on the abundance of large specimens of cladids with 10 or more arms, the Battleship Wash fauna is interpreted to have lived in a nearshore high energy shelf environment, which agrees with the paleogeographic position previously recognized for the Bird Spring Formation. New taxa introduced are: Poteriocrinites permicus n. sp., Bridgerocrinidae n. fam., Ekteinocrinus battleshipensis n. gen. and sp., Arroyocrius brachiatus n. sp., Plummericrinus jelli n. sp., Plummericrinus? bulbosus n. sp., Aesiocrinidae n. fam., Elassocrinus cyathus n. gen. and sp., Oklahomacrinus triangulus n. sp., and Pentaxocrinus quinarius n. gen. and comb.

Revision of Strunian crinoids and blastoids from Germany

AbstractIn 1930W.E. Schmidt described all known crinoids from the German Early Carboniferous, including the Etroeungt beds of Germany, which are now judged to be latest Devonian (Famennian) in age. On a global basis, Famennian camerate crinoids generally show a closer relationship to succeeding Early Carboniferous faunas than they do to older Frasnian or Middle Devonian crinoids, which also is the case for the Strunian fauna. Holdovers from older Devonian faunas include, among others,Adelocrinus, a descendant of olderArthroacantha, in England and Germany, andPetaloblastus, which is one of the youngest genera of the blastoid family Hyperoblastidae. Precursors of younger Early Carboniferous groups include platycrinoids, primitive actinocrinoids, dichocrinoids, and the blastoid genusDoryblastus, which is one of the oldest members of the family Orbitremitidae. All of these groups, which became important parts of the Early Carboniferous crinoid and blastoid radiation, give Famennian crinoid faunas much more of an Early Carboniferous than a Devonian aspect. Rhipidocrinus schmidti n. sp. is erected for specimens that originally were reported from the Etroeungt asRhodocrinus uniarticulatus. We judge that there are currently four valid species assigned toRhipidocrinus: R. crenatus, R. perloricatus, R. praecursor, and our new species,R. schmidti. Hydriocrinus ratingensis Schmidt is reassigned to ?Sostronocrinus. We note thatSchmidt (1906), notJaekel (1906) as has been reported previously, is the author ofRhipidocrinus perloricatus. Owing to the poor preservation of the Etroeungt material, we regard the namePlatycrinites wunstorfiSchmidt 1930 to be a nomen nudum.KurzfassungIm Jahre 1930 beschriebW.E. Schmidt alle damals bekannten Crinoiden des frühen Karbon Deutschlands, einschliesslich der Etroeungt-Schichten, die heute aber als spätestes Devon (Famenne) angesehen werden. Als Teil unserer laufenden weltweiten Untersuchungen an spätdevonisch bis frühkarbonischen Echinodermen haben wir nun auch die Crinoiden- und Blastoidenfauna der Etroeungt-Schichten überprüft. Auf globaler Ebene, wie auch im Fall der etroeungtischen Fauna, zeigen Kammercrinoiden des Famenne eine engere Beziehung zu den nachfolgenden frühkarbonischen Faunen als zu den älteren Crinoiden des Frasniums oder des Mitteldevons. Durchläufer aus den älteren devonischen Faunen schließen unter anderemAdelocrinus, einen Abkömmling der älterenArthroacantha Englands und Deutschlands ein, sowiePetaloblastus, eine der jüngsten Gattungen der Blastoidenfamilie Hyperoblastidae. Vorläufer jüngerer frühkarbonischer Gruppen beinhalten Platycrinoiden, primitive Actinocrinoiden, Dichocrinoiden und die BlastoidengattungDoryblastus, eines der ältesten Glieder der Familie Orbitremitidae. All diese Gruppen, die sich im frühen Karbon zu wichtigen Bestandteilen der Crinoiden- und Blastoidenverbreitung entwickelten, verleihen den Crinoidenfaunen des Famenniums einen mehr frühkarbonischen als devonischen Charakter. Rhipidocrinus schmidti n. sp. bezieht sich auf Exemplare, über die ursprünglich aus dem Etroeungt berichtet wurde, wieRhodocrinus unarticulatus. Wir gehen davon aus, dass es heute vier gültige Spezies gibt, dieRhipidocrinus zugeschrieben werden:R. crenatus, R. perloricatus, R. praecursor sowie unsere neue SpeziesR. schmidti. Hydriocrinus ratingensisSchmidt wird wieder ?Sostrocrinus zugeordnet. Wir möchten anmerken, dassSchmidt (1906) und nichtJaekel (1906), wie früher berichtet, der Autor vonRhipidocrinus perloricatus ist. Aufgrund der schlechten Erhaltung des Etroeungt-Materials betrachten wir den NamenPlatycrinites wunstorfi (Schmidt, 1930) als nomen nudum.

Unusual crinoids from the Ramp Creek Formation (Mississippian), Indian Creek, Montgomery County, Indiana

Three new species of inadunate crinoids of Early Mississippian age from the Ramp Creek Formation along Indiana Creek, southern Montgomery County, Indiana, are described. Poteriocrinites amplus n. sp. is the first correctly identified record from North America of this long-ranging Old World genus. Poteriocrinites macropleurus and P. doris from the Burlington Limestone are here reassigned to Springericrinus. Interchange of Mississippian crinoid genera between Europe and North America is rare, many genera being endemic. Springericrinus sacculus n. sp. is the youngest reported species of this North American counterpart of Poteriocrinites. This new species exhibits two advanced features: presence of only one, rather than three, anal plate, and presence of 3 or 4, rather than 1 or 2, primibrachial plates per ray. The third species, Decadocrinus stellatus n. sp., presents an interesting blend of characters usually used as generic discriminators between Decadocrinus and Histocrinus. The specimen could possibly be considered to be an intermediate between these two genera that are currently placed, incorrectly we believe, in two separate superfamilies.

Ontogenetic adaptations in some Pennsylvanian crinoids

Three species of Upper Pennsylvanian crinoids, two inadunates and one flexible, exhibit a sufficiently complete growth series to describe and quantify their ontogeny. Apographiocrinus typicalis (Moore and Plummer), Erisocrinus typus (Meek and Worthen), and Euonychocrinus simplex (Strimple and Moore) were collected from the middle shale of the Millersville Limestone Member of the Bond Formation at the Charleston Stone Quarry, Coles County, Illinois. Ten other crinoid species were collected in insufficient numbers for growth studies. Both bivariate and multivariate statistical procedures were used to analyze the growth of these crinoids. In the inadunate crinoids skeletal growth was highly coordinated in the dorsal cup and cup plates. Arm length increased by addition of secundibrachials. Food groove width increased almost three times from immature to adult stages, thus allowing a larger range of food particles to be consumed by adults. Growth of the cup is isometric in E. typus and slightly anisometric in A. typicalis. Primibrachials in both species develop anisometrically. Immature specimens possess long, slender primibrachials, with the A ray plate being longest. In maturity, the primibrachials become equidimensional and equalized in all rays. The A ray arm is followed by the C and D ray arms, and finally the B and E ray arms, in sharp contrast to arm development in disparid inadunates. Pinnules appear late in the immature stage of growth. Primary emphasis on the expansion of the arms in young inadunates demonstrates a rapid establishment of a filtration-fan mode of feeding. Subsequent development involves widening of the plates for strength and support of the arms and to accommodate wider food grooves that permit a larger array of food particles to be captured. The flexible crinoid, E. simplex , experienced a less correlated pattern of growth. Cup plates and arms grew isometrically and all arms were added simultaneously. Development suggests that flexibles fed differently than the associated inadunates and the cup may have played a less important role in functioning of the calyx. The upright, elevated growth pattern of stalked crinoids exposed them to a sequence of competitive interactions with other epifaunal animals that had important adaptational ramifications for their evolution, diversity, and extinction. The fact that most living crinoids, stalked and unstalked, have abandoned a permanently fixed place of growth may have been an advantageous factor in their survival.

Stratigraphic distribution and paleoecology of Pennsylvanian conchostracans (Crustacea: Branchiopoda) on the east side of the Illinois Basin

Conchostracans are known to occur at nine stratigraphic levels in Pennsylvanian rocks of the eastern side of the Illinois Basin. Two species, Pemphilimnadiopsis ortoni and Leaia tricarinata, have been identified in these rocks. Except for two occurrences, one of which represents transported material, the two species are mutually exclusive. The one in situ co-occurrence suggests that differences in salinity, alkalinity, or both influenced where the conchostracans lived. Other occurrences are generally characterized by having great numbers of specimens that nearly cover bedding surfaces of shale that is closely associated with a coal bed. The fact that these shales generally lack other invertebrate fossils and are usually rich in organic matter suggests that Pennsylvanian conchostracans of the Illinois Basin tolerated narrow salinities in standing bodies of water that were associated with a swampy, deltaic setting. Conchostracans are apparently limited to the upper part of the Pennsylvanian System within the field area, but they are not well correlated with large-scale, climatic cycles.Conchostracans are known to occur at nine stratigraphic levels in Pennsylvanian rocks of the eastern side of the Illinois Basin. Two species, Pemphilimnadiopsis ortoni and Leaia tricarinata, have been identified in these rocks. Except for two occurrences, one of which represents transported material, the two species are mutually exclusive. The one in situ co-occurrence suggests that differences in salinity, alkalinity, or both influenced where the conchostracans lived. Other occurrences are generally characterized by having great numbers of specimens that nearly cover bedding surfaces of shale that is closely associated with a coal bed. The fact that these shales generally lack other invertebrate fossils and are usually rich in organic matter suggests that Pennsylvanian conchostracans of the Illinois Basin tolerated narrow salinities in standing bodies of water that were associated with a swampy, deltaic setting. Conchostracans are apparently limited to the upper part of the Pennsylvanian System within the field area, but they are not well correlated with large-scale, climatic cycles.

Use of surfactants in disaggregation of argillaceous rocks

Effective disaggregation of samples commonly presents problems for micropaleontologists. Eight rock samples of differing ease or difficulty of disaggregation were tested by boiling in seven commercially available surfactants to determine the degree of disaggregation. Quaternary-O was used as a standard for comparison of results. Quaternary-O and Stepan Biosoft gave the best overall results, although different individual surfactants performed best on some samples. Continued experimentation is needed to estimate the value of surfactants in breaking down rock samples. Breaking down shales and mudstones to release small fossils or other embedded fragments without damage to limy skeletons, has traditionally relied on either soaking in a petrochemical (kerosene, oleum spirits and others) or boiling them in a single chemical surfactant, QuaternaryO (Zingula 1968). Hundreds of surfactants are commercially available, at least some of which are potentially useful in micropaleontology. We report here on preliminary trials of seven surfactants other than Quaternary-O for disaggregating argillaceous rocks. Quaternary-O was also used as a standard for comparison of the results. Eight different rock samples were chosen for testing to provide a range from those readily disaggregated to others that are very difficult to break down. Surfactants are surface-active chemicals. They interact primarily by physical adsorption of a carbon chain onto a rock substrate. Adsorption is accomplished by attachment of the polar head group on one end of the chain, which can be anionic, cationic, or non-ionic, onto the substrate. A cationic head group is adsorbed onto an anionic site of the

A microcrinoid colony from a cephalopod body chamber (Chesterian; Arkansas)

An unusual occurrence of a colony of microcrinoids from shale within a fragment of a large orthoconic nautiloid body chamber is described from the Imo Formation (Mississippian, Chesterian) near Elba, Arkansas. The colony, about 70 individuals, consists principally of immature specimens that lack facets for the arms, and a few mature specimens with four or five arm facets. The crinoids are interpreted as record of a census population that was engulfed suddenly by mud. The crinoids are assigned to Allagecrinus coronarius Gutschick, 1968. The body chamber may have been broken during predation by other large cephalopods, or sharks, known from the Imo, or by post-mortem transport. The shell served as a firm substrate on which the microcrinoid larvae could settle and the convex sides may have provided some protection from currents.