The record of Middle Ordovician (Oretanian, ca. Darriwilian 2) hyolithids from the Ossa Morena Zone of the Iberian Massif in southwestern Spain is increased with the recognition of Robardetlites sevillanus n. gen. n. sp., Andalucilites parvulus n. gen. n. sp., Pauxillites desolatus n. sp., Leolites malinkyi Marek and Gutiérrez-Marco n. sp., and Cavernolites sp. in that region. Andalucilites n. gen. and Robardetlites n. gen. are endemic whereas the other genera are known from coeval strata in the Barrandian region in central Europe, France, and Morocco, giving this assemblage a decidedly “Mediterranean province” character. The discovery of Pauxillites, Leolites, and Cavernolites in Iberia extends their geographic ranges to that region, and Leolites from this area extends its stratigraphic range downward, making its occurrence in Iberia the oldest known for that genus.

UUID: http://zoobank.org/f5b29223-6dac-4c7e-8851-551e634da667

Disc-like fossils from siltstones of the Taozichong Formation (Cambrian) in the Qingzhen area, Guizhou, South China are reported here. They are similar to some Ediacaran and Phanerozoic discoidal fossils, and assigned to Tirasiana? disciformis? Palij, 1976. Based on the study of 43 specimens, dewatering or fluid escape structures, soft-sediment loading, scratch circles or other inorganic origins are ruled out, and the fossil is interpreted as a discoidal body fossil of unknown affinities rather than trace fossils. Energy-dispersive X-ray spectroscopy and elemental mapping analyses reveal that the discoid fossils contain higher concentrations of C, Fe, and P than the surrounding matrix, indicating the possible presence of pyrite, apatite, and organic carbon as a result of authigenic mineralization in association with decay and early diagenetic processes. The possible presence of extracellular polymeric substance suggests that the discs were surrounded by thin microbial mats composed primarily of extracellular polymeric substances, which facilitated their fossilization by promoting conditions that are favorable to secondary mineral precipitation. The new specimens provide useful information about the phylogenetic affinities of these early discoidal fossils and help us to better understand the taphonomic modes of non-biomineralizing organisms in Ediacara-type and Burgess Shale-type biotas.

Based on multivariate morphometric analysis, Halysites catenularius is identified from the Rumba Formation (Telychian) and Jaagarahu Formation (Sheinwoodian) of Estonia; H. priscus is confirmed as a junior synonym. Halysites catenularius, H. junior, and H. senior are shown to be closely related; H. catenularius is morphologically intermediate. Cyclomorphism in H. catenularius, recorded by fluctuations of corallite tabularial area, indicates an average annual growth rate of 6.0 mm, which is typical for halysitids. Tubules in H. catenularius, generated from small intramural openings between adjacent corallites, were involved in two types of interstitial increase. The intramural openings, three types of lateral increase, temporary agglutinated patches of corallites, and axial increase documented in H. catenularius resemble features in some species of Catenipora. These similarities are consistent with the interpretation that Halysites evolved from Catenipora. Evaluation of the possibility that both genera are polyphyletic will require further detailed analysis of additional species.

Platymerella from the lower Red Mountain Formation in Georgia and Tennessee, the Bowling Green Dolomite of west-central Illinois, and the Elwood Dolomite of northeastern Illinois represents a paleosubtropical, cool-water occurrence of virgianid brachiopods in Laurentia during the early Silurian (middle–late Rhuddanian). These occurrences were located in the southern Appalachian foreland basin and the distal end of the Sebree Trough, likely subjected to frequent cool-water current and upwelling from Gondwana. Compared with broadly coeval species of Virgiana from lower paleotropical to equatorial latitudes, Platymerella has significantly smaller, dorsoventrally flattened shells, with subequal ventral and dorsal umbones and beaks that extend only slightly above the hinge line. Relative to its shell size, however, Platymerella has more prominent thickening of the shell wall, median septum, spondylium, and hinge plates than Virgiana, resembling more closely the extravagant shell thickening of Tcherskidium and Proconchidium from the Late Ordovician (late Katian) equatorial regions. The thickening of hinge plates resulted in the formation of a pseudocruralium, which separates Platymerella from Virgiana. In latest Ordovician–earliest Silurian virgianids, there was a general morphological gradient toward a smaller shell, reduction in the ventral-valve convexity, and reduction in the size and height of the ventral umbo from paleoequatorial to southern subtropical regions, with Platymerella representing the most southerly forms.

Analyses of shell shape variation in epifaunal and semi-infaunal myalinids from the LaSalle “cyclothem” attest to the extensive shape plasticity of some Late Pennsylvanian myalinids. Mean shell shapes differ significantly within and among species across three nearshore facies. Discriminant analyses of Fourier biometric data categorized by taxonomic, populational (habitat), life-mode, and “multi-species habitat assemblage”” discriminant groups reveal patterns of shape change and variation across an inferred environmental stress gradient in addition to taxonomic and life-mode shape differences. Fourier harmonic data are good indicators of shape differences between epifaunal and semi-infaunal life modes. Mean shapes of epifaunal species vary among habitats. Within-habitat shell shape convergence occurred between Myalina glossoidea and M. (Orthomyalina) slocomi. Interpopulational shape divergence occurred among all populations of M. (Orthomyalina) slocomi, M. glossoidea, and M. wyomingensis. Within-species variation among habitats produced significant mean shape differences among each of three “multi-species habitat assemblages.” Results indicate that a portion of the variation is of ecophenotypic origin.

Mean interspecific shape differences reflect internal functional organization and life modes. Intraspecific shape differences among epifaunal species could reflect physical and biotic habitat variables. Several harmonic amplitudes vary in concert with inferred environmental variation among habitats. Although biologic interpretation of harmonic data is problematic, parallel trends in fifth harmonic amplitudes of epifaunal species mirror inferred differences in water turbulence among habitats and could reflect shape variation related to byssal attachment.

Stress gradient trends in intraspecific shape variability cannot be collectively explained by either of the antithetical stability-diversity-variation hypotheses. Each species exhibits a different nonmonotonic trend. Maximal levels of intraspecific variation within each species occurred within different habitats. Within-species differences in levels of variation could result from genetic variation among populations as well as ecophenotypic influences. Comparative studies of ontogenetic shape change between valves of individuals, among individuals, and among populations are necessary to determine the relative influence of environmental variables on shape variation and evolutionary significance of phenotypic plasticity.

A diverse fauna of ostracodes comprising 21 species representing 20 genera are described from the Maxville Limestone in central Ohio. Eight new species are proposed—Roundyella incompta, Deloia spinula, Lokius morsei, Bairdia prolixa, Acratia prolata, Waylandella depresssa, Pseudobythocypris securis, and Paracavellina cooperi.

Oliganisus secunda (Croneis and Bristol), Glyptopleura costata (McCoy), and Geffenina praelonga Cooper are represented by tecnomorphs and heteromorphs. Specimens of Sansabella bradfieldi Coryell and Sohn show reversal of valve overlap.

The ostracode fauna indicates a Chesterian age for the Maxville Limestone.

More than 70 species of Paleozoic articulate brachiopods with color patterns have been reported in the literature (see Blodgett et al., 1983, table 1; Table 1). The majority of them are Devonian terebratuloid brachiopods. Twenty-two Permian brachiopod species were previously described as retaining color patterns. Most of them belong to Dielasma and have radial to subradial color patterns. Here we report a smooth spiriferid, Martinia? sp., with well-preserved radial color bands from Late Permian rocks of South China.

Ceratopsid diversity at the end of the Cretaceous plays a role in interpreting faunal events at or near the Cretaceous–Tertiary boundary in North America. The addition of a new ceratopsid genus within this time frame thus has potential ramifications for the interpretation of these events.

Several specimens of the gigantic new species, Wewokella costata, have been recovered from the Upper Missisippian Hartselle Sandstone of Marshall County, east of Huntsville, in northeastern Alabama. The large sponges have flutted columnar growths and basic skeletons of triactines that are grossly encrusted or overgrown by calcium carbonate to produce massive fused skeletons. These are the oldest and largest specimens of Wewokella yet certainly identified. Wewokella costata has a skeleton with reduced numbers of triactines, but with extensive calcareous cement. The species could be in the lineage leading to the Inozoida Rigby and Senowbari-Daryan, 1996, which have spicule-free skeletons of sphaeroidal aragonite.

A partial cranium and axial skeleton of an individual Symbos cavifrons were excavated in 1983 from the Mesa Verde Loess on Grass Mesa, Montezuma County, Colorado. Parts of at least 24 bones were recovered, including the first complete set of cervical vertebrae known for Symbos cavifrons. This individual, radiocarbon dated at 15,970 ± 155 yr B.P. (SI-6137), contributes to the definition of the southwestern edge of the range of the species and provides new information about the nature of the vertebral column. Pathologic constriction of the transverse canals is evident in the third and seventh cervical vertebrae. The pattern of bone distribution suggests that carnivores consumed part of this animal. The radiocarbon date also establishes the last major episode of loess deposition in the Four Corners region of the southwestern United States.

The genus Abertella Durham, 1953 initially was described to include one of several problematic species of Miocene sand dollars originally placed in Scutella Lamarck, 1816. Durham (1953) named Scutella aberti Conrad, 1842 as the type of Abertella, and later (1955) tried to resolve issues concerning familial relationships of North American scutellines by placing the genus in a monogeneric family, the Abertellidae. Durham (1953, p. 351) separated Abertella from other members in his assemblage of taxa related to Scutella because the former has: 1) an immediately submarginal periproct between the second pair of post-basicoronal plates; 2) moderately closed petaloids about three-quarters the length of the corresponding aboral ambulacrum (although he states this ratio as being two-thirds in the description itself); 3) widely disjunct oral interambulacra; 4) ambulacral basicoronals that are larger than interambulacral basicoronals (misstated, and corrected to say just the reverse in Durham [1955]); and 5) a well-developed notch in the posterior margin of the test. Abertella aberti (Conrad, 1842) is known from the coastal Miocene of the eastern United States, notably Maryland, North Carolina, and Florida (Durham, 1953; Cooke, 1959; McKinney, 1985).

Retiolitid graptolites are a very common component in Silurian graptolite faunas of the Canadian Arctic, both in flattened form on shale surfaces and in uncompressed form in limestone concretions found in the enclosing shales (Lenz and Melchin, 1987). Upper Wenlock and Ludlow rocks are particularly prolific, having yielded about 20 species of retiolitids to date. One of the collections made during the summer of 1991 was a single piece of talus-derived shale containing 10 complete and slightly fragmented retiolitids. These specimens are morphologically unique, and their description is the purpose of this note.

Argenthina emilyae is a new genus and species of extinct muricid gastropods from the early Middle Miocene of southern Argentina. Most of its shell features are consistent with those of the Acanthina-clade of Thais-like ocenebrines, including a broad, rounded body whorl, a large aperture lacking ornamentation, and a short, open siphonal canal, although other characters are consistent with the Ocinebrina-like ocenebrines, such as the differentiation of axials into varices and intervaricals and complex spiral sculpture. This combination of traits is unique in the Ocenebrinae. It is not yet clear whether this new taxon represents an episode of morphological experimentation by a stem group of Thais-like ocenebrines resulting in convergence on the Ocinebrina-like shell form or an evolutionarily intermediate step between Thais-like and Ocinebrina-like ocenebrines. Intermediates are expected from previously published phylogenetic hypotheses for the Ocenebrinae that suggest Ocinebrina-like ocenebrines have evolved multiple times from Thais-like ocenebrines. Until now, however, such intermediates have not been reported from the fossil record.

Turritelline Gastropods (family Turritellidae, subfamily Turritellinae; sensu Marwick, 1957) are common components of many Cretaceous to Recent benthic marine assemblages worldwide. They are frequently the dominant or even the sole macrofossil in such assemblages (Allmon, 1988), termed “turritelline- dominated assemblages” (TDAs; Allmon and Knight, 1993). They are defined as macrofaunal assemblages in which turritelline gastropods: 1) comprise either at least 20% of the total actual or estimated biomass or at least 20% of the macroscopic individuals in the assemblage, and 2) are at least twice as abundant as any other macroscopic species in the assemblage (Allmon, 2007). TDAs have been widely reported from siliciclastic and carbonate sediments of the U.S. Gulf and Atlantic Coastal Plains, but turritelline-dominated limestones (sometimes referred to as “turritella limestone” or “turritella rock”) appear to be limited to the Cretaceous and Paleogene (Allmon and Knight, 1993; Allmon, 2007; Allmon and Cohen, 2007).

The lower-middle Hetang Formation (Cambrian Stage 2–3) deposited in slope-basinal facies in South China is well known for its preservation of the earliest articulated sponge fossils, providing an important taphonomic window into the Cambrian Explosion. However, the Hetang Formation also hosts a number of problematic animal fossils that have not been systematically described. This omission results in an incomplete picture of the Hetang biota and limits its contribution to the understanding of the early evolution of animals. Here we describe a new animal taxon, Cambrowania ovata Tang and Xiao, new genus new species, from the middle Hetang Formation in the Lantian area of southern Anhui Province, South China. Specimens are preserved as carbonaceous compressions, although some are secondarily mineralized. A comprehensive analysis using reflected light microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and micro-CT reveals that the new species is characterized by a spheroidal to fusoidal truss-like structure consisting of rafter-like crossbars, some of which are secondarily baritized and may have been internally hollow. Some specimens have aperture-like structures that are broadly similar to oscula of sponges, whereas others show evidence of a medial split reminiscent of gaping carapaces. While the phylogenetic affinity of Cambrowania ovata Tang and Xiao, n. gen. n. sp. remains problematic, we propose that it may represent carapaces of bivalved arthropods or more likely sponges in early life stages. Along with other problematic metazoan fossils such as hyolithids and sphenothallids, Cambrowania ovata Tang and Xiao, n. gen. n. sp. adds to the diversity of the sponge-dominated Hetang biota in an early Cambrian deepwater slope-basinal environment.

UUID: http://zoobank.org/44de9472-7e3f-42d1-9554-7b3434df91d9

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.

Colonial rugose corals are uncommon in Pennsylvanian rocks in North America and until now the only massive form known from rocks of this age south of the Arctic is an undescribed species of Petalaxis reported by Sutherland (1985) from Morrowan rocks in Oklahoma, Texas, and New Mexico. This report concerns a second species of Petalaxis recovered from Desmoinesian rocks immediately west of Death Valley, California. Although only a single colony has been found, it is profoundly different from all other described species of this genus and is significant from the standpoint of its presence during a very long time span when there was an apparent dearth of massive rugose corals in most of North America.

The Actinocrinitidae were among the most abundant crinoids worldwide during the Lower Mississippian. Recent systematic revisions of the family allow a revised genus- and species-level understanding of these crinoids globally and a more precise means by which to understand the temporal and facies distribution of genera and species in this important Mississippian family. Two genera with a total of five species of Actinocrinitidae (and five additional forms left in open nomenclature) are recognized from the Fort Payne Formation, including Actinocrinites jugosus (Hall, 1859), Actinocrinites spp. indeterminate, Thinocrinus gibsoni (Miller and Gurley, 1893), Thinocrinus lowei (Hall, 1858), Thinocrinus probolos (Ausich and Kammer, 1991), Thinocrinus akanthos new species, Thinocrinus sp. aff. T. gibsoni, Thinocrinus spp. indeterminate, and two taxa recognized as only Actinocrinitidae genus and species indeterminate. Actinocrinites tripus Ehlers and Kesling, 1963 is recognized as a junior synonym of Thinocrinus gibsoni. Thinocrinus, rather than Actinocrinites as previously thought, is the dominant Fort Payne Formation actinocrinitid. Fort Payne Formation carbonate buildup facies (wackestone buildups and crinoidal packstone buildups) each have characteristic species of Thinocrinus. Actinocrinites is relatively rare in the Fort Payne Formation, but occurs preferentially in crinoidal packstone buildups.