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New collections of fossil sponges have been recovered from Devonian to Upper Carboniferous sections of Spain. These include two new hexactinellids from Devonian rocks of northwestern Spain: the small globular protospongiid Iberospongia globulara new genus and species, and the much larger, bowl-shaped, pelicaspongiid Asturiaspongia aqualiforma new genus and species. The three specimens of Asturiaspongia n. gen. were collected from the calcareous member of the Aguión Formation, of late Emsian age, at Arnao Beach, Asturias. This member has been interpreted as a developing patch reef. The single specimen of Iberospongia n. gen. was collected from late Zlichovian (Emsian) beds of the Cortés Member of the Abadía Formation, near Polentinos, Palencia. These beds represent the beginning of the transition to deeper water that took place during the Emsian and which lasted throughout the Devonian.
Lower Carboniferous sponges have been collected from southern Spain. The hexactinellid Estrellaspongia irregulara new genus and species, is a thick-walled, basin-shaped pelicaspongiid with irregular, branched, inhalant canals and coarser irregular canals in a skeleton of irregularly oriented and spaced small hexactines. It is from late Viséan rocks of Sierra de la Estrella, near Espiel in Córdoba. The reticulosid Stereodictyum orthoplectumFinks, 1960 was collected from Viséan beds at Las Pilitas 2, Badajoz. It has a body wall of alternating layers of regularly spaced vertical and horizontal bundles of spicules in the quadrate-appearing skeleton. This is the first report of the genus from Europe and it is the oldest known occurrence of the genus.
Upper Carboniferous sponges, Bashkirian to Moscovian-Kasimovian, have been collected from northern Spain. Demosponges include: Heliospongia excavataKing, 1933; Coelocladia spinosaGirty, 1908; small generically unidentifiable anthaspidellids; HaplistionGirty, 1908 sp. 1 and sp. 2; and a small fragmentary monaxonid demosponge of uncertain taxonomic assignment. Hexactinellida include the reticulosids, Stioderma perforata new species, and StiodermaFinks, 1960 sp. A, and the new amphidiscosids, Ascospongiella capdevilae new genus and species and Hadrophragmos soleniscus new genus and species. Root tufts A, B, and C are of uncertain taxonomic assignment.
The phylogenetic significance of archeopyles in calcareous dinoflagellates cysts has been evaluated, and a classification model is developed that focuses on the archeopyle categories and types established for organic-walled dinoflagellates by Evitt (1967, 1985). Several of Evitt's archeopyle categories are presently recognized within the calcareous dinoflagellate cysts: apical, intercalary, and combination archeopyles, which are here subdivided into eight archeopyle types and several variations. Archeopyles that cannot be assigned to a distinct type, and those with outlines that do not allow an accurate interpretation, are together placed in a separate category: miscellaneous archeopyles. The stratigraphic distribution of the different archeopyle types reveals a phylogenetic trend characterized by an increase of the number of plates involved in archeopyle formation. The first calcareous dinoflagellate cysts to appear in the late Triassic have a monoplacoid apical archeopyle. The first taxa that show an archeopyle involving more than one plate are from the Early Cretaceous, with the first triplacoid apical archeopyle appearing at the Berriasian/Valanginian boundary. This is followed by the first combination archeopyle, which includes six plates, in the middle Aptian. Epitractal archeopyles originated no earlier than the early Oligocene. At the beginning of the Paleogene, species with a combination archeopyle increased in abundance, progressively replacing species possessing an apical archeopyle that dominated during the Mesozoic. Newly described species are: Calciodinellum clamosum, accommodating the two subspecies Calciodinellum clamosum subsp. clamosum Autonym, and Calciodinellum clamosum subsp. latum; Calciodinellum kerguelense; Fuettererella belliata; and Pernambugia? patata. New combinations are: Cervisiella operculata (Bramlette and Martini, 1964); Praecalcigonellum sulcatum (Keupp, 1979a); and Praecalcigonellum dolium (Keupp, 1979b). Because of the new interpretation of their archeopyles we emend the following genera: CervisiellaHildebrand-Habel, Willems, and Versteegh, 1999; EchinodinellaKeupp, 1980; FuettererellaKohring, 1993a; and Pernambugia Janofske and Karwath inKarwath (2000). The species Orthopithonella? minuta and Pirumella johnstonei, which have been previously synonymized with Fuettererella deflandrei, are retained as independent taxa.
The Pacific Slope of North America's paleontologic record of Paosia, a nearshore-marine, pseudomelaniid gastropod primarily associated with the Old World Cretaceous Tethyan realm, is established for the first time. Former workers have almost universally referred to this genus by its junior synonym name TrajanellaPopovici-Hatzeg, 1899. Six species, including Paosia pentzensis new species, are recognized, and all are from siliciclastic facies. Their documentable geologic range is late early Albian to early Campanian. Four of the five previously named species were misallocated to genus Acteonina and one was placed in genus “Trajanella.”
Paosia originated in western Europe and in the Caucasus Mountains region during the latest Jurassic (Tithonian). It arrived in the study area, possibly in the Aptian, but certainly by the late early Albian and, most likely, by way of Japan and the north Pacific gyre. Worldwide, the genus had its peak diversity during the Albian and Cenomanian. The only other Western Hemisphere records of Paosia are a species from the Campanian of Jamaica and a possible species from the Coniacian of Texas. Paosia had a preference for tropical waters, but its presence in the study area indicates that it could live in temperate-tropical transition areas.
Most of the Pacific Slope of North America species are represented by a few specimens, but when plentiful, they display variability in overall shape between juvenile and adults, with the last whorl of the adults becoming more cylindrical with growth.
Paosia kollmannii new name is proposed for the homonym Trajanella acuminataKollmann, 1979.
A new coral, Blastozopsammia guerreroterion, from the mid-Cretaceous (upper Albian–lower Cenomanian) Mal Paso Formation of southwestern Mexico is the earliest known and the first Mesozoic colonial member of the Dendrophylliidae, an extant worldwide group. Blastozopsammia is characterized by a ramose corallum produced by extratentacular budding, dimorphic corallites, and branches with a continuous axial corallite sheathed in an orderly arrangement of radially arrayed secondary corallites and a robust layer of reticulate coenosteum. This growth form is similar to that of many modern reef-building species of Acropora Oken, 1815 and species of the nonreefal PetrophylliaConrad, 1855 (=ArchoheliaVaughan, 1919). Based on corallite configuration, growth form and analogy with Acropora, Blastozopsammia had a relatively high degree of colony integration and may have been zooxanthellate. The combination of an axial corallite with radially arrayed secondary corallites has been regarded as one of the morphological and ecological pinnacles of coral evolution, yet it is rare among the Scleractinia. This growth form has not been recognized in any Cenozoic dendrophylliids. Blastozopsammia is an evolutionary enigma because no ancestral lineage or closely related taxon has been identified. However, the most likely origin of colonial Dendrophylliidae is Jurassic or Early Cretaceous Actinacididae.
Upper Changhsingian strata occur as isolated outcrops in the Malaya Laba and Belaya river basins in the Peredovoy Range of the northwestern Caucasus Mountains and include shelfal limestone, reefal and biohermal buildups, and terrigenous clastics, here placed in the Belalabinskaya Group. These lithofacies contain a varied and rich assemblage of brachiopods, bivalves, ammonoids, inozoan sponges, and algae. This biota is Late Changhsingian in age and correlates with similar biotas described in south China, the Pamir Mountains, South Primorye in far eastern Russia, and Transcaucasia. The brachiopod genera and biotic assemblages are very similar to those of the Cathaysian Subprovince of the Tethyan Province. Two new families, Labaellidae and Licharewiconchidae; four new genera, Labaella, Licharewiconcha, Tethysiella, and Nikitinia; a new diagnosis of Caucasoproductus; and four new species of brachiopods, Rhipidomella caucasica, Cathaysia caucasica, Nikitinia licharewi, and Licharewina praetriassica, are described. One new genus and species of ammonoid, Neoglassoceras caucasicus, and one new species of bivalve, Claraioides labensis, are described.
A rich collection of Brachyura from the famous Cenomanian “Fish Beds” of western Lebanon has permitted the reevaluation of several families of decapod crustaceans during an important period of their evolution. The new subfamily Telamonocarcininae is erected to include the most primitive known dorippids, which possess a rostrate carapace and a mixture of characters present in the two modern subfamilies Dorippinae MacLeay, 1838 and Ethusinae Guinot, 1977. Telamonocarcininae new subfamily includes the three genera, Telamonocarcinus new genus, EodorippeGlaessner, 1980b, and Tepexicarcinus Feldmann, Vega, Applegate, and Bishop, 1998. Telamonocarcinus n. gen. exhibits the last two pair of pereiopods reduced and carried in a subdorsal and/or dorsal position.
The new genus Corazzatocarcinus, belonging to the Necrocarcinidae Förster, 1968, is here erected; C. hadjoulae (Roger, 1946) n. comb., the type species of the genus, is redescribed and a lectotype is here selected. The observation of preserved pereiopods, especially the reduced and dorsal last pairs, in many specimens of C. hadjoulae, together with new interpretations of already published data, has permitted questionable placement of the Necrocarcinidae in the Podotremata sensu Guinot and Tavares, 2001.
The discovery of a specimen attributed to Homolopsis aff. edwardsiiBell, 1863 adds to the understanding of the anatomy and distribution of Cretaceous homolids, seldom reported in Southern Tethys deposits.
The Figueroa sulfide deposit located in Franciscan Complex rocks in the San Rafael Mountains, California, contains the only known Jurassic hydrothermal vent community. Based on radiolarian biostratigraphy it is Pliensbachian (early Jurassic) in age. The Figueroa fossil organisms lived at a deepwater, high temperature vent site located on a mid-ocean ridge or seamount at an equatorial latitude. The vent site was then translated northeastward by the motion of the Farallon Plate and was subsequently accreted to its present location. The vent fossils are preserved as molds of pyrite and there is no remaining shell or tube material. The fossil assemblage is specimen rich, but of low diversity, and comprises, in order of decreasing abundance, vestimentiferan worm tubes, rhynchonellide brachiopods (Anarhynchia cf. gabbi), and trochoidean gastropods (Francisciconcha maslennikovi new genus and species). These fossils represent only primary consuming organisms, some of which may have had chemosynthetic microbial endosymbionts, like many modern dominant vent animals. The Figueroa vent assemblage shares vestimentiferan tube worms and gastropods with other fossil and modern vent communities, but is unique in having rhynchonellide brachiopods. It shares this feature with contemporary Mesozoic cold seep communities. Many other taxonomic groups found at modern vent sites are missing from the Figueroa assemblage. The presence of vestimentiferan tube worm fossils in the Figueroa deposit is at odds with the supposed time of origin of the modern vestimentiferans (∼100 Ma), based on molecular data.
More than 500 specimens of embryonic shells of orthocerid nautiloids from the Imo Formation were investigated. Although the material is recrystallized, the external and internal features of the early growth stages are exceptionally well preserved. The material comprises eight species of Pseudorthoceratidae: Pseudorthoceras knoxense (McChesney, 1860); Ristedtoceras teriliratum n. sp.; Mooreoceras imoense n. sp.; Mooreoceras striatulum n. sp.; Reticycloceras peytonenseGordon, 1965; Dolorthoceras tenuifilosumGordon, 1965; Mitorthoceras girtyiGordon, 1965; and Euloxoceras angustinusGordon, 1965. A new genus, Ristedtoceras, is erected and the genus PseudorthocerasGirty, 1911 is emended.
The analysis indicates that the morphologic diversity of the early growth stages of the shells of these species are much more diverse than expected. The different species vary strongly in the embryonic shell size, cicatrix position and shape, numbers of septa in the embryonic shell at the time of hatching, embryonic shell ornamentation, and the outline of the first segment of the siphuncle and its position in cross section. This study shows that the shape and position of the cicatrix is a morphologic feature that has been under utilized in previous investigations. The high morphologic variance of the embryonic shells in these Imo orthocerids requires a revision of our understanding of the Pseudorthoceratidae. In addition, the implication of this analysis strongly supports using the morphology of the embryonic shell, and especially the cicatrix, in all future orthocerid systematic and phylogenetic analyses because it is proving to be an important set of characters in detecting homeomorphic evolutionary relationships that are not discernable in mature specimens.
Halkieriids are part of a distinctive Early Cambrian fauna, the “Tommotian fauna” sensu Sepkoski (1992), that is preserved mostly as phosphatic and secondarily phosphatized skeletal elements. The distinctiveness of the Tommotian fauna is ascribed, in part, to its preferential elimination during the end-Early Cambrian mass extinction event (the “Botomian extinction”). Newly discovered halkieriids in phosphatic limestones of the Middle Cambrian (Ptychagnostus gibbus Zone) Monastery Creek Formation, Georgina Basin, Australia, now indicate that this group not only survived the end-Early Cambrian extinction, but was at least locally abundant thereafter. Most of the Georgina halkieriid sclerites can be accommodated within a single species, Australohalkieria superstes new genus and species, described and partly reconstructed here. Remaining sclerites probably represent two additional but rare halkieriid species. Additional newly discovered sclerites may have affinities with the sachitids, another problematic “Tommotian” taxon related to the halkieriids. Rare wiwaxiid sclerites extend the taphonomic and geographic distribution of this clade. The Monastery Creek Formation provides a valuable window on Middle Cambrian life, both because it provides information that is distinct from but complementary to other, similarly aged windows (e.g., the Burgess Shale) and because it represents a taphonomic window similar to those that preserve Early Cambrian small shelly problematica. A decline during the Cambrian in conditions necessary for the early diagenetic phosphatization of shallow-shelf and platform limestones may have effectively closed this taphonomic window, potentially biasing apparent patterns of diversity change through the period.
Previously undescribed trilobites associated with microbial patch reefs have been recovered from the Upper Cambrian (upper Steptoean Stage) Ore Hill Limestone Member of the Gatesburg Formation in south-central Pennsylvania. Reefs in the Imler Quarry and Drab-Beaverton measured sections yielded low-diversity assemblages of trilobites that we assign to the uppermost Cliffia lataegenae Subzone of the Elvinia Zone. The faunas are dominated by the catillicephalid Buttsia drabensisWilson, 1951, and include several new taxa that are not known from coeval off-reef facies. Fine-scale correlation between the two sections reveals that the reefs in the Drab-Beavertown section are slightly younger than those at Imler Quarry and represent the youngest Steptoean fauna described from the Appalachian region.
New taxa include Imlerella n. gen. (type species Imlerella praecipita n. sp.), Stittaspis n. gen. (type species Stittaspis loria n. sp.), and Dellea rogersi n. sp. Stigmacephalus? distortaWilson, 1951, is reassigned to Stittaspis and is restricted to the type. Additional material of Buttsia drabensis illustrates features not discernible in previous treatments of this variable species.
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