Vicarious Avicularia Research Articles

SPECIES OF THE GENUS MELICERITA MILNE EDWARDS (BRYOZOA, CHEILOSTOMATIDA) IN THE EARLY MIOCENE OF PATAGONIA (ARGENTINA)

Species of the cellariid genus Melicerita Milne Edwards develop bilaminar flattened colonies consisting of alternate transverse rows of hexagonal zooids. In South America, its stratigraphic range extends from the early Miocene to the Recent. Re-examination of the type material of M. triforis Ortmann from the Monte León Formation at Río Chalía, and scanning electron microscope images of M. ortmanni Canu from the early Miocene Chenque Formation, confirmed that the latter is a junior synonym of M. triforis. Vicarious avicularia are described for the first time in M. triforis. Lectotypes are herein chosen for both nominal species. M. imperforata sp. nov. is described from material obtained in Monte León Formation (early Miocene). It differs from all known Melicerita species in the size and shape of its vicarious avicularia, which are marginal and much larger than the autozooids. The Recent Magellanic species M. temaukeli Moyano and M. blancoae López Gappa share morphological similarities with M. triforis.

Free-living bryozoans (Cheilostomatida, Cupuladriidae) from northeastern and northern Brazil.

Free-living bryozoans, unlike most cheilostomes, live unattached from the substratum on or within soft sedimentary bottoms. Bryozoans of the family Cupuladriidae Lagaaij, 1952 are probably the best-studied free-living representatives. In Brazil, eight species of cupuladriids have been reported to date, including some regarded as species complexes. This paper documents cupuladriid taxa from northeastern and northern Brazil based on the examination of 1236 colonies. Three species previously reported from Brazil are described: Cupuladria monotrema (Busk, 1884), Discoporella gemmulifera Winston Vieira, 2013 and Discoporella salvadorensis Winston, Vieira Woollacott, 2014. A new species, Cupuladria minuta n. sp., is erected; it differs from its congeners in having small, flat discoid colonies, with the central area up to the fifth astogenetic generation composed of vicarious avicularia with an auriform opesia, and quadrangular to rectangular basal sectors with 1-6 small openings per sector. Our results suggest that four species previously recorded from Brazil are doubtful-Cupuladria canariensis (Busk, 1859), Cupuladria biporosa Canu Bassler, 1923, Discoporella umbellata (Defrance, 1923) and Discoporella depressa (Conrad, 1841). Some Brazilian specimens previously assigned to Discoporella umbellata var. conica are re-assigned to D. salvadorensis. The species studied here frequently co-occur on mainly sandy and muddy bottoms at 8-130 m depth, as it is typical of most living populations of cupuladriids. The sedimentation rate, and thus the bottom composition, likely influence the distribution of cupuladriids in Brazil, with Cupuladria species being more common in stabler and coarser sea bottoms than Discoporella species, which tend to be more broadly distributed.

Tobolocella levinae n. gen., n. sp., a cheilostome bryozoan from the late Maastrichtian of northern Kazakhstan: scanning electron microscope and micro-CT study

A cheilostome bryozoan Tobolocella levinae gen. et sp. nov. is described from a late Maastrichtian outcrop located on the right bank of the Tobol River in northern Kazakhstan. Its morphology is investigated in detail using combined scanning electron microscopy and X-ray micro-CT data. These studies reveal that colonies of this new genus generally consist of regularly arranged but morphologically different zooids: autozooids, T-zooids, and vicarious avicularia. The T-zooids first established in T. levinae gen. et sp. nov. are zooids with a modified cystid and can be interpreted as autozooidal polymorphs, if its polypide was identical to that of regular autozooids, or heterozooids, if its polypide was modified. The T-zooids probably can increase the distance between autozooidal polypides to improve their feeding efficiency.

Taxonomic status of some species of Aspidostomatidae (Bryozoa, Cheilostomata) from the Oligocene and Miocene of Patagonia (Argentina)

AbstractThe bryozoan genusAspidostomaHincks, 1881 has been regarded as the only representative of the Aspidostomatidae Jullien, 1888 in Argentina to date. Its type species,Aspidostoma giganteum(Busk, 1854), is presently distributed in the Magellanic Region (Argentina and Chile) and has been recorded in Oligocene and Miocene fossil deposits of Santa Cruz and Chubut, respectively. New material from San Julián (late Oligocene), Monte León (early Miocene), Chenque (early to middle Miocene), and Puerto Madryn (late Miocene) formations suggests, however, thatA. giganteumis not represented in the fossil record. Material from Puerto Madryn Formation previously regarded asA. giganteumis here recognized asAspidostoma roveretoinew species.Aspidostoma ortmanniCanu, 1904 is revalidated for the species from the San Julián Formation.Aspidostoma armatumnew species andAspidostoma tehuelchenew species are introduced for material from the Monte León and Chenque formations, respectively.Aspidostoma incrustansCanu, 1908, from the early Miocene, is redescribed.MelychocellaGordon and Taylor, 1999, which differs fromAspidostomain having vicarious avicularia and lacking a median ridge and a quadrangular process proximal to the opesia-orifice, is so far represented by three Paleogene species from the Chatham Islands (Southwest Pacific). The material from Monte León allowed us to transferAspidostoma flammulumCanu, 1908 toMelychocella, resulting in the new combinationMelychocella flammula(Canu, 1908).Melychocella biperforatanew species is described from the lower Miocene Monte León and Chenque formations. The presence ofMelychocellain the Neogene of Patagonia extends its geographic distribution and its temporal range.UUID:http://zoobank.org/d84df2d8-cab2-4e74-82b8-7c67d938a58f

Three new species of Calyptotheca (Bryozoa: Lanceoporidae) from the Great Barrier Reef, tropical Australia.

The cheilostome bryozoans Calyptotheca wulguru n. sp. and Calyptotheca tilbrooki n. sp. (Lanceoporidae) are described from inter-reefal, sediment-dominated habitats of the Great Barrier Reef, and Calyptotheca churro n. sp. was washed up on a Heron Island beach, with uncertain origin. Calyptotheca wulguru n. sp. and C. churro n. sp. belong to a subgroup of Calyptotheca species with numerous small, oval, marginal adventitious avicularia and suboral nodular thickening or umbones. The vicarious avicularia of C. tilbrooki n. sp. are elongate-oval, unlike those of other known Calyptotheca species, and C. tilbrooki n. sp. has more pronounced orificial dimorphism than in any other known Calyptotheca species. Calyptotheca churro n. sp. has the most pronounced suboral umbo of all known Calyptotheca species. This study increases the known Calyptotheca species of the Great Barrier Reef to ten, and of tropical Australia to 14.

Two new species of the genus Turbicellepora Ryland, 1963 (Bryozoa: Celleporidae) found on Lophelia coral from the Greenland slope.

The genus Turbicellepora was established by Ryland (1963) in the course of his work on the Norwegian bryozoan fauna. At present, the genus includes 71 recent and fossil species, which have been reported from all continents and seas (Bock & Gordon 2014). The distinctive characteristics of the genus include a multiporous ooecium, proximal orificial sinus, an asymmetrically placed peristomial avicularium and enlarged or vicarious avicularia (Ryland 1963). Occasionally, an additional pre-oral avicularium is also present (Hayward 1978). Colonies have a changeable form. They can be massive and branching or have the form of a mound or flat crust. The most comprehensive comparative study of European species of the genus, with detailed descriptions of 13 taxa, was carried out by Hayward (1978), who noted that the genus seemed to be centred in the Atlanto-Mediterranean region.

First Record of Cheilostome Encrusting Bryozoan, Celleporaria volsella from Coastal Waters of Sri Lanka

Sri Lanka is an Island country with very high faunal diversity. Yet, many species remain to be uncovered due to lack of interest on biodiversity in the marine environment. Therefore, it is imperative to carry out comprehensive studies to unveil these mysterious organisms from our coastal waters. Biofouling community is one such group that needs due attention in terms of taxonomy and distribution. Bryozoans are diverse and widely spread group owing to their long history; dating back to early Ordovician Period. Yet, inconspicuous and poorly known to most part of the world. Although most are marine, these colonial invertebrates occur in fresh water habitats as well. They comprise the major component of fouling communities growing on substrates. Therefore, the present study was designed to investigate the diversity of encrusting bryozoans in Colombo Port. Biofouling assemblages were collected from eight sampling locations using settlement collectors based on those developed by the Center for Research on Introduced Marine Pests (CRIMP). The collectors were suspended in four different depths. The first set was 1 m below the water surface and others settled in 1 m increments. Monthly samples were collected from October 2014 to July 2015 from both replacing and permanently settled collectors. Specimens were identified microscopically observing fine morphological features. Findings of the present study demonstrate presence of taxonomically diverse bryozoan community in Colombo port. Among other bryozoans the remarkable finding was the record of colonies of Celleporaria volsella found in all the sampling locations. This is the first record of C. volsella from Sri Lankan coastal waters. C. volsella is very rare encrusting colonial bryozoans of the family Lepraliellidae, sub-order Flustrina, and order Cheilostomatida originally described from Solomon Island, Anusha Islands and Florida Islands. C. volsella can be distinguish from close relatives of the genus from size and shape of the primary orifice with pair of spiny processes, large suboral avicularia and elongate vicarious avicularia with a smooth, truncated spatulate distal rim. Keywords: Celleporaria volsella, Encrusting bryozoa, Colombo port, Sri Lanka

Two tropical species of Stephanotheca (Bryozoa, Cheilostomata, Lanceoporidae) from the Gulf of Carpentaria, Australia.

Two new species of Stephanotheca are described from the southeast Gulf of Carpentaria, northern Australia, providing the first tropical records of this genus. Stephanotheca ipsum n. sp. is provisionally placed in the genus on the basis of a low ridge of calcification around the edge of the ooecium, which differs from the fully pseudoporous ooecium of Calyptotheca (Lanceoporidae) and resembles the 'crowned' ooecium of Stephanotheca, with a central porous area surrounded by a nodular imperforate area. Stephanotheca ipsum and Stephanotheca romajoyae n. sp. are the only species in the genus with more than one avicularium on some zooids. The latter species is distinguished by high variability in avicularium size, shape, position and orientation; it also shares dimorphic avicularia with S. ochracea (Hincks) and is the only species in which they sometimes occur together on the same zooid. This study increases the number of Australian Stephanotheca species to four. The Australian species all have smaller primary orifices and variations in ovicell morphology compared with other, all European, species. In S. ipsum n. sp. the ooecia are ridged, those of S. victoriensis Reverter-Gil et al. have a single row of pseudopores forming an arch, and those of S. ambita (Waters) and S. romajoyae n. sp. have a relatively large pseudoporous area and smaller, lower nodular imperforate area. None of the Australian species have vicarious avicularia, which are known only from the type species, S. barrosoi Reverter-Gil et al.

Phylogeny of Genus Cupuladria (Bryozoa, Cheilostomata) in the Neogene of Tropical America

We used 57 morphometric characters to discriminate 17 extant and fossil Cupuladria species and analyzed their phylogenetic relationships in relation to extant Discoporella species. Data were gathered from 496 extant and fossil Cupuladria specimens ranging in age from early Miocene to Recent and distributed from the Caribbean to tropical eastern Pacific. A first series of discriminant analyses distinguished three morphological groups: Cupuladria with vicarious avicularia, Cupuladria without vicarious avicularia, and Discoporella. Further discriminant analyses identified 17 species of Cupuladria. Cladistic analyses of these three groups yielded four equally parsimonious trees. All of the consensus trees exhibited the same topology, dividing the 25 tropical American cupuladriids into four distinct monophyletic clades, including Discoporella, and are consistent with previous molecular phylogenies except that there are no molecular data for the CV2 clade. Diversification of species was higher in the CV1 and CV2 clades than CNV clade, and involved mostly Caribbean species. Cupuladria with vicarious clade 1 (CV1) includes: C. monotrema, C. pacificiensis, C. exfragminis, C. cheethami, C. biporosa, and four new species: C. pervagata, C. floridensis, C. colonensis and C. dominicana. Cupuladria with vicarious clade 2 (CV2) includes: C. multesima, C. incognita, and three new species C. collyrida, C. veracruxiensis and C. planissima. Cupuladria clade without vicarious (CNV) includes: C. surinamensis, C. panamensis, and one new species C. gigas. The stratigraphic occurrence of species is consistent with cladogram topology within clades. However hypothesized cladistic relations among clades are the reverse of their stratigraphic occurrence with younger clade CNV appearing as the hypothetical ancestor of the two older clades CV1 and CV2. More extensive collections of early to middle Miocene specimens of Cupuladria and Discoporella will be required to resolve this apparent paradox.

Phylogeny of Genus Cupuladria (Bryozoa, Cheilostomata) in the Neogene of Tropical America

We used 57 morphometric characters to discriminate 17 extant and fossil Cupuladria species and analyzed their phylogenetic relationships in relation to extant Discoporella species. Data were gathered from 496 extant and fossil Cupuladria specimens ranging in age from early Miocene to Recent and distributed from the Caribbean to tropical eastern Pacific. A first series of discriminant analyses distinguished three morphological groups: Cupuladria with vicarious avicularia, Cupuladria without vicarious avicularia, and Discoporella. Further discriminant analyses identified 17 species of Cupuladria. Cladistic analyses of these three groups yielded four equally parsimonious trees. All of the consensus trees exhibited the same topology, dividing the 25 tropical American cupuladriids into four distinct monophyletic clades, including Discoporella, and are consistent with previous molecular phylogenies except that there are no molecular data for the CV2 clade. Diversification of species was higher in the CV1 and CV2 clades than CNV clade, and involved mostly Caribbean species. Cupuladria with vicarious clade 1 (CV1) includes: C. monotrema, C. pacificiensis, C. exfragminis, C. cheethami, C. biporosa, and four new species: C. pervagata, C. floridensis, C. colonensis and C. dominicana. Cupuladria with vicarious clade 2 (CV2) includes: C. multesima, C. incognita, and three new species C. collyrida, C. veracruxiensis and C. planissima. Cupuladria clade without vicarious (CNV) includes: C. surinamensis, C. panamensis, and one new species C. gigas. The stratigraphic occurrence of species is consistent with cladogram topology within clades. However hypothesized cladistic relations among clades are the reverse of their stratigraphic occurrence with younger clade CNV appearing as the hypothetical ancestor of the two older clades CV1 and CV2. More extensive collections of early to middle Miocene specimens of Cupuladria and Discoporella will be required to resolve this apparent paradox.

The Early Sarmatian bryozoan Celleporina medoborensis sp. nov. from the Medobory reefs of western Ukraine (Central Paratethys)

Moundlike, globular to hemispherical bryozoan colonies of Celleporina medoborensis sp. nov. are documented from the calcareous organodetrital, slightly marly facies of the Lower Sarmatian (Volhynian) serpulid-microbialite reefs, in the Polupanivka and Ditkivtsi quarries (Medobory Hills), located at the northeastern margin of the Carpathian Foreland Basin (Central Paratethys) in western Ukraine. The colonies of C. medoborensis are multilamellar, often with a subcircular hole and occur together with numerous cyclostome bryozoans (crisiids, tubuliporinids, branching colonies of entalophoroids) as well as schizoporellid and cryptosulid cheilostomes, accompanied by a few macro- and micro-fossil taxa. The combination of morphological characters such as: thick radial ribs in the pseudoporous, variably-shaped area of the ovicell, and one or two small adventitious oral, as well as large vicarious avicularia are the main characteristic features of species. The rich occurrence of the celleporiform colonies of C. medoborensis sp. nov. within the fine-grained calcareous sands of Polupanivka and Ditkivtsi suggests a shallow-water setting and high availability of soft substrates, probably dominated by calcareous algae upon which the bryozoans may have settled in the Medobory reef biota during the Early Sarmatian.

New and little known species of Bryozoa from Iberian Atlantic waters

ABSTRACT A new species of Cheilostomatous Bryozoa, collected in the Strait of Gibraltar area (Gulf of Cadiz) and previously cited as Hincksina sceletos (Busk, 1858), is described. Hincksina calpensis n. sp. is characterized by presenting a shield of 15–18 spines covering the frontal surface, the small, flattened oral spines in ovicellate zooids, and the short, oval vicarious avicularia transversally directed. Material collected in the Gulf of Cadiz is here reported as Setosella sp., characterized by presenting oval autozooids proximally truncate asymmetrically, arranged in spiral series; D-shaped opesia slightly wider than long, with a distinct distal lunula, and a pair of long, asymmetric opesiules with denticulate inner edges; the ancestrula presents a trifoliated opesia. This material seems to differ from Setosella vulnerata (Busk, 1860), a presumed widely distributed species that however presents some variability not correctly studied yet. The genus Clavodesia Harmelin & d'Hondt, 1992 is re-described,...

A new Antarctic Osthimosia (Bryozoa, Cheilostomata, Celleporidae) with dimorphic zooids

Osthimosia chaotica sp. nov., a new celleporid cheilostome bryozoan, is described from samples collected in the South Shetland Isles and the Antarctic Peninsula. It differs from other Antarctic and Subantarctic species of the genus Osthimosia in the absence of vicarious avicularia, the characteristic development of its peristome and the reduced size of the primary orifice of the ovicelled zooids compared to those of autozooids. The occurrence of sexual polymorphism in the Bryozoa is discussed. The new species lives on laminar and filamentous algae.

A new Miocene Bryozoa from the Sarmatian of the Danube basin

New species of Sarmatian Bryozoa Celleporina dubovaensis sp. n. has been found in the section Dubova (Slovakia) and described in details. The new species differs from all other known species of Celleporina having combination of thick radial ribs in the perforated area of the ovicells, only one suboral avicularium per zooecium and rare, very large vicarious avicularia.

NEOGENE CUPULADRIIDAE OF TROPICAL AMERICA. I: TAXONOMY OF RECENT CUPULADRIA FROM OPPOSITE SIDES OF THE ISTHMUS OF PANAMA

We used up to 28 morphological characters to discriminate and describe species of the genus Cupuladria based on entire colony specimens collected from both coasts of the Isthmus of Panama. The characters included a combination of zooidal features traditionally used in cheilostome taxonomy and nontraditional characters such as colony size, shape, and an index of calcification of the colony, as well as the size of the basal sectors and their number of pores. Species were discriminated by a series of repeated multivariate cluster and discriminant analyses until the majority of specimens were assigned to their putative species with high statistical confidence. Nontraditional characters contributed significantly to the power of the analyses. Colonies fell into two highly distinct groups most clearly recognized by the presence or absence of vicarious avicularia, which agrees well with previous molecular genetic analyses. Further analyses of each of these two groups considered separately resulted in the discrimination of eight species. These include two previously described Caribbean species, C. biporosa Canu and Bassler, 1919 and C. surinamensis Cadée, 1975, and six new species: C. multesima, C. incognita, C. cheethami, and C. panamensis from the Caribbean, and C. pacificiensis and C. exfragminis from the eastern Pacific. There was also good correspondence between major clades within these morphologically defined groups and the previous molecular analysis, although 20% of the specimens could not be distinguished from their cognate (“geminate”) species from the opposite ocean. The high ratio of undescribed to described species and higher diversity in the Caribbean than eastern Pacific agree well with newly described patterns from other cheilostome genera based on similar analyses. Quantitative morphometric studies are essential to study biologically meaningful patterns of cheilostome speciation and macroevolution in the fossil record.

I.—Notes on new or imperfectly known Cretaceous Polyzoa

Vicarious avicularia, that is to say avicularia substantially as large as zoœcia, have rarely been figured among the Cretaceous Cribrilinidse, the only good instances I call to mind being Escharipora incrassata, D'Orb., Membraniporella (Cribrilina) Falcoburgensis, Perg., the illustration of which shows a clear case, although no reference is made to it in the text, and Cribrilina ostreicola, Bryd. They are not, however, by any means so rare as this might suggest, and the four following species are probably not the only instances which will ultimately be added from the English Chalk.