02493nas a2200193 4500008004100000245007000041210006900111260006700180490000600247520188400253653001402137653001302151653001702164653001502181653001502196100002002211700002502231856004302256 2013 eng d00aWhy is the tropical Cenozoic fossil record so poor for bryozoans?0 aWhy is the tropical Cenozoic fossil record so poor for bryozoans aCatania, ItalybMuseo Tridentino di Scienze Naturalicin press0 v13 a

Diverse bryozoan assemblages have been recorded from widely across the Cenozoic palaeotropics, including the West Indies and Central America (Miocene-Pleistocene), Arabia (Oligocene), East Africa (Miocene), India (Eocene-Miocene) and the East Indies (Eocene-Miocene). However, records of Cenozoic tropical bryofaunas are relatively few compared with higher latitudes, and bryozoan limestones seem to be lacking. Insights into the reasons for this poor fossil record can be gleaned from comparisons with modern tropical bryozoan faunas, and consideration of the effects of diagenesis on fossil preservation and other factors that bias against the tropical Cenozoic fossil record. At least for the North Atlantic, bryozoan assemblage diversity in the modern tropics is not significantly less than in higher latitudes. However, a survey of colony-forms shows that encrusting species of small biomass are more dominant in tropical assemblages (mean 78% of species) than they are outside the tropics (mean 60% of species). These encrusting colonies may be difficult to observe and study when, as is often the case in tropical carbonate settings, diagenetic cement binds sediment firmly to the colony surfaces. Most erect bryozoan species living today in the tropics have weakly mineralized skeletons with a poor potential for fossilization; robust species capable of generating large quantities of carbonate sediment are uncommon. In addition, a higher proportion of cheilostomes in the tropics have metastable skeletons of aragonite: a Raman spectroscopic survey of 23 bryozoan species encrusting the undersides of platy corals from Puerto Rico and Malaysia showed 30% to be aragonitic and 27% bimineralic. Along with the typically higher Mg levels in the calcite of tropical cheilostomes, this further biases against preservation of bryozoans in the Cenozoic fossil record.

10aBryozoans10aCenozoic10acolony-forms10adiagenesis10amineralogy1 aTaylor, Paul, D1 aDi Martino, Emanuela uhttps://ipaeg.myspecies.info/node/203502143nas a2200193 4500008004100000245007200041210006700113260006800180490000600248520154200254653001401796653001401810653001101824653001101835653001501846100002501861700002001886856004301906 2013 eng d00aA brief review of seagrass-associated bryozoans, Recent and fossil.0 abrief review of seagrassassociated bryozoans Recent and fossil aCatania, ItalybMuseo Tridentino di Scienze Naturali cin press0 v13 a

Information concerning fossil and modern bryozoan assemblages reported from seagrass habitats is scattered through a large number of papers. The current paper groups taxonomically data from the literature on both modern and fossil bryozoans associated with seagrasses. Most of the modern data comes from studies focused on Posidonia oceanica meadows inhabiting the Mediterranean Sea, where a total of 152 bryozoan species have been recorded. Forty-one species have been reported on seagrasses from other geographical areas, such as Saudi Arabia, tropical America, Japan and Australia. Differences are outlined between the well-delineated communities of the leaves and the rhizomes, and some generalizations are made about morphological strategies for living as seagrass epiphytes. Seagrasses are seldom fossilized but examples of ancient communities can be inferred from the presence of bioimmurations of seagrass surfaces and from associated biota. They include a single Cretaceous community from the Maastrichtian of The Netherlands (43 bryozoan species), and a few Cenozoic communities described from several geographical regions (e.g. Europe, tropical America, Indo-Pacific; 72 species). New data is reported from a dark grey, silty clay in the Miocene of East Kalimantan (Indonesia) where the presence of the seagrass-indicative gastropod Smaragdia allows interpretation of the palaeoenvironment as a seagrass meadow with associated corals. The bryozoan assemblage here is monogeneric, comprising two species of Vincularia.

10aBryozoans10aepiphytes10afossil10aRECENT10aseagrasses1 aDi Martino, Emanuela1 aTaylor, Paul, D uhttps://ipaeg.myspecies.info/node/203402842nas a2200205 4500008004100000245012500041210006900166300001200235490000800247520207100255100001702326700002802343700001802371700002502389700002402414700002002438700002502458700001902483856013402502 2013 eng d00aEnvironmental reconstruction of a late Burdigalian (Miocene) patch reef in deltaic deposits (East Kalimantan, Indonesia)0 aEnvironmental reconstruction of a late Burdigalian Miocene patch a110-1220 v3743 a

Most studies of Cenozoic shallow-water, mixed carbonate-siliciclastic depositional systems have focused on their sedimentology. To date, however, comprehensive analyses of biotas and biofacies of Indo-West Pacific reefs that developed in mixed carbonate-siliciclastic systems are lacking. This study describes the palaeoenvironment and biodiversity of a late Burdigalian patch reef that developed in a mixed carbonate-siliciclastic depositional system. The studied exposure is located at the northeast margin of the Kutai Basin near Bontang (Indonesia), and is approximately 80 m wide and 25 m thick. Multi-taxon analysis of the most abundant fossil groups, including larger benthic foraminifera, corals, coralline algae, and bryozoans, aims to provide a model for environmental interpretation that will allow comparison with similar deposits of Indo-West Pacific region. Based on fossil content and lithology, five different facies types have been distinguished: foraminiferal packstone (FP), bioclastic packstone with foralgal communities (BP), thin-platy coral sheetstone (CS), platy-tabular coral platestone (CP), and shales (S). Among larger benthic foraminifera, smaller and more robust forms dominate in the FP and BP facies, while larger and flatter forms are the most abundant in the CS and CP facies. Thin-platy corals are dominant in the CS facies and gradually change into thicker platy-tabular forms in the CP facies. Assemblages and growth forms of coralline algae show no major differences between the facies types and are dominated by melobesioids and Sporolithon. The majority of bryozoan species are encrusting and were found only in the CS facies. Light-dependent organisms occurring in the reef indicate low light conditions typical for mesophotic reefs. The relatively small size of this reef complex and quite distinct vertical changes in the facies types, combined with the high siliciclastic content in most of the units, points to strong terrigenous input affecting water transparency as the main factor controlling the reef growth.

1 aNovak, Vibor1 aSantodomingo, Nadiezhda1 aRösler, Anja1 aDi Martino, Emanuela1 aBraga, Juan, Carlos1 aTaylor, Paul, D1 aJohnson, Kenneth, G.1 aRenema, Willem uhttps://ipaeg.myspecies.info/content/environmental-reconstruction-late-burdigalian-miocene-patch-reef-deltaic-deposits-east-kalim