Magdalena Łukowiak

Bathyal sponges from the late Early Miocene of the Vienna Basin (central Paratethys, Slovakia)

Here we report, for the first time, a very rich and diversified sponge assemblage from late Early Miocene deposits of a central part of the Vienna Basin (Paratethys) in Slovakia. Bodily preserved sponges are described as a new genus and species Paracinachyrella fossilis (Tetiliidae, Demospongiae). Dissociated spicules reveal the presence of the “soft” demosponges that belong to families Tetillidae, Theneidae, Geodiidae, Samidae, Thrombidae, Thoosidae, Agelasidae, Myxillidae, Bubaridae, and Tedaniidae, the lithistid family Pleromidae, and an undetermined rhizoclone-bearing lithistid. Fragments of dictyonal skeleton indicate the presence of hexactinellid sponges that belong to the families Farreidae and Euretidae, and lychniscosan sponges. We estimate that at least 16–19 different species of siliceous sponges inhabited this region of the Central Paratethys during the latest Burdigalian. Most of these sponges are reported for the first time from the Miocene of the Paratethys. This sponge fauna has clear Tethyan affinities and indicates the existence of connection between Paratethys and Tethys during the latest Burdigalian, as well as the presence of open marine, deep-water, bathyal conditions in this part of the Vienna Basin.KurzfassungWir beschreiben eine neue, sehr reiche und diverse Schwamm-Assoziation aus Ablagerungen des späten Unter-Miozän des zentralen Teils des Wiener Beckens (Paratethys) in der Slowakei. Körperlich Schwämme werden als neue Gattung und Art Paracinachyrella fossilis (Tetiliidae, Demospongiae) beschrieben. Disassoziierte Nadeln belegen die Anwesenheit von “weichen” bzw. skelettlosen Demospongiern, die zu den Familien Tetillidae, Theneidae, Geodiidae, Samidae, Thrombidae, Thoosidae, Agelasidae, Myxillidae, Bubaridae und Tedaniidae sowie zu den lithistiden Familien Pleromidae und einem unbestimmten Rhizoclon-tragenden Lithistiden gehören. Bruchstücke dictyonaler Skelette sprechen für die Anwesenheit hexactinellider Schwämme, die zur Familie Euretidae und lychniscosen Schwämmen gehören. Wir schätzen, dass mindestens 16-19 verschiedene Arten von kieseligen Schwämmen diese Region der zentralen Paratethys während des jüngsten Burdigal besiedelten. Die meisten dieser Schwämme werden zum ersten Mal aus dem Miozän der Paratethys beschrieben. Diese Schwamm-Fauna zeigt klare Affinitäten und spricht für eine offene Verbindung zwischen Paratethys und Tethys während des jüngsten Burdigal und impliziert, dass offen marine, tiefe, bathyale Bedingungen in diesem Teil des Wiener Beckens vorherrschten.

Do spicules in sediments reflect the living sponge community? A test in a Caribbean shallow-water lagoon

ABSTRACT We compared sponge spicules occurring in surface sediments with those of a living sponge community in a shallow-water reef environment of Bocas del Toro archipelago, Panama, with the goal of evaluating how faithfully spicular analysis reflects the living sponge community. Most megasclere morphotypes present in living species are also found in sediment. On the contrary, microscleres are underrepresented in the sediment samples. Apart from spicules that belong to taxa that live at present in the area, some morphotypes found in the sediment have no equivalent in the known living community. Forty species of living sponges have been recognized in the study area, but 9 (22%) do not produce mineral spicules and, therefore, are not recorded in sediment. Sediment spicules suggest the presence of 22 taxa, thus, loss of information in the process of fossilization is average to considerable, with most living taxa identified also with sediment spicules. Some morphotypes are abundant in sediment (i.e., ovoid spicules) even though the sponges bearing them are rare or absent, thus suggesting either preferential preservation or recent disappearances of taxa producing them. As transport did not play a significant role during the fossilization process, spicular analysis—when all limitations and constraints are considered—is a tenable tool in the reconstruction of former sponge communities, but not of the share of various sponge species. Spicular analysis may also help reveal the presence of cryptic and excavating species that are often overlooked in traditional studies.

First Record of Late Eocene Ascidians (Ascidiacea, Tunicata) from Southeastern Australia

Abstract Ascidian spicules are reported for the first time from the upper Eocene (Paleogene) biosiliceous marls and mudstones of the Blanche Point Formation in the St. Vincent Basin, southeastern Australia. The spicules that belong to the family Polycitoridae are identified as a Recent species Cystodytes cf. dellechiajei, and Cystodytes sp. and spicules of the family Didemnidae are indentified as representing genera Lissoclinum, Didemnum, and Polysyncraton. Five other different morphological spicule types which can be classified only at the family level also belong to the Didemnidae. This study demonstrates that ascidians had a very wide distribution by the late Eocene and that ascidian fauna was already of a modern character.

Bodily preserved Eocene non-lithistid demosponge fauna from southern Australia: taxonomy and affinities

Exceptionally well-preserved non-lithistid demosponge body fossils are reported from outcrops of the late Eocene Pallinup Formation, Fitzgerald River National Park, south-western Australia. Among 11 species, eight are new to science and belong to heteroscleromorph orders: Bubarida (Eolipastrotethya picketti gen. et sp. nov., Monocrepidium unispiculatum sp. nov. and M. pauli sp. nov.), Axinellida (Phycopsis arbusculum sp. nov.) and Tetractinellida (Triptolemma solida sp. nov., Pachastrella intermedia sp. nov., P. australis sp. nov. and Geodia hopetouni sp. nov.). A further three species are representatives of the orders Clionaida, Bubarida and Tetractinellida. This fauna has clear affinities with living taxa. Close relationships with some Recent Atlantic species may be understood in the context of a Tethyan legacy. New light is shed on the evolutionary histories of several taxa that are reported for the first time in the fossil record. http://zoobank.org/urn:lsid:zoobank.org:pub:6AA2FD29-A88E-49FA-B112-2FF4C6BE2787

Spicular analysis of surficial sediments as a supplementary tool for studies of modern sponge communities

The method of spicular analysis that examines surficial sediments has been used to study the sponge spicule assemblage in the lagoon reef of Bocas del Toro, Panama. The method allowed to recognize some highly diagnostic spicule morphotypes that may belong to four sponge species as yet unnoticed in this area. The presence of these sponges must have been overlooked while studying faunistic compositions within an ecosystem due to their cryptic and/or excavating nature. Despite some limitations, the method of spicular analysis may be used as a supplementary tool for the studies of modern shallow-water sponge communities.

A new echinocaridid phyllocaridan from the Lower Devonian of central-eastern Poland

A new specimen of a basal echinocaridid phyllocaridan is noted from the Lower Devonian sediments of the Izdebno IG-1 borehole of central-eastern Poland. The description and reconstruction are based on a three-dimensionally preserved incomplete left carapace valve. The unique characters of the valve surface, mainly in the form of the number and location of nodes, places this specimen within Ptychocaris . However, the unique arrangement of nodes on its carapace allows us to erect a new species, Ptychocaris sheldoni n. sp. The parallel and longitudinal ridges (‘striae’) preserved on the carapace suggest the ability of a fast burial into the muddy seafloor.

First record of the genus Vetulina Schmidt, 1879 (Porifera: Demospongiae: Sphaerocladina) from the Indian Ocean with the description of two new species: biogeographic and evolutionary significance

Two new species of the genus Vetulina Schmidt, 1879 (Demospongiae, Vetulinidae, Sphaerocladina) were found off the coast of Western Australia (Indian Ocean). This genus is characterized by acrepid polyaxial desmas (sphaeroclones) equipped with arborescent branched outgrowths with spine-like processes and isometric styles as microscleres. Vetulina indica sp. nov. is an irregular, laterally folded ear-shaped cup with smooth surfaces, and V. rugosa sp. nov. is similar in shape but with a distinctive ribbed inner surface. Both species are very similar in spicule composition, but are distinguished by their gross morphology and pattern of canal openings on the surface. Despite the fact that we could not distinguish the two specimens based on molecular (CO1) data, we consider them as two separate species based on the morphological species concept. Our molecular phylogeny confirms again that Vetulina is sister to spongillids (freshwater sponges). This is the first occurrence of this genus outside the Caribbean Atlantic, and the first report from the Indian Ocean. Such a disjunct distribution is considered here to be a relict of a once widely distributed sponge population in the ancient Tethys Sea.