Andrzej Pisera

Discovery of 505-million-year old chitin in the basal demosponge Vauxia gracilenta

Sponges are probably the earliest branching animals, and their fossil record dates back to the Precambrian. Identifying their skeletal structure and composition is thus a crucial step in improving our understanding of the early evolution of metazoans. Here, we present the discovery of 505–million-year-old chitin, found in exceptionally well preserved Vauxia gracilenta sponges from the Middle Cambrian Burgess Shale. Our new findings indicate that, given the right fossilization conditions, chitin is stable for much longer than previously suspected. The preservation of chitin in these fossils opens new avenues for research into other ancient fossil groups.

Deceptive desmas: molecular phylogenetics suggests a new classification and uncovers convergent evolution of lithistid demosponges.

Reconciling the fossil record with molecular phylogenies to enhance the understanding of animal evolution is a challenging task, especially for taxa with a mostly poor fossil record, such as sponges (Porifera). ‘Lithistida’, a polyphyletic group of recent and fossil sponges, are an exception as they provide the richest fossil record among demosponges. Lithistids, currently encompassing 13 families, 41 genera and >300 recent species, are defined by the common possession of peculiar siliceous spicules (desmas) that characteristically form rigid articulated skeletons. Their phylogenetic relationships are to a large extent unresolved and there has been no (taxonomically) comprehensive analysis to formally reallocate lithistid taxa to their closest relatives. This study, based on the most comprehensive molecular and morphological investigation of ‘lithistid’ demosponges to date, corroborates some previous weakly-supported hypotheses, and provides novel insights into the evolutionary relationships of the previous ‘order Lithistida’. Based on molecular data (partial mtDNA CO1 and 28S rDNA sequences), we show that 8 out of 13 ‘Lithistida’ families belong to the order Astrophorida, whereas Scleritodermidae and Siphonidiidae form a separate monophyletic clade within Tetractinellida. Most lithistid astrophorids are dispersed between different clades of the Astrophorida and we propose to formally reallocate them, respectively. Corallistidae, Theonellidae and Phymatellidae are monophyletic, whereas the families Pleromidae and Scleritodermidae are polyphyletic. Family Desmanthidae is polyphyletic and groups within Halichondriidae – we formally propose a reallocation. The sister group relationship of the family Vetulinidae to Spongillida is confirmed and we propose here for the first time to include Vetulina into a new Order Sphaerocladina. Megascleres and microscleres possibly evolved and/or were lost several times independently in different ‘lithistid’ taxa, and microscleres might at least be four times more likely lost than megascleres. Desma spicules occasionally may have undergone secondary losses too. Our study provides a framework for further detailed investigations of this important demosponge group.

Fossil ‘Lithistids’: An Overview

The oldest fossil lithistid sponges (Demospongiae, ‘lithistids’) are known from the Cambrian. Lithistids are very common in the fossil record since the Ordovician, but their distribution is very punctuated: large faunas of lithistid demosponges are known from the Ordovician, Silurian, Devonian, Permian, Upper Jurassic, Upper Cretaceous and the Eocene. The Paleozoic faunas are dominated by Orchocladina (extinct in the Permian) and Sphaerocladina (continuing up to the Recent); Mesozoic faunas are dominated by Tetracladina and Rhizomorina, which are also common in the Tertiary and Recent lithistid faunas. Phylogeny of fossil lithistids, especially relationships between the Paleozoic and later forms are still poorly understood, partly because only desmas are usually preserved in the fossil state, thus no microscleres or rarely ectosomal spicules are known. These megascleres are crucial diagnostic characters in Recent lithistid taxonomy. Given their good fossilization potential this fauna is diverse, with 13 suborders, 34 families and over 200 genera discussed in the present work, although many more nominal genera of fossil lithistids are known.

Upper Devonian Sponges from the Holy Cross Mountains, Central Poland

The rich fauna of Late Devonian (Late Frasnian) siliceous sponges from the Holy Cross Mountains, Poland is composed of 15 species and 11 genera. Both astylospongid demosponges (lithistids) and hexactinosan hexactinellids are present. The following new genera and/or species are proposed: D regulara Rigby and Pisera sp. nov., Jazwicella media Rigby and Pisera gen. et sp. nov., Astyloscyphia irregularia Rigby and Pisera gen. et sp. nov., A. turbinata Rigby and Pisera gen. et sp. nov., Astylotuba modica Rigby and Pisera gen. et sp. nov., Paleoregulara cupula Rigby and Pisera gen. et sp. nov., Paleoramospongia bifurcata Rigby and Pisera gen. et sp. nov., Cordiospongia conica Rigby and Pisera gen. et sp. nov., Paleocraticularia elongata Rigby and Pisera gen. et sp. nov., P gigantia Rigby and Pisera gen. et sp. nov., Polonospongiadevonica Rigby and Pisera gen. et sp. nov., P fistulata Rigby and Pisera gen. et sp. nov., Urnospongia modica Rigby and Pisera gen. et sp. nov., and Conicospongia annulata Rigby and Pisera gen. et sp. nov. The investigated fauna contains the youngest astylospongiids known and the oldest well-preserved, and most diversified Palaeozoic hexactinosans. The sponge fauna constituted a significant element of a brachiopod-coral-sponge assemblage that inhabited a deep slope of the local Dyminy Reef structure, during its final phase of growth, in a clearly hemipelagic setting. This fauna is limited to the intrashelf depression within an incipiently drowned carbonate platform.

Paleoenvironmental significance of a new species of freshwater sponge from the Late Miocene Quillagua Formation (N Chile)

This paper reports the first fossil (Tertiary) occurrence of freshwater sponges of the genus Ephydatia in the southern hemisphere. The sponges appear in diatomite lacustrine sediments of Late Miocene Quillagua Formation (Chile, Atacama region). The investigated specimens represent a new species, Ephydatia chileana sp. nov., which is close to the Recent cosmopolitan E. fluviatilis. On the basis of sedimentological and diatom assemblage data, sponge-bearing diatomites have been interpreted as deposited in open offshore shallow lacustrine conditions with slightly alkaline waters. The sponges show malformations, similar to some diatoms and probably caused by high heavy metal concentrations in a lake water. These concentrations are related to hydrothermal activity, which favored the leaching of volcanic rocks that outcrop extensively in the catchment. q 2003 Elsevier Science Ltd. All rights reserved.

Eocene siliceous sponges from the Ebro Basin (Catalonia, Spain)

The Eocene (Bartonian) marls of the La Guixa Member and Gurb Member, Vic Marls Formation (Ebro Basin, Catalonia, Spain), contain a very rich and diversified siliceous sponge fauna. The fauna is dominated by hexactinellids; lithistids and other demosponges are rare. It consists of 16 species representing 16 genera. Eleven new species and two new genera are proposed for these sponges: Reguantella cavernosa nov. gen. nov. sp., Regadrella concinna nov. sp. (both Hexactinellida, Lyssacinosa), Eurete clava nov. sp., Pleuroguettardia iberica nov. sp., Aphrocallistes almeriae nov. sp., Hexactinella informis nov. sp. (all Hexactinellida, Hexactinosa), Brachiolites munterensis nov. sp., Centrosia viquensis nov. sp., Callicylix eocenicus nov. sp., Rhizocheton robustus nov. sp. (all Hexactinellida, Lychniscosa), Propetrosia pristina nov. gen. nov. sp. (Demospongia, Haplosclerida). Some genera of sponges in this fauna are still extant, but, in general, the predominant ones are very close in morphology, and, without doubt, closely related to the Late Cretaceous sponges. This fauna also differs considerably, in terms of composition, from most other described faunas of Tertiary sponges from the Mediterranean region, which are dominated by lithistid sponges. Lithistid sponges are rare in this investigated assemblage, which seems most similar to an as yet undescribed Eocene fauna from Italy. There is ecological differentiation in the proportions of particular sponges in various outcrops and/or stratigraphical levels that is clearly associated with water-depth-related controlling factor(s): Munter, Tona and Sta. Cecilia represent the deepest facies, Gurb is intermediate, and St. Roc and Vespella are the most shallow. The exact bathymetric position of the sponge fauna is difficult to estimate, but it seems that 100 m (but probably 200 m and more in the case of the deepest parts) of water depth may be inferred for this facies.

Upper Jurassic Sponge Megafacies in Spain: Preliminary Report

The Upper Jurassic sponge megafacies (with siliceous sponges) extends in Europe from Romania through Poland, Germany, Switzerland, and France to Spain. This facies, unique in the fossil record, has in recent times gained considerable interest. So far the best-known megafacies development is in Southern Germany, where it has also the largest stratigraphical range from Oxfordian to Tithonian (see Wagenplast 1972; Nitzopoulos 1974; Gwinner 1976; Flugel and Steiger 1981; Schorr and Koch 1985; Wirsing and Koch 1986, and others, also literature therein). A recent and thorough monograph of sponge megafacies in France was presented by Gaillard (1983). Trammer (1982) investigated the taxonomy of the Lower Oxfordian sponges from Poland, giving short characteristics of all aspects of the megafacies. Data on sponge megafacies in Spain, however, are scarce and dispersed in the general geological literature. Because of Spain’s paleogeographical position as the southernmost area of occurrence, the study of all aspects (paleontology, sedimentology and stratigraphy) seems important. This chapter presents, therefore, a general introductory report on the Upper Jurassic sponge megafacies in Spain, based both on earlier published data and on my own observations. Detailed study of sponge taxonomy, paleoecology, and functional morphology, including also some sedimentological and paleogeographical problems, is now being carried out.

SILICEOUS SPONGE SPICULES FROM THE MIOCENE MEM MONIZ MARLS (PORTUGAL) AND THEIR ENVIRONMENTAL SIGNIFICANCE

The Miocene (middle Serravalian) Mem Moniz marls from Algarve (Portugal) contain a rich and well preserved assemblage of siliceous sponge spicules, which is described here for the first time. The assemblage indicates that the sponge fauna was dominated by Astrophorida, and in particular by Geodiidae. The presence of Eurylus sp. and probably Geodia sp. (both Astrophorida), Samus sp. (Spirophorida) and Alectona wallichii (Hadromerida) is also reported. Samus sp. and Alectona wallichii are reported from the fossil record for the first time. Additionally, the occurrence of lithistid demosponges (represented by Theonellidae and rhizomorinids), Hadromerida, Spirophorida and Hexactinellida is also shown. Ancorinidae, Pachastrellidae (and/or Cathropellidae), both Astrophorida, were also clearly recognized. Less certain is the occurrence, in the Mem Moniz marls, of Tethyidae (Hadromerida). Bathymetric reconstructions based on sponges are imprecise due to the fact that these organisms often have very wide bathymetric ranges. However, the studied sponge assemblage is clearly neither characteristic of very shallow nor very deep marine environments. The dominance of astrophorids and the presence of lithistids and hexactinellids suggest a depth of at least several tens to one hundred metres, or even more.

A new Mediterranean ‘lithistid’ sponge, Aciculites mediterranea sp. nov. (Porifera: Demospongiae) from a dark marine cave in Sardinia

A first record of the genus Aciculites in the Mediterranean Sea and the description of Aciculites mediterranea sp. nov. are here presented from a faunistic survey in a dark shallow marine cave of the north-western Sardinian karstic area. The new species is characterized by a massive cerebellum-like growth form, and a peculiar distribution of inhalant and exhalant areas, respectively, in depressed and elevated portions of the sponge surface. Oscules show a long narrow atrial cavity. Ectosomal skeleton is made of tangential anisostrongyles on elevated areas, and more or less vertical tufts of anisostrongyles in depressed inhalant areas. Anisostrongyles are smooth or with tips ornated by irregular tubercles. Sigmaspire microscleres are lacking. Choanosomal skeleton with tubercled irregular rizhoclone desmas and few scattered and variably oriented anisostrongyles. A comparative analysis of Aciculites mediterranea sp. nov. versus morphological diagnostic traits, geographical range and habitat of the species hitherto ascribed to Aciculites confirms that the peculiar distribution of the genus supports its relic condition of an ancient Tethyan fauna in the Mediterranean Sea.

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.