Biodiversity of museum and bulk field samples compared: The Eocene Chiampo sponge fauna, Lessini Mountains, Italy

The sponge body fossils from the Lutetian (Eocene) of Chiampo Valley in north-eastern Italy, Lessini Mountains, exhibit a high diversity. The fauna, comprising 32 species, was recently described in a systematic study based on museum material. Here we compare diversity measures and rank-abundance distributions between the museum material and new material from random surface collection at the original sampling site. Not surprisingly, we find that selectively collected museum material tends to have greater diversity and evenness than bulk field samples. Nevertheless, abundance rank- orders are maintained between samples. Bulk field sampling revealed hexactinellids to be strongly dominant over lithistids, which suggests a deep-water setting of greater than 200 m water depth

Eocene siliceous sponges (porifera: hexactinellida, demospongea) from eastern Lessini mountains (northen italy)

2 case studies of Eocene siliceous sponges from Eastern Lessini Mountains are reported. Case study 1— Bartonian Mt. Duello isolated spicules (Verona). This study documents exceptionally preserved isolated opaline spicules, unique for the Middle Eocene (Bartonian) of Italy. Interpretation of morphological types of spicules by comparison with living species lead to their attribution to 5 orders (Astrophorida, Hadromerida, Haplosclerida, Poecilosclerida, “Lithistida”), 7 families (Geodiidae, Placospongiidae, Tethyidae, Petrosiidae, Acarnidae, ?Corallistidae, Theonellidae) and 5 genera (Geodia, Erylus, Placospongia, Chondrilla, Petrosia, ?Zyzzya ). All the described genera are first reported from the Eocene of Europe. This study expands the geographical range of these taxa and fills a chronological gap in their fossil record. The spicules are often fragmented and bear signs of corrosion. They show 2 types of preservation: glassy and translucent. X-ray powder diffraction analysis confirms that both types are opal-CT with probable presence of original opal-A. Despite of that, at SEM, the texture of freshly broken surfaces is different. Milky spicules show a porous structure with incipient lepispheres. This feature, together with surface corrosion and the constant presence of the zeolite heulandite/clinoptilolite, point to a certain degree of diagenetic transformation. Macro and micro facies analysis define the sedimentary environment as a rocky shore succession, deepening upward within the photic zone. The spicule-rich sandy grainstone represents the deepest facies and was deposited in middle-outer carbonate ramp environment, in part in a fairly high energy environment close to storm wave base, within the photic zone. Case study 2 –Lutetian sponge fauna from Chiampo Valley (Vicenza). The fauna consists of non-compressed bodily preserved sponges. More than 900 specimens housed in Italian Museums were studied. The original siliceous skeleton is dissolved and substituted by calcite. There is evidence of presence of sulfate reducing bacteria. Observations of both complete specimens and thin sections lead to taxonomical attributions of 32 species (15 Hexactinellida, 17 Demospongea). Among these taxa, the institution of 10 new species is proposed: Stauractinella eocenica, Rigonia plicata, Hexactinella clampi, Camerospongia tuberculata, Camerospongia visentini, Toulminia italica, Coronispongia confossa, Cavispongia scarpae, Corallistes multiosculata, Bolidium bertii. 24 genera are described, 2 of which new (Rigonia and Coronispongia). The specimens were photographed before sectioning , and 3-D models of fossils were produced. Delicate sponge attachments were documented. The presence of both attachments to soft and hard substrate indicate a mixed bottom. Juvenile sponges were recorded too. The sponge fauna is presumably parautochthonous. The taxonomical study shears a new light on the scarce fossil record of Eocene siliceous sponges. Petrographic investigations of the sponges and the embedding sediment contributed to clarify the sequence of taphonomic events and the sedimentary environmentSono riportati 2 casi studio di spugne silicee eoceniche dei Monti Lessini orientali. Caso di studio 1 — spicole isolate bartoniane del Monte Duello (Verona) Questo studio documenta la presenza di spicole isolate opaline, eccezionalmente conservate che costituiscono un unicum per l’Eocene (Bartoniano) dell’Italia. L’interpretazione della morfologia dei tipi di spicole tramite il confronto con specie viventi ha portato all’attribuzione a 5 ordini (Astrophorida, Hadromerida, Haplosclerida, Poecilosclerida, “Lithistida”), 7 famiglie (Geodiidae, Placospongiidae, Tethyidae, Petrosiidae, Acarnidae, ?Corallistidae, Theonellidae) and 5 generi (Geodia, Erylus, Placospongia, Chondrilla, Petrosia, ?Zyzzya ). Tutti i generi descritti sono segnalati per la prima volta per l’Eocene dell’Europa. Il presente studio espande il range geografico di questi taxa e riempie un gap cronologico nel loro record fossile. Le spicole sono spesso frammentate e portano segni di corrosione. Esse mostrano 2 tipi di conservazione: una vitrea e una lattea. Le analisi alla diffrazione delle polveri ai raggi X confermano che entrambi i tipi sono formati da opale-CT con la probabile presenza di opale-A. Malgrado ciò, al SEM, la struttura delle superfici rotte di fresco, è differente. Le spicole lattiginose hanno una struttura porosa con lepisfere incipienti. Questa caratteristica, assieme alla corrosione della superficie e la costante presenza della zeolite heulandite/clinoptilolite, suggerisce un certo grado di trasformazione diagenetica. Macro e micro analisi di facies definiscono l’ambiente sedimentario come una successione di costa rocciosa, deepening upward, all’interno della zona fotica. Il grainstone sabbioso ricco di spicole rappresenta la facies più profonda e si è depositato in un ambiente di rampa mediana-esterna, in un ambiente di energia piuttosto alta vicino alla base d’onda di cattivo tempo, all’interno della zona fotica. Caso studio 2— Fauna a spugne luteziano della Valle del Chiampo (Vicenza). La fauna consiste in spugne intere non compresse. Sono stati studiati più di 900 esemplari conservati in Musei italiani. Lo scheletro siliceo originale si è dissolto ed è stato sostituito da calcite. C’è evidenza della presenza di batteri solfo-riduttori. L’osservazione sia di esemplari completi sia di sezioni sottili ha portato all’attribuzione di 32 specie (15 Hexactinellida, 17 Demospongea). Tra queste, è proposta l’istituzione di 10 nuove specie: Stauractinella eocenica, Rigonia plicata, Hexactinella clampi, Camerospongia tuberculata, Camerospongia visentini, Toulminia italica, Coronispongia confossa, Cavispongia scarpae, Corallistes multiosculata, Bolidium bertii. Sono inoltre descritti 24 generi, 2 dei quali nuovi per la Scienza: Rigonia e Coronispongia. Gli esemplari sono stati fotografati prima di essere sezionati e sono stati prodotti modelli 3-D. Sono stati inoltre documentate delicate strutture di ancoraggio al substrato. La presenza di strutture di ancoraggio sia di substrato molle che di substrato duro indicano un fondale di tipo misto. Sono state pure documentate spugne allo stato giovanile. La fauna a spugne è presumibilmente parautoctona. Questo studio tassonomico porta nuova luce sullo scarso record fossile delle spugne eoceniche. Le ricerche petrografiche sugli esemplari di spugne e sul sedimento inglobante ha contribuito a chiarire la sequenza di eventi tafonomici e l’ambiente sedimentari

Eocene siliceous sponges (porifera: hexactinellida, demospongea) from eastern Lessini mountains (northen italy)

2 case studies of Eocene siliceous sponges from Eastern Lessini Mountains are reported. Case study 1— Bartonian Mt. Duello isolated spicules (Verona). This study documents exceptionally preserved isolated opaline spicules, unique for the Middle Eocene (Bartonian) of Italy. Interpretation of morphological types of spicules by comparison with living species lead to their attribution to 5 orders (Astrophorida, Hadromerida, Haplosclerida, Poecilosclerida, “Lithistida”), 7 families (Geodiidae, Placospongiidae, Tethyidae, Petrosiidae, Acarnidae, ?Corallistidae, Theonellidae) and 5 genera (Geodia, Erylus, Placospongia, Chondrilla, Petrosia, ?Zyzzya ). All the described genera are first reported from the Eocene of Europe. This study expands the geographical range of these taxa and fills a chronological gap in their fossil record. The spicules are often fragmented and bear signs of corrosion. They show 2 types of preservation: glassy and translucent. X-ray powder diffraction analysis confirms that both types are opal-CT with probable presence of original opal-A. Despite of that, at SEM, the texture of freshly broken surfaces is different. Milky spicules show a porous structure with incipient lepispheres. This feature, together with surface corrosion and the constant presence of the zeolite heulandite/clinoptilolite, point to a certain degree of diagenetic transformation. Macro and micro facies analysis define the sedimentary environment as a rocky shore succession, deepening upward within the photic zone. The spicule-rich sandy grainstone represents the deepest facies and was deposited in middle-outer carbonate ramp environment, in part in a fairly high energy environment close to storm wave base, within the photic zone. Case study 2 –Lutetian sponge fauna from Chiampo Valley (Vicenza). The fauna consists of non-compressed bodily preserved sponges. More than 900 specimens housed in Italian Museums were studied. The original siliceous skeleton is dissolved and substituted by calcite. There is evidence of presence of sulfate reducing bacteria. Observations of both complete specimens and thin sections lead to taxonomical attributions of 32 species (15 Hexactinellida, 17 Demospongea). Among these taxa, the institution of 10 new species is proposed: Stauractinella eocenica, Rigonia plicata, Hexactinella clampi, Camerospongia tuberculata, Camerospongia visentini, Toulminia italica, Coronispongia confossa, Cavispongia scarpae, Corallistes multiosculata, Bolidium bertii. 24 genera are described, 2 of which new (Rigonia and Coronispongia). The specimens were photographed before sectioning , and 3-D models of fossils were produced. Delicate sponge attachments were documented. The presence of both attachments to soft and hard substrate indicate a mixed bottom. Juvenile sponges were recorded too. The sponge fauna is presumably parautochthonous. The taxonomical study shears a new light on the scarce fossil record of Eocene siliceous sponges. Petrographic investigations of the sponges and the embedding sediment contributed to clarify the sequence of taphonomic events and the sedimentary environmentSono riportati 2 casi studio di spugne silicee eoceniche dei Monti Lessini orientali. Caso di studio 1 — spicole isolate bartoniane del Monte Duello (Verona) Questo studio documenta la presenza di spicole isolate opaline, eccezionalmente conservate che costituiscono un unicum per l’Eocene (Bartoniano) dell’Italia. L’interpretazione della morfologia dei tipi di spicole tramite il confronto con specie viventi ha portato all’attribuzione a 5 ordini (Astrophorida, Hadromerida, Haplosclerida, Poecilosclerida, “Lithistida”), 7 famiglie (Geodiidae, Placospongiidae, Tethyidae, Petrosiidae, Acarnidae, ?Corallistidae, Theonellidae) and 5 generi (Geodia, Erylus, Placospongia, Chondrilla, Petrosia, ?Zyzzya ). Tutti i generi descritti sono segnalati per la prima volta per l’Eocene dell’Europa. Il presente studio espande il range geografico di questi taxa e riempie un gap cronologico nel loro record fossile. Le spicole sono spesso frammentate e portano segni di corrosione. Esse mostrano 2 tipi di conservazione: una vitrea e una lattea. Le analisi alla diffrazione delle polveri ai raggi X confermano che entrambi i tipi sono formati da opale-CT con la probabile presenza di opale-A. Malgrado ciò, al SEM, la struttura delle superfici rotte di fresco, è differente. Le spicole lattiginose hanno una struttura porosa con lepisfere incipienti. Questa caratteristica, assieme alla corrosione della superficie e la costante presenza della zeolite heulandite/clinoptilolite, suggerisce un certo grado di trasformazione diagenetica. Macro e micro analisi di facies definiscono l’ambiente sedimentario come una successione di costa rocciosa, deepening upward, all’interno della zona fotica. Il grainstone sabbioso ricco di spicole rappresenta la facies più profonda e si è depositato in un ambiente di rampa mediana-esterna, in un ambiente di energia piuttosto alta vicino alla base d’onda di cattivo tempo, all’interno della zona fotica. Caso studio 2— Fauna a spugne luteziano della Valle del Chiampo (Vicenza). La fauna consiste in spugne intere non compresse. Sono stati studiati più di 900 esemplari conservati in Musei italiani. Lo scheletro siliceo originale si è dissolto ed è stato sostituito da calcite. C’è evidenza della presenza di batteri solfo-riduttori. L’osservazione sia di esemplari completi sia di sezioni sottili ha portato all’attribuzione di 32 specie (15 Hexactinellida, 17 Demospongea). Tra queste, è proposta l’istituzione di 10 nuove specie: Stauractinella eocenica, Rigonia plicata, Hexactinella clampi, Camerospongia tuberculata, Camerospongia visentini, Toulminia italica, Coronispongia confossa, Cavispongia scarpae, Corallistes multiosculata, Bolidium bertii. Sono inoltre descritti 24 generi, 2 dei quali nuovi per la Scienza: Rigonia e Coronispongia. Gli esemplari sono stati fotografati prima di essere sezionati e sono stati prodotti modelli 3-D. Sono stati inoltre documentate delicate strutture di ancoraggio al substrato. La presenza di strutture di ancoraggio sia di substrato molle che di substrato duro indicano un fondale di tipo misto. Sono state pure documentate spugne allo stato giovanile. La fauna a spugne è presumibilmente parautoctona. Questo studio tassonomico porta nuova luce sullo scarso record fossile delle spugne eoceniche. Le ricerche petrografiche sugli esemplari di spugne e sul sedimento inglobante ha contribuito a chiarire la sequenza di eventi tafonomici e l’ambiente sedimentari

Isolated spicules of Demospongiae from Mt. Duello (Eocene, Lessini Mts., northern Italy): preservation, taxonomy, and depositional environment

Today, class Demospongiae is the largest of phylum Porifera but its fossil record, especially for \u201csoft\u201d demosponges, is rather scarce. This study documents exceptionally preserved isolated opaline spicules, unique for the Bartonian of Italy. Interpretation of morphological types of spicules by comparison with living species lead to their attribution to five orders (Astrophorida, Hadromerida, Haplosclerida, Poecilosclerida, \u201cLithistida\u201d), seven families (Geodiidae, Placospongiidae, Tethyidae, Petrosiidae, Acarnidae, ?Corallistidae, Theonellidae) and five genera (Geodia, Erylus, Placospongia, Chondrilla, Petrosia, ?Zyzzya). All the described genera are first reported from the Eocene of Europe. This study expands the geographical range of these taxa and fills a chronological gap in their fossil record. The spicules are often fragmented and bear signs of corrosion. They show two types of preservation: glassy and translucent. X-ray powder diffraction analysis confirms that both types are opal-CT with probable presence of original opal-A. Despite this, using a scanning electron microscope the texture of freshly broken surfaces is different. Milky spicules show a porous structure with incipient lepispheres. This feature, together with surface corrosion and the constant presence of the zeolite heulandite/clinoptilolite, point to a certain degree of diagenetic transformation. Macro and micro facies analysis define the sedimentary environment as a rocky shore succession, deepening upward within the photic zone. The spicule-rich sandy grainstone represents the deepest facies and was deposited in a middle-outer carbonate ramp environment, in part in a fairly high energy environment close to storm wave base

A first glimpse on the taphonomy and sedimentary environment of the Eocene siliceous sponges from Chiampo, Lessini Mts, NE Italy

A diverse assemblage of bodily preserved sponges has been recovered from a lower Lutetian tuffite horizon in the Chiampo Valley, Lessini Mountains, Italy. The sponge assemblage is dominated by hexactinellids and lithistids. Using uniformitarian criteria, the composition of the assemblage suggests a water depth greater than 200 m. Sponges are often preserved in growth position including sponge clusters. Taphonomic processes facilitating sponge preservation include rapid burial of a living sponge community and early diagenetic calcification. Different modes of attachment suggest heterogeneous substrate conditions. The associated fauna, such as abundant pteropods in the matrix and in-situ preserved crinoids, confirms a rather deep-water environment. However, there are also common benthic elements of shallow-water origin. Although some of these elements show signs of transport, others, such as decapod crustaceans, do not. Moreover, trace fossils indicate high-energy environments. To reconcile these observations, we propose rapid, tectonically triggered sea-level changes

A highly diverse siliceous sponge fauna (Porifera: Hexactinellida, Demospongiae) from the Eocene of north-eastern Italy: systematics and palaeoecology

A siliceous sponge fauna, consisting of more than 900 specimens, is described from an early Lutetian tuffite horizon in the Chiampo Valley, Lessini Mountains, north-eastern Italy. Thirty-two taxa (15 Hexactinellida, 17 Demospongiae) are determined and illustrated, belonging to 24 genera, two of which are new (Rigonia gen. nov. and Coronispongia gen. nov.). Among these, 10 new species are proposed: Stauractinella eocenica sp. nov., Rigonia plicata gen. et sp. nov., Hexactinella clampensis sp. nov., Camerospongia visentinae sp. nov., C. tuberculata sp. nov., Toulminia italica sp. nov., Coronispongia confossa gen. et sp. nov., Cavispongia scarpai sp. nov., Corallistes multiosculata sp. nov. and Bolidium bertii sp. nov. Of the genera identified at Chiampo, 14 range back to the Cretaceous, three to the Jurassic and one to the Triassic, while six are still extant. The studied fauna shows affinities with sponges from the Eocene of Spain and the Cretaceous of Germany. The sponge fossils are uncompressed and bodily preserved, but the original siliceous skeleton is dissolved and substituted by calcite. Delicate attachments can be nevertheless documented: some sponges attached to a hard substrate by encrustation, while others were anchored on soft sediments by root-like structures. The presence of different modes of attachment suggests heterogeneous substrate conditions. Small, possibly young, sponges are recorded too. The sponge fauna is essentially autochthonous and lived in the middle-outer part of a carbonate ramp, where it formed clusters. This study extends the geographical and stratigraphical range of many sponge taxa, including Camerospongia, Toulminia, Ozotrachelus and Bolidium, previously documented only from the Cretaceous. The Recent calcified demosponge genus Astrosclera is reported here in the Cenozoic for the first time, having been reported previously in the Triassic only. Additionally, this study documents the second worldwide occurrence of the Recent sphinctozoan genus Vaceletia in the Palaeogene, formerly recorded exclusively in Australia. http://zoobank.org/urn:lsid:zoobank.org:pub:B3466955-8E20-429A-89BE-42BAEB4002E8 \ua9 2016, \ua9 The Trustees of the Natural History Museum, London 2016. All Rights Reserved