Siliceous spicules in a vauxiid sponge (Demospongia) from the Kaili Biota(Cambrian Stage 5), Guizhou, South China

Siliceous spicules in a vauxiid sponge (Demospongia) from the Kaili Biota(Cambrian Stage 5), Guizhou, South China

Fossils of the sponge Angulosuspongia sinensis from calcareous mudstones of the middle and upper part of the Kaili Formation (Cambrian Stage 5) in the Jianhe area of Guizhou province, South China, exhibit an apparently reticulate pattern, characteristic of the Vauxiidae. Energy Dispersive X-Ray Spectrometry (EDS) and Raman spectroscopy analysis indicate the presence of silica in the skeletal el...

Carbon replicas of siliceous sponge spicules.

A Solid State NMR Investigation of Recent Marine Siliceous Sponge Spicules

The composition of four recent siliceous marine sponge spicules was studied and compared. In particular, multinuclear (29Si, 13C, 31P) solid state nuclear magnetic resonance (NMR) allowed the characterization of both the mineral and organic constituents in a non-destructive manner. The silica network condensation was similar for all samples. The organic matter showed a similar pattern but varie...

Late Eocene siliceous sponge fauna of southern Australia: reconstruction based on loose spicules record.

An abundant and diversified assemblage of siliceous loose sponge spicules has been identified in the Late Eocene deposits cropping out along the southern coasts of Australia. Based on the comparison of the obtained spicules with those of living sponges, representatives of at least 43 species within 33 genera, 26 families, and 9 orders of "soft" Demospongiae and Homoscleromorpha have been identi...

Where's the glass? Biomarkers, molecular clocks, and microRNAs suggest a 200-Myr missing Precambrian fossil record of siliceous sponge spicules.

The earliest evidence for animal life comes from the fossil record of 24-isopropylcholestane, a sterane found in Cryogenian deposits, and whose precursors are found in modern demosponges, but not choanoflagellates, calcareans, hexactinellids, or eumetazoans. However, many modern demosponges are also characterized by the presence of siliceous spicules, and there are no convincing demosponge spic...