Sponges, the members of the phylum Porifera, are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells.
Spicules are any of various small needle-like anatomical structures occurring in organisms
A sclerite is a hardened body part. In various branches of biology the term is applied to various structures, but not as a rule to vertebrate anatomical features such as bones and teeth. Instead it refers most commonly to the hardened parts of arthropod exoskeletons and the internal spicules of invertebrates such as certain sponges and soft corals. In paleontology, a scleritome is the complete set of sclerites of an organism, often all that is known from fossil invertebrates.
Ausia fenestrata is a curious Ediacaran period fossil represented by only one specimen 5 cm long from the Nama Group, a Vendian to Cambrian group of stratigraphic sequences deposited in the Nama foreland basin in central and southern Namibia. It has similarity to Burykhia from Ediacaran (Vendian) siliciclastic sediments exposed on the Syuzma River of Arkhangelsk Oblast, northwest Russia. This fossil is of the form of an elongate bag-like sandstone cast tapering to a cone on one end. The surface of the fossil is covered with oval depressions ("windows") regularly spaced over the surface in the manner of concentric/parallel rows. The taxonomic identity of Ausia is unresolved.
The Venus' flower basket is a glass sponge in the phylum Porifera. It is a marine sponge found in the deep waters of the Pacific ocean, usually at depths below 500 meters. Like other sponges, they feed by filtering sea water to capture plankton and marine snow. Similar to other glass sponges, they build their skeletons out of silica, which forms a unique lattice structure of spicules. The sponges are usually between 10 cm and 30 cm tall, and their bodies act as refuge for their mutualist shrimp partners. This body structure is of great interest in materials science as the optical and mechanical properties are in some ways superior to man-made materials. Little is known regarding their reproduction habits, however fluid dynamics of their body structure likely influence reproduction and it is hypothesized that they may be hermaphroditic.
A microfossil is a fossil that is generally between 0.001 mm and 1 mm in size, the visual study of which requires the use of light or electron microscopy. A fossil which can be studied with the naked eye or low-powered magnification, such as a hand lens, is referred to as a macrofossil.
A spongivore is an animal anatomically and physiologically adapted to eating animals of the phylum Porifera, commonly called sea sponges, for the main component of its diet. As a result of their diet, spongivore animals like the hawksbill turtle have developed sharp, narrow bird-like beak that allows them to reach within crevices on the reef to obtain sponges.
Marine invertebrates are the invertebrates that live in marine habitats. Invertebrate is a blanket term that includes all animals apart from the vertebrate members of the chordate phylum. Invertebrates lack a vertebral column, and some have evolved a shell or a hard exoskeleton. As on land and in the air, marine invertebrates have a large variety of body plans, and have been categorised into over 30 phyla. They make up most of the macroscopic life in the oceans.
Palaeophragmodictya is an extinct genus of sponge-grade organisms from the Ediacaran Period. Originally interpreted as a hexactinellid sponge, the organism also bears some coelomate characteristics, including bilateral symmetry.
The small shelly fauna, small shelly fossils (SSF), or early skeletal fossils (ESF) are mineralized fossils, many only a few millimetres long, with a nearly continuous record from the latest stages of the Ediacaran to the end of the Early Cambrian Period. They are very diverse, and there is no formal definition of "small shelly fauna" or "small shelly fossils". Almost all are from earlier rocks than more familiar fossils such as trilobites. Since most SSFs were preserved by being covered quickly with phosphate and this method of preservation is mainly limited to the late Ediacaran and early Cambrian periods, the animals that made them may actually have arisen earlier and persisted after this time span.
The Cambrian explosion, Cambrian radiation,Cambrian diversification, or the Biological Big Bang refers to an interval of time approximately 538.8 million years ago in the Cambrian Period of early Paleozoic when there was a sudden radiation of complex life and practically all major animal phyla started appearing in the fossil record. It lasted for about 13 – 25 million years and resulted in the divergence of most modern metazoan phyla. The event was accompanied by major diversification in other groups of organisms as well.
Vaveliksia is an extinct genus of Ediacaran Sponge-like organism with a long, tubular-shaped body and a attachment disk similar to that of Petalonamids. The Vaveliksia genus contained two species, Vaveliksia velikanovi as well as Vaveliksia vana. The two species vary in appearance to one another, with V. velikanovi having a more tubular-shaped, sack-like morphology with a crown of wrinkles on top of one of its ends as well as possessing a much more disk-like holdfast with V. vana having an appearance more similar to that of a Poriferan, with V. vana having a much more dome-shaped holdfast and a capsule-like body with no crown of wrinkles unlike V. velikanovi.
Spicules are structural elements found in most sponges. The meshing of many spicules serves as the sponge's skeleton and thus it provides structural support and potentially defense against predators.
Suberites is a genus of sea sponges in the family Suberitidae. Sponges, known scientifically as Porifera, are the oldest metazoans and are used to elucidate the basics of multicellular evolution. These living fossils are ideal for studying the principal features of metazoans, such as extracellular matrix interactions, signal-receptor systems, nervous or sensory systems, and primitive immune systems. Thus, sponges are useful tools with which to study early animal evolution. They appeared approximately 580 million years ago, in the Ediacaran.
Coronacollina acula is a multicellular organism from the Ediacaran period resembling the Cambrian 'sponge' Choia. The organism comprised a raised, tri-radially-symmetrical central mound with a central depression and resistant spicules, which were resistant — either chitinous or biomineralized — and grew to be 37 cm long.
Reticulosa is an extinct order of sea sponges in the class Hexactinellida and the subclass Amphidiscophora. Reticulosans were diverse in shape and size, similar to their modern relatives, the amphidiscosidans. Some were smooth and attached to a surface at a flat point, others were polyhedral or ornamented with nodes, many were covered in bristles, and a few were even suspended above the seabed by a rope-like anchor of braided glass spicules.
Until the late 1950s, the Precambrian was not believed to have hosted multicellular organisms. However, with radiometric dating techniques, it has been found that fossils initially found in the Ediacara Hills in Southern Australia date back to the late Precambrian. These fossils are body impressions of organisms shaped like disks, fronds and some with ribbon patterns that were most likely tentacles.
Silicateins are enzymes which catalyse the formation of biosilica from monomeric silicon compounds extracted from the natural environment. Environmental silicates are absorbed by specific biota, including diatoms, radiolaria, silicoflagellates, and siliceous sponges; silicateins have so far only been found in sponges. Silicateins are homologous to the cysteine protease cathepsin.
Gibbavasis kushkii is a species of an enigmatic member of the Ediacaran biota from central Iran. G. kushkii has been compared to the Namibian Ausia. The genus name "Gibbavasis" is a combination of the two Latin words Gibba and Vasis.
