Introduction

Ostracoda is a Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. Modern classification has its roots in the system of Carolus Linnaeus, who grouped species according to shared physical characteristics. These groupings have been revised since Linnaeus to improve consistency with the Darwinian... class of the Classes Remipedia Cephalocarida Branchiopoda Ostracoda Maxillopoda Malacostraca The crustaceans (Crustacea) are a large group of arthropods (55,000 species), usually treated as a subphylum. They include various familiar animals, such as lobsters, crabs, shrimp and barnacles. They are variously found in marine and freshwater, with a few terrestrial members (such... Crustacea, sometimes known as the seed shrimp because of their appearance. Some 50,000 extinct and extant species have been identified, grouped into several orders.

Ostracods are small crustaceans, typically around one mm in size, but varying between 0,2 to 3 mm, laterally compressed and protected by a Orders Subclass Protobranchia Solemyoida Nuculoida Subclass Pteriomorphia - oysters Arcoida Mytiloida Pterioida Subclass Paleoheterodonta - mussels Trigoinoida Unionoida Subclass Heterodonta - clams, zebra mussels Veneroida Myoida Subclass Anomalosdesmata Pholadomyoida Animals of the Class Bivalvia are known as bivalves because they typically have two-part shells, with both parts being more or less symmetrical... bivalve-like, In biology, chitin is one of the main components in the cell walls of fungi, the exoskeletons of insects and other arthropods, and in some other animals. It is a polysaccharide, made out of units of acetylglucosamine (more completely, N_acetyl_D_glucos_2_amine). These are linked together in β_1,4 fashion, the... chitinous or calcareous valve or "shell". The hinge of the two valves is in the upper, dorsal region of the body.

Ecologically ostracods can be part of the Photomontage of plankton organisms Plankton is the aggregate community of weakly swimming but mostly drifting small organisms that inhabit the water column of the ocean, seas, and bodies of freshwater. The name comes from the Greek term, —meaning wanderer or drifter. While some forms of plankton can move several... zooplankton, or (most commonly) they are part of the In marine geology and biology, benthos are the organisms and habitats of the sea floor; in freshwater biology they are the organisms and habitats of the bottoms of lakes, rivers, and creeks. From the size of organisms there are distinguished macrobenthos, size > 1 mm meiobenthos, size > 0.063... benthos, living on or inside the upper layer of the sea floor. Some groups of ostracods are also found in fresh waters and in humid continental soils (normally in humid forests).

Ostracods are particularly useful for the biozonation of marine strata on a local or regional scale, and they are invaluable indicators of ancient shorelines, salinities and relative sea-floor depths. They have a long and well documented FOSSIL is a standard for allowing serial communication for telecommunications programs under DOS. FOSSIL stands for Fido Opus SEAdog Standard Interface Layer and was made by a group of Fidonet sysops to make their software work on different machines. External link Fundamentals of FOSSIL implementation and use Categories: Telecommunications ... fossil record from the The Cambrian is a major division of the geologic timescale that begins about 542 million years before the present (BP) at the end of the Proterozoic eon_geology and ended about 490 million years BP with the beginning of the Ordovician period. It is the first period of the Paleozoic era... Cambrian to the present day. An outline microfaunal zonal scheme based on both Orders Allogromiida Carterinida Fusulinida - extinct Globigerinida Involutinida Lagenida Miliolida Robertinida Rotaliida Silicolocunida Spirillinida Textulariida The Foraminifera, or forams for short, are a large group of amoeboid protists with reticulating pseudopods, fine strands that branch and merge to form a dynamic net. They produce a shell, or test, which can have... foraminifera and ostracoda was compiled by M.B. Hart (1972).

Morphology

The body of an ostracod is encased by two valves, which together form the duplicature. A distinction is made between the valve (hard parts) and the body with its appendages (soft parts).

Soft parts and ontogeny

The body consists of a The cephalon is the foremost portion of the segmented body of a trilobite. Generally this region of the body can be thought of as the head of the animal, including the eyes on the dorsal surface of the body, and the hyperstome (part of simle mouth) on the venter (underside... cephalon (head), separated from the Diagram of a tsetse fly, showing the head, thorax and abdomen The thorax is a division of an animals body, that lies between the head and the abdomen. In humans, the thorax is the region of the body that extends from the neck to the diaphragm, not including the... thorax by a slight constriction. The Segmentation is a general term for the division or partition of something into separate pieces or segments. Here are some of its specialized uses: In computer/hardware, it states for memory segmentation. In computer network engineering, it is the splitting of a large or heavily used network into subnetworks in... segmentation is unclear. The The abdomen (from the Latin word meaning belly) is the part of the body between the pelvis and the thorax. The front of the abdomen is the abdominal cavity, which is separated from the thoracic cavity by the diaphragm. The lining of the abdomen is called the peritoneum, and the... abdomen is regressed or absent whereas the adult A sex organ, or primary sexual characteristic, narrowly defined, is any of those parts of the body (which are not always bodily organs according to the strict definition) which are involved in sexual reproduction and constitute the reproductive system in an complex organism; namely: Male: penis (notably the glans penis... gonads are relatively large. There are 5-8 pairs of appendages. The branchial plates are responsible for oxygenation.

During the Ontogeny (also ontogenesis or morphogenesis) describes the origin and the development of an organism from the fertilized egg to its mature form. Ontogeny is studied in developmental biology. The idea that ontogeny recapitulates phylogeny, i.e. that the development of an organism exactly mirrors the evolutionary development of the species... ontogeny the Epidermis could refer to: In plants, the outermost layer of cells covering the leaves and young parts of a plant, see plant dermal tissue system. In vertebrates, epidermis is the outermost layer of the skin. In invertebrates, the outermost layer of cells of the organism. Etymology: 17th Century, via Late... epidermis (containing Mesoderm is one of the three germ layers in the early developing embryo, the other two layers being the ectoderm and the endoderm. The mesoderm gives rise to tissues including connective tissue, muscles and the circulatory system. The mesoderm is also believed to be responsible for the formation of the... mesodermal tissue) is Invagination is one of the morphogenetic processes by which an embryo takes form, and is the initial step of gastrulation, the massive reorganization of the embryo from a simple spherical ball of cells, the blastula, into a multi-layered organism, with a differentiated endoderm, mesoderm, and ectoderm. More localized invaginations... invaginated ventrolaterally near the cephalon/thorax area. This invagination proceeds upwards and tailwards, until the whole animal is enveloped by lamellae on both sides: the duplicature is formed. The dorsal region never becomes invaginated, and is called the istmus. The mesodermal tissue in the duplicature develops into the Vestibule can have the following meanings: A large entrance, reception area, antechamber, or room A small room or passage that connects the outer door of a building to the interior of the building An area in a train where people get on and off. If there are seats at all... vestibulum. The vestibulum makes contact with the body near the istmus. The vestibulum plays a role in oxygenation. The two lamellae surrounding the animal each have an inner and an outer lamella.

Hard parts

External link

• Introduction to Ostracoda (http://www.gre.ac.uk/schools/nri/earth/ostracod/introduction.htm)