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Calamites
''Calamites'' is a genus of Extinction, extinct arborescent (tree-like) horsetails to which the modern horsetails (genus ''Equisetum'') are closely related. Unlike their Herbaceous plant, herbaceous modern cousins, these plants were medium-sized trees, growing to heights of . They were components of the understories of coal swamps of the Carboniferous, Carboniferous Period (around ). Taxonomy A number of organ taxon, organ taxa have been identified as part of a united organism, which has inherited the name ''Calamites'' in popular culture. ''Calamites'' correctly refers only to casts of the stem of Carboniferous/Permian sphenophytes, and as such is a form genus of little taxonomic value. There are two forms of casts, which can give mistaken impressions of the organisms. The most common is an internal cast of the hollow (or pith-filled) void in the centre of the trunk. This can cause some confusion: firstly, a fossil was probably surrounded with 4-5 times its width in (unprese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboniferous
The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the Permian Period, Ma. It is the fifth and penultimate period of the Paleozoic era and the fifth period of the Phanerozoic eon (geology), eon. In North America, the Carboniferous is often treated as two separate geological periods, the earlier Mississippian (geology), Mississippian and the later Pennsylvanian (geology), Pennsylvanian. The name ''Carboniferous'' means "coal-bearing", from the Latin ("coal") and ("bear, carry"), and refers to the many coal beds formed globally during that time. The first of the modern "system" names, it was coined by geologists William Conybeare (geologist), William Conybeare and William Phillips (geologist), William Phillips in 1822, based on a study of the British rock succession. Carboniferous is the per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taphonomic
Taphonomy is the study of how organisms decay and become fossilized or preserved in the paleontological record. The term ''taphonomy'' (from Greek , 'burial' and , 'law') was introduced to paleontology in 1940 by Soviet scientist Ivan Efremov to describe the study of the transition of remains, parts, or products of organisms from the biosphere to the lithosphere. The term taphomorph is used to describe fossil structures that represent poorly-preserved, deteriorated remains of a mixture of taxonomic groups, rather than of a single one. Description Taphonomic phenomena are grouped into two phases: biostratinomy, events that occur between death of the organism and the burial; and diagenesis, events that occur after the burial. Since Efremov's definition, taphonomy has expanded to include the fossilization of organic and inorganic materials through both cultural and environmental influences. Taphonomy is now most widely defined as the study of what happens to objects after they ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xylem
Xylem is one of the two types of transport tissue (biology), tissue in vascular plants, the other being phloem; both of these are part of the vascular bundle. The basic function of the xylem is to transport water upward from the roots to parts of the plants such as stems and leaves, but it also transports plant nutrition, nutrients. The word ''xylem'' is derived from the Ancient Greek word (), meaning "wood"; the best-known wood organism is plants, though it is found throughout a plant. The term was introduced by Carl Nägeli in 1858. Structure The most distinctive xylem cell (biology), cells are the long tracheary elements that transport water. Tracheids and vessel elements are distinguished by their shape; vessel elements are shorter, and are connected together into long tubes that are called ''vessels''. Wood also contains two other type of cells: Ground tissue#Parenchyma, parenchyma and ground tissue#Fibres, fibers. Xylem can be found: * in vascular bundles, present in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calamitaceae
Calamitaceae is an extinct Family (biology), family of Equisetales, equisetalean plants related to the modern horsetails, known from the Carboniferous and Permian periods. Some members of this family like ''Arthropitys'' attained tree-like stature, with heights over , with extensive underground rhizomes. They were largely found in wetland environments. Proposed genera and species of Calamitaceae * ''Annularia''. ** ''A. stellata''. * ''Arthropitys''. * ''Asterophyllites'' (or incorrectly ''Asterophyllum''). * ''Astromyelon''. * ''Calamites''. ** ''C. carinatus''. ** ''C. suckowi''. ** ''C. undulatus''. * ''Calamocarpon''. * ''Calamostachys''. ** ''C. binneyana''. * ''Cingularia''. * ''Mazostachys''. * ''Paleostachya''. References External links Link to information and pictures Equisetales Carboniferous plants Prehistoric plant families Fern families Carboniferous first appearances Carboniferous extinctions {{carboniferous-plant-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meristem
In cell biology, the meristem is a structure composed of specialized tissue found in plants, consisting of stem cells, known as meristematic cells, which are undifferentiated cells capable of continuous cellular division. These meristematic cells play a fundamental role in plant growth, regeneration, and acclimatization, as they serve as the source of all differentiated plant tissues and organs. They contribute to the formation of structures such as fruits, leaves, and seeds, as well as supportive tissues like stems and roots. Meristematic cells are totipotent, meaning they have the ability to differentiate into any plant cell type. As they divide, they generate new cells, some of which remain meristematic cells while others differentiate into specialized cells that typically lose the ability to divide or produce new cell types. Due to their active division and undifferentiated nature, meristematic cells form the foundation for the formation of new plant organs and the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calamites Sp
''Calamites'' is a genus of extinct arborescent (tree-like) horsetails to which the modern horsetails (genus ''Equisetum'') are closely related. Unlike their herbaceous modern cousins, these plants were medium-sized trees, growing to heights of . They were components of the understories of coal swamps of the Carboniferous Period (around ). Taxonomy A number of organ taxa have been identified as part of a united organism, which has inherited the name ''Calamites'' in popular culture. ''Calamites'' correctly refers only to casts of the stem of Carboniferous/Permian sphenophytes, and as such is a form genus of little taxonomic value. There are two forms of casts, which can give mistaken impressions of the organisms. The most common is an internal cast of the hollow (or pith-filled) void in the centre of the trunk. This can cause some confusion: firstly, a fossil was probably surrounded with 4-5 times its width in (unpreserved) vascular tissue, so the organisms were much wider ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asexual Reproduction
Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the full set of genes of their single parent and thus the newly created individual is genetically and physically similar to the parent or an exact clone of the parent. Asexual reproduction is the primary form of reproduction for single-celled organisms such as archaea and eubacteria, bacteria. Many Eukaryote, eukaryotic organisms including plants, animals, and Fungus, fungi can also reproduce asexually. In Vertebrate, vertebrates, the most common form of asexual reproduction is parthenogenesis, which is typically used as an alternative to sexual reproduction in times when reproductive opportunities are limited. Some Monitor lizard, monitor lizards, including Komodo dragons, can reproduce asexually. While all prokaryotes reproduce without the fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cloning
Cloning is the process of producing individual organisms with identical genomes, either by natural or artificial means. In nature, some organisms produce clones through asexual reproduction; this reproduction of an organism by itself without a mate is known as parthenogenesis. In the field of biotechnology, cloning is the process of creating cloned organisms of Cell (biology), cells and of DNA fragments. The artificial cloning of organisms, sometimes known as reproductive cloning, is often accomplished via somatic-cell nuclear transfer (SCNT), a cloning method in which a viable embryo is created from a somatic cell and an egg cell. In 1996, Dolly (sheep), Dolly the sheep achieved notoriety for being the first mammal cloned from a somatic cell. Another example of artificial cloning is molecular cloning, a technique in molecular biology in which a single living cell is used to clone a large population of cells that contain identical DNA molecules. In bioethics, there are a vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhizome
In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and Shoot (botany), shoots from its Node (botany), nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow horizontally. The rhizome also retains the ability to allow new shoots to grow upwards. A rhizome is the main stem of the plant that runs typically underground and horizontally to the soil surface. Rhizomes have nodes and internodes and auxiliary buds. Roots do not have nodes and internodes and have a root cap terminating their ends. In general, rhizomes have short internodes, send out roots from the bottom of the nodes, and generate new upward-growing shoots from the top of the nodes. A stolon is similar to a rhizome, but stolon sprouts from an existing stem having long internodes and generating new shoots at the ends, they are often also called runners such as in the strawberry plant. A stem tuber is a thickene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calamites Rhizoid
''Calamites'' is a genus of extinct arborescent (tree-like) horsetails to which the modern horsetails (genus ''Equisetum'') are closely related. Unlike their herbaceous modern cousins, these plants were medium-sized trees, growing to heights of . They were components of the understories of coal swamps of the Carboniferous Period (around ). Taxonomy A number of organ taxa have been identified as part of a united organism, which has inherited the name ''Calamites'' in popular culture. ''Calamites'' correctly refers only to casts of the stem of Carboniferous/Permian sphenophytes, and as such is a form genus of little taxonomic value. There are two forms of casts, which can give mistaken impressions of the organisms. The most common is an internal cast of the hollow (or pith-filled) void in the centre of the trunk. This can cause some confusion: firstly, a fossil was probably surrounded with 4-5 times its width in (unpreserved) vascular tissue, so the organisms were much wider ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Museo Civico Di Storia Naturale Di Milano
The Museo Civico di Storia Naturale di Milano (Milan Natural History Museum) is a museum in Milan, Italy. It was founded in 1838 when the naturalist Giuseppe de Cristoforis donated his collections to the city. Its first director was the taxonomist Giorgio Jan. The Museum is located within a 19th-century building in the Giardini Pubblici Indro Montanelli, Indro Montanelli Garden, near the historic city gate of Porta Venezia. The structure was built between 1888 and 1893 in Neo-Romanesque style with Gothic Revival, Gothic elements. The museum is divided into five different permanent sections: Mineralogy (with a large collection of minerals from all over the world); Paleontology (with several fossils of dinosaurs and other prehistoric organisms); Natural History of Man (dedicated to the origins and evolution of humans with a particular attention to the relationship of the latter with the environment); Invertebrate Zoology (dedicated to mollusks, arthropods and entomology); and V ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil Vegetable Phytolithus Derbyshire
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Though the fossil record is incomplete, numerous studies have demonstrated that there is enough information available to give a good understanding of the pattern of diversification of life on Earth. In addition, the record can predict and fill gaps such as the discovery of ''Tiktaalik'' in the arctic of Canada. Paleontology includes the study of fossils: their age, method of formation, and evolutionary significance. Specimens are sometimes considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years to 4.1 billion years old. Early edition, published online before print. The ob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
