Nyssaceae is a family of flowering trees sometimes included in the dogwood family. Nyssaceae is composed of 37 known species in the following five genera: Camptotheca, the happy trees: two species in China Davidia, the dove tree, handkerchief tree, or ghost tree: one species in central China Diplopanax: two species in southern China and Vietnam Mastixia: about nineteen species in Southeast Asia Nyssa, the tupelos: about 7–10 species in eastern North America and East to Southeast AsiaAmong the extinct genera of the family are Mastixicarpum similar to Diplopanax, Tsukada, an extinct relative of Davidia. In some treatments, Davidia is split off into the Davidiaceae. Diplopanax and Mastixia are sometimes separated into the family Mastixiaceae; the Angiosperm Phylogeny Group APG III system included the genera of Nyssaceae within Cornaceae. The APG IV system recognizes Nyssaceae as a distinct family
The Coniacian is an age or stage in the geologic timescale. It is a subdivision of the Late Cretaceous epoch or Upper Cretaceous series and spans the time between 89.8 ± 1 Ma and 86.3 ± 0.7 Ma. The Coniacian is followed by the Santonian; the Coniacian is named after the city of Cognac in the French region of Saintonge. It was first defined by French geologist Henri Coquand in 1857; the base of the Coniacian stage is at the first appearance of the inoceramid bivalve species Cremnoceramus rotundatus. An official reference profile for the base had in 2009 not yet been appointed; the top of the Coniacian is defined by the appearance of the inoceramid bivalve Cladoceramus undulatoplicatus. The Coniacian overlaps the regional Emscherian stage of Germany, coeval with the Coniacian and Santonian stages. In magnetostratigraphy, the Coniacian is part of magnetic chronozone C34, the so-called Cretaceous Magnetic Quiet Zone, a long period with normal polarity. After a maximum of the global sea level during the early Turonian, the Coniacian was characterized by a gradual fall of the sea level.
This cycle is in sequence stratigraphy seen as a first order cycle. During the middle Coniacian a shorter, second order cycle, caused a temporary rise of the sea level on top of the longer first order trend; the following regression separates the Middle from the Upper Coniacian substage. An shorter third order cycle caused a new transgression during the Late Coniacian. Beginning in the Middle Coniacian, an anoxic event occurred in the Atlantic Ocean, causing large scale deposition of black shales in the Atlantic domain; the anoxic event lasted till the Middle Santonian and is the longest and last such event during the Cretaceous period. The Coniacian is subdivided into Lower and Upper substages, it encompasses three ammonite biozones in the Tethys domain: zone of Paratexanites serratomarginatus zone of Gauthiericeras margae zone of Peroniceras tridorsatumIn the boreal domain the Coniacian overlaps just one ammonite biozone: that of Forresteria petrocoriensis Gradstein, F. M.. G. & Smith, A. G.. Meyers, P.
A.. M. & Forster, A.. GeoWhen Database - Coniacian Late Cretaceous timescale, at the website of the subcommission for stratigraphic information of the ICS Stratigraphic chart of the Late Cretaceous, at the website of Norges Network of offshore records of geology and stratigraphy
Loasaceae is a family of 15–20 genera and about 200–260 species of flowering plants in the order Cornales, native to the Americas and Africa. Members of the family include annual and perennial herbaceous plants, a few shrubs and small trees. In the classification system of Dahlgren the Loasaceae were placed in the order Loasales in the superorder Loasiflorae; the Angiosperm Phylogeny Group system places them in the related order Cornales in the asterid clade. Genera include: Aosa Weigend Blumenbachia Schrad. Caiophora C. Presl Cevallia Lag. Chichicaste Weigend Eucnide Zucc. Fuertesia Urb. Gronovia L. Huidobria Gay Kissenia R. Br. ex Endl. Klaprothia Kunth Loasa Adans. Mentzelia L. Nasa Weigend Petalonyx A. Gray Plakothira Florence Presliophytum Weigend Schismocarpus S. F. Blake Scyphanthus Sweet Xylopodia Weigend Germplasm Resources Information Network: Loasaceae Chilean Loasaceae in Chileflora, seed provider Loasaceae in BoDD – Botanical Dermatology Database
The Devonian is a geologic period and system of the Paleozoic, spanning 60 million years from the end of the Silurian, 419.2 million years ago, to the beginning of the Carboniferous, 358.9 Mya. It is named after Devon, where rocks from this period were first studied; the first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, by the end of the period the first seed-bearing plants appeared. Various terrestrial arthropods became well-established. Fish reached substantial diversity during this time, leading the Devonian to be dubbed the "Age of Fishes." The first ray-finned and lobe-finned bony fish appeared, while the placoderms began dominating every known aquatic environment. The ancestors of all four-limbed vertebrates began adapting to walking on land, as their strong pectoral and pelvic fins evolved into legs.
In the oceans, primitive sharks became more numerous than in the Late Ordovician. The first ammonites, species of molluscs, appeared. Trilobites, the mollusc-like brachiopods and the great coral reefs, were still common; the Late Devonian extinction which started about 375 million years ago affected marine life, killing off all placodermi, all trilobites, save for a few species of the order Proetida. The palaeogeography was dominated by the supercontinent of Gondwana to the south, the continent of Siberia to the north, the early formation of the small continent of Euramerica in between; the period is named after Devon, a county in southwestern England, where a controversial argument in the 1830s over the age and structure of the rocks found distributed throughout the county was resolved by the definition of the Devonian period in the geological timescale. The Great Devonian Controversy was a long period of vigorous argument and counter-argument between the main protagonists of Roderick Murchison with Adam Sedgwick against Henry De la Beche supported by George Bellas Greenough.
Murchison and Sedgwick named the period they proposed as the Devonian System. While the rock beds that define the start and end of the Devonian period are well identified, the exact dates are uncertain. According to the International Commission on Stratigraphy, the Devonian extends from the end of the Silurian 419.2 Mya, to the beginning of the Carboniferous 358.9 Mya. In nineteenth-century texts the Devonian has been called the "Old Red Age", after the red and brown terrestrial deposits known in the United Kingdom as the Old Red Sandstone in which early fossil discoveries were found. Another common term is "Age of the Fishes", referring to the evolution of several major groups of fish that took place during the period. Older literature on the Anglo-Welsh basin divides it into the Downtonian, Dittonian and Farlovian stages, the latter three of which are placed in the Devonian; the Devonian has erroneously been characterised as a "greenhouse age", due to sampling bias: most of the early Devonian-age discoveries came from the strata of western Europe and eastern North America, which at the time straddled the Equator as part of the supercontinent of Euramerica where fossil signatures of widespread reefs indicate tropical climates that were warm and moderately humid but in fact the climate in the Devonian differed during its epochs and between geographic regions.
For example, during the Early Devonian, arid conditions were prevalent through much of the world including Siberia, North America, China, but Africa and South America had a warm temperate climate. In the Late Devonian, by contrast, arid conditions were less prevalent across the world and temperate climates were more common; the Devonian Period is formally broken into Early and Late subdivisions. The rocks corresponding to those epochs are referred to as belonging to the Lower and Upper parts of the Devonian System. Early DevonianThe Early Devonian lasted from 419.2 ± 2.8 to 393.3 ± 2.5 and began with the Lochkovian stage, which lasted until the Pragian. It spanned from 410.8 ± 2.8 to 407.6 ± 2.5, was followed by the Emsian, which lasted until the Middle Devonian began, 393.3± 2.7 million years ago. During this time, the first ammonoids appeared. Ammonoids during this time period differed little from their nautiloid counterparts; these ammonoids belong to the order Agoniatitida, which in epochs evolved to new ammonoid orders, for example Goniatitida and Clymeniida.
This class of cephalopod molluscs would dominate the marine fauna until the beginning of the Mesozoic era. Middle DevonianThe Middle Devonian comprised two subdivisions: first the Eifelian, which gave way to the Givetian 387.7± 2.7 million years ago. During this time the jawless agnathan fishes began to decline in diversity in freshwater and marine environments due to drastic environmental changes and due to the increasing competition and diversity of jawed fishes; the shallow, oxygen-depleted waters of Devonian inland lakes, surrounded by primitive plants, provided the environment necessary for certain early fish to develop such essential characteristics as well developed lungs, the ability to crawl out of the water and onto the land for short periods of time. Late DevonianFinally, the Late Devonian started with the Frasnian, 382.7 ± 2.8 to 372.2 ± 2.5, during which the first forests took shape on land. The first tetrapods appeared in the fossil record in the ensuing Famennian subdivisi
Johann Heinrich Friedrich Link
Johann Heinrich Friedrich Link was a German naturalist and botanist. Link was born at Hildesheim as a son of the minister August Heinrich Link, who taught him love of nature through collection of'natural objects', he studied medicine and natural sciences at the Hannoverschen Landesuniversität of Göttingen, graduated as MD in 1789, promoting on his thesis "Flora der Felsgesteine rund um Göttingen". One of his teachers was the famous natural scientist Johann Friedrich Blumenbach, he became a private tutor in Göttingen. In 1792 he became the first professor of the new department of chemistry and botany at the University of Rostock. During his stay at Rostock, he became an early follower of the antiphlogistic theory of Lavoisier, teaching about the existence of oxygen instead of phlogiston, he was a proponent of the attempts of Richter to involve mathematics in chemistry, introducing stoichiometry in his chemistry lessons. In 1806 he set up the first chemical laboratory at Rostock in the "Seminargebäude".
He began to write an abundant number of articles and books on the most different subjects, such as physics and chemistry and mineralogy, botany and zoology, natural philosophy and ethics and early history. He was twice elected rector of the university. In 1793 he married Charlotte Juliane Josephi, sister of his colleague at the university Prof. Wilhelm Josephi. During 1797–1799 he visited Portugal with Count Johann Centurius Hoffmannsegg, a botanist and ornithologist from Dresden; this trip made him choose botany as his main scientific calling. In 1800 he was elected to the prestigious Leopoldina Academy, the oldest school for natural history in Europe. In 1808 he was awarded a prize at the Academy of Saint Petersburg for his monography Von der Natur und den Eigenschaften des Lichts, his scientific reputation grew and became known. In 1811 he was appointed professor of chemistry and botany at Breslau university, where he was elected twice rector of the university. After the death of Carl Ludwig Willdenow in 1815, he became professor of natural history, curator of the herbarium and director of the botanic garden in Berlin until he died.
This period became the most fruitful period of his academic life. He augmented the collection of the garden to many of them rare plants, he worked in close collaboration with conservator at the botanical garden. In 1827 he named with him the cacti genera Melocactus. Most of the fungi that he named, are still recognised under the original name, proving the high quality of his work, he was elected member of the Berlin Academy of Science and many other scientific societies, including the Royal Swedish Academy of Sciences, which elected him a foreign member in 1840. He trained a whole new generation such as Christian Gottfried Ehrenberg. Throughout his life, he travelled extensively throughout Europe, he benefited including Arabic and ancient Sanskrit. He died in Berlin on 1 January 1851 84 years old, he was succeeded by Alexander Heinrich Braun, He is recognised as one of the last scientists of the 19th century with a universal knowledge. Link was one of the few German botanists of his time, who aimed at a complete understanding of plants, through a systematic anatomical and physiological research.
His most important work is the Handbuch zur Erkennung der nutzbarsten und am häufigsten vorkommenden Gewächse. Grundlehren der Anatomie und Physiologie der Pflanzen. Nachträge zu den Grundlehren etc. Die Urwelt und das Altertum, erläutert durch die Naturkunde. Handbuch zur Erkennung der nutzbarsten und am häufigsten vorkommenden Gewächse. Berlin: Haude und Spener. Retrieved 5 February 2015. Digital edition by State Library Düsseldorf Erster Theil. Zweiter Theil. Dritter Theil. Das Altertum und der Übergang zur neuern Zeit, he published together with Friedrich Otto: Icones plantarum selectarum horti regii botanici Berolinensis He published with Christoph Friedrich Otto Icones plantarum rariorum horti regii botanici Berolinensis He published together with count von Hoffmansegg Flore
In phylogenetics, basal is the direction of the base of a rooted phylogenetic tree or cladogram. The term may be more applied only to nodes adjacent to the root, or more loosely applied to nodes regarded as being close to the root; each node in the tree corresponds to a clade. The terms deep-branching or early-branching are similar in meaning. While there must always be two or more basal clades sprouting from the root of every cladogram, those clades may differ in taxonomic rank and/or species diversity. If C is a basal clade within D that has the lowest rank of all basal clades within D, C may be described as the basal taxon of that rank within D. Greater diversification may be associated with more evolutionary innovation, but ancestral characters should not be imputed to the members of a less species-rich basal clade without additional evidence, as there can be no assurance such an assumption is valid. In general, clade A is more basal than clade B if B is a subgroup of the sister group of A.
Within large groups, "basal" may be used loosely to mean'closer to the root than the great majority of', in this context terminology such as "very basal" may arise. A'core clade' is a clade representing all but the basal clade of lowest rank within a larger clade. A basal group in the stricter sense forms a sister group to the rest of the larger clade, as in the following case: While it is easy to identify a basal clade in such a cladogram, the appropriateness of such an identification is dependent on the accuracy and completeness of the diagram, it is assumed in this example that the terminal branches of the cladogram depict all the extant taxa of a given rank within the clade. Additionally, this qualification does not ensure. In phylogenetics, the term basal can be objectively applied to clades of organisms, but tends to be applied selectively and more controversially to groups or lineages thought to possess ancestral characters, or to such presumed ancestral traits themselves. In describing characters, "ancestral" or "plesiomorphic" are preferred to "basal" or "primitive", the latter of which may carry false connotations of inferiority or a lack of complexity.
Despite the ubiquity of the usage of basal, some systematists believe its application to extant groups is unnecessary and misleading. The term is more applied when one branch is less diverse than another branch; the term may be equivocal in that it refers to the direction of the root of the tree, which represents a hypothetical ancestor. An extant basal group may or may not resemble the last common ancestor of a larger clade to a greater degree than other groups, is separated from that ancestor by the same amount of time as all other extant groups. However, there are cases where the unsually small size of a sister group does indeed correlate with an unusual number of ancestral traits, as in Amborella. Other famous examples of this phenomenon are the oviparous reproduction and nipple-less lactation of monotremes, a basal clade of mammals with just five species, the archaic anatomy of the tuatara, a basal clade of lepidosaurian with a single species; the flowering plant family Amborellaceae, restricted to New Caledonia in the southwestern Pacific, is a basal clade of extant angiosperms, consisting of the most basal species, genus and order within the group.
The traits of Amborella trichopoda are regarded as providing significant insight into the evolution of flowering plants. However, those traits are a mix of archaic and apomorphic features that have only been sorted out via comparison with other angiosperms and their positions within the phylogenetic tree. Within the primate family Hominidae, gorillas are a sister group to common chimpanzees and humans; these five species form the subfamily Homininae, of which Gorilla is the basal genus. However, if the analysis is not restricted to genera, the Homo plus Pan clade is basal. Moreover, orangutans are a sister group to Homininae and are the basal genus in the family as a whole. Subfamilies Homininae and Ponginae are both basal within Hominidae, but given that there are no nonbasal subfamilies in the cladogram it is unlikely the term would be applied to either. In general, a statement to the effect that one group is basal, or branches off first, within another group may not make sense unless the appropriate taxonomic level is specified.
If that level cannot be specified a more detailed description of the relevant sister groups may be needed. In this example, orangutans differ from the other genera in their Asian range; this fact plus their basal status provides a hint that the most recent common ancestor of extant great apes may have been Eurasian, a suggestion, consistent with other evidence. Orangutans differ from African apes in their more arboreal lifestyle, a
The Ordovician is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.2 million years from the end of the Cambrian Period 485.4 million years ago to the start of the Silurian Period 443.8 Mya. The Ordovician, named after the Celtic tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in northern Wales into the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian systems, placed them in a system of their own; the Ordovician received international approval in 1960, when it was adopted as an official period of the Paleozoic Era by the International Geological Congress. Life continued to flourish during the Ordovician as it did in the earlier Cambrian period, although the end of the period was marked by the Ordovician–Silurian extinction events.
Invertebrates, namely molluscs and arthropods, dominated the oceans. The Great Ordovician Biodiversification Event increased the diversity of life. Fish, the world's first true vertebrates, continued to evolve, those with jaws may have first appeared late in the period. Life had yet to diversify on land. About 100 times as many meteorites struck the Earth per year during the Ordovician compared with today; the Ordovician Period began with a major extinction called the Cambrian–Ordovician extinction event, about 485.4 Mya. It lasted for about 42 million years and ended with the Ordovician–Silurian extinction events, about 443.8 Mya which wiped out 60% of marine genera. The dates given are recent radiometric dates and vary from those found in other sources; this second period of the Paleozoic era created abundant fossils that became major petroleum and gas reservoirs. The boundary chosen for the beginning of both the Ordovician Period and the Tremadocian stage is significant, it correlates well with the occurrence of widespread graptolite and trilobite species.
The base of the Tremadocian allows scientists to relate these species not only to each other, but to species that occur with them in other areas. This makes it easier to place many more species in time relative to the beginning of the Ordovician Period. A number of regional terms have been used to subdivide the Ordovician Period. In 2008, the ICS erected a formal international system of subdivisions. There exist Baltoscandic, Siberian, North American, Chinese Mediterranean and North-Gondwanan regional stratigraphic schemes; the Ordovician Period in Britain was traditionally broken into Early and Late epochs. The corresponding rocks of the Ordovician System are referred to as coming from the Lower, Middle, or Upper part of the column; the faunal stages from youngest to oldest are: Late Ordovician Hirnantian/Gamach Rawtheyan/Richmond Cautleyan/Richmond Pusgillian/Maysville/Richmond Middle Ordovician Trenton Onnian/Maysville/Eden Actonian/Eden Marshbrookian/Sherman Longvillian/Sherman Soudleyan/Kirkfield Harnagian/Rockland Costonian/Black River Chazy Llandeilo Whiterock Llanvirn Early Ordovician Cassinian Arenig/Jefferson/Castleman Tremadoc/Deming/Gaconadian The Tremadoc corresponds to the Tremadocian.
The Floian corresponds to the lower Arenig. The Llanvirn occupies the rest of the Darriwilian, terminates with it at the base of the Late Ordovician; the Sandbian represents the first half of the Caradoc. During the Ordovician, the southern continents were collected into Gondwana. Gondwana started the period in equatorial latitudes and, as the period progressed, drifted toward the South Pole. Early in the Ordovician, the continents of Laurentia and Baltica were still independent continents, but Baltica began to move towards Laurentia in the period, causing the Iapetus Ocean between them to shrink; the small continent Avalonia separated from Gondwana and began to move north towards Baltica and Laurentia, opening the Rheic Ocean between Gondwana and Avalonia. The Taconic orogeny, a major mountain-building episode, was well under way in Cambrian times. In the early and middle Ordovician, temperatures were mild, but at the beginning of the Late Ordovician, from 460 to 450 Ma, volcanoes along the margin of the Iapetus Ocean spewed massive amounts of carbon dioxide, a greenhouse gas, into the atmosphere, turning the planet into a hothouse.
Sea levels were high, but as Gondwana moved south, ice accumulated into glaciers and sea levels dropped. At first, low-lying sea beds increased diversity, but glaciation led to mass extinctions as the seas drained and continental shelves became dry land. During the Ordovician, in fact during the Tremadocian, marine transgressions worldwide were the greatest for which evidence is preserved; these volcanic island arcs collided with proto North America to form the Appalachian mountains. By the end of the Late Ordovician the volcanic emissions had stopped. Gondwana had by that time neared the South Pole and was glaciated