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Derived palaeotheres are generally diagnosed as having selenolophodont (selenodont-lophodont ridge form) upper molars (M/m) and selenodont (crescent-shaped ridge form) lower molars that are mesodont, or medium-crowned, in height. The canines (C/c) strongly protrude and are separated from the premolars (P/p) by medium t... | Palaeotherium | Wikipedia | 413 | 4004214 | https://en.wikipedia.org/wiki/Palaeotherium | Biology and health sciences | Perissodactyla | Animals |
The premolars and preceding deciduous teeth both tend to have molarized forms (meaning molar-like shapes) and have newly developing hypocone cusps on them. The forms of the deciduous premolars (dP) of juvenile Palaeotherium and other palaeotheriines distinguish them from the earlier pachynolophines, where the dP2-dP4 o... | Palaeotherium | Wikipedia | 341 | 4004214 | https://en.wikipedia.org/wiki/Palaeotherium | Biology and health sciences | Perissodactyla | Animals |
The overall postcranial anatomy of Palaeotherium is best known from a skeleton of P. magnum uncovered from Mormoiron. The vertebral column is made up of seven large cervical vertebrae, seventeen thoracic vertebrae, six lumbar vertebrae, six sacral vertebrae, and fifteen caudal vertebrae. The cervical vertebrae, compris... | Palaeotherium | Wikipedia | 475 | 4004214 | https://en.wikipedia.org/wiki/Palaeotherium | Biology and health sciences | Perissodactyla | Animals |
Palaeotherium shows an exceptional amount of variation in the shape of its third metacarpal and its manus dimensions. P. curtum has very robust forelimb bones including a short and stocky manus, which suggests that it was stocky in build. P. magnum and P. crassum resemble tapirs, especially the mountain tapir (Tapirus ... | Palaeotherium | Wikipedia | 494 | 4004214 | https://en.wikipedia.org/wiki/Palaeotherium | Biology and health sciences | Perissodactyla | Animals |
Two ichnospecies of Palaeotheriipus have been named. The type ichnospecies is Palaeotheriipus similimedius and based on the French material. These footprints are wider () than long (), with fingers that diverge widely from each other at angles of at least 50°. The hoof of finger III appears to be wider than those of th... | Palaeotherium | Wikipedia | 444 | 4004214 | https://en.wikipedia.org/wiki/Palaeotherium | Biology and health sciences | Perissodactyla | Animals |
In 2015, Remy calculated the body mass of several Eocene European perissodactyl species based on a formula originally proposed by Christine M. Janis in 1990. He estimated that the small species P. lautricense could have weighed just . P. siderolithicum could have had an average weight of around . P. aff. ruetimeyeri co... | Palaeotherium | Wikipedia | 170 | 4004214 | https://en.wikipedia.org/wiki/Palaeotherium | Biology and health sciences | Perissodactyla | Animals |
Palaeotherium species vary substantially in size, morphology, and build. The skeletons of P. magnum, P. curtum, and P. crassum were relatively robust, while that of P. medium was more gracile, suggesting increased cursoriality. The evolutionary history of palaeotheres might have emphasized the sense of smell rather tha... | Palaeotherium | Wikipedia | 367 | 4004214 | https://en.wikipedia.org/wiki/Palaeotherium | Biology and health sciences | Perissodactyla | Animals |
According to Sandra Engels in a conference paper, both Palaeotherium and Plagiolophus have dentitions capable of processing harder items such as hard fruits, while their predecessors, such as Hyracotherium and Propalaeotherium, were adapted to softer food. Unlike in equids and basal equoids, the molars of later palaeot... | Palaeotherium | Wikipedia | 374 | 4004214 | https://en.wikipedia.org/wiki/Palaeotherium | Biology and health sciences | Perissodactyla | Animals |
For much of the Eocene, a hothouse climate with humid, tropical environments with consistently high precipitations prevailed. Modern mammalian orders including the Perissodactyla, Artiodactyla, and Primates (or the suborder Euprimates) appeared already by the early Eocene, diversifying rapidly and developing dentitions... | Palaeotherium | Wikipedia | 334 | 4004214 | https://en.wikipedia.org/wiki/Palaeotherium | Biology and health sciences | Perissodactyla | Animals |
Palaeotherium made its first appearance with the species P. eocaenum in the MP13 unit. By then, it would have coexisted with perissodactyls (Palaeotheriidae, Lophiodontidae, and Hyrachyidae), non-endemic artiodactyls (Dichobunidae and Tapirulidae), endemic European artiodactyls (Choeropotamidae (possibly polyphyletic, ... | Palaeotherium | Wikipedia | 320 | 4004214 | https://en.wikipedia.org/wiki/Palaeotherium | Biology and health sciences | Perissodactyla | Animals |
The Egerkingen α + β locality, dating to MP14, records fossils of P. eocaenum, P. ruetimeyeri, and P. castrense castrense. Other mammal genera recorded within the locality include the herpetotheriid Amphiperatherium, ischyromyids Ailuravus and Plesiarctomys, pseudosciurid Treposciurus, omomyid Necrolemur, adapid Leptad... | Palaeotherium | Wikipedia | 254 | 4004214 | https://en.wikipedia.org/wiki/Palaeotherium | Biology and health sciences | Perissodactyla | Animals |
MP16 marks the first appearances of several species of Palaeotherium in the Central European region, namely P. castrense robiacense, P. pomeli, P. siderolithicum, and P. lautricense, some of which are exclusive to the unit (P. pomeli and P. lautricense) and one of which makes its latest appearance (P. castrense). The l... | Palaeotherium | Wikipedia | 446 | 4004214 | https://en.wikipedia.org/wiki/Palaeotherium | Biology and health sciences | Perissodactyla | Animals |
MP16 also records two species that are restricted to the unit, P. llamaquiquense and P. giganteum, both of which were endemic to the Iberian region. MP17 marks the restricted appearance of another Iberian endemic species P. crusafonti. The endemic species of Palaeotherium were amongst the many taxa of palaeotheres only... | Palaeotherium | Wikipedia | 427 | 4004214 | https://en.wikipedia.org/wiki/Palaeotherium | Biology and health sciences | Perissodactyla | Animals |
The late Eocene MP17 unit marks the first appearances of several species of Palaeotherium, namely P. magnum, P. medium, P. curtum, P. crassum, P. duvali, and P. muehlbergi. The temporal range of P. siderolithicum, first known in MP16, continued up to MP19, and P. renevieri made its first and only appearance in MP19. So... | Palaeotherium | Wikipedia | 445 | 4004214 | https://en.wikipedia.org/wiki/Palaeotherium | Biology and health sciences | Perissodactyla | Animals |
The MP18 locality of La Débruge in France holds fossil records of multiple species of Palaeotherium, namely P. curtum villerealense, P. duvali duvali, P. muehlbergi thaleri, P. medium perrealense, P. crassum robustum, and P. magnum girondicum. The locality indicates that the multiple subspecies of Palaeotherium coexist... | Palaeotherium | Wikipedia | 489 | 4004214 | https://en.wikipedia.org/wiki/Palaeotherium | Biology and health sciences | Perissodactyla | Animals |
Many palaeontologists agree that glaciation and the resulting drops in sea level allowed for increased migrations between Balkanatolia and western Europe. The Turgai Strait, which once separated much of Europe from Asia, is often proposed as the main European seaway barrier prior to the Grande Coupure, but some researc... | Palaeotherium | Wikipedia | 412 | 4004214 | https://en.wikipedia.org/wiki/Palaeotherium | Biology and health sciences | Perissodactyla | Animals |
Researchers have proposed theories as to why both P. medium and Plagiolophus minor survived the Grande Coupure event up to the early Oligocene whereas other species went extinct. Santi proposed that the dentition and cranial musculature of Palaeotherium were generally unsuited for the closed habitat turnovers caused by... | Palaeotherium | Wikipedia | 269 | 4004214 | https://en.wikipedia.org/wiki/Palaeotherium | Biology and health sciences | Perissodactyla | Animals |
Plant litter (also leaf litter, tree litter, soil litter, litterfall or duff) is dead plant material (such as leaves, bark, needles, twigs, and cladodes) that have fallen to the ground. This detritus or dead organic material and its constituent nutrients are added to the top layer of soil, commonly known as the litter ... | Plant litter | Wikipedia | 444 | 26137572 | https://en.wikipedia.org/wiki/Plant%20litter | Physical sciences | Soil science | Earth science |
Latitude also has a strong effect on litterfall rates and thickness. Specifically, litterfall declines with increasing latitude. In tropical rainforests, there is a thin litter layer due to the rapid decomposition, while in boreal forests, the rate of decomposition is slower and leads to the accumulation of a thick lit... | Plant litter | Wikipedia | 508 | 26137572 | https://en.wikipedia.org/wiki/Plant%20litter | Physical sciences | Soil science | Earth science |
Many organisms that live on the forest floor are decomposers, such as fungi. Organisms whose diet consists of plant detritus, such as earthworms, are termed detritivores. The community of decomposers in the litter layer also includes bacteria, amoeba, nematodes, rotifer, tardigrades, springtails, cryptostigmata, potwor... | Plant litter | Wikipedia | 512 | 26137572 | https://en.wikipedia.org/wiki/Plant%20litter | Physical sciences | Soil science | Earth science |
Nutrient cycle
During leaf senescence, a portion of the plant's nutrients are reabsorbed from the leaves. The nutrient concentrations in litterfall differ from the nutrient concentrations in the mature foliage by the reabsorption of constituents during leaf senescence. Plants that grow in areas with low nutrient avail... | Plant litter | Wikipedia | 485 | 26137572 | https://en.wikipedia.org/wiki/Plant%20litter | Physical sciences | Soil science | Earth science |
Once nutrients have re-entered the soil, the plants can then reabsorb them through their roots. Therefore, nutrient reabsorption during senescence presents an opportunity for a plant's future net primary production use. A relationship between nutrient stores can also be defined as:
annual storage of nutrients in plant... | Plant litter | Wikipedia | 429 | 26137572 | https://en.wikipedia.org/wiki/Plant%20litter | Physical sciences | Soil science | Earth science |
Litterbags are generally set in random locations within a given area and marked with GPS or local coordinates, and then monitored on a specific time interval. Once the samples have been collected, they are usually classified on type, size and species (if possible) and recorded on a spreadsheet. When measuring bulk litt... | Plant litter | Wikipedia | 328 | 26137572 | https://en.wikipedia.org/wiki/Plant%20litter | Physical sciences | Soil science | Earth science |
Forest litter raking
Leaf litter accumulation depends on factors like wind, decomposition rate and species composition of the forest. The quantity, depth and humidity of leaf litter varies in different habitats. The leaf litter found in primary forests is more abundant, deeper and holds more humidity than in secondary... | Plant litter | Wikipedia | 206 | 26137572 | https://en.wikipedia.org/wiki/Plant%20litter | Physical sciences | Soil science | Earth science |
Ammonium ferric citrate (also known as ferric ammonium citrate or ammoniacal ferrous citrate) has the formula . The iron in this compound is trivalent. All three carboxyl groups and the central hydroxyl group of citric acid are deprotonated. A distinguishing feature of this compound is that it is very soluble in water,... | Ammonium ferric citrate | Wikipedia | 296 | 5381102 | https://en.wikipedia.org/wiki/Ammonium%20ferric%20citrate | Physical sciences | Citrates | Chemistry |
Eupleridae is a family of carnivorans endemic to Madagascar and comprising 10 known living species in seven genera, commonly known as euplerids, Malagasy mongooses or Malagasy carnivorans. The best known species is the fossa (Cryptoprocta ferox), in the subfamily Euplerinae. All species of Euplerinae were formerly clas... | Eupleridae | Wikipedia | 341 | 5381912 | https://en.wikipedia.org/wiki/Eupleridae | Biology and health sciences | Other carnivora | Animals |
The evolutionary divergence between the herpestids and the euplerids dates back to the Oligocene. At that time, feliforms shared many similarities, particularly between the cats and the viverrids. Palaeoprionodon (within the clade Aeluroidea), found in Europe and Asia from the late Eocene or early Oligocene, looked sim... | Eupleridae | Wikipedia | 364 | 5381912 | https://en.wikipedia.org/wiki/Eupleridae | Biology and health sciences | Other carnivora | Animals |
The European seabass (Dicentrarchus labrax), also known as the branzino, European bass, sea bass, common bass, white bass, capemouth, white salmon, sea perch, white mullet, sea dace or loup de mer, is a primarily ocean-going fish native to the waters off Europe's western and southern and Africa's northern coasts, thoug... | European seabass | Wikipedia | 362 | 5382118 | https://en.wikipedia.org/wiki/European%20seabass | Biology and health sciences | Acanthomorpha | null |
Taxonomy and phylogeny
The European seabass was first described in 1758 by Swedish zoologist Carl Linnaeus in his work Systema Naturae. He named it Perca labrax. In the century and a half following, it was classified under a variety of new synonyms, with Dicentrarchus labrax winning out as the accepted name in 1987. I... | European seabass | Wikipedia | 478 | 5382118 | https://en.wikipedia.org/wiki/European%20seabass | Biology and health sciences | Acanthomorpha | null |
The European seabass hunts as much during the day as it does at night, feeding on small fish (both pelagic, such as sardines, sprats, and sand smelts, and demersal, such as sand eels), polychaetes, cephalopods (such as squid), and crustaceans. The big fish weighing more than are mostly night hunters. They spawn from F... | European seabass | Wikipedia | 450 | 5382118 | https://en.wikipedia.org/wiki/European%20seabass | Biology and health sciences | Acanthomorpha | null |
Branzino, sometimes known as "spigola" in southern Italy, is popular in Italian cuisine as a main course. It is often prepared by roasting the entire fish and serving it with lemon. The meat is often desired because of its sweet taste and flaky white texture. In French it is sometimes known as "barr" or "loup de mar", ... | European seabass | Wikipedia | 102 | 5382118 | https://en.wikipedia.org/wiki/European%20seabass | Biology and health sciences | Acanthomorpha | null |
Thalassodromeus is a genus of pterosaur that lived in what is now Brazil during the Early Cretaceous period, about a hundred million years ago. The original skull, discovered in 1983 in the Araripe Basin of northeastern Brazil, was collected in several pieces. In 2002, the skull was made the holotype specimen of Thalas... | Thalassodromeus | Wikipedia | 478 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
Several theories have been suggested to explain the function of Thalassodromeuss crest, including thermoregulation and display, but it likely had more than one function. The crests of thalassodromids appear to have developed late in growth (probably correlated with sexual maturity) and they may have been sexually dimor... | Thalassodromeus | Wikipedia | 453 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
In 2002, Kellner and Campos described and named the new genus and species Thalassodromeus sethi, skull DGM 1476-R being the holotype specimen. The generic name is derived from the Ancient Greek words and , meaning "sea runner" in reference to the animal's supposed skim-feeding behaviour. The specific name refers to th... | Thalassodromeus | Wikipedia | 424 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
Assigned and formerly assigned species
Veldmeijer and colleagues assigned the front part of a mandible collected from the same formation to T. sethi in 2005. They concluded that although the two specimens differed in several details, the differences were not significant enough to base a new species on the mandible, an... | Thalassodromeus | Wikipedia | 406 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
In 2015 palaeontologists Gerald Grellet Tinner and Vlad A. Codrea named a new species, T. sebesensis, based on what they interpreted as part of a cranial crest in a concretion found near the Sebeș River in Romania. The authors said that this would extend the range in time and space for the genus Thalassodromeus conside... | Thalassodromeus | Wikipedia | 454 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
The skull of T. sethi had a streamlined profile, especially from the tip of the snout to the front edge of the nasoantorbital fenestra (opening which combined the antorbital fenestra in front of the eye with the bony nostril). The most conspicuous feature of the skull was the large crest, which ran along the upper edge... | Thalassodromeus | Wikipedia | 295 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
Despite its size, the crest was lightly built and essentially hollow; some areas indicate signs of skeletal pneumatisation and a well-developed trabecular system uniting the bones. The crest's surface had a system of channels of varying size and thickness, probably the impressions of extensive blood vessels. A small, ... | Thalassodromeus | Wikipedia | 231 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
The upper jaw of T. sethi was primarily composed of premaxillae and maxillae; the suture which formed the border between these bones is not visible. As in all members of its clade, the jaws were edentulous (toothless). The rostrum (snout) was long from the tip of the premaxilla to the joint where the quadrate bone of ... | Thalassodromeus | Wikipedia | 323 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
The palatal area at the tip of T. sethis snout was a sharp ridge, similar to the keel seen on the upper surface of the mandibular symphysis where the two halves of the lower jaw connected. Small slit-like foramina (openings) on the lower side edges of the ridge indicate that it had a horny covering in life, similar to ... | Thalassodromeus | Wikipedia | 284 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
Although the lower jaw of T. sethi is incomplete, its total length is estimated at 47 percent of which was occupied by the mandibular symphysis. The tip of the mandible is missing, but its front surface indicates that it might have been turned slightly upwards as in T. oberlii (the possible second species of Thalassodr... | Thalassodromeus | Wikipedia | 412 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
The classification of Thalassodromeus and its closest relatives is one of the most contentious issues regarding their group. Kellner and Campos originally assigned Thalassodromeus to the family Tapejaridae, based on its large crest and large nasoantorbital fenestra. Within this clade, they found that it differed from t... | Thalassodromeus | Wikipedia | 407 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
The interrelationship of these clades within the larger clade Azhdarchoidea remained disputed, and the clade containing Thalassodromeus and Tupuxuara had received different names from different researchers (Thalassodrominae and Tupuxuaridae). Palaeontologist Mark Witton attempted to resolve the naming issue in 2009, no... | Thalassodromeus | Wikipedia | 379 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
In 2023, having considered that the clade containing Thalassodromeus and Tupuxuara has received two different denominations throughout the years (Thalassodromidae and Thalassodrominae), palaeontologist Rodrigo Pêgas and colleagues argued that despite the disagreements between the position of said clade within Azhdarcho... | Thalassodromeus | Wikipedia | 469 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
In 2006, Martill and Naish found that the crests of Tupuxuara and its relatives developed by the premaxillary portion of the crests growing backwards over the skull-roof (as indicated by the well-defined suture between the premaxilla and the underlying bones). The hind margin of the premaxillary part of this specimen's... | Thalassodromeus | Wikipedia | 230 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
Palaeontologists David W. E. Hone, Naish, and Innes C. Cuthill reiterated Martill and Naish's growth hypothesis in 2012; since pterosaurs were probably precocial and able to fly shortly after hatching, the role of the crest was relevant only after maturity (when the structure was fully grown). They deemed the thermoreg... | Thalassodromeus | Wikipedia | 399 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
Pêgas and colleagues noted that sexual dimorphism in crest size and shape has been proposed for some pterosaurs; the crest shape seen in the T. sethi holotype may correlate with one sex and may have been the result of sexual selection. They suggested that both sexes could have had similar crests due to mutual sexual se... | Thalassodromeus | Wikipedia | 201 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
Kellner and Campos originally found the jaws of Thalassodromeus similar to those of modern skimmersthree bird species in the genus Rhynchopswith their sideways-compressed jaws, blade-like beak, and protruding lower jaw (resembling scissors in side view). They argued that Thalassodromeus would have fed in a similar way,... | Thalassodromeus | Wikipedia | 362 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
In 2004, palaeontologist Sankar Chatterjee and engineer R. Jack Templin said that smaller pterosaurs may have been able to skim-feed. They doubted that this was possible for larger ones, due to their lesser manoeuvrability and flying capability while resisting water. Chatterjee and Templin noted that skimmers have blun... | Thalassodromeus | Wikipedia | 353 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
Unwin and Martill suggested in 2007 that thalassodromids may have foraged similarly to storks, as had been suggested for azhdarchids. Witton said in 2013 that although skim-feeding had been suggested for many pterosaur groups, the idea was criticised in recent years; pterosaurs lacked virtually all adaptations for skim... | Thalassodromeus | Wikipedia | 317 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
Pêgas and Kellner presented a reconstruction of the mandibular muscles of T. sethi at a conference in 2015. They found that its well-developed jaw muscles differed from those of the possible dip-feeder Anhanguera and the terrestrially stalking azhdarchids, indicating that T. sethi had a strong bite force. In 2018, Pêga... | Thalassodromeus | Wikipedia | 221 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
In a 2002 comment on the original description of T. sethi, engineer John Michael Williams noted that although Kellner and Campos had mentioned that the large crest might have interfered aerodynamically during flight, they had not elaborated on this point and had compared the pterosaur with a bird one-fifth its size. He... | Thalassodromeus | Wikipedia | 306 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
Witton also expressed hope for further analysis of thalassodromid locomotion. He noted that since their limb proportions were similar to those of the better-studied azhdarchids, the shape of their wings and style of flight might have been similar. Thalassodromids might also have been adapted for inland flight; their wi... | Thalassodromeus | Wikipedia | 498 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
Other pterosaurs from the Romualdo Formation include Anhanguera, Araripedactylus, Araripesaurus, Brasileodactylus, Cearadactylus, Coloborhynchus, Santanadactylus, Tapejara, Tupuxuara, Barbosania, Maaradactylus, Tropeognathus, and Unwindia. Thalassodromines are known only from this formation, and though well-preserved p... | Thalassodromeus | Wikipedia | 412 | 5382243 | https://en.wikipedia.org/wiki/Thalassodromeus | Biology and health sciences | Pterosaurs | Animals |
Stegodontidae is an extinct family of proboscideans from Africa and Asia (with a single occurrence in Europe) from the Early Miocene (at least 17.3 million years ago) to the Late Pleistocene. It contains two genera, the earlier Stegolophodon, known from the Miocene of Asia and the later Stegodon, from the Late Miocene ... | Stegodontidae | Wikipedia | 275 | 24740532 | https://en.wikipedia.org/wiki/Stegodontidae | Biology and health sciences | Proboscidea | Animals |
The annelids (), also known as the segmented worms, comprise a large phylum called Annelida (; ). The phylum contains over 22,000 extant species, including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecologies – some in marine environments as distinct as tidal zones and hydrother... | Annelid | Wikipedia | 289 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
The basic annelid form consists of multiple segments. Each segment has the same sets of organs and, in most polychaetes, has a pair of parapodia that many species use for locomotion. Septa separate the segments of many species, but are poorly defined or absent in others, and Echiura and Sipuncula show no obvious signs ... | Annelid | Wikipedia | 397 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
Since annelids are soft-bodied, their fossils are rare – mostly jaws and the mineralized tubes that some of the species secreted. Although some late Ediacaran fossils may represent annelids, the oldest known fossil that is identified with confidence comes from about in the early Cambrian period. Fossils of most modern... | Annelid | Wikipedia | 316 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
Clitellates (about 10,000 species ). These have few or no chetae per segment, and no nuchal organs or parapodia. However, they have a unique reproductive organ, the ring-shaped clitellum ("pack saddle") around their bodies, which produces a cocoon that stores and nourishes fertilized eggs until they hatch or, in moni... | Annelid | Wikipedia | 224 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
The Archiannelida, minute annelids that live in the spaces between grains of marine sediment, were treated as a separate class because of their simple body structure, but are now regarded as polychaetes. Some other groups of animals have been classified in various ways, but are now widely regarded as annelids:
Pogonoph... | Annelid | Wikipedia | 493 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
Mitogenomic and phylogenomic analysis also implies that Orthonectida, a group of extremely simplified parasites traditionally placed in Mesozoa, are actually reduced annelids. Research suggest that also nemerteans are annelids, with Oweniidae and Magelonidae as their closest relatives.
Distinguishing features
No singl... | Annelid | Wikipedia | 282 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
In addition to Sipuncula and Echiura, also lineages like Lobatocerebrum, Diurodrilus and Polygordius have lost their segmentation, but these are the exceptions from the rule. Most of an annelid's body consists of segments that are practically identical, having the same sets of internal organs and external chaetae (Gree... | Annelid | Wikipedia | 404 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
Annelids' cuticles are made of collagen fibers, usually in layers that spiral in alternating directions so that the fibers cross each other. These are secreted by the one-cell deep epidermis (outermost skin layer). A few marine annelids that live in tubes lack cuticles, but their tubes have a similar structure, and muc... | Annelid | Wikipedia | 495 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
Nearly all polychaetes have parapodia that function as limbs, while other major annelid groups lack them. Parapodia are unjointed paired extensions of the body wall, and their muscles are derived from the circular muscles of the body. They are often supported internally by one or more large, thick chetae. The parapodia... | Annelid | Wikipedia | 399 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
As in arthropods, each muscle fiber (cell) is controlled by more than one neuron, and the speed and power of the fiber's contractions depends on the combined effects of all its neurons. Vertebrates have a different system, in which one neuron controls a group of muscle fibers. Most annelids' longitudinal nerve trunks i... | Annelid | Wikipedia | 374 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
Coelom, locomotion and circulatory system
Most annelids have a pair of coelomata (body cavities) in each segment, separated from other segments by septa and from each other by vertical mesenteries. Each septum forms a sandwich with connective tissue in the middle and mesothelium (membrane that serves as a lining) from ... | Annelid | Wikipedia | 447 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
The fluid in the coelomata contains coelomocyte cells that defend the animals against parasites and infections. In some species coelomocytes may also contain a respiratory pigment – red hemoglobin in some species, green chlorocruorin in others (dissolved in the plasma) – and provide oxygen transport within their segmen... | Annelid | Wikipedia | 497 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
Feeding structures in the mouth region vary widely, and have little correlation with the animals' diets. Many polychaetes have a muscular pharynx that can be everted (turned inside out to extend it). In these animals the foremost few segments often lack septa so that, when the muscles in these segments contract, the sh... | Annelid | Wikipedia | 413 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
Annelids with blood vessels use metanephridia to remove soluble waste products, while those without use protonephridia. Both of these systems use a two-stage filtration process, in which fluid and waste products are first extracted and these are filtered again to re-absorb any re-usable materials while dumping toxic an... | Annelid | Wikipedia | 496 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
It is thought that annelids were originally animals with two separate sexes, which released ova and sperm into the water via their nephridia. The fertilized eggs develop into trochophore larvae, which live as plankton. Later they sink to the sea-floor and metamorphose into miniature adults: the part of the trochophore ... | Annelid | Wikipedia | 487 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
Most mature clitellates (the group that includes earthworms and leeches) are full hermaphrodites, although in a few leech species younger adults function as males and become female at maturity. All have well-developed gonads, and all copulate. Earthworms store their partners' sperm in spermathecae ("sperm stores") and ... | Annelid | Wikipedia | 479 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
Earthworms migrate only a limited distance annually on their own, and the spread of invasive worms is increased rapidly by anglers and from worms or their cocoons in the dirt on vehicle tires or footwear.
Marine annelids may account for over one-third of bottom-dwelling animal species around coral reefs and in tidal z... | Annelid | Wikipedia | 512 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
Evolutionary history
Fossil record
Since annelids are soft-bodied, their fossils are rare. Polychaetes' fossil record consists mainly of the jaws that some species had and the mineralized tubes that some secreted. Some Ediacaran fossils such as Dickinsonia in some ways resemble polychaetes, but the similarities are t... | Annelid | Wikipedia | 470 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
The earliest good evidence for oligochaetes occurs in the Tertiary period, which began , and it has been suggested that these animals evolved around the same time as flowering plants in the early Cretaceous, from . A trace fossil consisting of a convoluted burrow partly filled with small fecal pellets may be evidence t... | Annelid | Wikipedia | 448 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
In 2007 Torsten Struck and colleagues compared three genes in 81 taxa, of which nine were outgroups, in other words not considered closely related to annelids but included to give an indication of where the organisms under study are placed on the larger tree of life. For a cross-check the study used an analysis of 11 g... | Annelid | Wikipedia | 413 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
The updated phylogenetic tree of the Annelid phylum is comprised by a grade of basal groups of polychaetes: Palaeoannelida, Chaetopteriformia and the Amphinomida/Sipuncula/Lobatocerebrum clade. This grade is followed by Pleistoannelida, the clade containing nearly all of annelid diversity, divided into two highly diver... | Annelid | Wikipedia | 461 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
The "Lophotrochozoa" hypothesis is also supported by the fact that many phyla within this group, including annelids, molluscs, nemerteans and flatworms, follow a similar pattern in the fertilized egg's development. When their cells divide after the 4-cell stage, descendants of these four cells form a spiral pattern. In... | Annelid | Wikipedia | 237 | 43116674 | https://en.wikipedia.org/wiki/Annelid | Biology and health sciences | Lophotrochozoa | null |
Neonatal herpes simplex, or simply neonatal herpes, is a herpes infection in a newborn baby, caused by the herpes simplex virus (HSV). It occurs mostly as a result of vertical transmission of the HSV from an affected mother to her baby. Types include skin, eye, and mouth herpes (SEM), disseminated herpes (DIS), and cen... | Neonatal herpes | Wikipedia | 470 | 21754264 | https://en.wikipedia.org/wiki/Neonatal%20herpes | Biology and health sciences | Viral diseases | Health |
CNS herpes is associated with higher morbidity, while DIS herpes has a higher mortality rate. These categories are not mutually exclusive and there is often overlap of two or more types. SEM herpes has the best prognosis of the three, however if left untreated it may progress to disseminated or CNS herpes with attendan... | Neonatal herpes | Wikipedia | 416 | 21754264 | https://en.wikipedia.org/wiki/Neonatal%20herpes | Biology and health sciences | Viral diseases | Health |
Transmission
The majority of cases (85%) occur during birth when the baby comes in contact with infected genital secretions in the birth canal, most common with mothers that have newly been exposed to the virus (mothers that had the virus before pregnancy have a lower risk of transmission). An estimated 5% are infected... | Neonatal herpes | Wikipedia | 398 | 21754264 | https://en.wikipedia.org/wiki/Neonatal%20herpes | Biology and health sciences | Viral diseases | Health |
Treatment
Reductions in morbidity and mortality are due to the use of antiviral treatments such as vidarabine and acyclovir. However, morbidity and mortality still remain high due to diagnosis of DIS and CNS herpes coming too late for effective antiviral administration; early diagnosis is difficult in the 20–40% of inf... | Neonatal herpes | Wikipedia | 422 | 21754264 | https://en.wikipedia.org/wiki/Neonatal%20herpes | Biology and health sciences | Viral diseases | Health |
HSV-1 neonatal herpes is extremely rare in developing countries because development of HSV-1 specific antibodies usually occurs in childhood or adolescence, precluding a later genital HSV-1 infection. HSV-2 infections are much more common in these countries. In industrialized nations, the adolescent HSV-1 seroprevalenc... | Neonatal herpes | Wikipedia | 384 | 21754264 | https://en.wikipedia.org/wiki/Neonatal%20herpes | Biology and health sciences | Viral diseases | Health |
Herpes meningitis is inflammation of the meninges, the protective tissues surrounding the spinal cord and brain, due to infection from viruses of the Herpesviridae family - the most common amongst adults is HSV-2. Symptoms are self-limiting over 2 weeks with severe headache, nausea, vomiting, neck-stiffness, and photop... | Herpes meningitis | Wikipedia | 497 | 21754355 | https://en.wikipedia.org/wiki/Herpes%20meningitis | Biology and health sciences | Viral diseases | Health |
Diagnosis
Differential diagnoses are broad including other causes of meningitis (bacterial, fungal, drug-induced), systemic infection, vasculitis, auto-immune disease, and cancer. As such, patient presentation of fever, headache, stiff neck, and altered mental status is not sufficient information for diagnosis and lumb... | Herpes meningitis | Wikipedia | 354 | 21754355 | https://en.wikipedia.org/wiki/Herpes%20meningitis | Biology and health sciences | Viral diseases | Health |
Herpes simplex encephalitis (HSE), or simply herpes encephalitis, is encephalitis due to herpes simplex virus. It is estimated to affect at least 1 in 500,000 individuals per year, and some studies suggest an incidence rate of 5.9 cases per 100,000 live births.
About 90% of cases of herpes encephalitis are caused by h... | Herpes simplex encephalitis | Wikipedia | 473 | 21754358 | https://en.wikipedia.org/wiki/Herpes%20simplex%20encephalitis | Biology and health sciences | Viral diseases | Health |
Definite diagnosis requires testing of the cerebrospinal fluid (CSF) by a lumbar puncture (spinal tap) for presence of the virus. The testing takes several days to perform, and patients with suspected Herpes encephalitis should be treated with acyclovir immediately while waiting for test results. Atypical stroke-like p... | Herpes simplex encephalitis | Wikipedia | 424 | 21754358 | https://en.wikipedia.org/wiki/Herpes%20simplex%20encephalitis | Biology and health sciences | Viral diseases | Health |
Treatment
Herpesviral encephalitis can be treated with high-dose intravenous acyclovir, which should be infused 10 mg/kg(adult) over 1 hour to avoid kidney failure. Without treatment, HSE results in rapid death in approximately 70% of cases; survivors suffer severe neurological damage. When treated, HSE is still fatal ... | Herpes simplex encephalitis | Wikipedia | 282 | 21754358 | https://en.wikipedia.org/wiki/Herpes%20simplex%20encephalitis | Biology and health sciences | Viral diseases | Health |
A cold sore is a type of herpes infection caused by the herpes simplex virus that affects primarily the lip. Symptoms typically include a burning pain followed by small blisters or sores. The first attack may also be accompanied by fever, sore throat, and enlarged lymph nodes. The rash usually heals within ten days, bu... | Cold sore | Wikipedia | 488 | 21754540 | https://en.wikipedia.org/wiki/Cold%20sore | Biology and health sciences | Viral diseases | Health |
Herpes infections usually show no symptoms; when symptoms do appear they typically resolve within two weeks. The main symptom of oral infection is inflammation of the mucosa of the cheek and gums—known as acute herpetic gingivostomatitis—which occurs within 5–10 days of infection. Other symptoms may also develop, incl... | Cold sore | Wikipedia | 189 | 21754540 | https://en.wikipedia.org/wiki/Cold%20sore | Biology and health sciences | Viral diseases | Health |
Recurrent oral infection is more common with HSV-1 infections than with HSV-2. Symptoms typically progress in a series of eight stages:
Latent (weeks to months incident-free): The remission period; After initial infection, the viruses move to sensory nerve ganglia (trigeminal ganglion), where they reside as lifelong,... | Cold sore | Wikipedia | 509 | 21754540 | https://en.wikipedia.org/wiki/Cold%20sore | Biology and health sciences | Viral diseases | Health |
Healing (day 9–14): New skin begins to form underneath the scab as the virus retreats into latency. A series of scabs will form over the sore (called Meier Complex), each one smaller than the last. During this phase irritation, itching, and some pain are common.
Post-scab (12–14 days): A reddish area may linger at the... | Cold sore | Wikipedia | 171 | 21754540 | https://en.wikipedia.org/wiki/Cold%20sore | Biology and health sciences | Viral diseases | Health |
A lesion caused by herpes simplex can occur in the corner of the mouth and be mistaken for angular cheilitis of another cause. Sometimes termed "angular herpes simplex". A cold sore at the corner of the mouth behaves similarly to elsewhere on the lips. Rather than utilizing antifungal creams, angular herpes simplex is ... | Cold sore | Wikipedia | 502 | 21754540 | https://en.wikipedia.org/wiki/Cold%20sore | Biology and health sciences | Viral diseases | Health |
Blood tests for herpes may differentiate between type 1 and type 2. When a person is not experiencing any symptoms, a blood test alone does not reveal the site of infection. Genital herpes infections occurred with almost equal frequency as type 1 or 2 in younger adults when samples were taken from genital lesions. Herp... | Cold sore | Wikipedia | 431 | 21754540 | https://en.wikipedia.org/wiki/Cold%20sore | Biology and health sciences | Viral diseases | Health |
Treatment
Despite no cure or vaccine for the virus, a human body's immune system and specific antibodies typically fight the virus. Treatment options include no treatment, topical creams (indifferent, antiviral, and anaesthetic), and oral antiviral medications. Indifferent topical creams include zinc oxide and glycerin... | Cold sore | Wikipedia | 472 | 21754540 | https://en.wikipedia.org/wiki/Cold%20sore | Biology and health sciences | Viral diseases | Health |
Epidemiology
Herpes labialis is common throughout the world. A large survey of young adults on six continents reported that 33% of males and 28% of females had herpes labialis on two or more occasions during the year before the study. The lifetime prevalence in the United States of America is estimated at 20–45% of the... | Cold sore | Wikipedia | 154 | 21754540 | https://en.wikipedia.org/wiki/Cold%20sore | Biology and health sciences | Viral diseases | Health |
Earthlight is the diffuse reflection of sunlight reflected from Earth's surface and clouds. Earthshine (an example of planetshine), also known as the Moon's ashen glow, is the dim illumination of the otherwise unilluminated portion of the Moon by this indirect sunlight. Earthlight on the Moon during the waxing crescent... | Earthlight (astronomy) | Wikipedia | 471 | 21756816 | https://en.wikipedia.org/wiki/Earthlight%20%28astronomy%29 | Physical sciences | Solar System | Astronomy |
Astronaut Dr Sian Proctor was moved by seeing and experiencing earthlight from orbit as mission pilot of Inspiration4 space mission and wrote the poem, "Earthlight". In 2024, Proctor authored EarthLight: The Power of EarthLight and the Human Perspective on the concept and nature of earthlight. | Earthlight (astronomy) | Wikipedia | 60 | 21756816 | https://en.wikipedia.org/wiki/Earthlight%20%28astronomy%29 | Physical sciences | Solar System | Astronomy |
Plastics are a wide range of synthetic or semisynthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be molded, extruded, or pressed into solid objects of various shapes. This adaptability, combined with a wide range of other properties, such as being lightweight,... | Plastic | Wikipedia | 446 | 26145195 | https://en.wikipedia.org/wiki/Plastic | Technology | Materials | null |
The world's first fully synthetic plastic was Bakelite, invented in New York in 1907, by Leo Baekeland, who coined the term "plastics". Dozens of different types of plastics are produced today, such as polyethylene, which is widely used in product packaging, and polyvinyl chloride (PVC), used in construction and pipes ... | Plastic | Wikipedia | 428 | 26145195 | https://en.wikipedia.org/wiki/Plastic | Technology | Materials | null |
Classifications
Plastics are usually classified by the chemical structure of the polymer's backbone and side chains. Important groups classified in this way include the acrylics, polyesters, silicones, polyurethanes, and halogenated plastics. Plastics can be classified by the chemical process used in their synthesis, s... | Plastic | Wikipedia | 399 | 26145195 | https://en.wikipedia.org/wiki/Plastic | Technology | Materials | null |
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