1.
Archaeopteryx
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Archaeopteryx, sometimes referred to by its German name Urvogel, is a genus of bird-like dinosaurs that is transitional between non-avian feathered dinosaurs and modern birds. The name derives from the ancient Greek ἀρχαῖος meaning ancient, and πτέρυξ, between the late nineteenth century and the early twenty-first century, Archaeopteryx had been generally accepted by palaeontologists and popular reference books as the oldest known bird. Older potential avialans have since been identified, including Anchiornis, Xiaotingia, similar in size to a Eurasian magpie, with the largest individuals possibly attaining the size of a raven, the largest species of Archaeopteryx could grow to about 0.5 m in length. Despite their small size, broad wings, and inferred ability to fly or glide and these features make Archaeopteryx a clear candidate for a transitional fossil between non-avian dinosaurs and birds. Thus, Archaeopteryx plays an important role, not only in the study of the origin of birds and it was named from a single feather in 1861. That same year, the first complete specimen of Archaeopteryx was announced, over the years, ten more fossils of Archaeopteryx have surfaced. Despite variation among these fossils, most experts regard all the remains that have been discovered as belonging to a single species, most of these eleven fossils include impressions of feathers. Because these feathers are of a form, these fossils are evidence that the evolution of feathers began before the Late Jurassic. The type specimen of Archaeopteryx was discovered just two years after Charles Darwin published On the Origin of Species, Archaeopteryx was roughly the size of a raven, with broad wings that were rounded at the ends and a long tail compared to its body length. It could reach up to 500 millimetres in length, with an estimated mass of 0.8 to 1 kilogram. Archaeopteryx feathers, although less documented than its other features, were similar in structure to modern-day bird feathers. Despite the presence of numerous features, Archaeopteryx had many non-avian theropod dinosaur characteristics. Unlike modern birds, Archaeopteryx had small teeth, as well as a bony tail. Because it displays features common to both birds and non-avian dinosaurs, Archaeopteryx has often considered a link between them. For instance, it has an ascending process of the ankle bone, interdental plates, an obturator process of the ischium. In particular, Ostrom found that Archaeopteryx was remarkably similar to the theropod family Dromaeosauridae, specimens of Archaeopteryx were most notable for their well-developed flight feathers. They were markedly asymmetrical and showed the structure of feathers in modern birds. The tail feathers were asymmetrical, again in line with the situation in modern birds
2.
Palaeontological Museum, Munich
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The Paläontologische Museum München is a German national natural history museum situated in Munich, Bavaria. It is associated with the Ludwig-Maximilians-Universität and it has a large collection of fossils of animals and plants such as Mesozoic reptiles, early elephants and saber-toothed cats. One of its highlights is the specimen of the early bird Archaeopteryx discovered in 1991, the museum is also interesting because of the architecture of its building, the former urban college of arts and crafts. List of museums in Germany List of natural history museums Media related to Paläontologisches Museum München at Wikimedia Commons Homepage Munich museums
3.
Jurassic
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The Jurassic is a geologic period and system that spans 56.3 million years from the end of the Triassic Period 201.3 million years ago to the beginning of the Cretaceous Period 145 Mya. The Jurassic constitutes the middle period of the Mesozoic Era, also known as the Age of Reptiles, the start of the period is marked by the major Triassic–Jurassic extinction event. The Jurassic is named after the Jura Mountains within the European Alps, by the beginning of the Jurassic, the supercontinent Pangaea had begun rifting into two landmasses, Laurasia to the north and Gondwana to the south. This created more coastlines and shifted the continental climate from dry to humid, on land, the fauna transitioned from the Triassic fauna, dominated by both dinosauromorph and crocodylomorph archosaurs, to one dominated by dinosaurs alone. The first birds also appeared during the Jurassic, having evolved from a branch of theropod dinosaurs, other major events include the appearance of the earliest lizards, and the evolution of therian mammals, including primitive placentals. Crocodilians made the transition from a terrestrial to a mode of life. The oceans were inhabited by marine reptiles such as ichthyosaurs and plesiosaurs, the chronostratigraphic term Jurassic is directly linked to the Jura Mountains. The name Jura is derived from the Celtic root jor, which was Latinised into juria, the Jurassic period is divided into the Early Jurassic, Middle, and Late Jurassic epochs. The Jurassic System, in stratigraphy, is divided into the Lower Jurassic, Middle, the separation of the term Jurassic into three sections goes back to Leopold von Buch. The Jurassic North Atlantic Ocean was relatively narrow, while the South Atlantic did not open until the following Cretaceous period, the Tethys Sea closed, and the Neotethys basin appeared. Climates were warm, with no evidence of glaciation, as in the Triassic, there was apparently no land over either pole, and no extensive ice caps existed. In contrast, the North American Jurassic record is the poorest of the Mesozoic, the Jurassic was a time of calcite sea geochemistry in which low-magnesium calcite was the primary inorganic marine precipitate of calcium carbonate. Carbonate hardgrounds were thus very common, along with calcitic ooids, calcitic cements, the first of several massive batholiths were emplaced in the northern American cordillera beginning in the mid-Jurassic, marking the Nevadan orogeny. Important Jurassic exposures are found in Russia, India, South America, Japan, Australasia. As the Jurassic proceeded, larger and more groups of dinosaurs like sauropods and ornithopods proliferated in Africa. Middle Jurassic strata are well represented nor well studied in Africa. Late Jurassic strata are also poorly represented apart from the spectacular Tendaguru fauna in Tanzania, the Late Jurassic life of Tendaguru is very similar to that found in western North Americas Morrison Formation. During the Jurassic period, the primary living in the sea were fish
4.
Bird
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Birds, a subgroup of Reptiles, are the last living examples of Dinosaurs. Birds live worldwide and range in size from the 5 cm bee hummingbird to the 2.75 m ostrich. They rank as the class of tetrapods with the most living species, at ten thousand. Birds are the closest living relatives of crocodilians, the fossil record indicates that birds evolved from feathered ancestors within the theropod group of saurischian dinosaurs. True birds first appeared during the Cretaceous period, around 100 million years ago, Birds, especially those in the southern continents, survived this event and then migrated to other parts of the world while diversifying during periods of global cooling. Primitive bird-like dinosaurs that lie outside class Aves proper, in the broader group Avialae, have been found dating back to the mid-Jurassic period, around 170 million years ago. Birds have wings which are more or less developed depending on the species, the digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have evolved for swimming. Many species annually migrate great distances, Birds are social, communicating with visual signals, calls, and bird songs, and participating in such social behaviours as cooperative breeding and hunting, flocking, and mobbing of predators. The vast majority of species are socially monogamous, usually for one breeding season at a time, sometimes for years. Other species have breeding systems that are polygynous or, rarely, Birds produce offspring by laying eggs which are fertilised through sexual reproduction. They are usually laid in a nest and incubated by the parents, most birds have an extended period of parental care after hatching. Some birds, such as hens, lay eggs even when not fertilised, songbirds, parrots, and other species are popular as pets. Guano is harvested for use as a fertiliser, Birds prominently figure throughout human culture. About 120–130 species have become extinct due to human activity since the 17th century, human activity threatens about 1,200 bird species with extinction, though efforts are underway to protect them. Recreational birdwatching is an important part of the ecotourism industry, the first classification of birds was developed by Francis Willughby and John Ray in their 1676 volume Ornithologiae. Carl Linnaeus modified that work in 1758 to devise the taxonomic classification system currently in use, Birds are categorised as the biological class Aves in Linnaean taxonomy. Phylogenetic taxonomy places Aves in the dinosaur clade Theropoda, Aves and a sister group, the clade Crocodilia, contain the only living representatives of the reptile clade Archosauria
5.
Clade
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A clade is a group of organisms that consists of a common ancestor and all its lineal descendants, and represents a single branch on the tree of life. The common ancestor may be an individual, a population, a species, clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently, over the last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming taxa that are not clades, the term clade was coined in 1957 by the biologist Julian Huxley to refer to the result of cladogenesis, a concept Huxley borrowed from Bernhard Rensch. Many commonly named groups are clades, for example, rodents or insects, because in each case, their name refers to a common ancestor with all its descendant branches. Rodents, for example, are a branch of mammals that split off after the end of the period when the clade Dinosauria stopped being the dominant terrestrial vertebrates 66 million years ago, the original population and all its descendants are a clade. The rodent clade corresponds to the order Rodentia, and insects to the class Insecta and these clades include smaller clades, such as chipmunk or ant, each of which consists of even smaller clades. The clade rodent is in included in the mammal, vertebrate. The phenomenon of convergent evolution is, however, responsible for cases where there are misleading similarities in the morphology of groups that evolved from different lineages. The publication of Darwins theory of evolution in 1859 gave this view increasing weight, thomas Henry Huxley, an early advocate of evolutionary theory, proposed a revised taxonomy based on clades. For example, he grouped birds with reptiles, based on fossil evidence, german biologist Emil Hans Willi Hennig is considered to be the founder of cladistics. Taxonomists have increasingly worked to make the taxonomic system reflect evolution, when it comes to naming, however, this principle is not always compatible with the traditional rank-based nomenclature. For these and other reasons, phylogenetic nomenclature has been developed, a clade is by definition monophyletic, meaning that it contains one ancestor and all its descendants. The ancestor can be known or unknown, any and all members of a clade can be extant or extinct, the science that tries to reconstruct phylogenetic trees and thus discover clades is called phylogenetics or cladistics, the latter term coined by Ernst Mayr, derived from clade. The results of analyses are tree-shaped diagrams called cladograms, they. Three methods of defining clades are featured in phylogenetic nomenclature, node-, stem-, the relationship between clades can be described in several ways, A clade located within a clade is said to be nested within that clade. In the diagram, the clade, i. e. the apes. Two clades are sisters if they have a common ancestor
6.
Theropoda
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Theropoda or theropods are a group of saurischian dinosaurs. Theropods were ancestrally carnivorous, although a number of theropod groups evolved herbivory, omnivory, piscivory, in the Jurassic, birds evolved from small specialized coelurosaurian theropods, and are today represented by 10,000 living species. Theropods exhibit a range of diets, from insectivores to herbivores and carnivores. Strict carnivory has always considered the ancestral diet for theropods as a group. However, discoveries in the late 20th and early 21st centuries showed that a variety of diets existed even in more basal lineages, all early finds of theropod fossils showed them to be primarily carnivorous. For example, a Compsognathus longipes fossil was found with a lizard in its stomach, the first confirmed non-carnivorous fossil theropods found were the therizinosaurs, originally known as segnosaurs. First thought to be prosauropods, these enigmatic dinosaurs were later proven to be highly specialized, therizinosaurs possessed large abdomens for processing plant food, and small heads with beaks and leaf-shaped teeth. Further study of maniraptoran theropods and their relationships showed that therizinosaurs were not the early members of this group to abandon carnivory. Several other lineages of early maniraptors show adaptations for an omnivorous diet, oviraptorosaurs, ornithomimosaurs and advanced troodontids were likely omnivorous as well, and some early theropods appear to have specialized in catching fish. Diet is largely deduced by the morphology, tooth marks on bones of the prey. Some theropods, such as Baryonyx, Lourinhanosaurus, ornithomimosaurs, and birds, are known to use gastroliths, the majority of theropod teeth are blade-like, with serration on the edges, called ziphodont. Others are pachydont or phyllodont depending on the shape of the tooth or denticles, the morphology of the teeth is distinct enough to tell the major families apart, which indicate different diet strategies. The folds helped the teeth stay in place longer, especially as theropods evolved into larger sizes and had more force in their bite, Mesozoic theropods were also very diverse in terms of skin texture and covering. Feathers or feather-like structures are attested in most lineages of theropods, however, outside the coelurosaurs, feathers may have been confined to the young, smaller species, or limited parts of the animal. Many larger theropods had skin covered in small, bumpy scales, in some species, these were interspersed with larger scales with bony cores, or osteoderms. This type of skin is best known in the ceratosaur Carnotaurus, the coelurosaur lineages most distant from birds had feathers that were relatively short and composed of simple, possibly branching filaments. Simple filaments are also seen in therizinosaurs, which also possessed large, more fully feathered theropods, such as dromaeosaurs, usually retain scales only on the feet. Some species may have mixed feathers elsewhere on the body as well, scansoriopteryx preserved scales near the underside of the tail, and Juravenator may have been predominantly scaly with some simple filaments interspersed
7.
Dinosaur
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Dinosaurs are a diverse group of reptiles of the clade Dinosauria that first appeared during the Triassic. Although the exact origin and timing of the evolution of dinosaurs is the subject of active research and they became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201 million years ago. Their dominance continued through the Jurassic and Cretaceous periods and ended when the Cretaceous–Paleogene extinction event led to the extinction of most dinosaur groups 66 million years ago, until the late 20th century, all groups of dinosaurs were believed to be extinct. As such, birds were the dinosaur lineage to survive the mass extinction event. This article deals primarily with non-avian dinosaurs, Dinosaurs are a varied group of animals from taxonomic, morphological and ecological standpoints. Birds, at over 10,000 living species, are the most diverse group of vertebrates besides perciform fish, using fossil evidence, paleontologists have identified over 500 distinct genera and more than 1,000 different species of non-avian dinosaurs. Dinosaurs are represented on every continent by both extant species and fossil remains, while dinosaurs were ancestrally bipedal, many extinct groups included quadrupedal species, and some were able to shift between these stances. Elaborate display structures such as horns or crests are common to all dinosaur groups, evidence suggests that egg laying and nest building are additional traits shared by all dinosaurs.7 meters and heights of 18 meters and were the largest land animals of all time. Still, the idea that dinosaurs were uniformly gigantic is a misconception based in part on preservation bias, as large. Many dinosaurs were small, Xixianykus, for example, was only about 50 cm long. Through the first half of the 20th century, before birds were recognized to be dinosaurs, most of the community believed dinosaurs to have been sluggish. Most research conducted since the 1970s, however, has indicated that all dinosaurs were active animals with elevated metabolisms and numerous adaptations for social interaction. The large sizes of some groups, as well as their seemingly monstrous and fantastic nature, have ensured dinosaurs regular appearance in best-selling books and films. Persistent public enthusiasm for the animals has resulted in significant funding for dinosaur science, the term is derived from the Greek words δεινός and σαῦρος. Though the taxonomic name has often interpreted as a reference to dinosaurs teeth, claws. Instead, dinosaurs, like many forms of reptile sub-groups, did not exhibit characteristics which were traditionally regarded as reptilian. Under phylogenetic nomenclature, dinosaurs are usually defined as the group consisting of Triceratops, Neornithes, their most recent common ancestor, Birds are now recognized as being the sole surviving lineage of theropod dinosaurs. In traditional taxonomy, birds were considered a class that had evolved from dinosaurs
8.
Paraves
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Paraves are a widespread group of theropod dinosaurs that originated in the Late Jurassic period. In addition to the extinct dromaeosaurids, troodontids, and scansoriopterygids, primitive members of Paraves are well-known for the possession of an enlarged claw on the second digit of the foot, which was held off the ground when walking in some species. Like other theropods, all paravians are bipedal, walking on their two hind legs, the teeth of primitive paravians were curved and serrated, but not blade-like except in some specialized species such as Dromaeosaurus albertensis. The serrations on the front edge of dromaeosaurid and troodontid teeth were small and fine, while the back edge had serrations which were very large. Paravians generally have long, winged forelimbs, though these have become smaller in many flightless species, the wings usually bore three large, flexible, clawed fingers in early forms. The fingers became fused and stiffened and the highly reduced or lost in some advanced lineages. Many early members of Paraves had both well-developed wings and long feathers on the legs, which in some cases, formed a second set of airfoils. These species, most famously represented by Microraptor gui, have often referred to as four winged dinosaurs. Microraptor in particular seems to represent a case of flight evolving independently of the bird lineage within Paraves. The enlarged second toe bore a large, curved sickle-shaped claw. This claw was especially large and flattened from side to side in the large-bodied predatory eudromaeosaurs, in these early species, the first toe was usually small and angled inward toward the center of the body, but only became fully reversed in more specialized members of the bird lineage. One species, Balaur bondoc, possessed a first toe which was modified in parallel with the second. Both the first and second toes on each foot of B. bondoc were held retracted, initial speculation regarded the claws as slashing implements used to disembowel large prey. In this scenario, the upper foot would serve as an anchor point for powerful tendons to improve kicking ability. However, subsequent studies of the actual claw shape showed that the underside of the claw was only weakly keeled, instead, it appeared to be more of a hooking implement. Manning et al. suggested in 2006 that the claws were similar to crampons and were used for climbing and they compared the claw and overall foot anatomy of various primitive species with modern birds to shed light on their actual function. Fowler and colleagues showed that many modern birds also have enlarged claws on the second toes. Other lines of evidence for this behavior include teeth which had large, in more primitive dromaeosaurids and in troodontids, the feet were not as specialized and the claws were not as large or as hooked
9.
Class (biology)
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In biological classification, class is, a taxonomic rank. Other well-known ranks in descending order of size are life, domain, kingdom, phylum, order, family, genus, as for the other well-known ranks, there is the option of an immediately lower rank, indicated by the prefix sub-, subclass. A taxonomic unit, a taxon, in that rank, in that case the plural is classes The composition of each class is determined by a taxonomist. Often there is no agreement, with different taxonomists taking different positions. There are no rules that a taxonomist needs to follow in describing a class. For example, dogs are assigned to the phylum Chordata, in the class Mammalia. In botany, classes are now rarely discussed, for some clades, a number of alternative classifications are used. In the first edition of his Systema Naturae, carl Linnaeus divided all three of his kingdoms of Nature into classes. The class was considered the highest level of the hierarchy until George Cuviers embranchements. Cladistics List of animal classes Phylogenetics Systematics Taxonomy
10.
Order (biology)
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In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized by the nomenclature codes. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, an immediately higher rank, superorder, may be added directly above order, while suborder would be a lower rank. A taxonomic unit, a taxon, in that rank, in that case the plural is orders. Example, The Juglans and Hickory trees belong to the family Juglandaceae, what does and does not belong to each order is determined by a taxonomist, as is whether a particular order should be recognized at all. Often there is no agreement, with different taxonomists each taking a different position. There are no rules that a taxonomist needs to follow in describing or recognizing an order. Some taxa are accepted almost universally, while others are recognised only rarely, for some groups of organisms, consistent suffixes are used to denote that the rank is an order. The Latin suffix -formes meaning having the form of is used for the name of orders of birds and fishes. The suffix -ales is for the name of orders of plants, fungi, for some clades covered by the International Code of Zoological Nomenclature, a number of additional classifications are sometimes used, although not all of these are officially recognised. In their 1997 classification of mammals, McKenna and Bell used two levels between superorder and order, grandorder and mirorder. Michael Novacek inserted them at the same position, michael Benton inserted them between superorder and magnorder instead. This position was adopted by Systema Naturae 2000 and others, in botany, the ranks of subclass and suborder are secondary ranks pre-defined as respectively above and below the rank of order. Any number of further ranks can be used as long as they are clearly defined, the superorder rank is commonly used, with the ending -anae that was initiated by Armen Takhtajans publications from 1966 onwards. Carl Linnaeus was the first to apply it consistently to the division of all three kingdoms of nature in his Systema Naturae, for plants, Linnaeus orders in the Systema Naturae and the Species Plantarum were strictly artificial, introduced to subdivide the artificial classes into more comprehensible smaller groups. In French botanical publications, from Michel Adansons Familles naturelles des plantes and until the end of the 19th century, some of the plant families still retain the names of Linnaean natural orders or even the names of pre-Linnaean natural groups recognised by Linnaeus as orders in his natural classification. Such names are known as family names. In zoology, the Linnaean orders were used more consistently and that is, the orders in the zoology part of the Systema Naturae refer to natural groups. Some of his names are still in use
11.
Crocodilia
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The Crocodilia is an order of mostly large, predatory, semiaquatic reptiles, known as crocodilians. They first appeared 83.5 million years ago in the Late Cretaceous period and are the closest living relatives of birds, as the two groups are the only known survivors of the Archosauria. Members of the total group, the clade Pseudosuchia, appeared about 250 million years ago in the Early Triassic period. The order Crocodilia includes the true crocodiles, the alligators and caimans, although the term crocodiles is sometimes used to refer to all of these, crocodilians is a less ambiguous vernacular term for members of this group. Large, solidly built, lizard-like reptiles, crocodilians have flattened snouts, laterally compressed tails, and eyes, ears. They swim well and can move on land in a high walk and their skin is thick and covered in non-overlapping scales. They have conical, peg-like teeth and a powerful bite and they have a four-chambered heart and, somewhat like birds, a unidirectional looping system of airflow within the lungs, but like other non-avian reptiles they are ectotherms. Crocodilians are found mainly in lowlands in the tropics, but alligators also live in the southeastern United States, Crocodilians are typically solitary and territorial, though cooperative feeding does occur. During breeding, dominant males try to monopolise available females, females lay eggs in holes or in mounds and, unlike most other reptiles, care for their hatched young. Eight species of crocodilians are known to have attacked humans, the largest number of attacks comes from the Nile crocodile. Artistic and literary representations of crocodilians have appeared in cultures around the world since at least Ancient Egypt. Crocodilia and Crocodylia have been used interchangeably for decades starting with Schmidts redescription of the group from the defunct term Loricata. Schmidt used the older term Crocodilia, based on Owens original name for the group, shortly after, Wermuth opted for Crocodylia as the proper name for this redescribed group, basing it on the type genus Crocodylus. Dundee—in a revision of many reptilian and amphibian names—argued strongly for Crocodylia to be the spelling for the group, however, it was not until the advent of cladistics and phylogenetic nomenclature that a more solid justification for assuming one spelling over the other was proposed. Prior to 2003, Crocodilia/Crocodylia was a group that encompassed the modern-day animals as well as their distant relatives now in the larger groups called Crocodylomorpha. Under its current definition Crocodylia is restricted to only the most recent ancestor of todays modern-day crocodilians and this distinction is more important for paleontologists studying crocodilian evolution. As such, the alternate spellings Crocodilia and Crocodylia are still used interchangeably in the neontological literature, Crocodilia appears to be a Latinizing of the Greek κροκόδειλος, which means both lizard and Nile crocodile. Crocodylia, as coined by Wermuth, in regards to the genus Crocodylus appears to be derived from the ancient Greek κρόκη —meaning shingle or pebble—and δρîλος or δρεîλος for worm, the name may refer to the animals habit of basking on the pebbled shores of the Nile
12.
Reptile
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Reptiles are tetrapod animals in the class Reptilia, comprising todays turtles, crocodilians, snakes, amphisbaenians, lizards, tuatara, and their extinct relatives. The study of these traditional reptile orders, historically combined with that of amphibians, is called herpetology. Because some reptiles are more related to birds than they are to other reptiles. For this reason, many scientists prefer to consider the birds part of Reptilia as well. Some early examples include the lizard-like Hylonomus and Casineria, in addition to the living reptiles, there are many diverse groups that are now extinct, in some cases due to mass extinction events. In particular, the K–Pg extinction wiped out the pterosaurs, plesiosaurs, ornithischians, and sauropods, as well as species of theropods, crocodyliforms. Modern non-avian reptiles inhabit every continent with the exception of Antarctica, several living subgroups are recognized, Testudines, approximately 400 species, Sphenodontia,1 species, Squamata, over 9,600 species, Crocodilia,25 species, and Aves,10,000 species. Reptiles are tetrapod vertebrates, creatures that either have four limbs or, unlike amphibians, reptiles do not have an aquatic larval stage. As amniotes, reptile eggs are surrounded by membranes for protection and transport, many of the viviparous species feed their fetuses through various forms of placenta analogous to those of mammals, with some providing initial care for their hatchlings. In the 18th century, the reptiles were, from the outset of classification, the terms reptile and amphibian were largely interchangeable, reptile being preferred by the French. Josephus Nicolaus Laurenti was the first to use the term Reptilia for an expanded selection of reptiles. Today, the two groups are commonly treated under the same heading as herptiles. He subsequently proposed the names of Sauropsida and Ichthyopsida for the two groups. In 1866, Haeckel demonstrated that vertebrates could be divided based on their strategies, and that reptiles, birds. The terms Sauropsida and Theropsida were used again in 1916 by E. S, Goodrich to distinguish between lizards, birds, and their relatives on the one hand and mammals and their extinct relatives on the other. Goodrich supported this division by the nature of the hearts and blood vessels in each group, according to Goodrich, both lineages evolved from an earlier stem group, Protosauria in which he included some animals today considered reptile-like amphibians, as well as early reptiles. Watson observed that the first two groups diverged very early in history, so he divided Goodrichs Protosauria between them. He also reinterpreted Sauropsida and Theropsida to exclude birds and mammals, thus his Sauropsida included Procolophonia, Eosuchia, Millerosauria, Chelonia, Squamata, Rhynchocephalia, Crocodilia, thecodonts, non-avian dinosaurs, pterosaurs, ichthyosaurs, and sauropterygians
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Archosaur
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Archosaurs are a group of diapsid amniotes whose living representatives consist of birds and crocodilians. This group also includes all extinct dinosaurs, extinct crocodilian relatives. Archosauria, the clade, is a crown group that includes the most recent common ancestor of living birds. It includes two clades, Pseudosuchia, which includes crocodilians and their extinct relatives, and Ornithosuchia. Archosaurs can be distinguished from other tetrapods on the basis of synapomorphies, or shared characteristics. The simplest and most widely agreed synapomorphies of archosaurs include teeth set in sockets, antorbital and mandibular fenestrae, being set in sockets, the teeth were less likely to be torn loose during feeding. This feature is responsible for the name thecodont, which used to apply to many Triassic archosaurs. Some archosaurs, such as birds, are secondarily toothless, antorbital fenestrae reduced the weight of the skull, which was relatively large in early archosaurs, rather like that of modern crocodilians. Mandibular fenestrae may also have reduced the weight of the jaw in some forms, the fourth trochanter provides a large site for the attachment of muscles on the femur. There is some debate about when archosaurs first appeared and those who classify the Permian reptiles Archosaurus rossicus and/or Protorosaurus speneri as true archosaurs maintain that archosaurs first appeared in the late Permian. The earliest archosaurs were rauisuchians, such as Scythosuchus and Tsylmosuchus, synapsids were the dominant land vertebrates throughout the Permian, but most perished in the Permian-Triassic extinction event. Very few large synapsids survived the event, although one form, Lystrosaurus, but archosaurs quickly became the dominant land vertebrates in the early Triassic. The two most commonly suggested explanations for this are, Archosaurs made more progress towards erect limbs than synapsids. An objection to this explanation is that became dominant while they still had sprawling or semi-erect limbs, similar to those of Lystrosaurus. The early Triassic was predominantly arid, because most of the land was concentrated in the supercontinent Pangaea. Archosaurs were probably better at conserving water than early synapsids because, Modern diapsids excrete uric acid and it is reasonable to suppose that archosaurs also excreted uric acid, and therefore were good at conserving water. The aglandular skins of diapsids would also have helped to conserve water, Modern mammals excrete urea, which requires a lot of water to keep it dissolved. Their skins also contain many glands, which also lose water, assuming that early synapsids had similar features, e. g. as argued by the authors of Palaeos, they were at a disadvantage in a mainly arid world
14.
Palaeognathae
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Palaeognathae, or paleognaths, is one of the two living clades of birds – the other being Neognathae. Together, these two form the clade Neornithes. Palaeognathae contains five extant branches of flightless lineages, termed ratites, and one flying lineage, there are 47 species of tinamous,5 of kiwis,3 of cassowaries,1 of emus,2 of rheas and 2 of ostrich. There are three groups, the Lithornithiformes, the Dinornithiformes and the Aepyornithiformes, that are undisputed members of Palaeognathae. There are other extinct birds which have been allied with the Palaeognathae by at least one author, but their affinities are a matter of dispute. The word Paleognath is derived from the ancient Greek for old jaws in reference to the anatomy of the palate. There are also other scientific controversies about their evolution. Given the northern location of the morphologically most basal fossil forms. One study of molecular and paleontological data found that modern bird orders, including the paleognathous ones, benton summarized this and other molecular studies as implying that paleognaths should have arisen 110 to 120 million years ago in the Early Cretaceous. He points out, however, that there is no fossil record until 70 million years ago, unrelated birds might have developed ratite-like anatomies multiple times around the world through convergent evolution. McDowell asserted that the similarities in the anatomy of paleognathes might actually be neoteny. He noted that there were other feature of the skull, such as the retention of sutures into adulthood, thus, perhaps the characteristic palate was actually a frozen stage that many carinate bird embryos passed through during development. The retention of early stages, then, may have been a mechanism by which various birds became flightless. Hope reviewed all known fossils from the Mesozoic looking for evidence of the origin of the evolutionary radiation of the Neornithes. That radiation would also signal that the paleognaths had already diverged and she notes five Early Cretaceous taxa that have been assigned to the Palaeognathae. She finds that none of them can be assigned as such. However, she find evidence that the Neognathae and, therefore. Vegavis is a bird from the Maastrichtian period of Late Cretaceous Antarctica
15.
Anseriformes
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In fact, these living species are all included in Anatidae except for the three screamers and the magpie goose. All species in the order are highly adapted for an aquatic existence at the water surface, the males, except for the screamers, also have a penis, a trait that has disappeared in Neoaves. All are web-footed for efficient swimming, the earliest known Anseriform is the recently discovered Vegavis, which lived during the Cretaceous period. It is thought that the Anseriformes originated when the original Galloanserae split into the two main lineages, the extinct dromornithids may possibly represent early offshoots of the anseriform line, if they arent stem-Galliformes instead, and so maybe Gastornis. The ancestors of the Anseriformes developed the characteristic bill structure that they still share, the prehistoric wading presbyornithids were even more bizarre. The Anseriformes and the Galliformes are the most primitive neognathous birds, Anatidae systematics, especially regarding placement of some odd genera in the dabbling ducks or shelducks, is not fully resolved. See the Anatidae article for information, and for alternate taxonomic approaches. Some unusual groups, such as the extinct Gastornithidae and Dromornithidae, are found to be at the base of the Anseriformes family tree. Anatidae is traditionally divided into subfamilies Anatinae and Anserinae, the Anatinae consists of tribes Anatini, Aythyini, Mergini and Tadornini. The higher-order classification below follows a phylogenetic analysis performed by Angolin,2007, Mikkos Phylogeny Archive, the clade Somaterini has a single genus Somateria. List of Anseriformes by population Agnolin, F. Brontornis burmeisteri Moreno & Mercerat, un Anseriformes gigante del Mioceno Medio de Patagonia, revista del Museo Argentino de Ciencias Naturales. Clarke, J. A. Tambussi, C. P. Noriega, erickson, G. M. & Ketcham, R. A. Definitive fossil evidence for the extant avian radiation in the Cretaceous, & Zusi, R. L. Higher-order phylogeny of modern birds based on comparative anatomy. Zoological Journal of the Linnen Society, murray, P. F. & Vickers-Rich, P. Magnificent Mihirungs, The Colossal Flightless Birds of the Australian Dreamtime
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Galliformes
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The name derives from gallus, Latin for cock or rooster. Common names are gamefowl or gamebirds, landfowl, gallinaceous birds, wildfowl or just fowl are also often used for the Galliformes, but usually these terms also refer to waterfowl, and occasionally to other commonly hunted birds. This group has about 290 species, one or more of which are found in every part of the worlds continents. They are rarer on islands, and in contrast to the closely related waterfowl, are absent from oceanic islands—unless introduced there by humans. Several species have been domesticated during their long and extensive relationships with humans and this order contains five families, Phasianidae, Odontophoridae, Numididae, Cracidae, and Megapodiidae. They are important as seed dispersers and predators in the ecosystems they inhabit, many gallinaceous species are skilled runners and escape predators by running rather than flying. Males of most species are more colorful than the females, males often have elaborate courtship behaviors that include strutting, fluffing of tail or head feathers, and vocal sounds. The living Galliformes were once divided into seven or more families, despite their distinctive appearance, grouse and turkeys probably do not warrant separation as families due to their recent origin from partridge- or pheasant-like birds. The turkeys became larger after their ancestors colonized temperate and subtropical North America, the ancestors of grouse, though, adapted to harsh climates and could thereby colonize subarctic regions. Consequently, the Phasianidae are expanded in current taxonomy to include the former Tetraonidae and Meleagrididae as subfamilies, the Anseriformes and the Galliformes together make up the Galloanserae. They are basal among the living birds, and normally follow the Paleognathae in modern bird classification systems. This was first proposed in the Sibley-Ahlquist taxonomy and has been the one major change of that proposed scheme that was almost universally adopted. However, the Galliformes as they were traditionally delimited are called Gallomorphae in the Sibley-Ahlquist taxonomy and this is not a natural group, however, but rather an erroneous result of the now-obsolete phenetic methodology employed in the Sibley-Ahlquist taxonomy. Phenetic studies do not distinguish between plesiomorphic and apomorphic characters, which leads to basal lineages appearing as monophyletic groups, historically, the buttonquails, mesites and the hoatzin were placed in the Galliformes, too. The former are now known to be adapted to an inland lifestyle, whereas the mesites are probably closely related to pigeons. The relationships of the hoatzin are entirely obscure, and it is treated as a monotypic order Opisthocomiformes to signify this. The earliest galliform-like fossils hail from the Late Cretaceous, most notably those of Austinornis lentus and its partial left tarsometatarsus was found in the Austin Chalk near Fort McKinney, Texas, dating to about 85 million years ago. This bird was quite closely related to Galliformes, but whether it was a part of these or belongs elsewhere in the little-known galliform branch of Galloanserae is not clear
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Neoaves
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Neoaves is a clade that consists of all modern birds with the exception of Paleognathae and Galloanserae. The early diversification of the various neoavian groups occurred very rapidly, one hypothesis for the phylogeny of modern birds was presented by Prum, R. O. et al. The following cladogram illustrates the relationships, with some taxon names following Yury
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Phylogenetics
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In biology, phylogenetics /ˌfaɪloʊdʒəˈnɛtɪks, -lə-/ is the study of the evolutionary history and relationships among individuals or groups of organisms. These relationships are discovered through phylogenetic inference methods that evaluate observed heritable traits, the result of these analyses is a phylogeny – a diagrammatic hypothesis about the history of the evolutionary relationships of a group of organisms. The tips of a tree can be living organisms or fossils. Phylogenetic analyses have become central to understanding biodiversity, evolution, ecology, taxonomy is the classification, identification and naming of organisms. It is usually richly informed by phylogenetics, but remains a methodologically and logically distinct discipline, usual methods of phylogenetic inference involve computational approaches implementing the optimality criteria and methods of parsimony, maximum likelihood, and MCMC-based Bayesian inference. All these depend upon an implicit or explicit mathematical model describing the evolution of characters observed, prior to 1990, phylogenetic inferences were generally presented as narrative scenarios. Such methods are often ambiguous and lack explicit criteria for evaluating alternative hypotheses, the term phylogeny derives from the German Phylogenie, introduced by Haeckel in 1866, and the Darwinian approach to classification became known as the phyletic approach. During the late 19th century, Ernst Haeckels recapitulation theory, or biogenetic fundamental law, was widely accepted, but this theory has long been rejected. O. See, Huerta-Cepas, Jaime, Dopazo, Joaquín, Gabaldón, ETE, A python Environment for Tree Exploration. PhylomeDB, A public database hosting thousands of gene phylogenies ranging many different species, See, Huerta-Cepas, J. Capella-Gutierrez, S. Pryszcz, L. P. Denisov, I. Kormes, D. Marcet-Houben, M. Gabaldón, T. PhylomeDB v3.0, An expanding repository of genome-wide collections of trees, alignments, lents, N. H. Cifuentes, O. E. Carpi, A. Teaching the Process of Molecular Phylogeny and Systematics, A Multi-Part Inquiry-Based Exercise
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House sparrow
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The house sparrow is a bird of the sparrow family Passeridae, found in most parts of the world. A small bird, it has a length of 16 cm. Females and young birds are coloured brown and grey, and males have brighter black, white. One of about 25 species in the genus Passer, the sparrow is native to most of Europe, the Mediterranean region. Its intentional or accidental introductions to many regions, including parts of Australia, Africa, the house sparrow is strongly associated with human habitations, and can live in urban or rural settings. Though found in varied habitats and climates, it typically avoids extensive woodlands, grasslands. It feeds mostly on the seeds of grains and weeds, but it is an opportunistic eater and commonly eats insects and its predators include domestic cats, hawks, owls, and many other predatory birds and mammals. Because of its numbers, ubiquity, and association with human settlements, though it is widespread and abundant, its numbers have declined in some areas. The animals conservation status is listed as least concern on the IUCN Red List, the house sparrow is typically about 16 cm long, ranging from 14 to 18 cm. It is a bird with a full chest and a large. Its bill is stout and conical with a length of 1. 1–1.5 cm. Its tail is short, at 5. 2–6.5 cm long, the wing chord is 6. 7–8.9 cm, and the tarsus is 1. 6–2.5 cm. In mass, the house sparrow ranges from 24 to 39.5 g, females usually are slightly smaller than males. The median mass on the European continent for both sexes is about 30 g, and in more southerly subspecies is around 26 g, younger birds are smaller, males are larger during the winter, and females are larger during the breeding season. Birds at higher latitudes, colder climates, and sometimes higher altitudes are larger, the plumage of the house sparrow is mostly different shades of grey and brown. The sexes exhibit strong dimorphism, the female is mostly buffish above and below, while the male has boldly coloured head markings, a reddish back, and grey underparts. The male has a grey crown from the top of its bill to its back. It has black around its bill, on its throat, and it has a small white stripe between the lores and crown and small white spots immediately behind the eyes, with black patches below and above them
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Timeline of the evolutionary history of life
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This timeline of the evolutionary history of life represents the current scientific theory outlining the major events during the development of life on planet Earth. In biology, evolution is any change across generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of organization, from kingdoms to species. The similarities between all present day organisms indicate the presence of an ancestor from which all known species, living. More than 99 percent of all species, amounting to five billion species. Estimates on the number of Earths current species range from 10 million to 14 million, of which about 1.2 million have been documented and over 86 percent have not yet been described. Species go extinct constantly as environments change, organisms compete for environmental niches, occasionally biodiversity on the planet takes a hit in the form of a mass extinction in which the extinction rate is much higher than usual. A large extinction event often represents an accumulation of smaller extinction events that take place in a brief period of time. The first known mass extinction in earths history was the Great Oxygenation Event 2.4 billion years ago, the event led to the loss of most of the planets obligate anaerobes. The Holocene extinction event is currently under way, in this timeline, Ma means million years ago, ka means thousand years ago, and ya means years ago. 4000 Ma –2500 Ma 2500 Ma –542 Ma, contains the Palaeoproterozoic, Mesoproterozoic and Neoproterozoic eras. 542 Ma – present The Phanerozoic Eon, literally the period of well-displayed life, marks the appearance in the record of abundant. It is subdivided into three eras, the Paleozoic, Mesozoic and Cenozoic, which are divided by mass extinctions. 542 Ma –251.0 Ma and contains the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, from 251.4 Ma to 66 Ma and containing the Triassic, Jurassic and Cretaceous periods. 66 Ma – present Dawkins, Richard, the Ancestors Tale, A Pilgrimage to the Dawn of Life. Understanding Evolution, your one-stop resource for information on evolution, explore complete phylogenetic tree interactively Brandt, Niel. Houston, TX, The TalkOrigins Foundation, Inc, interactive timeline from Big Bang to present Plant Evolution. Sequence of Plant Evolution The History of Animal Evolution, sequence of Animal Evolution Yeo, Dannel, Drage, Thomas
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Water
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Water is a transparent and nearly colorless chemical substance that is the main constituent of Earths streams, lakes, and oceans, and the fluids of most living organisms. Its chemical formula is H2O, meaning that its molecule contains one oxygen, Water strictly refers to the liquid state of that substance, that prevails at standard ambient temperature and pressure, but it often refers also to its solid state or its gaseous state. It also occurs in nature as snow, glaciers, ice packs and icebergs, clouds, fog, dew, aquifers, Water covers 71% of the Earths surface. It is vital for all forms of life. Only 2. 5% of this water is freshwater, and 98. 8% of that water is in ice and groundwater. Less than 0. 3% of all freshwater is in rivers, lakes, and the atmosphere, a greater quantity of water is found in the earths interior. Water on Earth moves continually through the cycle of evaporation and transpiration, condensation, precipitation. Evaporation and transpiration contribute to the precipitation over land, large amounts of water are also chemically combined or adsorbed in hydrated minerals. Safe drinking water is essential to humans and other even though it provides no calories or organic nutrients. There is a correlation between access to safe water and gross domestic product per capita. However, some observers have estimated that by 2025 more than half of the population will be facing water-based vulnerability. A report, issued in November 2009, suggests that by 2030, in developing regions of the world. Water plays an important role in the world economy, approximately 70% of the freshwater used by humans goes to agriculture. Fishing in salt and fresh water bodies is a source of food for many parts of the world. Much of long-distance trade of commodities and manufactured products is transported by boats through seas, rivers, lakes, large quantities of water, ice, and steam are used for cooling and heating, in industry and homes. Water is an excellent solvent for a variety of chemical substances, as such it is widely used in industrial processes. Water is also central to many sports and other forms of entertainment, such as swimming, pleasure boating, boat racing, surfing, sport fishing, Water is a liquid at the temperatures and pressures that are most adequate for life. Specifically, at atmospheric pressure of 1 bar, water is a liquid between the temperatures of 273.15 K and 373.15 K
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Unicellular organism
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A unicellular organism, also known as a single-celled organism, is an organism that consists of only one cell, unlike a multicellular organism that consists of more than one cell. Historically, simple unicellular organisms have been referred to as monads, though this term is used more specifically to describe organisms of the genus Monas. The main groups of organisms are bacteria, archaea, protozoa, unicellular algae. Unicellular organisms fall into two categories, prokaryotic organisms and eukaryotic organisms. Unicellular organisms are thought to be the oldest form of life, prokaryotes, most Protista, and some fungi are unicellular. Although some of these live in colonies, they dont exhibit specialization. These organisms live together, and each cell in the colony is the same, however, each individual cell must carry out all life processes to survive. In contrast, even the simplest multicellular organisms have cells that depend on each other to survive, most multicellular organisms have a unicellular life-cycle stage. Gametes, for example, are reproductive unicells for multicellular organisms, additionally, multicellularity appears to have evolved independently many times in the history of life. Some organisms are partially uni- and multicellular, like Dictyostelium discoideum, additionally, unicellular organisms can be multinucleate, like Myxogastria and Plasmodium. Candidatus Magnetoglobus multicellular, related to Deltaproteobacteria, is a multicellular prokaryote and it is neither unicellular, nor a colony. Primitive cells, often referred to as protocells, are the precursors to todays unicellular organisms, the RNA world hypothesis assumes that RNA molecules could form in abiotic conditions, which would require nucleic acids and ribose to be present. Theoretical and experimental findings show that nucleic acids and sugars could have been synthesized in early prebiotic conditions, compartmentalization was necessary for chemical reactions to be more likely as well as to differentiate reactions with the external environment. For example, an early RNA replicator ribozyme may have replicated other replicator ribozymes of different RNA sequences if not kept separate, when amphiphiles like lipids are placed in water, the hydrophobic tails aggregate to form micelles and vesicles, with the hydrophilic ends facing outwards. Primitive cells likely used self-assembling fatty-acid vesicles to separate chemical reactions, because of their simplicity and ability to self-assemble in water, its likely that these simple membranes predated other forms of early biological molecules. Prokaryotes lack membrane-bound organelles, such as mitochondria or a nucleus, instead, most prokaryotes have an irregular region that contains DNA, known as the nucleoid. Most prokaryotes have a single, circular chromosome, which is in contrast to eukaryotes, nutritionally, prokaryotes have the ability to utilize a wide range of organic and inorganic material for use in metabolism, including sulfur, cellulose, ammonia, or nitrite. Prokaryotes as a whole are ubiquitous in the environment and exist in extreme environments as well, bacteria are one of the world’s oldest forms of life, and are found virtually everywhere in nature
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Evolution of photosynthesis
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The first photosynthetic organisms probably evolved early in the evolutionary history of life and most likely used reducing agents such as hydrogen or electrons, rather than water. There are three major metabolic pathways by which photosynthesis is carried out, C3 photosynthesis, C4 photosynthesis, C3 photosynthesis is the oldest and most common form. The biochemical capacity to use water as the source for electrons in photosynthesis evolved in an ancestor of extant cyanobacteria. The geological record indicates that this event took place early in Earths history, at least 2450–2320 million years ago. Available evidence from studies of Archean sedimentary rocks indicates that life existed 3500 Ma. A clear paleontological window on cyanobacterial evolution opened about 2000 Ma, cyanobacteria remained principal primary producers throughout the Proterozoic Eon, in part because the redox structure of the oceans favored photoautotrophs capable of nitrogen fixation. Cyanobacteria remain critical to marine ecosystems as primary producers in oceanic gyres, as agents of biological nitrogen fixation, and, in modified form, as the plastids of marine algae. Early photosynthetic systems, such as those from green and purple sulfur and green and purple bacteria, are thought to have been anoxygenic. Green and purple sulfur bacteria are thought to have used hydrogen, green nonsulfur bacteria used various amino and other organic acids. Purple nonsulfur bacteria used a variety of organic molecules. Fossils of what are thought to be filamentous photosynthetic organisms have been dated at 3.4 billion years old, the main source of oxygen in the atmosphere is oxygenic photosynthesis, and its first appearance is sometimes referred to as the oxygen catastrophe. Geological evidence suggests that oxygenic photosynthesis, such as that in cyanobacteria, modern photosynthesis in plants and most photosynthetic prokaryotes is oxygenic. Oxygenic photosynthesis uses water as a donor, which is oxidized to molecular oxygen in the photosynthetic reaction center. Several groups of animals have formed relationships with photosynthetic algae. These are most common in corals, sponges and sea anemones and it is presumed that this is due to the particularly simple body plans and large surface areas of these animals compared to their volumes. This allows the mollusks to survive solely by photosynthesis for several months at a time, some of the genes from the plant cell nucleus have even been transferred to the slugs, so that the chloroplasts can be supplied with proteins that they need to survive. An even closer form of symbiosis may explain the origin of chloroplasts, chloroplasts have many similarities with photosynthetic bacteria, including a circular chromosome, prokaryotic-type ribosomes, and similar proteins in the photosynthetic reaction center. The endosymbiotic theory suggests that bacteria were acquired by early eukaryotic cells to form the first plant cells
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Eukaryote
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A eukaryote is any organism whose cells contain a nucleus and other organelles enclosed within membranes. Eukaryotes belong to the taxon Eukarya or Eukaryota, the presence of a nucleus gives eukaryotes their name, which comes from the Greek εὖ and κάρυον. Eukaryotic cells also contain other membrane-bound organelles such as mitochondria and the Golgi apparatus, in addition, plants and algae contain chloroplasts. Eukaryotic organisms may be unicellular or multicellular, only eukaryotes form multicellular organisms consisting of many kinds of tissue made up of different cell types. Eukaryotes can reproduce asexually through mitosis and sexually through meiosis and gamete fusion. In mitosis, one cell divides to produce two identical cells. In meiosis, DNA replication is followed by two rounds of division to produce four daughter cells each with half the number of chromosomes as the original parent cell. These act as sex cells resulting from genetic recombination during meiosis, the domain Eukaryota appears to be monophyletic, and so makes up one of the three domains of life. The two other domains, Bacteria and Archaea, are prokaryotes and have none of the above features, eukaryotes represent a tiny minority of all living things. However, due to their larger size, eukaryotes collective worldwide biomass is estimated at about equal to that of prokaryotes. Eukaryotes first developed approximately 1. 6–2.1 billion years ago, in 1905 and 1910, the Russian biologist Konstantin Mereschkowsky argued three things about the origin of nucleated cells. Firstly, plastids were reduced cyanobacteria in a symbiosis with a non-photosynthetic host, secondly, the host had earlier in evolution formed by symbiosis between an amoeba-like host and a bacteria-like cell that formed the nucleus. Thirdly, plants inherited photosynthesis from cyanobacteria, the split between the prokaryotes and eukaryotes was introduced in the 1960s. The concept of the eukaryote has been attributed to the French biologist Edouard Chatton, the terms prokaryote and eukaryote were more definitively reintroduced by the Canadian microbiologist Roger Stanier and the Dutch-American microbiologist C. B. van Niel in 1962. In his 1938 work Titres et Travaux Scientifiques, Chatton had proposed the two terms, calling the bacteria prokaryotes and organisms with nuclei in their cells eukaryotes. However he mentioned this in one paragraph, and the idea was effectively ignored until Chattons statement was rediscovered by Stanier. In 1967, Lynn Margulis provided microbiological evidence for endosymbiosis as the origin of chloroplasts and mitochondria in cells in her paper. In the 1970s, Carl Woese explored microbial phylogenetics, studying variations in 16S ribosomal RNA and this helped to uncover the origin of the eukaryotes and the symbiogenesis of two important eukaryote organelles, mitochondria and chloroplasts
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