117-701: "Labyrinthodontia" ( Greek , 'maze-toothed') is an informal grouping of extinct predatory amphibians which were major components of ecosystems in the late Paleozoic and early Mesozoic eras (about 390 to 150 million years ago). Traditionally considered a subclass of the class Amphibia, modern classification systems recognize that labyrinthodonts are not a formal natural group ( clade ) exclusive of other tetrapods . Instead, they consistute an evolutionary grade (a paraphyletic group ), ancestral to living tetrapods such as lissamphibians (modern amphibians) and amniotes ( reptiles , mammals , and kin). "Labyrinthodont"-grade vertebrates evolved from lobe-finned fishes in
234-570: A basis for coinages: anthropology , photography , telephony , isomer , biomechanics , cinematography , etc. Together with Latin words , they form the foundation of international scientific and technical vocabulary ; for example, all words ending in -logy ('discourse'). There are many English words of Greek origin . Greek is an independent branch of the Indo-European language family. The ancient language most closely related to it may be ancient Macedonian , which, by most accounts,
351-552: A biphyletic Amphibia, but his scheme, either with the Lepospondyli as a separate subclass or sunk into Temnospondyli , was continued by Romer in his much used Vertebrate Paleontology of 1933 and later editions, and followed by several subsequent authors with minor variations: Colbert 1969, Daly 1973, Carroll 1988 and Hildebrand & Goslow 2001. The classification cited here is from Romer & Parson, 1985: Labyrinthodontia has fallen out of favor in recent taxonomies because it
468-522: A broad, strongly-built skull roof composed of many small heavily-textured skull bones. "Labyrinthodonts" generally have complex multi-part vertebrae, and several classification schemes have utilized vertebrae to define subgroups. Because labyrinthodonts do not form a monophyletic group, many modern researchers have abandoned the term. However, some have continued to use the group in their classifications, at least informally, pending more detailed study of their relationships. Many authors prefer to simply use
585-440: A deeper skull with laterally placed eyes. They probably had watertight skin, possibly covered with a horny epidermis overlaying small bony nodules, forming scutes , similar to those found in modern caecilians. To the modern eye, these animals would appear like heavyset, lizards betraying their amphibious nature only by their lack of claws and by spawning aquatic eggs. In the middle or late Carboniferous, smaller forms gave rise to
702-552: A fairly stable set of consonantal contrasts . The main phonological changes occurred during the Hellenistic and Roman period (see Koine Greek phonology for details): In all its stages, the morphology of Greek shows an extensive set of productive derivational affixes , a limited but productive system of compounding and a rich inflectional system. Although its morphological categories have been fairly stable over time, morphological changes are present throughout, particularly in
819-621: A family of correspondingly large carnivores, the Limnoscelidae , that flourished briefly in the late Carboniferous. The herbivorous Diadectidae reached their maximum diversity in the late Carboniferous/early Permian , and then quickly declined, their role taken over by early reptilian herbivores like Pareiasaurs and Edaphosaurs . Unlike the reptile-like amphibians, the Temnospondyli remained mostly denizens of rivers and swampland, feeding on fish and perhaps other labyrinthodonts. They underwent
936-556: A faster, more convenient cursive writing style with the use of ink and quill . The Greek alphabet consists of 24 letters, each with an uppercase ( majuscule ) and lowercase ( minuscule ) form. The letter sigma has an additional lowercase form (ς) used in the final position of a word: In addition to the letters, the Greek alphabet features a number of diacritical signs : three different accent marks ( acute , grave , and circumflex ), originally denoting different shapes of pitch accent on
1053-474: A few hundred thousand years. The Pennsylvanian is named after the U.S. state of Pennsylvania , where the coal beds of this age are widespread. The division between Pennsylvanian and Mississippian comes from North American stratigraphy. In North America, where the early Carboniferous beds are primarily marine limestones , the Pennsylvanian was in the past treated as a full-fledged geologic period between
1170-531: A foreign language. It is also often stated that the historical changes have been relatively slight compared with some other languages. According to one estimation, " Homeric Greek is probably closer to Demotic than 12-century Middle English is to modern spoken English ". Greek is spoken today by at least 13 million people, principally in Greece and Cyprus along with a sizable Greek-speaking minority in Albania near
1287-409: A handy reference for the early amphibian tetrapods , and as an apt anatomical description of their distinct tooth pattern. Thus it remains in use as an informal term of convenience by some modern scientists. The largely synonymous name Stegocephalia has been taken up by Michel Laurin and defined cladistically for all traditional labyrinthodonts (including their descendants), so that the name with
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#17328549629791404-576: A major diversification in the wake of the Carboniferous rainforest collapse and they too subsequently reached their greatest diversity in the late Carboniferous and early Permian, thriving in the rivers and brackish coal forests in continental shallow basins around equatorial Pangaea and around the Paleo-Tethys Ocean . Several adaptations to piscivory evolved with some groups having crocodile -like skulls with slender snouts, and presumably had
1521-413: A mixture of anuran and caudatan features, including a broad skull, short tail, and small pedicellate teeth . Complicating the picture is the question of whether Lissamphibia itself may be polyphyletic . Though a minority view, several variants have been forwarded through history. The "Stockholm school" under Gunnar Säve-Söderbergh and Erik Jarvik argued during much of the 20th century that Amphibia as
1638-477: A more refined hunting style. The labyrinthodonts had an amphibious reproduction — they laid eggs in water, where they would hatch to tadpoles . They would remain in water throughout the larval stage until metamorphosis . Only the metamorphosed individuals would eventually venture onto land on occasion. Fossil tadpoles from several species are known, as are neotenic adults with feathery external gills similar to those found in modern lissamphibian tadpoles and in
1755-506: A similar life-style ( Archegosauridae , Melosauridae , Cochleosauridae and Eryopidae , and the reptile-like suborder Embolomeri ). Others evolved as aquatic ambush predators, with short, broad skulls that allowed for opening the mouth by tipping the skull back rather than dropping the jaw ( Plagiosauridae and the Dvinosauria ). In life they would have hunted rather like the modern day monkfish , and several groups are known to have retained
1872-546: A single element, rather than the complex system found in other labyrinthodont groups. Most were aquatic and external gills are sometimes found preserved. The Leposondyli were generally salamander-like, but one group, the Aïstopoda , was snakelike with flexible, reduced skulls, though whether the families belong with the other lepospondyls is uncertain. Some microsaur lepospondyls were squat and short-tailed and appear to have been well adapted to terrestrial life. The best known genus
1989-505: A whole is biphyletic , based on details of the nasal capsule and cranial nerves. In their view lepospondyls are ancestors of frogs, while salamanders and caecilians have evolved independently from porolepiform fish . Robert L. Carroll suggested the tailed amphibians (salamanders and caecilians) are derived from lepospondyl microsaurs and frogs from temnospondyls. The cladistic analysis of Gerobatrachus suggested salamanders and frogs evolved from temnospondyl stock and caecilians being
2106-473: Is Diplocaulus , a nectridean with a boomerang -shaped head. The position of Lepospondyli in relation to other labyrinthodont groups is uncertain, and it is sometimes classified as a separate subclass . The teeth were not labyrinthodont, and the group has classically been seen as separate from the Labyrinthodontia. There is some doubt as to whether the lepospondyls form a phylogenetic unit at all, or
2223-528: Is paraphyletic : the group does not include all the descendants of their most recent common ancestor. Various groups that have traditionally been placed within Labyrinthodontia are currently variously classified as stem tetrapods , basal tetrapods, non-amniote Reptiliomorpha and as a monophyletic or paraphyletic Temnospondyli, according to various cladistic analysis . This reflects the emphasis of ascertaining lineage and ancestral-descendant relatedness in modern-day cladistics . The name does however linger as
2340-438: Is a wastebin taxon containing the padamorphic forms and tadpoles of other labyrinthodonts, notably the reptile-like amphibians, or even very small primitive amniotes with reduced skulls. The labyrinthodonts have their origin in the early middle Devonian (398–392 Mya) or possibly earlier. They evolved from a bony fish group: the fleshy-finned Rhipidistia . The only other living group of Rhipidistans alive today are
2457-463: Is a gap in the fossil record in the early Carboniferous (the " Romer's gap ") when most of the groups appear to have evolved. Further complicating the picture is the amphibian larval-adult life cycle, with physical changes throughout life complicating phylogenetic analysis. The Labyrinthodontia appear to be composed of several nested clades . The two best understood groups, the Ichthyostegalia and
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#17328549629792574-766: Is also found in Bulgaria near the Greek-Bulgarian border. Greek is also spoken worldwide by the sizable Greek diaspora which has notable communities in the United States , Australia , Canada , South Africa , Chile , Brazil , Argentina , Russia , Ukraine , the United Kingdom , and throughout the European Union , especially in Germany . Historically, significant Greek-speaking communities and regions were found throughout
2691-742: Is an Indo-European language, constituting an independent Hellenic branch within the Indo-European language family. It is native to Greece , Cyprus , Italy (in Calabria and Salento ), southern Albania , and other regions of the Balkans , Caucasus , the Black Sea coast, Asia Minor , and the Eastern Mediterranean . It has the longest documented history of any Indo-European language, spanning at least 3,400 years of written records. Its writing system
2808-474: Is an Indo-European language, but also includes a number of borrowings from the languages of the populations that inhabited Greece before the arrival of Proto-Greeks, some documented in Mycenaean texts ; they include a large number of Greek toponyms . The form and meaning of many words have changed. Loanwords (words of foreign origin) have entered the language, mainly from Latin, Venetian , and Turkish . During
2925-510: Is protected and promoted officially as a regional and minority language in Armenia, Hungary , Romania, and Ukraine. It is recognized as a minority language and protected in Turkey by the 1923 Treaty of Lausanne . The phonology , morphology , syntax , and vocabulary of the language show both conservative and innovative tendencies across the entire attestation of the language from the ancient to
3042-933: Is sometimes called aljamiado , as when Romance languages are written in the Arabic alphabet. Article 1 of the Universal Declaration of Human Rights in Greek: Transcription of the example text into Latin alphabet : Article 1 of the Universal Declaration of Human Rights in English: Proto-Greek Mycenaean Ancient Koine Medieval Modern Pennsylvanian (geology) The Pennsylvanian ( / ˌ p ɛ n s əl ˈ v eɪ n i . ən / pen-səl- VAYN -i-ən , also known as Upper Carboniferous or Late Carboniferous ) is, on
3159-518: Is spoken by at least 13.5 million people today in Greece, Cyprus, Italy, Albania, Turkey , and the many other countries of the Greek diaspora . Greek roots have been widely used for centuries and continue to be widely used to coin new words in other languages; Greek and Latin are the predominant sources of international scientific vocabulary . Greek has been spoken in the Balkan peninsula since around
3276-758: Is still used internationally for the writing of Ancient Greek . In Greek, the question mark is written as the English semicolon, while the functions of the colon and semicolon are performed by a raised point (•), known as the ano teleia ( άνω τελεία ). In Greek the comma also functions as a silent letter in a handful of Greek words, principally distinguishing ό,τι ( ó,ti , 'whatever') from ότι ( óti , 'that'). Ancient Greek texts often used scriptio continua ('continuous writing'), which means that ancient authors and scribes would write word after word with no spaces or punctuation between words to differentiate or mark boundaries. Boustrophedon , or bi-directional text,
3393-630: Is the Greek alphabet , which has been used for approximately 2,800 years; previously, Greek was recorded in writing systems such as Linear B and the Cypriot syllabary . The alphabet arose from the Phoenician script and was in turn the basis of the Latin , Cyrillic , Coptic , Gothic , and many other writing systems. The Greek language holds a very important place in the history of the Western world. Beginning with
3510-524: Is the question of whether Lepospondyli actually is monophyletic in the first place. Temnospondyl affinity for the Lissamphibia is suggested by other works. The temnospondyl family Amphibamidae has been considered a possible candidate for the ancestors of lissamphibians. The amphibamid Gerobatrachus , described in 2008, was proposed to be a transitional form between temnospondyls and anurans (frogs and toads) and caudatans (salamanders). It possessed
3627-557: Is uncertainty as to whether it was a true image producing organ or one that could only register light and dark, like that of the modern tuatara . Most labyrinthodonts had special sense organs in the skin, forming a lateral line organ for perception of water flow and pressure, like those found in fish and a number of modern amphibians . This would enable them to pick up the vibration of their prey and other waterborne sounds while hunting in murky, weed filled waters. Early labyrinthodont groups had massive stapes , likely primarily anchoring
Labyrinthodontia - Misplaced Pages Continue
3744-641: The Carboniferous . The end of the Devonian saw the late Devonian extinction event, followed by a gap in the fossil record of some 15 million years at the start of the Carboniferous, called " Romer's gap ". The gap marks the disappearance of the ichthyostegalian forms as well as the origin of the higher labyrinthodonts. Finds from this period found in East Kirkton Quarry includes the peculiar, probably secondarily aquatic Crassigyrinus , which may represent
3861-472: The Devonian , though a formal boundary between fish and amphibian is difficult to define at this point in time. "Labyrinthodont" generally refers to extinct four-limbed tetrapods with a large body size and a crocodile -like lifestyle. The name describes the pattern of infolding of the dentin and enamel of the teeth, which are often the only part of the creatures that fossilize . They are also distinguished by
3978-596: The Dvinosauria , and even marine forms such as the Trematosauridae . The Temnospondyli may have given rise to the modern frogs and salamanders in the late Permian or early Triassic . A small group of uncertain origin, the Lepospondyli evolved mostly small species that can be found in European and North American Carboniferous and early Permian strata. They are characterized by simple spool-shaped vertebrae formed from
4095-486: The Eastern Mediterranean , in what are today Southern Italy , Turkey , Cyprus , Syria , Lebanon , Israel , Palestine , Egypt , and Libya ; in the area of the Black Sea , in what are today Turkey, Bulgaria , Romania , Ukraine , Russia , Georgia , Armenia , and Azerbaijan ; and, to a lesser extent, in the Western Mediterranean in and around colonies such as Massalia , Monoikos , and Mainake . It
4212-592: The ICS geologic timescale , the younger of two subperiods of the Carboniferous Period (or the upper of two subsystems of the Carboniferous System). It lasted from roughly 323.2 million years ago to 298.9 million years ago . As with most other geochronologic units, the rock beds that define the Pennsylvanian are well identified, but the exact date of the start and end are uncertain by
4329-510: The Indo-Iranian languages (see Graeco-Aryan ), but little definitive evidence has been found. In addition, Albanian has also been considered somewhat related to Greek and Armenian, and it has been proposed that they all form a higher-order subgroup along with other extinct languages of the ancient Balkans; this higher-order subgroup is usually termed Palaeo-Balkan , and Greek has a central position in it. Linear B , attested as early as
4446-480: The Late Carboniferous and Early Permian were fully terrestrial with stout skeletons, and were the heaviest land animals of their time. The Mesozoic labyrinthodonts were primarily aquatic with increasingly cartilaginous skeleton. The eyes of most labyrinthodonts were situated at the top of the skull, offering good vision upwards, but very little lateral vision. The parietal eye was prominent, although there
4563-545: The Lepospondyli has been favored as lissamphibian ancestors. Like the modern amphibians, they were mostly small with simple vertebrae, resembling lissamphibians in many aspects of external anatomy and presumably ecological niches . At a subclass level, it was thought that labyrinthodonts gave rise to lepospondyls, and lepospondyls to lissamphibians. Several cladistic studies also favour the lepospondyl link, though placing Lepospondyli as close relatives or even derived from reptile-like amphibians . One problem with this position
4680-515: The end of the Permian , during which their cynodont descendants became smaller and nocturnal , as the reptilian archosaurs took over, although dicynodonts would remain megafaunal until their extinction at the end of the Triassic . Most pre-rainforest collapse tetrapods remained smaller, probably due to the land being primarily occupied by the gigantic millipedes, scorpions, and flying insects. After
4797-425: The esophagus and were capable of functioning as lungs (a condition still found in lungfish and some physostome ray-finned fishes ), allowing them to hunt in stagnant water or in waterways where rotting vegetation would have lowered oxygen content. The earliest forms, such as Acanthostega , had vertebrae and limbs quite unsuited to life on land. This is in contrast to the earlier view that fish had first invaded
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4914-663: The lungfish , the sister group of the landliving vertebrates . Earliest traces of the land-living forms are fossil trackways from Zachełmie quarry , Poland , dated to 395 million years ago, attributed to an animal with feet very similar to Ichthyostega . By the late Devonian, land plants had stabilized freshwater habitats, allowing the first wetland ecosystems to develop, with increasingly complex food webs that afforded new opportunities. The early labyrinthodonts were wholly aquatic, hunting in shallow water along tidal shores or weed filled tidal channels. From their piscine ancestors, they had inherited swim bladders that opened to
5031-492: The nominal and verbal systems. The major change in the nominal morphology since the classical stage was the disuse of the dative case (its functions being largely taken over by the genitive ). The verbal system has lost the infinitive , the synthetically -formed future, and perfect tenses and the optative mood . Many have been replaced by periphrastic ( analytical ) forms. Pronouns show distinctions in person (1st, 2nd, and 3rd), number (singular, dual , and plural in
5148-468: The order Ichthyostegalia , though the group is an evolutionary grade rather than a clade . Ichthyostegalians were predominantly aquatic and most show evidence of functional internal gills throughout life, and probably only occasionally ventured onto land. Their polydactylous feet had more than the usual five digits for tetrapods and were paddle-like. The tail bore true fin rays like those found in fish. The vertebrae were complex and rather weak. At
5265-451: The reptile-like amphibians have from the outset been known to be paraphyletic . Tellingly, labyrinthodont systematics was the subject of the inaugural meeting of International Society for Phylogenetic Nomenclature . The early labyrinthodonts are known from the Devonian and possibly extending into the Romer's Gap of the early Carboniferous . These labyrinthodonts are often grouped together as
5382-427: The swim bladders of their ancestors. They could breathe air, which would have been a great advantage for residents of warm shoals with low oxygen levels in the water. There was no diaphragma and the ribs in many forms were too short or spaced too closely to aid in expanding the lungs. Likely air was inflated into the lungs by contractions of a throat sac against the skull floor like in modern amphibians, which may be
5499-501: The temnospondyls , lepospondyls and reptile-like amphibians , the latter which were the relatives and ancestors of the Amniota . While most labyrinthodonts remained aquatic or semi-aquatic, some of the reptile-like amphibians adapted to explore the terrestrial ecological niches as small or medium-sized predators . They evolved increasingly terrestrial adaptions during the Carboniferous, including stronger vertebrae and slender limbs, and
5616-465: The 3rd millennium BC, or possibly earlier. The earliest written evidence is a Linear B clay tablet found in Messenia that dates to between 1450 and 1350 BC, making Greek the world's oldest recorded living language . Among the Indo-European languages, its date of earliest written attestation is matched only by the now-extinct Anatolian languages . The Greek language is conventionally divided into
5733-486: The Greek alphabet since approximately the 9th century BC. It was created by modifying the Phoenician alphabet , with the innovation of adopting certain letters to represent the vowels. The variant of the alphabet in use today is essentially the late Ionic variant, introduced for writing classical Attic in 403 BC. In classical Greek, as in classical Latin, only upper-case letters existed. The lower-case Greek letters were developed much later by medieval scribes to permit
5850-425: The Greek language are often emphasized. Although Greek has undergone morphological and phonological changes comparable to those seen in other languages, never since classical antiquity has its cultural, literary, and orthographic tradition been interrupted to the extent that one can speak of a new language emerging. Greek speakers today still tend to regard literary works of ancient Greek as part of their own rather than
5967-491: The Greek language was the Cypriot syllabary (also a descendant of Linear A via the intermediate Cypro-Minoan syllabary ), which is closely related to Linear B but uses somewhat different syllabic conventions to represent phoneme sequences. The Cypriot syllabary is attested in Cyprus from the 11th century BC until its gradual abandonment in the late Classical period, in favor of the standard Greek alphabet. Greek has been written in
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#17328549629796084-629: The Greek verb have likewise remained largely the same over the course of the language's history but with significant changes in the number of distinctions within each category and their morphological expression. Greek verbs have synthetic inflectional forms for: Many aspects of the syntax of Greek have remained constant: verbs agree with their subject only, the use of the surviving cases is largely intact (nominative for subjects and predicates, accusative for objects of most verbs and many prepositions, genitive for possessors), articles precede nouns, adpositions are largely prepositional, relative clauses follow
6201-661: The Greek-Albanian border. A significant percentage of Albania's population has knowledge of the Greek language due in part to the Albanian wave of immigration to Greece in the 1980s and '90s and the Greek community in the country. Prior to the Greco-Turkish War and the resulting population exchange in 1923 a very large population of Greek-speakers also existed in Turkey , though very few remain today. A small Greek-speaking community
6318-679: The Gzhelian plus the uppermost Kasimovian. The Missourian or Monongahela corresponds to the rest of the Kasimovian. The Desmoinesian or Allegheny corresponds to the upper half of the Moscovian. The Atokan or upper Pottsville corresponds to the lower half of the Moscovian. The Morrowan corresponds to the Bashkirian. In the European subdivision, the Carboniferous is divided into two epochs: Dinantian (early) and Silesian (late). The Silesian starts earlier than
6435-686: The Mississippian and the Permian . In parts of Europe, the Mississippian and Pennsylvanian are one more-or-less continuous sequence of lowland continental deposits and are grouped together as the Carboniferous Period. The current internationally used geologic timescale of the ICS gives the Mississippian and Pennsylvanian the rank of subperiods, subdivisions of the Carboniferous Period. All modern classes of fungi have been found in rocks of Pennsylvanian age. The major forms of life at this time were
6552-454: The Permian, the peculiar Nectridea found their way from Euramerica to Gondwanaland . From the middle of the Permian, the climate dried up, making life difficult for the amphibians. The terrestrial reptiliomorphs disappeared, though aquatic crocodile-like Embolomeri continued to thrive until going extinct in the Triassic . The diverse lepospondyl inhabitants of the undergrowth disappear from
6669-404: The acute during the late 20th century, and it has only been retained in typography . After the writing reform of 1982, most diacritics are no longer used. Since then, Greek has been written mostly in the simplified monotonic orthography (or monotonic system), which employs only the acute accent and the diaeresis. The traditional system, now called the polytonic orthography (or polytonic system),
6786-479: The adult size, thus the amniotes would have evolved from very small animals. A number of small, fragmentary fossils of possibly diadectomorph affinity has been proposed as the first amniote, including Gephyrostegus , Solenodonsaurus , Westlothiana and Casineria . Fossilized footprints found in New Brunswick indicate the first reptiles were established by 315 million years ago. The term labyrinthodont
6903-402: The ancient language; singular and plural alone in later stages), and gender (masculine, feminine, and neuter), and decline for case (from six cases in the earliest forms attested to four in the modern language). Nouns, articles, and adjectives show all the distinctions except for a person. Both attributive and predicative adjectives agree with the noun. The inflectional categories of
7020-403: The animal across sandbanks and through vegetation filled waterways. Ichthyostega and Acanthostega had paddle-like polydactyl feet with stout bony toes that also would have enabled them to drag themselves across land. The aquatic ichthyostegalians flourished in tidal channels and swampland through the remainder of the Devonian, only to disappear from the fossil record at the transition to
7137-446: The ankle had limited mobility and the toes lacked claws , limiting the amount of traction the feet could produce. This would have made most labyrinthodonts slow and clumsy on land. In adulthood, most of the larger species were likely confined to water. Some late Paleozoic groups, particularly microsaurs and seymouriamorphs , were small to medium-sized and appear to have been competent terrestrial animals. The advanced diadectomorphs from
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#17328549629797254-534: The arthropods. Arthropods were far larger than modern ones. Arthropleura , a giant millipede , was a common sight and the giant griffinfly Meganeura "flew the skies". It is commonly considered that is because of high oxygen level, however some of those large arthropod records are also known from period with relatively low oxygen, which suggest high oxygen pressure may not have been a primary reason for their gigantism. Amphibians were diverse and common; some were several meters long as adults. The collapse of
7371-498: The brain case to the skull roof . It is a question of some doubt whether early terrestrial labyrinthodonts had the stapes connected to a tympanum covering their otic notch, and if they had an aerial sense of hearing at all. The tympanum in anurans and amniotes appear to have evolved separately, indicating most, if not all, labyrinthodonts were unable to pick up airborne sound. The early labyrinthodonts possessed well developed internal gills as well as primitive lungs , derived from
7488-416: The close of the Devonian, forms with progressively stronger legs and vertebrae evolved, and the later groups lacked functional gills as adults. All were however predominantly aquatic and some spent all or nearly all their lives in water. An early branch was the terrestrial reptile-like amphibians, variously called Anthracosauria or Reptiliomorpha . Tulerpeton has been suggested as the earliest member of
7605-428: The closest known relatives of modern amniotes. They too are thought to have been on the amphibian side of the divide, despite no known diadectomorph fossil tadpoles. Analysis of new finds and composition of larger trees do however indicate the phylogeny may not be as well understood as traditionally thought. Several authors have suggested that terrestrial eggs evolved from amphibian eggs laid on land to avoid predation on
7722-405: The copious amounts of dermal armour some of the larger forms evidently had. This term is widely used in 19th and early 20th century literature. Classification of the earliest finds was attempted on the basis of the skull roof , often the only part of the specimen preserved. With the frequent convergent evolution of head shape in labyrinthodonts, this led to form taxa only. The relationship of
7839-414: The diadectomorphs gave rise to the first reptiles in the Late Carboniferous . The most diverse group of labyrinthodonts was the Temnospondyli . Temnospondyls appeared in the early Carboniferous and came in all sizes, from small salamander-like Stereospondyli that scurried along the waters edge and undergrowth, to giant, well armoured Archegosauroidea that looked more like crocodiles. Prionosuchus
7956-428: The earliest sauropsid reptiles ( Hylonomus ), and the earliest known " pelycosaur " synapsids ( Archaeothyris ). Small lizard-like animals quickly gave rise to many descendants. Amniotes underwent a major evolutionary radiation, in response to the drier climate that followed the rainforest collapse . For some reason, pelycosaurs were able to reach larger sizes before reptiles could, and this trend continued until
8073-429: The early Carboniferous labyrinthodonts to the amniotes has traditionally been seen as fairly well mapped out since the early 20th century, mainly leaving only the question of the demarcation line between the amphibian and reptilian grade of reproduction. Work by Carroll and Laurin around the turn of the millennium has greatly helped in pinpointing the transition. The early reptile-like amphibians were mostly aquatic,
8190-404: The early 19th century that was used for literary and official purposes in the newly formed Greek state. In 1976, Dimotiki was declared the official language of Greece, after having incorporated features of Katharevousa and thus giving birth to Standard Modern Greek , used today for all official purposes and in education . The historical unity and continuing identity between the various stages of
8307-399: The early forms can readily be separated from Rhipidistan fish by the cleithrum / scapula complex being separate from the skull to form a pectoral girdle able to carry the weight of the front end of the animals. They were all carnivorous , initially eating fish and possibly going ashore to feed off washed up carrion of sea animals caught in tidal ponds, only later turning into predators of
8424-439: The eggs and competition from other labyrinthodonts. The amniote egg would necessarily have had to evolve from one with an anamniote structure, as those found in fish and modern amphibians. In order for such an egg to excrete CO 2 on land without the specialized membranes to aid in respiration, it would have to be very small, 1 cm in diameter or smaller. Such very small eggs with direct development would severely restrict
8541-602: The epics of Homer , ancient Greek literature includes many works of lasting importance in the European canon . Greek is also the language in which many of the foundational texts in science and philosophy were originally composed. The New Testament of the Christian Bible was also originally written in Greek. Together with the Latin texts and traditions of the Roman world , the Greek texts and Greek societies of antiquity constitute
8658-402: The exception of the snake-like aïstopods , the skulls of labyrinthodonts were massive. The broad head and short neck may have been a result of respiratory constraints. Their jaws were lined with small, sharp, conical teeth and the roof of the mouth bore larger tusk-like teeth. The teeth were replaced in waves that traveled from the front of the jaw to the back in such a way that every other tooth
8775-550: The field: Labyrinthodonts were generally amphibian-like in build. They were short-legged and mostly large headed, with moderately short to long tails. Many groups, and all the early forms, were large animals. Primitive members of all labyrinthodont groups were probably true water predators, and various degrees of amphibious, semi-aquatic and semi terrestrial modes of living arose independently in different groups. Some lineages remained waterbound or became secondarily fully aquatic with reduced limbs and elongated, eel -like bodies. With
8892-431: The first reptiles . In the late Carboniferous, a global rainforest collapse favoured the more terrestrially adapted reptiles, while the many of their amphibian relatives failed to reestablish. Some reptile-like amphibians did flourish in the new seasonal environment. The reptiliomorph family Diadectidae evolved herbivory, becoming the largest terrestrial animals of the day with barrel-shaped, heavy bodies. There were also
9009-748: The first highly terrestrially adapted groups being the Seymouriamorpha and the Diadectomorpha . The seymouriamorphs were small to medium-sized animals with stout limbs, their remains are sometimes found in what has been interpreted as dry environments, indicating their skin had a water-tight epidermal horny overlay or even scales as evident in Discosauriscus . Their skeletons are very similar to those of early reptiles, though finds of seymouriamorph tadpoles have shown they retained an amphibian reproduction. The diadectomorph families are generally considered to be
9126-452: The following periods: In the modern era, the Greek language entered a state of diglossia : the coexistence of vernacular and archaizing written forms of the language. What came to be known as the Greek language question was a polarization between two competing varieties of Modern Greek: Dimotiki , the vernacular form of Modern Greek proper, and Katharevousa , meaning 'purified', a compromise between Dimotiki and Ancient Greek developed in
9243-818: The fossil record, among them the snake-like Aïstopoda . With the close of the Paleozoic , most of the Permian groups disappeared , with the exceptions of the Mastodonsauroidea , Metoposauridae and Plagiosauridae , who continued into the Triassic. In the early Triassic these groups enjoyed a brief renaissance in the waterways of continental shallows, with large forms like Thoosuchus , Benthosuchus and Eryosuchus . Their ecological niches were probably similar to those of modern-day crocodiles, as fish hunters and riverside carnivores. All groups developed progressively weaker vertebrae, reduced limb ossification and flatter skulls with prominent lateral line organs, indicating
9360-497: The fry of lungfish and bichirs . The existence of a larval stage as the primitive condition in all groups of labyrinthodonts can be fairly safely assumed, in that tadpoles of Discosauriscus , a close relative of the amniotes , are known. The systematic placement of groups within Labyrinthodontia is notoriously fickle. Several groups are identified, but there is no consensus of their phylogenetic relationship. Many key groups were small with moderately ossified skeletons, and there
9477-454: The hind-foot five, similar to the pattern seen in modern amphibians. Temnospondyls had a conservative vertebral column in which the pleurocentra remained small in primitive forms, vanishing entirely in the more advanced ones. The intercentra bore the weight of the animal, being large and forming a complete ring. All were more or less flat-headed with either strong or secondarily weak vertebrae and limbs. There were also fully aquatic forms, like
9594-439: The infinitive entirely (employing a raft of new periphrastic constructions instead) and uses participles more restrictively. The loss of the dative led to a rise of prepositional indirect objects (and the use of the genitive to directly mark these as well). Ancient Greek tended to be verb-final, but neutral word order in the modern language is VSO or SVO. Modern Greek inherits most of its vocabulary from Ancient Greek, which in turn
9711-412: The labyrinthodonts were carnivorous. The rather broad, flat skulls and hence short jaw muscle would however not allow them to open their mouth to any great extent. Likely the majority of them would employ a sit-and-wait strategy, similar to that of many modern amphibians. When suitable prey swam or walked within reach, the jaw would slam shut, the palatine tusks stabbing the hapless victim. The strain put on
9828-710: The land—either in search of prey like modern mudskippers , or to find water when the pond they lived in dried out. Early fossil tetrapods have been found in marine sediments, suggesting marine and brackish areas were their primary habitat. This is further corroborated by fossils of early labyrinthodonts being found scattered all around the world, indicating they must have spread by following the coastal lines rather than through freshwater only. The first labyrinthodonts were all large to moderately large animals, and would have suffered considerable problems on land despite their members ending in toes rather than fin-rays. While they retained gills and fish-like skulls and tails with fin rays ,
9945-510: The large invertebrates of the Devonian at the waters edge. The various early forms are for convenience grouped together as Ichthyostegalia . While the body shape and proportions of the ichthyostegalians went largely unchanged throughout their evolutionary history, the limbs underwent a rapid evolution. The proto-tetrapods like from Elginerpeton and Tiktaalik had extremities ending in fin-rays with no clear fingers, primarily suited for movement in open water, but also capable of propelling
10062-464: The large forms. Getting rid of carbon dioxide would present a greater problem on land, and the larger labyrinthodonts probably combined a high tolerance for blood carbonic acid with returning to the water to dissipate the carbon dioxide through the skin. The loss of the armour of rhomboid scales of their piscine ancestors allowed for this as well as additional respiration through the skin as in modern amphibians. Like their sarcopterygian ancestors,
10179-407: The largely traditional meaning is still employed. An informal term with a broader meaning is stem tetrapod , a stem group consisting of all species more closely related to modern tetrapods than to lungfish , but excluding the crown group . This group includes both traditional "labyrinthodonts" as well as more basal tetrapodomorph fish, though its total content is a matter of some uncertainty, as
10296-446: The larval gills into adulthood, being fully aquatic. The Metoposauridae adapted to hunting in shallows and murky swamps, with ∩-shaped skull, much like their Devonian ancestors. In Euramerica , the Lepospondyli , a host of small, mostly aquatic amphibians of uncertain phylogeny, appeared in the Carboniferous. They lived in the tropical forest undergrowth and in small ponds, in ecological niches similar to those of modern amphibians. In
10413-463: The late 15th century BC, was the first script used to write Greek. It is basically a syllabary , which was finally deciphered by Michael Ventris and John Chadwick in the 1950s (its precursor, Linear A , has not been deciphered and most likely encodes a non-Greek language). The language of the Linear B texts, Mycenaean Greek , is the earliest known form of Greek. Another similar system used to write
10530-477: The late Permian/early Triassic temnospondyls rarely if ever left the water. An extremely large brachyopid (likely a plagiosaur or a close relative) is estimated to have been 7 meters long, and probably just as heavy as the Permian Prionosuchus . With the rise of the real crocodiles in the middle Triassic, even these Temnospondyli went into decline, though some hung on to at least early Cretaceous on
10647-419: The line, indicating the split may have happened before the Devonian -Carboniferous transition. Their skulls were relatively deep and narrow compared to other labyrinthodonts. Front and hind feet bore five digits on most forms. Several of the early groups are known from brackish or even marine environments, having returned to a more or less fully aquatic mode of living. With the exception of the diadectomorphs ,
10764-621: The membership of Greece and Cyprus in the European Union, Greek is one of the organization's 24 official languages . Greek is recognized as a minority language in Albania, and used co-officially in some of its municipalities, in the districts of Gjirokastër and Sarandë . It is also an official minority language in the regions of Apulia and Calabria in Italy. In the framework of the European Charter for Regional or Minority Languages , Greek
10881-441: The modern period. The division into conventional periods is, as with all such periodizations, relatively arbitrary, especially because, in all periods, Ancient Greek has enjoyed high prestige, and the literate borrowed heavily from it. Across its history, the syllabic structure of Greek has varied little: Greek shows a mixed syllable structure, permitting complex syllabic onsets but very restricted codas. It has only oral vowels and
10998-399: The noun they modify and relative pronouns are clause-initial. However, the morphological changes also have their counterparts in the syntax, and there are also significant differences between the syntax of the ancient and that of the modern form of the language . Ancient Greek made great use of participial constructions and of constructions involving the infinitive, and the modern variety lacks
11115-521: The objects of study of the discipline of Classics . During antiquity , Greek was by far the most widely spoken lingua franca in the Mediterranean world . It eventually became the official language of the Byzantine Empire and developed into Medieval Greek . In its modern form , Greek is the official language of Greece and Cyprus and one of the 24 official languages of the European Union . It
11232-706: The older periods of Greek, loanwords into Greek acquired Greek inflections, thus leaving only a foreign root word. Modern borrowings (from the 20th century on), especially from French and English, are typically not inflected; other modern borrowings are derived from Albanian , South Slavic ( Macedonian / Bulgarian ) and Eastern Romance languages ( Aromanian and Megleno-Romanian ). Greek words have been widely borrowed into other languages, including English. Example words include: mathematics , physics , astronomy , democracy , philosophy , athletics , theatre, rhetoric , baptism , evangelist , etc. Moreover, Greek words and word elements continue to be productive as
11349-487: The rainforest collapse, the giant arthropods disappeared, allowing amniote tetrapods to achieve larger sizes. The Pennsylvanian has been variously subdivided. The international timescale of the ICS follows the Russian subdivision into four stages: North American subdivision is into five stages, but not precisely the same, with additional (older) Appalachian series names following: The Virgilian or Conemaugh corresponds to
11466-483: The rainforest ecology in the mid-Pennsylvanian (between the Moscovian and the Kasimovian) removed many amphibian species that did not survive as well in the cooler, drier conditions. Amniotes, however, prospered due to specific key adaptations. One of the greatest evolutionary innovations of the Carboniferous was the amniote egg, which allowed for the further exploitation of the land by certain tetrapods . These included
11583-416: The reason for the retention of the very flat skull in later forms. Exhalation with the aid of the ribs probably evolved only in the line leading to amniotes . Many aquatic forms retained their larval gills in adulthood. With the high atmospheric oxygen and carbon dioxide pressure, particularly during the Carboniferous, the primitive throat sac breathing would have been sufficient for obtaining oxygen even for
11700-446: The relationships of these animals are not well understood. Below is a suggested evolutionary tree of Vertebrates including the Labyrinthodontia, from Colbert 1969 and Caroll 1997. Dashed lines indicate relationships that commonly vary between authors. Greek language Greek ( Modern Greek : Ελληνικά , romanized : Elliniká , [eliniˈka] ; Ancient Greek : Ἑλληνική , romanized : Hellēnikḗ )
11817-458: The same animal, and already by the middle of the 20th century several of the small-bodied groups were suspected of being larval or neotenic forms. The classification presented here is from Watson, 1920: The traditional classification was initiated by Säve-Söderbergh in the 1930s. He believed that Amphibia was biphyletic , and that salamanders and caecilians had evolved independently from porolopiform fish . Few shared Säve-Söderbergh's view of
11934-595: The sister group of the reptile-like amphibians, rendering Lissamphibia itself an evolutionary grade relative to the remaining tetrapod classes. The cladistic analysis of Chinlestegophis by Pardo et al. (2017) does recover Lissamphibia as polyphyletic, but with all groups of lissamphibians falling within Temnospondyli; Batrachia is recovered in the analysis as part of Dissorophoidea, while Gymnophonia falls within Stereospondylomorpha. The fossil sequence leading from
12051-471: The sister group to later labyrinthodont groups. Early Carboniferous saw the radiation of the family Loxommatidae , a distinct if mysterious group that may have been the ancestors or sister taxon of the higher groups, characterized by keyhole-shaped eye openings. By the Visean age of mid-Carboniferous times the labyrinthodonts had radiated into at least three main branches. Recognizable groups are representative of
12168-471: The southern Gondwanaland , in regions too cold for crocodiles. There is today a general consensus that all modern amphibians, the Lissamphibia , have their origin in labyrinthodont stock, but this is where consensus ends. The fragile bones of the lissamphibians are extremely rare as fossils, and the modern amphibians are highly derived, making comparison with fossil labyrinthodonts difficult. Traditionally,
12285-437: The stressed vowel; the so-called breathing marks ( rough and smooth breathing ), originally used to signal presence or absence of word-initial /h/; and the diaeresis , used to mark the full syllabic value of a vowel that would otherwise be read as part of a diphthong. These marks were introduced during the course of the Hellenistic period. Actual usage of the grave in handwriting saw a rapid decline in favor of uniform usage of
12402-448: The teeth by this mode of feeding may have been the reason for the reinforcing labyrinthodont enamel typifying the group. Swallowing was done by tipping the head back, as seen in many modern amphibians and in crocodiles . Evolution of a deeper skull, better jaw control and a reduction of the palatine tusks is only seen in the more advanced reptile-like forms, possibly in connection with the evolution of more effective breathing, allowing for
12519-416: The term tetrapod , while others have re-defined the previously obsolete term Stegocephalia ("roof heads") as a cladistic alternative to "Labyrinthodontia" or "Tetrapoda". The labyrinthodonts flourished for more than 200 million years. Particularly the early forms exhibited a lot of variation, yet there are still a few basic anatomical traits that make their fossils very distinct and easily recognizable in
12636-538: The terrestrial forms were moderately sized creatures that appeared in the early Carboniferous . The vertebrae of the group foreshadowed that of primitive reptiles, with small pleurocentra , which grew and fused to become the true centrum in later vertebrates. The most well known genus is Seymouria . Some members of the most advanced group, the Diadectomorpha, were herbivorous and grew to several meters in length, with great, barrel-shaped bodies. Small relatives of
12753-573: The various groups to each other and to the lissamphibians (and to some degree the first reptiles ) is still a matter of some debate. Several schemes have been forwarded, and at present there is no consensus among workers in the field. A systematic approach based on the relative size and shape of the elements of the complex labyrinthodont vertebrae was favored in the early 20th century. This classification quickly fell into disuse as some forms of backbones appear to have appeared more than once and different types are found in close relatives, sometimes even in
12870-568: Was a distinct dialect of Greek itself. Aside from the Macedonian question, current consensus regards Phrygian as the closest relative of Greek, since they share a number of phonological, morphological and lexical isoglosses , with some being exclusive between them. Scholars have proposed a Graeco-Phrygian subgroup out of which Greek and Phrygian originated. Among living languages, some Indo-Europeanists suggest that Greek may be most closely related to Armenian (see Graeco-Armenian ) or
12987-549: Was also used as the official language of government and religion in the Christian Nubian kingdoms , for most of their history. Greek, in its modern form, is the official language of Greece, where it is spoken by almost the entire population. It is also the official language of Cyprus (nominally alongside Turkish ) and the British Overseas Territory of Akrotiri and Dhekelia (alongside English ). Because of
13104-546: Was also used in Ancient Greek. Greek has occasionally been written in the Latin script , especially in areas under Venetian rule or by Greek Catholics . The term Frankolevantinika / Φραγκολεβαντίνικα applies when the Latin script is used to write Greek in the cultural ambit of Catholicism (because Frankos / Φράγκος is an older Greek term for West-European dating to when most of (Roman Catholic Christian) West Europe
13221-548: Was an exceptionally large member of the Archegosauridae, estimated to have been up to 9 meters long, it is the largest amphibian ever known to have lived. Temnospondyls typically had large heads and heavy shoulder girdles with moderately long tails. A fossil trackway from Lesotho shows larger forms dragged themselves by the front limbs over slippery surfaces with limited sideways movement of the body, very unlike modern salamanders. A temnospondyl's fore-foot had only four toes, and
13338-491: Was coined by Hermann Burmeister in reference to the tooth structure. Labyrinthodontia was first used as a systematic term by Richard Owen in 1860, and assigned to Amphibia the following year. It was ranked as an order under class Amphibia by Watson in 1920 and as a superorder by Romer in 1947. An alternative name, Stegocephalia was created in 1868 by American paleontologist Edward Drinker Cope , from Greek stego cephalia —"roofed head", and refer to anapsid skull and
13455-427: Was mature, and the ones in between were young. All teeth were labyrinthodont. The sole exception were the chisel-like teeth of some of the advanced herbivorous diadectomorphs . The skull had prominent otic notches behind each eye and a parietal eye . The vertebrae were complex and not particularly strong, consisting of numerous, often poorly ossified elements. The long bones of the limbs were short and broad and
13572-566: Was under the control of the Frankish Empire ). Frankochiotika / Φραγκοχιώτικα (meaning 'Catholic Chiot') alludes to the significant presence of Catholic missionaries based on the island of Chios . Additionally, the term Greeklish is often used when the Greek language is written in a Latin script in online communications. The Latin script is nowadays used by the Greek-speaking communities of Southern Italy . The Yevanic dialect
13689-653: Was written by Romaniote and Constantinopolitan Karaite Jews using the Hebrew Alphabet . In a tradition, that in modern time, has come to be known as Greek Aljamiado , some Greek Muslims from Crete wrote their Cretan Greek in the Arabic alphabet . The same happened among Epirote Muslims in Ioannina . This also happened among Arabic-speaking Byzantine rite Christians in the Levant ( Lebanon , Palestine, and Syria ). This usage
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