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117-429: The Blasticotomidae are a very small family of sawflies , containing only 13 species in 3 genera worldwide, restricted to temperate regions of Eurasia where the larvae are specialized stem borers of ferns . The family has antennae somewhat similar to the family Argidae , with only one or two flagellomeres , but can be distinguished by the lateral portions of the metasomal tergites being sharply creased beneath

234-630: A bolide impact, for which an impact crater containing Manicouagan Reservoir in Quebec , Canada , has been singled out. However, the Manicouagan impact melt has been dated to 214±1 Mya. The date of the Triassic-Jurassic boundary has also been more accurately fixed recently, at 201.4 Mya. Both dates are gaining accuracy by using more accurate forms of radiometric dating, in particular the decay of uranium to lead in zircons formed at time of

351-626: A cosmopolitan distribution . Coelacanths show their highest post- Devonian diversity in the Early Triassic . Ray-finned fishes (actinopterygians) went through a remarkable diversification in the beginning of the Triassic, leading to peak diversity during the Middle Triassic; however, the pattern of this diversification is still not well understood due to a taphonomic megabias . The first stem-group teleosts appeared during

468-428: A dagger ( † ). Many species of sawfly have retained their ancestral attributes throughout time, specifically their plant-eating habits, wing veins and the unmodified abdomen, where the first two segments appear like the succeeding segments. The absence of the narrow wasp waist distinguishes sawflies from other members of hymenoptera, although some are Batesian mimics with coloration similar to wasps and bees, and

585-555: A chain of mountain ranges stretching from Turkey to Malaysia . Pangaea was fractured by widespread faulting and rift basins during the Triassic—especially late in that period—but had not yet separated. The first nonmarine sediments in the rift that marks the initial break-up of Pangaea, which separated eastern North America from Morocco , are of Late Triassic age; in the United States , these thick sediments comprise

702-402: A family or genus of hosts. For example, Iris sawfly larvae, emerging in summer, can quickly defoliate species of Iris including the yellow flag and other freshwater species. Similarly the rose sawflies, Arge pagana and A. ochropus , defoliate rose bushes. The giant woodwasp or horntail, Urocerus gigas , has a long ovipositor, which with its black and yellow colouration make it

819-474: A few exposures in the west. During the Triassic peneplains are thought to have formed in what is now Norway and southern Sweden. Remnants of this peneplain can be traced as a tilted summit accordance in the Swedish West Coast . In northern Norway Triassic peneplains may have been buried in sediments to be then re-exposed as coastal plains called strandflats . Dating of illite clay from

936-465: A good mimic of a hornet . Despite the alarming appearance, the insect cannot sting. The eggs are laid in the wood of conifers such as Douglas fir , pine, spruce , and larch . The larvae eat tunnels in the wood, causing economic damage. Alternative measures to control sawflies can be taken. Small-scale, mechanical methods include visually confirming larval presence on a plant and subsequently removing them, either by pruning damaged leaves or removing

1053-835: A humid and warm climate. The cladogram is based on Schulmeister 2003. Xyeloidea ( Triassic –present) [REDACTED] Tenthredinoidea [REDACTED] Pamphilioidea [REDACTED] Cephoidea (stem sawflies) [REDACTED] Siricoidea (horntails or wood wasps) [REDACTED] Xiphydrioidea (wood wasps) [REDACTED] Orussoidea ( parasitic wood wasps) [REDACTED] Apocrita ( ants , bees , wasps ) [REDACTED] There are approximately 8,000 species of sawfly in more than 800 genera, although new species continue to be discovered. However, earlier studies indicated that 10,000 species grouped into about 1,000 genera were known. Early phylogenies such as that of Alexandr Rasnitsyn , based on morphology and behaviour, identified nine clades which did not reflect

1170-416: A leaf. Larvae that feed on wood will pupate in the tunnels they have constructed. In one species, the jumping-disc sawfly ( Phyllotoma aceris ) forms a cocoon which can act like a parachute. The larvae live in sycamore trees and do not damage the upper or lower cuticles of leaves that they feed on. When fully developed, they cut small perforations in the upper cuticle to form a circle. After this, they weave

1287-471: A long beak-like snout), and Shringasaurus (a horned herbivore which reached a body length of 3–4 metres (9.8–13.1 ft)). One group of archosauromorphs, the archosauriforms , were distinguished by their active predatory lifestyle, with serrated teeth and upright limb postures. Archosauriforms were diverse in the Triassic, including various terrestrial and semiaquatic predators of all shapes and sizes. The large-headed and robust erythrosuchids were among

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1404-542: A number of chemicals, including maldison , dimethoate , carbaryl , imidacloprid , etc., if removing larvae from trees is not effective enough. Triassic The Triassic began in the wake of the Permian–Triassic extinction event , which left the Earth's biosphere impoverished; it was well into the middle of the Triassic before life recovered its former diversity. Three categories of organisms can be distinguished in

1521-617: A pseudosuchian. Pseudosuchians were far more ecologically dominant in the Triassic, including large herbivores (such as aetosaurs ), large carnivores (" rauisuchians "), and the first crocodylomorphs (" sphenosuchians "). Aetosaurs were heavily-armored reptiles that were common during the last 30 million years of the Late Triassic until they died out at the Triassic-Jurassic extinction. Most aetosaurs were herbivorous and fed on low-growing plants, but some may have eaten meat. " rauisuchians " (formally known as paracrocodylomorphs ) were

1638-458: A short period of time, becoming extinct about 220 million years ago. They were exceptionally abundant in the middle of the Triassic, as the primary large herbivores in many Carnian-age ecosystems. They sheared plants with premaxillary beaks and plates along the upper jaw with multiple rows of teeth. Allokotosaurs were iguana-like reptiles, including Trilophosaurus (a common Late Triassic reptile with three-crowned teeth), Teraterpeton (which had

1755-569: A silk hammocks within the circle; this silk hammock never touches the lower cuticle. Once inside, the upper-cuticle's disc separates and descends towards the surface with the larvae attaching themselves to the hammock. Once they reach the round, the larvae work their way into a sheltered area by jerking their discs along. The majority of sawfly species produce a single generation per year, but others may only have one generation every two years. Most sawflies are also female, making males rare. Sawflies are major economic pests of forestry . Species in

1872-567: A specialized subgroup of cynodonts, appeared during the Triassic and would survive the extinction event, allowing them to radiate during the Jurassic. Amphibians were primarily represented by the temnospondyls , giant aquatic predators that had survived the end-Permian extinction and saw a new burst of diversification in the Triassic, before going extinct by the end; however, early crown-group lissamphibians (including stem-group frogs , salamanders and caecilians ) also became more common during

1989-449: A strandflat of Bømlo , southern Norway, have shown that landscape there became weathered in Late Triassic times ( c. 210 million years ago) with the landscape likely also being shaped during that time. Eustatic sea level in the Triassic was consistently low compared to the other geological periods. The beginning of the Triassic was around present sea level, rising to about 10–20 metres (33–66 ft) above present-day sea level during

2106-585: A supercontinent has less shoreline compared to a series of smaller continents, Triassic marine deposits are relatively uncommon on a global scale. A major exception is in Western Europe , where the Triassic was first studied. The northeastern margin of Gondwana was a stable passive margin along the Neo-Tethys Ocean, and marine sediments have been preserved in parts of northern India and Arabia . In North America , marine deposits are limited to

2223-436: A wingspan of 92 mm ( 3 + 1 ⁄ 2  in). The smaller species only reach lengths of 2.5 mm ( 3 ⁄ 32  in). Heads of sawflies vary in size, shape and sturdiness, as well as the positions of the eyes and antennae. They are characterised in four head types: open head, maxapontal head, closed head and genapontal head. The open head is simplistic, whereas all the other heads are derived. The head

2340-520: Is Hymenoptera, the Symphyta has long been seen to be paraphyletic. Cladistic methods and molecular phylogenetics are improving the understanding of relationships between the superfamilies, resulting in revisions at the level of superfamily and family. The Symphyta are the most primitive ( basal ) taxa within the Hymenoptera (some going back 250 million years), and one of the taxa within

2457-601: Is a warning colouration because some larvae can secrete irritating fluids from glands located on their undersides. Sawflies are widely distributed throughout the world. The largest family, the Tenthredinidae, with some 5,000 species, are found on all continents except Antarctica, though they are most abundant and diverse in the temperate regions of the northern hemisphere; they are absent from New Zealand and there are few of them in Australia. The next largest family,

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2574-468: Is a recent study of North American faunas. In the Petrified Forest of northeast Arizona there is a unique sequence of late Carnian-early Norian terrestrial sediments. An analysis in 2002 found no significant change in the paleoenvironment. Phytosaurs , the most common fossils there, experienced a change-over only at the genus level, and the number of species remained the same. Some aetosaurs ,

2691-460: Is also hypognathous, meaning that the lower mouthparts are directed downwards. When in use, the mouthparts may be directed forwards, but this is only caused when the sawfly swings its entire head forward in a pendulum motion. Unlike most primitive insects, the sutures (rigid joints between two or more hard elements on an organism) and sclerites (hardened body parts) are obsolescent or absent. The clypeus (a sclerite that makes up an insects "face")

2808-572: Is associated especially with the Tenthredinoidea , by far the largest superfamily in the suborder, with about 7,000 known species; in the entire suborder, there are 8,000 described species in more than 800 genera. Symphyta is paraphyletic , consisting of several basal groups within the order Hymenoptera, each one rooted inside the previous group, ending with the Apocrita which are not sawflies. The primary distinction between sawflies and

2925-606: Is between 205.6 and 221.5   million years of age, making it among the oldest of all sawfly fossils. More Xyelid fossils have been discovered from the Middle Jurassic and the Cretaceous , but the family was less diverse then than during the Mesozoic and Tertiary . The subfamily Xyelinae were plentiful during these time periods, in which Tertiary faunas were dominated by the tribe Xyelini; these are indicative of

3042-508: Is likely a paraphyletic group rather than a true clade. Tanystropheids were a family of protorosaurs which elevated their neck size to extremes, with the largest genus Tanystropheus having a neck longer than its body. The protorosaur family Sharovipterygidae used their elongated hindlimbs for gliding. Other archosauromorphs, such as rhynchosaurs and allokotosaurs , were mostly stocky-bodied herbivores with specialized jaw structures. Rhynchosaurs, barrel-gutted herbivores, thrived for only

3159-432: Is minimal, and fewer than 10 of these species actually cause a significant impact on sawfly populations. Many of these species attack their hosts in the grass or in other parasitoids. Well known and important parasitoids include Braconidae , Eulophidae and Ichneumonidae . Braconid wasps attack sawflies in many regions throughout the world, in which they are ectoparasitoids, meaning that the larvae live and feed outside of

3276-679: Is most frequent in the anal veins. In all sawflies, 2A and 3A tend to fuse with the first anal vein. This occurs in several families including Argidae, Diprionidae and Cimbicidae. The larvae of sawflies are easily mistaken for lepidopteran larvae (caterpillars). However, several morphological differences can distinguish the two: while both larvae share three pairs of thoracic legs and an apical pair of abdominal prolegs , lepidopteran caterpillars have four pairs of prolegs on abdominal segments 3–6 while sawfly larvae have five pairs of prolegs located on abdominal segments 2–6; crochets are present on lepidopteran larvae, whereas on sawfly larvae they are not;

3393-469: Is no evidence of glaciation at or near either pole; in fact, the polar regions were apparently moist and temperate , providing a climate suitable for forests and vertebrates, including reptiles. Pangaea's large size limited the moderating effect of the global ocean; its continental climate was highly seasonal, with very hot summers and cold winters. The strong contrast between the Pangea supercontinent and

3510-434: Is not always the case; Monterey pine sawfly ( Itycorsia ) larvae are solitary web-spinners that feed on Monterey pine trees inside a silken web. The adults feed on pollen and nectar. Sawflies are eaten by a wide variety of predators. While many birds find the larvae distasteful, some such as the currawong ( Strepera ) and stonechats ( Saxicola ) eat both adults and larvae. The larvae are an important food source for

3627-531: Is not divided into a pre- and postclypeus, but rather separated from the front. The antennal sclerites are fused with the surrounding head capsule, but these are sometimes separated by a suture. The number of segments in the antennae vary from six in the Accorduleceridae to 30 or more in the Pamphiliidae. The compound eyes are large with a number of facets, and there are three ocelli between

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3744-460: Is superimposed by 22 sea level drop events widespread in the geologic record, mostly of minor (less than 25-metre (82 ft)) and medium (25–75-metre (82–246 ft)) magnitudes. A lack of evidence for Triassic continental ice sheets suggest that glacial eustasy is unlikely to be the cause of these changes. The Triassic continental interior climate was generally hot and dry, so that typical deposits are red bed sandstones and evaporites . There

3861-404: Is two months to two years, though the adult life stage is often very short (approximately 7 – 9 days), only long enough for the females to lay their eggs. The female uses its ovipositor to drill into plant material to lay her eggs (though the family Orussoidea lay their eggs in other insects). Plant-eating sawflies most commonly are associated with leafy material but some specialize on wood, and

3978-411: Is usually divided into Early , Middle , and Late Triassic Epochs , and the corresponding rocks are referred to as Lower, Middle, or Upper Triassic. The faunal stages from the youngest to oldest are: During the Triassic, almost all the Earth's land mass was concentrated into a single supercontinent , Pangaea ( lit.   ' entire land ' ). This supercontinent was more-or-less centered on

4095-856: The Argidae , with some 800 species, is also worldwide, but is most common in the tropics, especially in Africa, where they feed on woody and herbaceous angiosperms . Of the other families, the Blasticotomidae and Megalodontidae are Palearctic ; the Xyelidae, Pamphilidae , Diprionidae , Cimbicidae , and Cephidae are Holarctic , while the Siricidae are mainly Holarctic with some tropical species. The parasitic Orussidae are found worldwide, mostly in tropical and subtropical regions. The wood-boring Xiphydriidae are worldwide, but most species live in

4212-578: The Carnian (early part of the Late Triassic), some advanced cynodonts gave rise to the first mammals . During the Triassic, archosaurs displaced therapsids as the largest and most ecologically prolific terrestrial amniotes. This "Triassic Takeover" may have contributed to the evolution of mammals by forcing the surviving therapsids and their mammaliaform successors to live as small, mainly nocturnal insectivores . Nocturnal life may have forced

4329-614: The Jurassic , when the temnospondyls had become very rare. Most of the Reptiliomorpha , stem-amniotes that gave rise to the amniotes, disappeared in the Triassic, but two water-dwelling groups survived: Embolomeri that only survived into the early part of the period, and the Chroniosuchia , which survived until the end of the Triassic. The Permian–Triassic extinction devastated terrestrial life. Biodiversity rebounded as

4446-568: The Lake Lugano region of northern Italy and southern Switzerland , was in Middle Triassic times a lagoon behind reefs with an anoxic bottom layer, so there were no scavengers and little turbulence to disturb fossilization, a situation that can be compared to the better-known Jurassic Solnhofen Limestone lagerstätte . The remains of fish and various marine reptiles (including the common pachypleurosaur Neusticosaurus , and

4563-658: The Newark Supergroup . Rift basins are also common in South America, Europe, and Africa. Terrestrial environments are particularly well-represented in the South Africa, Russia, central Europe, and the southwest United States. Terrestrial Triassic biostratigraphy is mostly based on terrestrial and freshwater tetrapods, as well as conchostracans ("clam shrimps"), a type of fast-breeding crustacean which lived in lakes and hypersaline environments. Because

4680-474: The Olenekian and Anisian of Gondwana . Both kannemeyeriiform dicynodonts and gomphodont cynodonts remained important herbivores during much of the period. Therocephalians included both large predators ( Moschorhinus ) and herbivorous forms ( bauriids ) until their extinction midway through the period. Ecteniniid cynodonts played a role as large-sized, cursorial predators in the Late Triassic. During

4797-620: The Triassic . The oldest superfamily, the Xyeloidea , has existed into the presents. Over 200   million years ago, a lineage of sawflies evolved a parasitoid lifestyle, with carnivorous larvae that ate the eggs or larvae of other insects. Sawflies are distributed globally, though they are more diverse in the northernmost hemispheres. The suborder name "Symphyta" derives from the Greek word symphyton , meaning 'grown together', referring to

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4914-458: The masked shrew ( Sorex cinereus ), the northern short-tailed shrew ( Blarina brevicauda ) and the deer mouse ( Peromyscus maniculatus ) predate heavily on sawfly cocoons. Insects such as ants and certain species of predatory wasps ( Vespula vulgaris ) eat adult sawflies and the larvae, as do lizards and frogs. Pardalotes , honeyeaters and fantails ( Rhipidura ) occasionally consume laid eggs, and several species of beetle larvae prey on

5031-416: The spiracles . This sawfly -related article is a stub . You can help Misplaced Pages by expanding it . Sawflies Sawflies are wasp -like insects that are in the suborder Symphyta within the order Hymenoptera , alongside ants, bees, and wasps. The common name comes from the saw-like appearance of the ovipositor , which the females use to cut into the plants where they lay their eggs. The name

5148-735: The surviving species repopulated empty terrain, but these were short-lived. Diverse communities with complex food-web structures took 30 million years to reestablish. Archosauromorph reptiles, which had already appeared and diversified to an extent in the Permian Period, exploded in diversity as an adaptive radiation in response to the Permian-Triassic mass extinction. By the Early Triassic, several major archosauromorph groups had appeared. Long-necked, lizard-like early archosauromorphs were known as protorosaurs , which

5265-468: The thecodonts ) disappeared, as did most of the large labyrinthodont amphibians, groups of small reptiles, and most synapsids. Some of the early, primitive dinosaurs also became extinct, but more adaptive ones survived to evolve into the Jurassic. Surviving plants that went on to dominate the Mesozoic world included modern conifers and cycadeoids. The cause of the Late Triassic extinction is uncertain. It

5382-437: The traversodont cynodonts—were much reduced in the northern half of Pangaea ( Laurasia ). These extinctions within the Triassic and at its end allowed the dinosaurs to expand into many niches that had become unoccupied. Dinosaurs became increasingly dominant, abundant and diverse, and remained that way for the next 150 million years. The true "Age of Dinosaurs" is during the following Jurassic and Cretaceous periods, rather than

5499-449: The 1930s and 1950s and C. pygmaeus in the 1930s and 1940s. Like all other hymenopteran insects, sawflies go through a complete metamorphosis with four distinct life stages – egg, larva, pupa and adult. Many species are parthenogenetic , meaning that females do not need fertilization to create viable eggs. Unfertilized eggs develop as male, while fertilized eggs develop into females ( arrhenotoky ). The lifespan of an individual sawfly

5616-832: The Anisian to Ladinian of the Tethysian domain, and from the Carnian and Rhaetian of a larger area that includes also the Boreal domain (e.g., Svalbard Islands), the North American continent, the South China block and Argentina . The best-studied of such episodes of humid climate, and probably the most intense and widespread, was the Carnian Pluvial Event . The Early Triassic was the hottest portion of

5733-571: The Apocrita – the ants, bees, and wasps – is that the adults lack a "wasp waist", and instead have a broad connection between the abdomen and the thorax . Some sawflies are Batesian mimics of wasps and bees, and the ovipositor can be mistaken for a stinger . Sawflies vary in length, most measuring 2.5 to 20 millimetres ( 3 ⁄ 32 to 25 ⁄ 32  in); the largest known sawfly measured 55 mm ( 2 + 1 ⁄ 4  in). The larvae are caterpillar-like, but can be distinguished by

5850-561: The Apocrita, to form one of two suborders of Hymenoptera. Symphyta are the more primitive group, with comparatively complete venation , larvae that are largely phytophagous , and without a "wasp-waist", a symplesiomorphic feature. Together, the Symphyta make up less than 10% of hymenopteran species. While the terms sawfly and Symphyta have been used synonymously, the Symphyta have also been divided into three groups, true sawflies (phyllophaga), woodwasps or xylophaga (Siricidae), and Orussidae . The three groupings have been distinguished by

5967-405: The Carnian and include early sauropodomorphs and theropods. Most Triassic dinosaurs were small predators and only a few were common, such as Coelophysis , which was 1 to 2 metres (3.3 to 6.6 ft) long. Triassic sauropodomorphs primarily inhabited cooler regions of the world. The large predator Smok was most likely also an archosaur, but it is uncertain if it was a primitive dinosaur or

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6084-518: The Diprionidae, such as the pine sawflies, Diprion pini and Neodiprion sertifer , cause serious damage to pines in regions such as Scandinavia. D. pini larvae defoliated 500,000 hectares (1,200,000 acres) in the largest outbreak in Finland, between 1998 and 2001. Up to 75% of the trees may die after such outbreaks, as D. pini can remove all the leaves late in the growing season, leaving

6201-563: The Early Triassic, forming small patches of reefs of modest extent compared to the great reef systems of Devonian or modern times. At the end of the Carnian, a reef crisis occurred in South China. Serpulids appeared in the Middle Triassic. Microconchids were abundant. The shelled cephalopods called ammonites recovered, diversifying from a single line that survived the Permian extinction. Bivalves began to rapidly diversify during

6318-402: The Early Triassic, while others (e.g. capitosaurs ) remained successful throughout the whole period, or only came to prominence in the Late Triassic (e.g. Plagiosaurus , metoposaurs ). The first Lissamphibians (modern amphibians) appear in the Triassic, with the progenitors of the first frogs already present by the Early Triassic. However, the group as a whole did not become common until

6435-562: The Early and Middle Triassic. Sea level rise accelerated in the Ladinian, culminating with a sea level up to 50 metres (164 ft) above present-day levels during the Carnian. Sea level began to decline in the Norian, reaching a low of 50 metres (164 ft) below present sea level during the mid-Rhaetian. Low global sea levels persisted into the earliest Jurassic. The long-term sea level trend

6552-403: The Jurassic. The Triassic was named in 1834 by Friedrich August von Alberti , after a succession of three distinct rock layers (Greek triás meaning 'triad') that are widespread in southern Germany : the lower Buntsandstein (colourful sandstone ) , the middle Muschelkalk (shell-bearing limestone ) and the upper Keuper (coloured clay ). On the geologic time scale , the Triassic

6669-613: The Jurassic. There were many types of marine reptiles. These included the Sauropterygia , which featured pachypleurosaurus and nothosaurs (both common during the Middle Triassic, especially in the Tethys region), placodonts , the earliest known herbivorous marine reptile Atopodentatus , and the first plesiosaurs . The first of the lizardlike Thalattosauria ( askeptosaurs ) and the highly successful ichthyopterygians , which appeared in Early Triassic seas, soon diversified. By

6786-600: The Latest Olenekian Cooling (LOC), from 248 to 247 Ma, temperatures cooled by about 6 °C. The Middle Triassic was cooler than the Early Triassic, with temperatures falling over most of the Anisian, with the exception of a warming spike in the latter portion of the stage. From 242 to 233 Ma, the Ladinian-Carnian Cooling (LCC) ensued. At the beginning of the Carnian, global temperatures continued to be relatively cool. The eruption of

6903-486: The Middle Triassic, becoming highly abundant in the oceans. Aquatic insects rapidly diversified during the Middle Triassic, with this time interval representing a crucial diversification for Holometabola , the clade containing the majority of modern insect species. In the wake of the Permian-Triassic mass extinction event , the fish fauna was remarkably uniform, with many families and genera exhibiting

7020-618: The Middle Triassic, some ichthyopterygians were achieving very large body masses. Among other reptiles, the earliest turtles , like Proganochelys and Proterochersis , appeared during the Norian Age (Stage) of the Late Triassic Period. The Lepidosauromorpha , specifically the Sphenodontia , are first found in the fossil record of the earlier Carnian Age, though the earliest lepidosauromorphs likely occurred in

7137-450: The Permian extinction, Archaeplastida (red and green algae) had been the major marine phytoplanktons since about 659–645 million years ago, when they replaced marine planktonic cyanobacteria , which first appeared about 800 million years ago, as the dominant phytoplankton in the oceans. In the Triassic, secondary endosymbiotic algae became the most important plankton. In marine environments , new modern types of corals appeared in

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7254-475: The Permian. The Procolophonidae , the last surviving parareptiles , were an important group of small lizard-like herbivores. The drepanosaurs were a clade of unusual, chameleon-like arboreal reptiles with birdlike heads and specialised claws. Three therapsid groups survived into the Triassic: dicynodonts , therocephalians , and cynodonts . The cynodont Cynognathus was a characteristic top predator in

7371-515: The Symphyta gave rise to the monophyletic suborder Apocrita ( wasps , bees , and ants ). In cladistic analyses the Orussoidea are consistently the sister group to the Apocrita. The oldest unambiguous sawfly fossils date back to the Middle or Late Triassic. These fossils, from the family Xyelidae , are the oldest of all Hymenoptera. One fossil, Archexyela ipswichensis from Queensland

7488-408: The Triassic (teleosts are by far the most diverse group of fish today). Predatory actinopterygians such as saurichthyids and birgeriids , some of which grew over 1.2 m (3.9 ft) in length, appeared in the Early Triassic and became widespread and successful during the period as a whole. Lakes and rivers were populated by lungfish (Dipnoi), such as Ceratodus , which are mainly known from

7605-497: The Triassic and survived the extinction event. The earliest known neopterygian fish, including early holosteans and teleosts , appeared near the beginning of the Triassic, and quickly diversified to become among the dominant groups of fish in both freshwater and marine habitats. The vast supercontinent of Pangaea dominated the globe during the Triassic, but in the latest Triassic ( Rhaetian ) and Early Jurassic it began to gradually rift into two separate landmasses: Laurasia to

7722-649: The Triassic record: survivors from the extinction event, new groups that flourished briefly, and other new groups that went on to dominate the Mesozoic Era. Reptiles , especially archosaurs , were the chief terrestrial vertebrates during this time. A specialized group of archosaurs, called dinosaurs , first appeared in the Late Triassic but did not become dominant until the succeeding Jurassic Period. Archosaurs that became dominant in this period were primarily pseudosuchians , relatives and ancestors of modern crocodilians , while some archosaurs specialized in flight,

7839-609: The Triassic, enlarging the Neo-Tethys Ocean which formed in their wake. At the same time, they forced the Paleo-Tethys Ocean to shrink as it was being subducted under Asia. By the end of the Triassic, the Paleo-Tethys Ocean occupied a small area and the Cimmerian terranes began to collide with southern Asia. This collision, known as the Cimmerian Orogeny , continued into the Jurassic and Cretaceous to produce

7956-839: The Wrangellia Large Igneous Province around 234 Ma caused abrupt global warming, terminating the cooling trend of the LCC. This warming was responsible for the Carnian Pluvial Event and resulted in an episode of widespread global humidity. The CPE ushered in the Mid-Carnian Warm Interval (MCWI), which lasted from 234 to 227 Ma. At the Carnian-Norian boundary occurred a positive δ C excursion believed to signify an increase in organic carbon burial. From 227 to 217 Ma, there

8073-455: The bizarre long-necked archosauromorph Tanystropheus ), along with some terrestrial forms like Ticinosuchus and Macrocnemus , have been recovered from this locality. All these fossils date from the Anisian and Ladinian ages (about 242 Ma ago). The Triassic Period ended with a mass extinction, which was particularly severe in the oceans; the conodonts disappeared, as did all

8190-429: The chicks of several birds, including partridges . Sawfly and moth larvae form one third of the diet of nestling corn buntings ( Emberiza calandra ), with sawfly larvae being eaten more frequently on cool days. Black grouse ( Tetrao tetrix ) chicks show a strong preference for sawfly larvae. Sawfly larvae formed 43% of the diet of chestnut-backed chickadees ( Poecile rufescens ). Small carnivorous mammals such as

8307-506: The dental plates, abundant in the fossils record. Hybodonts , a group of shark-like cartilaginous fish , were dominant in both freshwater and marine environments throughout the Triassic. Last survivors of the mainly Palaeozoic Eugeneodontida are known from the Early Triassic. Temnospondyl amphibians were among those groups that survived the Permian–Triassic extinction. Once abundant in both terrestrial and aquatic environments,

8424-428: The dominant carnivores in the early Triassic. Phytosaurs were a particularly common group which prospered during the Late Triassic. These long-snouted and semiaquatic predators resemble living crocodiles and probably had a similar lifestyle, hunting for fish and small reptiles around the water's edge. However, this resemblance is only superficial and is a prime-case of convergent evolution. True archosaurs appeared in

8541-462: The dorsal portions of the compound eyes. The tentorium comprises the whole inner skeleton of the head. Three segments make up the thorax: the mesothorax , metathorax and prothorax , as well as the exoskeletal plates that connect with these segments. The legs have spurs on their fourth segments, the tibiae. Sawflies have two pairs of translucent wings. The fore and hind wings are locked together with hooks. Parallel development in sawfly wings

8658-405: The early Triassic, splitting into two branches: Avemetatarsalia (the ancestors to birds) and Pseudosuchia (the ancestors to crocodilians). Avemetatarsalians were a minor component of their ecosystems, but eventually produced the earliest pterosaurs and dinosaurs in the Late Triassic. Early long-tailed pterosaurs appeared in the Norian and quickly spread worldwide. Triassic dinosaurs evolved in

8775-418: The eggs have hatched, some species such as the small brown sawfly will remain with them and protects the eggs by buzzing loudly and beating her wings to deter predators. There are six larval stages that sawflies go through, lasting 2 – 4 months, but this also depends on the species. When fully grown, the larvae emerge from the trees en masse and burrow themselves into the soil to pupate. During their time outside,

8892-640: The entire Phanerozoic, seeing as it occurred during and immediately after the discharge of titanic volumes of greenhouse gases from the Siberian Traps. The Early Triassic began with the Permian-Triassic Thermal Maximum (PTTM) and was followed by the brief Dienerian Cooling (DC) from 251 to 249 Ma, which was in turn followed by the Latest Smithian Thermal Maximum (LSTT) around 249 to 248 Ma. During

9009-467: The equator and extended between the poles, though it did drift northwards as the period progressed. Southern Pangea, also known as Gondwana , was made up by closely-appressed cratons corresponding to modern South America , Africa , Madagascar , India , Antarctica , and Australia . North Pangea, also known as Laurussia or Laurasia , corresponds to modern-day North America and the fragmented predecessors of Eurasia . The western edge of Pangea lay at

9126-480: The extinct family Cheirolepidiaceae , which first appeared in the Late Triassic, and would be prominent throughout most of the rest of the Mesozoic. No known coal deposits date from the start of the Triassic Period. This is known as the Early Triassic "coal gap" and can be seen as part of the Permian–Triassic extinction event . Possible explanations for the coal gap include sharp drops in sea level at

9243-899: The family Eulophidae attack sawflies, although their impact is low. Two species in the genus Pediobius have been studied; the two species are internal larval parasitoids and have only been found in the northern hemisphere. Parasitism of sawflies by eulophids in grass exceeds 50%, but only 5% in wheat. It is unknown as to why the attack rate in wheat is low. Furthermore, some fungal and bacterial diseases are known to infect eggs and pupa in warm wet weather. Outbreaks of certain sawfly species, such as Diprion polytomum , have led scientists to investigate and possibly collect their natural enemies to control them. Parasites of D. polytomum have been extensively investigated, showing that 31 species of hymenopterous and dipterous parasites attack it. These parasites have been used in successful biological control against pest sawflies, including Cephus cinctus throughout

9360-406: The first time among vertebrates, becoming the pterosaurs . Therapsids , the dominant vertebrates of the preceding Permian period, saw a brief surge in diversification in the Triassic, with dicynodonts and cynodonts quickly becoming dominant, but they declined throughout the period with the majority becoming extinct by the end. However, the first stem-group mammals ( mammaliamorphs ), themselves

9477-571: The genus Collyria . Unlike braconids, the larvae are endoparasitoids, meaning that the larvae live and feed inside the hosts body. One well known ichneumonid is Collyria coxator , which is a dominant parasitoid of C. pygmaeus . Recorded parasitism rates in Europe are between 20–76%, and as many as eight eggs can be found in a single larva, but only one Collyria individual will emerge from its host. The larva may remain inside of their host until spring, where it emerges and pupates. Several species in

9594-521: The global ocean triggered intense cross-equatorial monsoons , sometimes referred to as the Pangean megamonsoons . The Triassic may have mostly been a dry period, but evidence exists that it was punctuated by several episodes of increased rainfall in tropical and subtropical latitudes of the Tethys Sea and its surrounding land. Sediments and fossils suggestive of a more humid climate are known from

9711-699: The group's distinctive lack of a wasp waist between prostomium and peristomium. Its common name, "sawfly", derives from the saw -like ovipositor that is used for egg-laying, in which a female makes a slit in either a stem or plant leaf to deposit the eggs. The first known use of this name was in 1773. Sawflies are also known as "wood-wasps". In his original description of Hymenoptera in 1863, German zoologist Carl Gerstaecker divided them into three groups, Hymenoptera aculeata , Hymenoptera apocrita and Hymenoptera phytophaga . However, four years later in 1867, he described just two groups, H. apocrita syn. genuina and H. symphyta syn. phytophaga . Consequently,

9828-531: The historical superfamilies. Such classifications were replaced by those using molecular methods, starting with Dowton and Austin (1994). As of 2013, the Symphyta are treated as nine superfamilies (one extinct) and 25 families. Most sawflies belong to the Tenthredinoidea superfamily, with about 7,000 species worldwide. Tenthredinoidea has six families, of which Tenthredinidae is by far the largest with some 5,500 species. Extinct taxa are indicated by

9945-610: The hosts body; braconids have more of an impact on sawfly populations in the New World than they do in the Old World, possibly because there are no ichneumonid parasitoids in North America. Some braconid wasps that attack sawflies include Bracon cephi , B. lisogaster , B. terabeila and Heteropilus cephi . Female braconids locate sawfly larvae through the vibrations they produce when feeding, followed by inserting

10062-420: The impact. So, the evidence suggests the Manicouagan impact preceded the end of the Triassic by approximately 10±2 Ma. It could not therefore be the immediate cause of the observed mass extinction. The number of Late Triassic extinctions is disputed. Some studies suggest that there are at least two periods of extinction towards the end of the Triassic, separated by 12 to 17 million years. But arguing against this

10179-401: The keystone predators of most Triassic terrestrial ecosystems. Over 25 species have been found, including giant quadrupedal hunters, sleek bipedal omnivores, and lumbering beasts with deep sails on their backs. They probably occupied the large-predator niche later filled by theropods. "Rauisuchians" were ancestral to small, lightly-built crocodylomorphs, the only pseudosuchians which survived into

10296-416: The larvae can be quickly dispatched by simply dropping foliage into a vessel of plain or saltwater, diluted hydrogen peroxide or isopropyl alcohol, insecticidal soap, or other garden chemical. In large-scale, industrial settings, where beneficial insect predators can also be used to eliminate larvae, as well as parasites, which have both been previously used in control programs. Small trees can be sprayed with

10413-403: The larvae from the leaves they are on. Larvae typically try to remain hidden on the underside of foliage. Upon removing larvae and/or the affected leaves from plants, they may be dispatched by squishing, or, alternatively, the cut leaves with larvae still attached may be fed to birds; if larger animals do not prey upon them, other insects will. However, this is not practical or useful for some, thus

10530-428: The larvae hosts; they have mouth pieces adapted to these types of feeding. Sawflies go through a complete metamorphosis with four distinct life stages – egg, larva, pupa and adult. The female uses her ovipositor to drill into plant material (or, in the case of Orussoidea, other insects) and then lays eggs in groups called rafts or pods. After hatching, larvae feed on plants, often in groups. As they approach adulthood,

10647-417: The larvae may link up to form a large colony if many other individuals are present. They gather in large groups during the day which gives them protection from potential enemies, and during the night they disperse to feed. The emergence of adults takes awhile, with some emerging anywhere between a couple months to 2 years. Some will reach the ground to form pupal chambers, but others may spin a cocoon attached to

10764-519: The larvae seek a protected spot to pupate, typically in bark or the soil. Large populations of species such as the pine sawfly can cause substantial damage to economic forestry , while others such as the iris sawfly are major pests in horticulture . Outbreaks of sawfly larvae can defoliate trees and may cause dieback, stunting or death. Sawflies can be controlled through the use of insecticides, natural predators and parasitoids, or mechanical methods. Sawflies first appeared 250 million years ago in

10881-545: The mammaliaforms to develop fur and a higher metabolic rate . Two Early Triassic lagerstätten (high-quality fossil beds), the Dienerian aged Guiyang biota and the earliest Spathian aged Paris biota stand out due to their exceptional preservation and diversity . They represent the earliest lagerstätten of the Mesozoic era and provide insight into the biotic recovery from the Permian-Triassic mass extinction event. The Monte San Giorgio lagerstätte, now in

10998-573: The margin of an enormous ocean, Panthalassa ( lit.   ' entire sea ' ), which roughly corresponds to the modern Pacific Ocean . Practically all deep-ocean crust present during the Triassic has been recycled through the subduction of oceanic plates, so very little is known about the open ocean from this time period. Most information on Panthalassan geology and marine life is derived from island arcs and rare seafloor sediments accreted onto surrounding land masses, such as present-day Japan and western North America. The eastern edge of Pangea

11115-453: The marine reptiles except ichthyosaurs and plesiosaurs . Invertebrates like brachiopods and molluscs (such as gastropods ) were severely affected. In the oceans, 22% of marine families and possibly about half of marine genera went missing. Though the end-Triassic extinction event was not equally devastating in all terrestrial ecosystems, several important clades of crurotarsans (large archosaurian reptiles previously grouped together as

11232-461: The name Symphyta is given to Gerstaecker as the zoological authority . In his description, Gerstaecker distinguished the two groups by the transfer of the first abdominal segment to the thorax in the Apocrita , compared to the Symphyta. Consequently, there are only eight dorsal half segments in the Apocrita, against nine in the Symphyta. The larvae are distinguished in a similar way. The Symphyta have therefore traditionally been considered, alongside

11349-430: The next most common tetrapods, and early dinosaurs, passed through unchanged. However, both phytosaurs and aetosaurs were among the groups of archosaur reptiles completely wiped out by the end-Triassic extinction event. It seems likely then that there was some sort of end-Carnian extinction, when several herbivorous archosauromorph groups died out, while the large herbivorous therapsids —the kannemeyeriid dicynodonts and

11466-512: The north and Gondwana to the south. The global climate during the Triassic was mostly hot and dry, with deserts spanning much of Pangaea's interior. However, the climate shifted and became more humid as Pangaea began to drift apart. The end of the period was marked by yet another major mass extinction, the Triassic–Jurassic extinction event , that wiped out many groups, including most pseudosuchians, and allowed dinosaurs to assume dominance in

11583-462: The number of prolegs and the absence of crochets in sawfly larvae. The great majority of sawflies are plant-eating , though the members of the superfamily Orussoidea are parasitic . Predators include birds, insects and small animals. The larvae of some species have anti-predator adaptations such as regurgitating irritating liquid and clustering together for safety in numbers. Sawflies are hosts to many parasitoids, most of which are Hymenoptera,

11700-402: The order Isoetales (which contains living quillworts ), rose to prominence due to the environmental instability following the Permian-Triassic extinction, with one particularly notable example being the genus Pleuromeia , which grew in columnar like fashion, sometimes reaching a height of 2 metres (6.6 ft). The relevance of lycophytes declined from the Middle Triassic onwards, following

11817-453: The ovipositor can be mistaken for a stinger. Most sawflies are stubby and soft-bodied, and fly weakly. Sawflies vary in length: Urocerus gigas , which can be mistaken as a wasp due to its black-and-yellow striped body, can grow up to 20 mm ( 3 ⁄ 4  in) in length, but among the largest sawflies ever discovered was Hoplitolyda duolunica from the Mesozoic, with a body length of 55 mm ( 2 + 1 ⁄ 4  in) and

11934-583: The ovipositors of these species (such as the family Siricidae ) are specially adapted for the task of drilling through bark. Once the incision has been made, the female will lay as many as 30 to 90 eggs. Females avoid the shade when laying their eggs because the larvae develop much slower and may not even survive, and they may not also survive if they are laid on immature and glaucous leaves. Hence, female sawflies search for young adult leaves to lay their eggs on. These eggs hatch in two to eight weeks, but such duration varies by species and also by temperature. Until

12051-511: The ovipostior and paralysing the larva before laying eggs inside the host. These eggs hatch inside the larva within a few days, where they feed on the host. The entire host's body may be consumed by the braconid larvae, except for the head capsule and epidermis . The larvae complete their development within two or three weeks. Ten species of wasps in the family Ichneumonidae attack sawfly populations, although these species are usually rare. The most important parasitoids in this family are species in

12168-629: The prolegs of both larvae gradually disappear by the time they burrow into the ground, therefore making it difficult to distinguish the two; and sawfly larvae only have a single pair of minute eyes, whereas lepidopteran larvae have four to six eyes on each side of the head. Sawfly larvae behave like lepidopteran larvae, walking about and eating foliage. Some groups have larvae that are eyeless and almost legless; these larvae make tunnels in plant tissues including wood. Many species of sawfly larvae are strikingly coloured, exhibiting colour combinations such as black and white while others are black and yellow. This

12285-679: The pupae. The larvae have several anti-predator adaptations . While adults are unable to sting, the larvae of species such as the spitfire sawfly regurgitate a distasteful irritating liquid, which makes predators such as ants avoid the larvae. In some species, the larvae cluster together, reducing their chances of being killed, and in some cases form together with their heads pointing outwards or tap their abdomens up and down. Some adults bear black and yellow markings that mimic wasps. Sawflies are hosts to many parasitoids, most of which are parasitic Hymenoptera; more than 40 species are known to attack them. However, information regarding these species

12402-405: The rest being Diptera . Adult sawflies are short-lived, with a life expectancy of 7–9 days, though the larval stage can last from months to years, depending on the species. Parthenogenetic females, which do not need to mate to produce fertilised eggs, are common in the suborder, though many species have males. The adults feed on pollen, nectar, honeydew, sap, other insects, including hemolymph of

12519-487: The return of more stable environmental conditions. While having first appeared during the Permian, the extinct seed plant group Bennettitales first became a prominent element in global floras during the Late Triassic, a position they would hold for much of the Mesozoic. In the Southern Hemisphere landmasses of Gondwana, the tree Dicroidium , an extinct " seed fern " belong to the order Corystospermales

12636-435: The subtropical parts of Asia. Sawflies are mostly herbivores , feeding on plants that have a high concentration of chemical defences. These insects are either resistant to the chemical substances, or they avoid areas of the plant that have high concentrations of chemicals. The larvae primarily feed in groups; they are folivores , eating plants and fruits on native trees and shrubs, though some are parasitic. However, this

12753-676: The terminus of the Triassic, there was an extreme warming event referred to as the End-Triassic Thermal Event (ETTE), which was responsible for the Triassic-Jurassic mass extinction. Bubbles of carbon dioxide in basaltic rocks dating back to the end of the Triassic indicate that volcanic activity from the Central Atlantic Magmatic Province helped trigger climate change in the ETTE. During the Early Triassic, lycophytes , particularly those of

12870-595: The terrestrial species had mostly died out during the extinction event. The Triassic survivors were aquatic or semi-aquatic, and were represented by Tupilakosaurus , Thabanchuia , Branchiosauridae and Micropholis , all of which died out in Early Triassic, and the successful Stereospondyli , with survivors into the Cretaceous Period. The largest Triassic stereospondyls, such as Mastodonsaurus , were up to 4 to 6 metres (13 to 20 ft) in length. Some lineages (e.g. trematosaurs ) flourished briefly in

12987-577: The time of the Permo-Triassic boundary; acid rain from the Siberian Traps eruptions or from an impact event that overwhelmed acidic swamps; climate shift to a greenhouse climate that was too hot and dry for peat accumulation; evolution of fungi or herbivores that were more destructive of wetlands; the extinction of all plants adapted to peat swamps, with a hiatus of several million years before new plant species evolved that were adapted to peat swamps; or soil anoxia as oxygen levels plummeted. Before

13104-522: The trees too weak to survive the winter. Little damage to trees only occurs when the tree is large or when there is minimal presence of larvae. Eucalyptus trees can regenerate quickly from damage inflicted by the larvae; however, they can be substantially damaged from outbreaks, especially if they are young. The trees can be defoliated completely and may cause "dieback", stunting or even death. Sawflies are serious pests in horticulture . Different species prefer different host plants, often being specific to

13221-501: The true sawflies' ventral serrated or saw-like ovipositor for sawing holes in vegetation to deposit eggs, while the woodwasp ovipositor penetrates wood and the Orussidae behave as external parasitoids of wood-boring beetles . The woodwasps themselves are a paraphyletic ancestral grade . Despite these limitations, the terms have utility and are common in the literature. While most hymenopteran superfamilies are monophyletic , as

13338-615: Was a dominant element in forest habitats across the region during the Middle-Late Triassic. During the Late Triassic, the Ginkgoales (which today are represented by only a single species, Ginkgo biloba ) underwent considerable diversification. Conifers were abundant during the Triassic, and included the Voltziales (which contains various lineages, probably including those ancestral to modern conifers), as well as

13455-673: Was a relatively cool period known as the Early Norian Cool Interval (ENCI), after which occurred the Mid-Norian Warm Interval (MNWI) from 217 to 209 Ma. The MNWI was briefly interrupted around 214 Ma by a cooling possibly related to the Manicouagan impact . Around 212 Ma, a 10 Myr eccentricity maximum caused a paludification of Pangaea and a reduction in the size of arid climatic zones. The Rhaetian Cool Interval (RCI) lasted from 209 to 201 Ma. At

13572-505: Was accompanied by huge volcanic eruptions that occurred as the supercontinent Pangaea began to break apart about 202 to 191 million years ago (40Ar/39Ar dates), forming the Central Atlantic Magmatic Province (CAMP), one of the largest known inland volcanic events since the planet had first cooled and stabilized. Other possible but less likely causes for the extinction events include global cooling or even

13689-484: Was encroached upon by a pair of extensive oceanic basins: The Neo-Tethys (or simply Tethys) and Paleo-Tethys Oceans . These extended from China to Iberia, hosting abundant marine life along their shallow tropical peripheries. They were divided from each other by a long string of microcontinents known as the Cimmerian terranes . Cimmerian crust had detached from Gondwana in the early Permian and drifted northwards during

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