This is an accepted version of this page
60-528: See text Lagopus is a genus of birds in the grouse subfamily commonly known as ptarmigans ( / ˈ t ɑːr m ɪ ɡ ən z / ). The genus contains four living species with numerous described subspecies, all living in tundra or cold upland areas. The genus Lagopus was introduced by the French zoologist Mathurin Jacques Brisson in 1760 with the willow ptarmigan ( Lagopus lagopus ) as
120-814: A better sense of smell. A third stage of bird evolution starting with Ornithothoraces (the "bird-chested" avialans) can be associated with the refining of aerodynamics and flight capabilities, and the loss or co-ossification of several skeletal features. Particularly significant are the development of an enlarged, keeled sternum and the alula , and the loss of grasping hands. † Anchiornis † Archaeopteryx † Xiaotingia † Rahonavis † Jeholornis † Jixiangornis † Balaur † Zhongjianornis † Sapeornis † Confuciusornithiformes † Protopteryx † Pengornis Ornithothoraces † Enantiornithes Moa See text Moa ( order Dinornithiformes ) are an extinct group of flightless birds formerly endemic to New Zealand . During
180-767: A certain selectivity in the choice of gizzard stones and chose the hardest pebbles. The pairs of species of moa described as Euryapteryx curtus / E. exilis , Emeus huttonii / E. crassus , and Pachyornis septentrionalis / P. mappini have long been suggested to constitute males and females, respectively. This has been confirmed by analysis for sex-specific genetic markers of DNA extracted from bone material. For example, before 2003, three species of Dinornis were recognised: South Island giant moa ( D. robustus ), North Island giant moa ( D. novaezealandiae ), and slender moa ( D. struthioides ). However, DNA showed that all D. struthioides were males, and all D. robustus were females. Therefore,
240-473: A definition similar to "all theropods closer to birds than to Deinonychus ", with Troodon being sometimes added as a second external specifier in case it is closer to birds than to Deinonychus . Avialae is also occasionally defined as an apomorphy-based clade (that is, one based on physical characteristics). Jacques Gauthier , who named Avialae in 1986, re-defined it in 2001 as all dinosaurs that possessed feathered wings used in flapping flight , and
300-457: A grinding action that allowed them to eat coarse plant material. This grinding action suggests that moa were not effective seed dispersers, with only the smallest seeds passing through their gut intact. These stones were commonly smooth rounded quartz pebbles, but stones over 110 millimetres (4 in) long have been found among preserved moa gizzard contents. Dinornis gizzards could often contain several kilograms of stones. Moa likely exercised
360-442: A group called Paraves . Some basal members of Deinonychosauria, such as Microraptor , have features which may have enabled them to glide or fly. The most basal deinonychosaurs were very small. This evidence raises the possibility that the ancestor of all paravians may have been arboreal , have been able to glide, or both. Unlike Archaeopteryx and the non-avialan feathered dinosaurs, who primarily ate meat, studies suggest that
420-411: A large loop within the body cavity. They are the only ratites known to exhibit this feature, which is also present in several other bird groups, including swans , cranes , and guinea fowl . The feature is associated with deep resonant vocalisations that can travel long distances. The moa's closest relatives are small terrestrial South American birds called the tinamous , which can fly. Previously,
480-447: A low fecundity and a long maturation period, taking about 10 years to reach adult size. The large Dinornis species took as long to reach adult size as small moa species, and as a result, had fast skeletal growth during their juvenile years. No evidence has been found to suggest that moa were colonial nesters. Moa nesting is often inferred from accumulations of eggshell fragments in caves and rock shelters, little evidence exists of
540-453: A mistaken belief in a Greek origin, as if the word were related to the Greek word πτερόν ( pterón ), 'wing'. The four species are all sedentary specialists of cold regions. Willow ptarmigan is a circumpolar boreal forest species, white-tailed ptarmigan is a North American alpine bird, and rock ptarmigan breeds in both Arctic and mountain habitats across Eurasia and North America. With
600-426: A more detailed, species-level phylogeny, of the moa branch (Dinornithiformes) of the "ancient jawed" birds (Palaeognathae) shown above: † Megalapteryx didinus † D. robustus † D. novaezealandiae † P. australis † P. elephantopus † P. geranoides † Anomalopteryx didiformis † Emeus crassus † Euryapteryx curtus Analyses of fossil moa bone assemblages have provided detailed data on
660-401: A number of cryptic evolutionary lineages occurred in several moa genera. These may eventually be classified as species or subspecies; Megalapteryx benhami (Archey) is synonymised with M. didinus (Owen) because the bones of both share all essential characters. Size differences can be explained by a north–south cline combined with temporal variation such that specimens were larger during
SECTION 10
#1732780393031720-556: A number of plant species evolved to avoid moa browsing. Divaricating plants such as Pennantia corymbosa (the kaikōmako), which have small leaves and a dense mesh of branches, and Pseudopanax crassifolius (the horoeka or lancewood), which has tough juvenile leaves, are possible examples of plants that evolved in such a way. Likewise, it has been suggested that heteroblasty might be a response to moa browsing. Like many other birds, moa swallowed gizzard stones ( gastroliths ), which were retained in their muscular gizzards , providing
780-466: A range of plant species and plant parts, including fibrous twigs and leaves taken from low trees and shrubs. The beak of Pachyornis elephantopus was analogous to a pair of secateurs , and could clip the fibrous leaves of New Zealand flax ( Phormium tenax ) and twigs up to at least 8 mm in diameter. Moa filled the ecological niche occupied in other countries by large browsing mammals such as antelope and llamas . Some biologists contend that
840-538: A similar pattern to the South Island. The other moa species present in the North Island ( Euryapteryx gravis , E. curtus , and Pachyornis geranoides ) tended to inhabit drier forest and shrubland habitats. P. geranoides occurred throughout the North Island. The distributions of E. gravis and E. curtus were almost mutually exclusive, the former having only been found in coastal sites around
900-406: A sister group, the order Crocodilia , contain the only living representatives of the reptile clade Archosauria . During the late 1990s, Aves was most commonly defined phylogenetically as all descendants of the most recent common ancestor of modern birds and Archaeopteryx lithographica . However, an earlier definition proposed by Jacques Gauthier gained wide currency in the 21st century, and
960-717: A time, sometimes for years, and rarely for life. Other species have breeding systems that are polygynous (one male with many females) or, rarely, polyandrous (one female with many males). Birds produce offspring by laying eggs which are fertilised through sexual reproduction . They are usually laid in a nest and incubated by the parents. Most birds have an extended period of parental care after hatching. Many species of birds are economically important as food for human consumption and raw material in manufacturing, with domesticated and undomesticated birds being important sources of eggs, meat, and feathers. Songbirds , parrots, and other species are popular as pets. Guano (bird excrement)
1020-643: Is a phylogeny of Palaeognathae generated by Mitchell (2014) with some clade names after Yuri et al. (2013). It provides the position of the moa (Dinornithiformes) within the larger context of the "ancient jawed" (Palaeognathae) birds: Struthioniformes ( ostriches ) [REDACTED] Rheiformes ( rhea ) [REDACTED] Tinamiformes ( tinamous ) [REDACTED] † Dinornithiformes (moa) [REDACTED] Apterygiformes ( kiwi ) [REDACTED] † Aepyornithiformes ( elephant bird ) [REDACTED] Casuariidae ( cassowary ) [REDACTED] Dromaiidae ( emu ) [REDACTED] The cladogram below gives
1080-540: Is called ornithology . Birds are feathered theropod dinosaurs and constitute the only known living dinosaurs . Likewise, birds are considered reptiles in the modern cladistic sense of the term, and their closest living relatives are the crocodilians . Birds are descendants of the primitive avialans (whose members include Archaeopteryx ) which first appeared during the Late Jurassic . According to recent estimates, modern birds ( Neornithes ) evolved in
1140-465: Is characterised by small, slit-shaped pores. The eggs of most moa species were white, although those of the upland moa ( Megalapteryx didinus ) were blue-green. A 2010 study by Huynen et al. found that the eggs of certain species were fragile, only around a millimetre in shell thickness: "Unexpectedly, several thin-shelled eggs were also shown to belong to the heaviest moa of the genera Dinornis , Euryapteryx , and Emeus , making these, to our knowledge,
1200-429: Is harvested for use as a fertiliser. Birds figure throughout human culture. About 120 to 130 species have become extinct due to human activity since the 17th century, and hundreds more before then. Human activity threatens about 1,200 bird species with extinction, though efforts are underway to protect them. Recreational birdwatching is an important part of the ecotourism industry. The first classification of birds
1260-503: Is not considered a direct ancestor of birds, though it is possibly closely related to the true ancestor. Over 40% of key traits found in modern birds evolved during the 60 million year transition from the earliest bird-line archosaurs to the first maniraptoromorphs , i.e. the first dinosaurs closer to living birds than to Tyrannosaurus rex . The loss of osteoderms otherwise common in archosaurs and acquisition of primitive feathers might have occurred early during this phase. After
SECTION 20
#17327803930311320-516: Is synonymous to Avifilopluma. † Scansoriopterygidae † Eosinopteryx † Jinfengopteryx † Aurornis † Dromaeosauridae † Troodontidae Avialae Based on fossil and biological evidence, most scientists accept that birds are a specialised subgroup of theropod dinosaurs and, more specifically, members of Maniraptora , a group of theropods which includes dromaeosaurids and oviraptorosaurs , among others. As scientists have discovered more theropods closely related to birds,
1380-674: Is the intraspecific variation of bone sizes, between glacial and interglacial periods (see Bergmann’s rule and Allen’s rule ), as well as sexual dimorphism being evident in several species. Dinornis seems to have had the most pronounced sexual dimorphism, with females being up to 150% as tall and 280% as heavy as males—so much bigger that they were classified as separate species until 2003. A 2009 study showed that Euryapteryx curtus and E. gravis were synonyms. A 2010 study explained size differences among them as sexual dimorphism. A 2012 morphological study interpreted them as subspecies, instead. Analyses of ancient DNA have determined that
1440-535: Is used by many scientists including adherents to the PhyloCode . Gauthier defined Aves to include only the crown group of the set of modern birds. This was done by excluding most groups known only from fossils , and assigning them, instead, to the broader group Avialae, on the principle that a clade based on extant species should be limited to those extant species and their closest extinct relatives. Gauthier and de Queiroz identified four different definitions for
1500-722: The Late Cretaceous and diversified dramatically around the time of the Cretaceous–Paleogene extinction event 66 million years ago, which killed off the pterosaurs and all non- ornithuran dinosaurs. Many social species preserve knowledge across generations ( culture ). Birds are social, communicating with visual signals, calls, and songs , and participating in such behaviour as cooperative breeding and hunting, flocking , and mobbing of predators. The vast majority of bird species are socially (but not necessarily sexually) monogamous , usually for one breeding season at
1560-612: The Late Pleistocene - Holocene , there were nine species (in six genera). The two largest species, Dinornis robustus and Dinornis novaezelandiae , reached about 3.6 metres (12 ft) in height with neck outstretched, and weighed about 230 kilograms (510 lb) while the smallest, the bush moa ( Anomalopteryx didiformis ), was around the size of a turkey . Estimates of the moa population when Polynesians settled New Zealand circa 1300 vary between 58,000 and approximately 2.5 million. Moa are traditionally placed in
1620-492: The Oligocene drowning. This does not imply that moa were previously absent from the North Island, but that only those from the South Island survived, because only the South Island was above sea level. Bunce et al. (2009) argued that moa ancestors survived on the South Island and then recolonised the North Island about 2 Myr later, when the two islands rejoined after 30 Myr of separation. The presence of Miocene moa in
1680-669: The Tiaojishan Formation of China, which has been dated to the late Jurassic period ( Oxfordian stage), about 160 million years ago. The avialan species from this time period include Anchiornis huxleyi , Xiaotingia zhengi , and Aurornis xui . The well-known probable early avialan, Archaeopteryx , dates from slightly later Jurassic rocks (about 155 million years old) from Germany . Many of these early avialans shared unusual anatomical features that may be ancestral to modern birds but were later lost during bird evolution. These features include enlarged claws on
1740-497: The arrival of the Māori , and were hunted only by Haast's eagle . Moa extinction occurred within 100 years of human settlement of New Zealand, primarily due to overhunting. The word moa is a Polynesian term for domestic fowl. The name was not in common use among the Māori by the time of European contact, likely because the bird it described had been extinct for some time, and traditional stories about it were rare. The earliest record of
1800-565: The kiwi , the Australian emu , and cassowary were thought to be most closely related to moa. Although dozens of species were described in the late 19th and early 20th centuries, many were based on partial skeletons and turned out to be synonyms . Currently, 11 species are formally recognised, although recent studies using ancient DNA recovered from bones in museum collections suggest that distinct lineages exist within some of these. One factor that has caused much confusion in moa taxonomy
1860-476: The laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart , and a strong yet lightweight skeleton . Birds live worldwide and range in size from the 5.5 cm (2.2 in) bee hummingbird to the 2.8 m (9 ft 2 in) common ostrich . There are over 11,000 living species and they are split into 44 orders . More than half are passerine or "perching" birds. Birds have wings whose development varies according to species;
Lagopus - Misplaced Pages Continue
1920-567: The nests themselves. Excavations of rock shelters in the eastern North Island during the 1940s found moa nests, which were described as "small depressions obviously scratched out in the soft dry pumice ". Moa nesting material has also been recovered from rock shelters in the Central Otago region of the South Island, where the dry climate has preserved plant material used to build the nesting platform (including twigs clipped by moa bills). Seeds and pollen within moa coprolites found among
1980-490: The ratite group. However, genetic studies have found that their closest relatives are the flighted South American tinamous , once considered a sister group to ratites. The nine species of moa were the only wingless birds, lacking even the vestigial wings that all other ratites have. They were the largest terrestrial animals and dominant herbivores in New Zealand's forest, shrubland, and subalpine ecosystems until
2040-460: The type species . The genus name Lagopus is derived from Ancient Greek lagos ( λαγος ), meaning " hare , rabbit ", + pous ( πους ), "foot", in reference to the feathered feet and toes typical of this cold-adapted group (such as the snowshoe hare ). The specific epithets muta and leucura were for a long time misspelt mutus and leucurus , in the erroneous belief that the ending of Lagopus denotes masculine gender . However, as
2100-412: The 18.5 Mya split suggested by Baker et al. (2005). This does not necessarily mean there was no speciation between the arrival 60 Mya and the basal split 5.8 Mya, but the fossil record is lacking and most likely the early moa lineages existed, but became extinct before the basal split 5.8 Mya. The presence of Miocene -aged species certainly suggests that moa diversification began before
2160-533: The Ancient Greek term λαγωπους is of feminine gender, and the specific epithet has to agree with that, the feminine muta and leucura are correct. The English name ptarmigan comes from the Scottish Gaelic name for L. muta , tarmachan ([ Scottish Gaelic pronunciation: ['t̪ʰaɾaməxan] ]), meaning “croaker”, which refers to the bird’s frog-like call. The p- was added due to
2220-750: The Otiran glacial period (the last ice age in New Zealand). Similar temporal size variation is known for the North Island's Pachyornis mappini . Some of the other size variation for moa species can probably be explained by similar geographic and temporal factors. The earliest moa remains come from the Miocene Saint Bathans Fauna . Known from multiple eggshells and hind limb elements, these represent at least two already fairly large-sized species. The currently recognised genera and species are: Two unnamed species are also known from
2280-536: The Saint Bathans Fauna. Because moa are a group of flightless birds with no vestiges of wing bones, questions have been raised about how they arrived in New Zealand, and from where. Many theories exist about the moa's arrival and radiation in New Zealand, but the most recent theory suggests that they arrived in New Zealand about 60 million years ago (Mya) and split from the "basal" (see below) moa species, Megalapteryx , about 5.8 Mya instead of
2340-633: The Saint Bathans fauna seems to suggest that these birds increased in size soon after the Oligocene drowning event, if they were affected by it at all. Bunce et al. also concluded that the highly complex structure of the moa lineage was caused by the formation of the Southern Alps about 6 Mya, and the habitat fragmentation on both islands resulting from Pleistocene glacial cycles, volcanism , and landscape changes. The cladogram below
2400-612: The South Island, but the basic pattern of moa-habitat relationships was the same. The South Island and the North Island shared some moa species ( Euryapteryx gravis , Anomalopteryx didiformis ), but most were exclusive to one island, reflecting divergence over several thousand years since lower sea level in the Ice Age had made a land bridge across the Cook Strait . In the North Island, Dinornis novaezealandiae and Anomalopteryx didiformis dominated in high-rainfall forest habitat,
2460-428: The appearance of Maniraptoromorpha, the next 40 million years marked a continuous reduction of body size and the accumulation of neotenic (juvenile-like) characteristics. Hypercarnivory became increasingly less common while braincases enlarged and forelimbs became longer. The integument evolved into complex, pennaceous feathers . The oldest known paravian (and probably the earliest avialan) fossils come from
Lagopus - Misplaced Pages Continue
2520-509: The birds that descended from them. Despite being currently one of the most widely used, the crown-group definition of Aves has been criticised by some researchers. Lee and Spencer (1997) argued that, contrary to what Gauthier defended, this definition would not increase the stability of the clade and the exact content of Aves will always be uncertain because any defined clade (either crown or not) will have few synapomorphies distinguishing it from its closest relatives. Their alternative definition
2580-483: The developing young. In all species except for the willow ptarmigan, the female takes all responsibility for nesting and caring for the chicks, as is typical with gamebirds . The genus contains four species: Two prehistoric species and two paleosubspecies are only known from fossils : Bird Birds are a group of warm-blooded vertebrates constituting the class Aves ( Latin: [ˈaveːs] ), characterised by feathers , toothless beaked jaws,
2640-665: The earliest members of Aves, is removed from this group, becoming a non-avian dinosaur instead. These proposals have been adopted by many researchers in the field of palaeontology and bird evolution , though the exact definitions applied have been inconsistent. Avialae, initially proposed to replace the traditional fossil content of Aves, is often used synonymously with the vernacular term "bird" by these researchers. † Coelurus † Ornitholestes † Ornithomimosauria † Alvarezsauridae † Oviraptorosauria Paraves Most researchers define Avialae as branch-based clade, though definitions vary. Many authors have used
2700-633: The exception of the red grouse (until recently considered a subspecies of willow ptarmigan), all have a white winter plumage that helps them blend into the snowy background. Even their remiges are white, while these feathers are black in almost all birds (even birds that are predominantly white, such as the Bali myna ) because melanin makes them more resilient and thus improves flight performance. The Lagopus grouse apparently found it easier to escape predators by not being seen than by flying away. These are hardy vegetarian birds, but insects are also taken by
2760-451: The first avialans were omnivores . The Late Jurassic Archaeopteryx is well known as one of the first transitional fossils to be found, and it provided support for the theory of evolution in the late 19th century. Archaeopteryx was the first fossil to display both clearly traditional reptilian characteristics—teeth, clawed fingers, and a long, lizard-like tail—as well as wings with flight feathers similar to those of modern birds. It
2820-488: The habitat preferences of individual moa species, and revealed distinctive regional moa faunas: The two main faunas identified in the South Island include: A ' subalpine fauna' might include the widespread D. robustus , and the two other moa species that existed in the South Island: Significantly less is known about North Island paleofaunas, due to the scarcity of fossil sites compared to
2880-930: The manner of a kiwi . The spine was attached to the rear of the head rather than the base, indicating the horizontal alignment. This would have let them graze on low vegetation, while being able to lift their heads and browse trees when necessary. This has resulted in a reconsideration of the height of larger moa. However, Māori rock art depicts moa or moa-like birds (likely geese or adzebills ) with necks upright, indicating that moa were more than capable of assuming both neck postures. No records survive of what sounds moa made, though some idea of their calls can be gained from fossil evidence. The trachea of moa were supported by many small rings of bone known as tracheal rings. Excavation of these rings from articulated skeletons has shown that at least two moa genera ( Euryapteryx and Emeus ) exhibited tracheal elongation, that is, their trachea were up to 1 m (3 ft) long and formed
2940-436: The most fragile of all avian eggs measured to date. Moreover, sex-specific DNA recovered from the outer surfaces of eggshells belonging to species of Dinornis and Euryapteryx suggest that these very thin eggs were likely to have been incubated by the lighter males. The thin nature of the eggshells of these larger species of moa, even if incubated by the male, suggests that egg breakage in these species would have been common if
3000-525: The name was by missionaries William Williams and William Colenso in January 1838; Colenso speculated that the birds may have resembled gigantic fowl. In 1912, Māori chief Urupeni Pūhara claimed that the moa's traditional name was "te kura" (the red bird). Moa skeletons were traditionally reconstructed in an upright position to create impressive height, but analysis of their vertebral articulations indicates that they probably carried their heads forward, in
3060-422: The nesting material provide evidence that the nesting season was late spring to summer. Fragments of moa eggshell are often found in archaeological sites and sand dunes around the New Zealand coast. Thirty-six whole moa eggs exist in museum collections and vary greatly in size (from 120–240 millimetres (4.7–9.4 in) in length and 91–178 millimetres (3.6–7.0 in) wide). The outer surface of moa eggshell
SECTION 50
#17327803930313120-523: The only known groups without wings are the extinct moa and elephant birds . Wings, which are modified forelimbs , gave birds the ability to fly, although further evolution has led to the loss of flight in some birds , including ratites , penguins , and diverse endemic island species. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds , have further evolved for swimming. The study of birds
3180-402: The outermost half) can be seen in the evolution of maniraptoromorphs, and this process culminated in the appearance of the pygostyle , an ossification of fused tail vertebrae. In the late Cretaceous, about 100 million years ago, the ancestors of all modern birds evolved a more open pelvis, allowing them to lay larger eggs compared to body size. Around 95 million years ago, they evolved
3240-536: The previously clear distinction between non-birds and birds has become blurred. By the 2000s, discoveries in the Liaoning Province of northeast China, which demonstrated many small theropod feathered dinosaurs , contributed to this ambiguity. The consensus view in contemporary palaeontology is that the flying theropods, or avialans , are the closest relatives of the deinonychosaurs , which include dromaeosaurids and troodontids . Together, these form
3300-452: The same biological name "Aves", which is a problem. The authors proposed to reserve the term Aves only for the crown group consisting of the last common ancestor of all living birds and all of its descendants, which corresponds to meaning number 4 below. They assigned other names to the other groups. Lizards & snakes Turtles Crocodiles Birds Under the fourth definition Archaeopteryx , traditionally considered one of
3360-551: The second toe which may have been held clear of the ground in life, and long feathers or "hind wings" covering the hind limbs and feet, which may have been used in aerial maneuvering. Avialans diversified into a wide variety of forms during the Cretaceous period. Many groups retained primitive characteristics , such as clawed wings and teeth, though the latter were lost independently in a number of avialan groups, including modern birds (Aves). Increasingly stiff tails (especially
3420-775: The southern half of the North Island. About eight moa trackways , with fossilised moa footprint impressions in fluvial silts, have been found in the North Island, including Waikanae Creek (1872), Napier (1887), Manawatū River (1895), Marton (1896), Palmerston North (1911) (see photograph to left), Rangitīkei River (1939), and under water in Lake Taupō (1973). Analysis of the spacing of these tracks indicates walking speeds between 3 and 5 km/h (1.75–3 mph). Their diet has been deduced from fossilised contents of their gizzards and coprolites , as well as indirectly through morphological analysis of skull and beak, and stable isotope analysis of their bones. Moa fed on
3480-546: The split between Megalapteryx and the other taxa. The Oligocene Drowning Maximum event, which occurred about 22 Mya, when only 18% of present-day New Zealand was above sea level, is very important in the moa radiation. Because the basal moa split occurred so recently (5.8 Mya), it was argued that ancestors of the Quaternary moa lineages could not have been present on both the South and North Island remnants during
3540-517: The three species of Dinornis were reclassified as two species, one each formerly occurring on New Zealand's North Island ( D. novaezealandiae ) and South Island ( D. robustus ); D. robustus however, comprises three distinct genetic lineages and may eventually be classified as many species, as discussed above. Examination of growth rings in moa cortical bone has revealed that these birds were K-selected , as are many other large endemic New Zealand birds. They are characterised by having
3600-466: Was developed by Francis Willughby and John Ray in their 1676 volume Ornithologiae . Carl Linnaeus modified that work in 1758 to devise the taxonomic classification system currently in use. Birds are categorised as the biological class Aves in Linnaean taxonomy . Phylogenetic taxonomy places Aves in the clade Theropoda as an infraclass or a subclass, more recently a subclass. Aves and
#30969