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The late Pleistocene-early Holocene rails (Gruiformes: Rallidae) of Laguna de Tagua Tagua Formation, central Chile, with the description of a new extinct giant coot
Abstract
Rallidae, which includes coots, crakes and moorhens, is one of the most speciose families among the Gruiformes. This family exhibits a pattern of diversification that has involved significant episodes of regional expansion and speciation resulting in the presence of members of this group in every continent with the exception of Antarctica. In this work, we describe the diversity of fossil rallids from late Pleistocene-early Holocene deposits of the Laguna de Tagua Tagua Formation located in central Chile. We report the presence of the extant taxa, Fulica armillata, Fulica rufifrons, Fulica cf. F. rufifrons, Fulica cf. F. ardesiaca and Pardirallus sanguinolentus, and also identify a large new extinct coot, Fulica montanei sp. nov. represented by three left tarsometatarsi. Fulica montanei corresponds to the first extinct rallid recorded in the Quaternary of South America. The most remarkable feature of the tarsometatarsus of Fulica montanei is their large size, which falls in the range of the extant Andean species Fulica cornuta and the extinct Fulica prisca from New Zealand. An autapomorphic combination of characters observed in the tarsometatarsi also supports the erection of a new species. These rails coexisted with extinct megafauna, as well as small and medium-sized vertebrates and, presumably, with humans, constituting a faunal assemblage with no analogous today. Fulica montanei probably became extinct during the late Pleistocene-early Holocene.
... In central Chile, the archaeo-paleontological site of Taguatagua 1 (TT-1) ( Fig. 1) is one of the few late Pleistocene deposits with an undisturbed lithic-megafauna association, specially proboscideans (Casamiquela, 1976;Montan e, 1968;Nuñez et al., 1994). New radiocarbon dates situate the human occupation around 12,590 cal AP (Labarca et al., 2020). According to lithic analysis (M endez, 2015), the site can be interpreted as a small base camp, in which several activities were carried out, including artefact preparation and/or maintenance and big mammal processing. ...
... Recently, Labarca et al., (2020) presented a detailed taxonomic analysis of a sample of TT-1 fossil collection, identifying 28 different taxa mostly corresponding to small vertebrates (taxa <15 kg, Lyman, 2013;Mengoni-Goñalons, 1999;Monteiro, 2016). They also observed several natural modifications on the bones' surface, proposing some broad taphonomic scenarios. ...
... According to Varela's (1976) description, within the LTTF, TT-1 is situated at the unconformity between members 5 and 6, at a depth of around 2.4 m (Fig. 1). Beginning with charcoal and charred megafauna samples, Labarca et al., (2020) recently re-dated this human occupation event to around 12,510e12,670 cal BP. ...
Taguatagua 1 is a late Pleistocene open-air archaeological site located on an ancient lakeshore in central Chile and dated to around 12,600 cal BP. It presents clear evidence of human and megafauna (Equidae, Gomphotheriidae and Cervidae) interaction that includes burned, fractured and cut-marked bones, as well as tusk and bone-made instruments. Mixed with artefacts and megafauna bones, an outstanding small vertebrate record (Class Actinopterygii, Amphibia, Reptilia, Aves and Mammalia) has also been reported, which has remained largely unstudied. In this paper, we present the first comprehensive taphonomic study of a selected sample of this ensemble. Birds are the most common taxa, followed by anurans, fish and rodents. Surface modifications, bone breakage, skeletal frequencies and the sample's ecological/biological attributes indicate different taphonomic trajectories for an averaged sample. A portion of the ensemble entered the context via predators and natural deaths, but the presence of anthropogenic marks, especially in aquatic birds, and to a lesser extent in Myocastor coypus and Calyptocephalella sp., indicates cultural exploitation of these taxa. These results portray a more precise image of the late Pleistocene hunter-gatherer subsistence strategies in central Chile, which is consistent with the settlement's lacustrine context.
Across the last ~50,000 years (the late Quaternary) terrestrial vertebrate faunas have experienced severe losses of large species (megafauna), with most extinctions occurring in the Late Pleistocene and Early to Middle Holocene. Debate on the causes has been ongoing for over 200 years, intensifying from the 1960s onward. Here, we outline criteria that any causal hypothesis needs to account for. Importantly, this extinction event is unique relative to other Cenozoic (the last 66 million years) extinctions in its strong size bias. For example, only 11 out of 57 species of megaherbivores (body mass ≥1,000 kg) survived to the present. In addition to mammalian megafauna, certain other groups also experienced substantial extinctions, mainly large non-mammalian vertebrates and smaller but megafauna-associated taxa. Further, extinction severity and dates varied among continents, but severely affected all biomes, from the Arctic to the tropics. We synthesise the evidence for and against climatic or modern human (Homo sapiens) causation, the only existing tenable hypotheses. Our review shows that there is little support for any major influence of climate, neither in global extinction patterns nor in fine-scale spatiotemporal and mechanistic evidence. Conversely, there is strong and increasing support for human pressures as the key driver of these extinctions, with emerging evidence for an initial onset linked to pre-sapiens hominins prior to the Late Pleistocene. Subsequently, we synthesize the evidence for ecosystem consequences of megafauna extinctions and discuss the implications for conservation and restoration. A broad range of evidence indicates that the megafauna extinctions have elicited profound changes to ecosystem structure and functioning. The late-Quaternary megafauna extinctions thereby represent an early, large-scale human-driven environmental transformation, constituting a progenitor of the Anthropocene, where humans are now a major player in planetary functioning. Finally, we conclude that megafauna restoration via trophic rewilding can be expected to have positive effects on biodiversity across varied Anthropocene settings.
El sitio arqueo-paleontológico de Taguatagua 1, es el asentamiento humano más antiguo de la zona central de Chile, con una cronología de 12.510-12.670 años cal AP. Este sitio fue descubierto y excavado en dos campañas separadas por casi 20 años, registrándose un contexto de megafauna (> 15 kg) directamente asociada a instrumentos líticos y óseos, junto a restos de vertebrados y también de invertebrados. Los autores lo interpretaron como un lugar en el cual se realizaron actividades de caza y faenamiento de fauna extinta y formatización de instrumental lítico. Sin embargo, entre los hallazgos más numerosos del sitio, se encuentra un conjunto muy diverso de restos óseos de animales pequeños. En el presente trabajo se evalúan los agentes acumuladores tanto naturales como culturales y la incidencia de la fauna menor (≤ 15 kg), en la economía de los cazadores recolectores del Pleistoceno terminal a través de un análisis taxonómico y tafonómico, identificando evidencias de su explotación. Los resultados señalan que algunos de estos recursos fueron parte de la subsistencia de los grupos del Pleistoceno terminal, quienes aprovecharon la abundancia que ofrece un ecotono lacustre como lo fue la laguna de Taguatagua
The Aldabra rail, Dryolimnas cuvieri subsp. aldabranus, endemic to the Aldabra Atoll, Seychelles, is the last surviving flightless bird in the Indian Ocean. Aldabra has undergone at least one major, total inundation event during an Upper Pleistocene (Tarantian age) sea-level high-stand, resulting in the loss of all terrestrial fauna. A flightless Dryolimnas has been identified from two temporally separated Aldabran fossil localities, deposited before and after the inundation event, providing irrefutable evidence that a member of Rallidae colonized the atoll, most likely from Madagascar, and became flightless independently on each occasion. Fossil evidence presented here is unique for Rallidae and epitomizes the ability of birds from this clade to successfully colonize isolated islands and evolve flightlessness on multiple occasions.
The integration of state-of-the-art molecular techniques and analyses, together with a broad taxonomic sampling, can provide new insights into bird interrelationships and divergence. Despite their evolutionary significance, the relationships among several rail lineages remain unresolved as does the general timescale of rail evolution. Here, we disentangle the deep phylogenetic structure of rails using anchored phylogenomics. We analysed a set of 393 loci from 63 species, representing approximately 40% of the extant familial diversity. Our phylogenomic analyses reconstruct the phylogeny of rails and robustly infer several previously contentious relationships. Concatenated maximum likelihood and coalescent species-tree approaches recover identical topologies with strong node support. The results are concordant with previous phylogenetic studies using small DNA datasets, but they also supply an additional resolution. Our dating analysis provides contrasting divergence times using fossils and Bayesian and non-Bayesian approaches. Our study refines the evolutionary history of rails, offering a foundation for future evolutionary studies of birds.
Five species in five genera of extinct endemic rails have been described from the Mascarene Islands of Mauritius, Réunion and Rodrigues: the Mauritian Red Rail or Poule Rouge Aphanapteryx bonasia; Mascarene Coot or Poule d’eau Fulica newtonii; which occurred on Mauritius and Réunion; Réunion Wood Rail Dryolimnas augusti; Réunion Gallinule or Oiseaux bleu ‘Porphyrio caerulescens’; and Rodrigues or Leguat’s Rail Erythromachus leguati. All are known from fossil remains and/or from contemporary accounts and illustrations. A sixth species of rail Dryolimnas sp. nov. is described
herein from fossils from Mauritius, but was not unequivocally previously reported in the contemporary literature. This paper provides an analysis of the Rallidae of the Mascarene Islands based on existing and newly discovered fossil remains, and details historical reports and accounts. Comprehensive osteological descriptions and synonymies are also included. Their ecology and extinction chronologies are interpreted from historical evidence. The relationships of Aphanapteryx and Erythromachus are unresolved, having clearly been isolated for a considerable time; the middle Miocene is the earliest their ancestors could have arrived on the Mascarenes, but this may have happened more recently. Mascarene derivatives of Fulica, Porphyrio and Dryolimnas are of much more recent origin, and appear to have originated in Africa or Madagascar. All terrestrial rails on Mauritius, Réunion and Rodrigues, were probable victims of cat predation following their historic introduction to the islands, whereas over-hunting by humans was probably the primary cause of extinction of ‘Porphyrio caerulescens’ on Réunion. The only extant rail on the Mascarenes today, the Madagascar race of Eurasian Moorhen Gallinula chloropus pyrrhorrhoa, is a recent arrival, having colonised Mauritius and Réunion after the extinction of Fulica newtonii.
While known for over a decade to exist, fossil rails of the early Miocene (19–16 Ma) St Bathans Fauna, from the South Island of New Zealand, have not previously been described taxonomically or studied in detail. Here we use qualitative osteological features and analyse measurements from wing and leg bones to determine the number of taxa represented, their flight ability, and the presence and nature of sexual dimorphism within the identified taxa. We describe two new rail species in monospecific genera from the St Bathans Fauna: Priscaweka parvales gen. et sp. nov., which is extremely common, and Litorallus livezeyi gen. et sp. nov., a distinctly larger, uncommon species. Priscaweka parvales exhibited a significant degree of sexual dimorphism and was tiny, being the size of the extinct Chatham Island Rail Cabalus modestus. Both newly described species exhibit skeletal proportions and osteological features that indicate they had reduced wings and were flightless. These observations reveal that flightless rallid species have been present in New Zealand for millions of years. The distinctiveness of the St Bathans rails from their closest geographical and chronological neighbours suggests some hidden diversity of volant rails in Australia's fossil record. However, the combined data from Australasian and European records reveal no evidence for a diverse early Miocene crown rallid fauna as predicted by some molecular studies. A subsequent, middle Miocene radiation for crown rallids seems more likely, and appears to have produced the high taxonomic diversity seen in Holocene Australasian rail faunas.
http://zoobank.org/urn:lsid:zoobank.org:pub:9F638A1E-C17D-4A85-9D6E-3D0F24D5AE1E
We examined 53 bones of rails (Rallidae), previously referred to Gallirallus n. spp., from archaeological sites on four islands in the Marquesas Islands, French Polynesia. We describe three new, extinct, flightless species of Gallirallus: G. roletti (Tahuata), G. gracilitibia (Ua Huka), and G. epulare (Nuku Hiva). Two bones from Hiva Oa, although probably representing another extinct species of Gallirallus, are regarded as an inadequate basis for describing a species. At first human contact, the genus Gallirallus probably included many scores if not hundreds of flightless species on islands from the far western Pacific (Okinawa, Philippines, Halmahera) eastward across most of Oceania. As currently understood, the Marquesas Islands represent the eastern range limit of Gallirallus.
We present new observations of Andean Coot Fulica ardesiaca (Gruiformes: Rallidae) in the Carrizal Bajo wetlands, extending its known distribution and confirming the breeding of the species through direct observation of chicks and the vocalization of alert calls in the face of the human presence near them. We propose a probable case of natural hybridization with the other Coots species inhabiting in the area.
Tagua Tagua (Chile Central), y sus nuevas edades radiocarbónicas, han permitido definir este sitio como un asentamiento habitacional con varios eventos ocupacionales asociados a prácticas funerarias. Las primeras ocupaciones corresponderían a cazadores-recolectores del Holoceno Medio y Tardío y el último a un evento del Alfarero Temprano. Abstract The study of archaeological and bioanthropological evidence from the Santa Inés site (central Chile), together withnew radiocarbon dates available, have allowed us to definethis site as a residential settlement with several occupational events associated with funerary practices. The first occupations correspond to mid-to-late Holocene hunter-gatherers, whilethe last event to the Early Ceramic Period. Santa Inés presents strong affinities to the Cuchipuy site located in the vicinity. As a whole, they formed part of a settlement pattern clustered along the shoreline of the Tagua Tagua basin and its lake-basin resources.
Gallinula disneyi Boles, 2005, was based on Late Oligocene-Middle Miocene (c. 25–15 Ma) fossils from Riversleigh World Heritage Property in Boodjamulla (Lawn Hill) National Park, northwestern Queensland, Australia. If the generic assignment is correct, this species would be the earliest known crown group representative of Rallidae. We have therefore reassessed the phylogenetic relationships of this rail using both the original and newly recovered material. It is found to be a relatively basal rallid with some affinity to Porphyrio, and the new genus Australlus is erected for this taxon. A second species in the genus is described from Middle Miocene sites at Riversleigh World Heritage Property. A third rallid, smaller than either species of Australlus, is indicated by a mandible fragment, also from Riversleigh, but is not named. These rails are the only gruiforms known from Riversleigh and, with a single species of stork, are the only small non-passerine ground-birds known from these faunas.
Flightlessness in birds occurs in a taxonomically diverse array of families, but is best exemplified in the rails (Rallidae). Most flightless species of rails live on islands, where the absence of native mammalian predators may make flight superfluous. Fossil rails from Oligo-Miocene sites at Riversleigh, northwestern Queensland, Australia, are considered to represent a single species of gallinule Gallinula, described here as new. Compared with four Quaternary species of Gallinula from Australasia (two volant, two non-volant), it shows similarities with the flightless species in the development of the fore- and hindlimb elements and in other characteristics of limb bone morphology associated with flightlessness. These indicate that the Riversleigh species was non-volant. Its relationships with the Quaternary species, including the flightless Gallinula mortierii, now restricted to Tasmania, but known from Plio-Pleistocene deposits in eastern mainland Australia, are considered.
We examined 53 bones of rails (Rallidae), previously referred to Gallirallus n. spp., from archaeological sites on four islands in the Marquesas Islands, French Polynesia. We describe three new, extinct, flightless species of Gallirallus: G. roletti (Tahuata), G. gracilitibia (Ua Huka), and G. epulare (Nuku Hiva). Two bones from Hiva Oa, although probably representing another extinct species of Gallirallus, are regarded as an inadequate basis for describing a species. At first human contact, the genus Gallirallus probably included many scores if not hundreds of flightless species on islands from the far western Pacific (Okinawa, Philippines, Halmahera) eastward across most of Oceania. As currently understood, the Marquesas Islands represent the eastern range limit of Gallirallus.
We describe the prehistoric bones of Gallirallus spp. from 14 prehistoric sites on seven islands in the Kingdom of Tonga, South Pacific. Two specimens (tibiotarsi) from Ha'afeva (Ha'apai Group) probably represent an extinct species but are considered to be an inadequate basis for description. Otherwise, all bones from cultural sites (<3000 years old) are referred to the extant G. philippensis, which is widespread in Oceania today. From an older site on ‘Eua Island, we describe a new extinct species, G. vekamatolu. Qualitative osteological characters, as well as multivariate statistical analysis of hind-limb and forelimb measurements, indicate that this new species was flightless. On ‘Eua, G. vekamatolu is the only rail recorded from pre-cultural strata, whereas three extant volant species of rails (G. philippensis, Porzana tabuensis, Porphyrio porphyrio) are recorded from strata that post-date human arrival. Gallirallus vekamatolu is the third flightless species of Gallirallus described from prehistoric sites in tropical Polynesia. It adds to the growing list of Pacific island birds that went extinct after human colonization.
A new genus and species of Gallirallus‐like flightless extinct rail is described from deposits in western Viti Levu, Fiji, south‐west Pacific. It is distinguished by having a longer, more decurved bill, than all other rails. Fossils of the barred‐wing rail Nesoclopeus poicilopterus (Hautlaub, 1866) are reported from eastern parts of Viti Levu and several fossil bones suggest the former presence of a probable gallinule. A total of seven rails in seven genera were, therefore, sympatric on Viti Levu in the immediate prehuman period.
We present an annotated working list of the bird species breeding in New Zealand during the late Pleistocene and Holocene, up to the time of human contact. New Zealand is defined as including the three main islands and the surrounding smaller islands, plus outlying island groups from Norfolk Island in the northwest, the Kermadec, Chatham, Bounty, Antipodes, Campbell, Auckland, Snares, to Macquarie Islands, but excluding islands south of Macquarie Island and the Ross Dependency. Inclusions or exclusions of species from the list were based on specified criteria. We include only species with a breeding population and not vagrants that occur in New Zealand but which breed elsewhere. Species with validly published names were included if there was fossil evidence for a breeding population before human contact. Species with a breeding population at the time of European contact were included unless contrary evidence from the fossil record indicates that they actually colonised after human settlement. Species without a fossil record were included if a breeding population exists on a relatively undisturbed island within the New Zealand archipelago as defined above. Species now present on the main islands were excluded if they are absent from all well‐documented fossil faunas. Species were excluded from the breeding fauna and treated as vagrants where sustained breeding has not been demonstrated. The phylogenetic species concept is applied both to fossil and to living taxa. The late Quaternary fossil record of birds in New Zealand is excellent, and the contribution of extinct taxa to the total list is understood at least as well as that of the surviving taxa. Many taxa presently recognised at subspecific level are treated here as full species. Twelve extinct species whose former presence is known from fossil evidence, but for which no description has been published, are listed under informal species designations. Taxonomic considerations limited the extent to which the main list could reflect present understanding of the diversity of the avifauna; some undescribed species are at present subsumed under one species name. Where previous taxonomic publications provide precedence, available names at the species‐level have been used. A supplementary hypothetical species list includes all nomenclatural changes signalled in extensive annotations to the main list. In this list we accept 245 species in 110 genera representing 46 families; 176 species were endemic to the archipelago. Preliminary biogeographic analyses based on the composition of the supplementary list show that there were four separate regional faunas: a northern subtropical fauna (Norfolk, Kermadecs); the major fauna of the main islands (North, South, Stewart, and offshore islands); a Chathams fauna (Chatham Islands only); and a subantarctic fauna on the southern islands. Species with wider distributions formed link groups. The origin and compositions of the regional avifaunas and their endemic species differ with their geographic position, climate, and proximity to source faunas. Instances of speciation in groups such as the Coenocoiypha snipe and Petroica flycatchers, and adaptive radiations in groups including moa and acanthisittid wrens, show that there are many avenues for research on the rate of evolution in island and mainland populations of New Zealand birds and that there are large gaps in knowledge of even common taxa. A brief case study demonstrates the inadequacies of using species lists that do not include Holocene fossil species. Species‐area curves based on the total fauna differ substantially from those developed in previous studies based on incomplete, or biased, lists. Pleistocene glaciations caused the pattern of distribution of species on the main islands to change in concert with vegetation changes. Other possible effects include the elimination of warm climate species early in the cooling phase more than 1 million years ago, the speciation in groups including waders and parrots as new habitats (e.g., braided riverbeds and alpine areas) appeared, and the appearance regularly during the Pleistocene of islands that were potential staging points for colonisation of the Chatham Islands. For at least the past 100 000 years, until 2000 years ago, the fauna appears to have been very stable in composition, despite strong cyclic fluctuations in climate and vegetation. The effects of extinctions within the past 2000 years on the composition of the present fauna include the elimination of most of the endemic taxa from all but the subantarctic faunas. Only 169 species of the original late Holocene breeding fauna survive. The extinctions have resulted in a strong bias towards marine and coastal taxa in the present avifauna, in contrast to the balanced representation of terrestrial and marine species in the Pleistocene and Holocene fauna. The importance of systematic studies and the determination of the status of island populations to conservation and basic ornithological research is emphasised. The systematic status of many New Zealand birds is poorly known at present.
The Laguna de Tagua Tagua has yielded two important late Pleistocene archaeological sites, Taguatagua 1 and Taguatagua 2, in which a clear early human exploitation of megafauna has been recorded. Particularly in Taguatagua 1 (TT-1), here re-dated around 12,600 cal yr BP, an abundant small faunal assemblage was also recovered, which had not been previously studied in detail. Here we report the first comprehensive taxonomic and taphonomic analysis of this site. We identified 28 different taxa, including mollusks, fish, anurans, reptiles, birds, marsupials, rodents, carnivores, gomphotheres, horses and cervids, making this the richest late Pleistocene site in Chile so far. Among these, sixteen taxa are new for the Chilean late Pleistocene. Birds are the richest group, with ten taxa, followed by rodents with eight taxa. Most of the species currently inhabit the area, but we identified some locally extirpated taxa, together with extinct taxa (exclusively megamammals). Taphonomic analysis suggests a very complex depositional scenario, mostly related to lake-level oscillations which covered and exposed a mainly natural deposited small faunal assemblage. So far, we detected human-made modifications exclusively in horse and cervid bones. Current habitat requirements of the extant fauna, as well as dietary reconstruction of extinct fauna, suggest a highly variable climate and vegetation during the formation of TT-1 since taxa with preferences from semiarid to humid/wooded environments were identified. These results can be related to the changes from cold/wet to dry/warm conditions documented during the Pleistocene - Holocene transition.
We describe a late Pleistocene species of extinct rail, Rallus gracilipes n. sp., from Sawmill Sink blue hole on Abaco Island, Little Bahama Bank, The Bahamas. The only other extinct rail known from any Bahamian island is the smaller Rallus cyanocavi, also from late Pleistocene contexts at Sawmill Sink. No fossils of R. gracilipes or R. cyanocavi have been found in Holocene sites on Abaco; the loss of both of these species is likely to be due to changes in climate, habitat, and island area during the Pleistocene-Holocene Transition.
The Miocene was an important period for the assembly of present-day avian faunas of the North Temperate Zone. Details of this process, however, remain largely unexplored due to the scarcity of diverse late Miocene avian localities throughout the Eurasian continent. Here, we present a survey of the osteological diversity of extant rails and, based on these results, assess the diversity of rails from the late Miocene (7.5–7.1 Ma) locality Morskaya-2 in the south of European Russia. We document three taxa, two of which are described as Crexica crexica gen. et sp. nov. and Miohypotaenidia tanaisensis gen. et sp. nov. These taxa show affinities with the modern species Crex crex and Hypotaenidia (Gallirallus) philippensis respectively and thus may represent the oldest records of the Crex and Hypotaenidia-Gallirallus lineages in the fossil record. The taxonomic composition of rails from Morskaya-2 locality considerably differs from that observed at the roughly coeval locality Polgárdi in Hungary, which likely reflects palaeogeographic differences during the late Miocene in Europe. Although Central Europe was already inhabited by modern-type rails in the late Miocene, more ancestral groups were present in the East. Some other aspects of the evolution of the modern fauna of Rallidae are discussed.
The Paleogene fossil record of rails (Sarothruridae and Rallidae) is very scanty. Here we describe a postcranial skeleton of a new rail from the early Oligocene locality Jamna Dolna in southeastern Poland. Although the preservation of the bones is poor, the fossil constitutes the most substantial record of a Paleogene rail. The new specimen is clearly distinguished from the coeval taxon Belgirallus, the only other temporally well-constrained early Oligocene rail. Neither Belgirallus nor the new Oligocene rail appear to have been directly ancestral to the rallid crown group taxa found in Europe today. A well-based phylogenetic placement of the new fossil is, however, impeded by its unusual character mosaic and the fact that morphological apomorphies are unknown for the ralloid subclades resulting from sequence-based phylogenies. © 2016 E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, Germany.
This work serves as a compendium of anatomical resources upon which a companion phylogenetic analysis of Aves and related Theropoda (Avialae) was based (Livezey and Zusi 2006). Following a brief historical overview of avian anatomy and avian systematics, the rich published literature pertinent to these topics is classified chronologically and geographically. The former also was organized with respect to eras of predominant methodologies in avian systematics, with an emphasis on recent paleontological finds bearing importantly on the origins of modern birds (Neornithes). This was followed by an exposition on the theoretical and abstract underpinnings of morphological characterization for purposes of phylogenetic reconstructions (to be published separately), with aspects of analysis for phylogenetic inference (e.g., tactics for employment of currently available software, ordering, criteria for optimization of trees) considered elsewhere. The principal contribution of this exposition is a listing of characters and states manifesting what was inferred to hold promise with respect to phylogenetic or historical signal. In total, 2,954 anatomical characters were defined—2,451 osteological, 256 myological, and 247 miscellaneous—of which 981 (approximately one-third) were multiple-state (i.e., comprised three or more states), the latter including 537 characters treated as ordered. Bibliographic provenance for characters was provided, where possible, but exact equivalence of characters and states among workers was seldom feasible. In many cases, previously published characters were listed on the grounds that these pertained most closely to the structure or complex at hand in the present study, and that such listings provided at least a historical grasp of the magnitude of prior usages of a given character. We also summarized, to the extent feasible, previously published characters for which inclusion in the present work was judged to be unreliable or lacking sufficient clarity. In addition to the descriptions of characters, a limited series of figures are provided, in no small part to ameliorate the challenges posed by new terms and formal anatomical nomenclature. We are adherents to nomenclatural formalism (Livezey and Zusi 2001) in anatomical contexts sensu the ICAAN (International Committee on Avian Anatomical Nomenclature; Baumel 1993). I.e., we consider that characters and states—implicitly proposals of homology—warrant clarity with respect to surrounding text in the same sense that binomial taxa—i.e., as hypotheses of historical lineages—are subject to formal conventions. Finally, literature cited herein is listed, as a work of this kind is impossible without access to the wealth of information and insight provided by such a resource. As this literature is integrated by citation with the descriptions of characters, it is hoped that the bibliography will lessen the challenges posed by a deep, multilingual, and variably technical literature for systematists using these descriptions. The dimension of the character matrix also led us to enclose a CD of the data set in the present work to assist those seeking to improve, append, or refine our efforts. A phylogenetic (cladistic) analysis of these data will appear separately (Livezey and Zusi 2006). Soon thereafter a collaboration with an unparalleled compilation of molecular data (i.e., DNA sequences) and confirmatory paleontological data is planned to conclude with the publication of a total-evidence analysis of avian phylogeny under the auspices of the NSF “Tree of Life” program, one to encompass extant birds (Neornithes), avian relatives from the Mesozoic (outgroups), and nonavialian fossil taxa from the Mesozoic (“deep” outgroups).
Crown group (neornithine birds) exhibit a great variation in the morphology of the hypotarsus, a structure on the proximal end of the tarsometatarsus, which guides the tendons of the flexor muscles of the toes. Hypotarsus morphology is of significance for the identification of fossil taxa, and several extant groups show characteristic patterns that are of phylogenetic interest. So far, however, the diversity of hypotarsus morphologies has been little studied, and there are no comprehensive studies across all neornithine birds. In particular, the identities of the involved canals and sulci remain elusive, and some confusion exists about their correct homologies. In this study, hypotarsus morphologies are for the first time surveyed among all extant birds, and basic patterns are characterized. Instances are identified, in which particular hypotarsus morphologies are correlated with certain locomotion types, inferences are made about possible ancestral morphologies, and some patterns of phylogenetic interest are discussed.
More than 50 species of flightless rails (Gruiformes: Rallidae) have been discovered on islands throughout the world, including members from most of the tribes and genera of the family. In the present study, qualitative and morphometric analysis of 3,220 study skins, more than 1,200 associated (complete and partial) skeletons, approximately 4,000 disassociated subfossil elements, and pectoral dissections of 41 fluid-preserved specimens formed the primary basis for investigation. Analyses emphasized statistical comparisons of flightless species with closest flighted relatives, augmented by analyses of data on body mass, wing areas, wing lengths, clutch sizes, egg dimensions, and ecophysiological parameters. These were integrated with a companion cladistic analysis and current evolutionary theory. Flightless members of the Rallidae span more than two orders of magnitude in body mass. Univariate comparisons of skin specimens confirmed a repeated pattern of relatively or absolutely shortened wings and (with a few exceptions) tails in flightless taxa. Greatest reductions in relative wing size were evident in Habroptila wallacii, Gallirallus australis-group, Tricholimnas spp., Habropteryx insignis, Amaurornis ineptus, and Tribonyx mortierii. These shifts were confounded by diverse changes in body size; most flightless species were characterized by increases in body size of various magnitudes (greatest in Porphyrio mantelligroup, Nesotrochis debooyi, Gallirallus australis-group, Tricholimnas lafresnayanus, Aphanapteryx bonasia, Erythromachus leguati, Diaphorapteryx hawkinsi, and Amaurornis ineptus), whereas a minority showed substantial decreases (Cabalus modestus), modest decreases (Dryolimnas aldabranus, Rallus recessus, Gallirallus wakensis, Atlantisia rogersi, most flightless Porzana, and Tribonyx hodgenorum), or virtual stasis (Porzana palmeri) in directly measured or estimated body masses. Sexual dimorphism was significant in virtually all external dimensions, although magnitudes of these differences were substantially less than within-sex differences between congeners. Although confounded by subspecific variation in some taxa, indications were found of inflated variance in some external dimensions (e.g., tail length) of flightless species relative to flighted relatives (e.g., Amaurornis ineptus). Limited data on wing loadings--ratios of body mass divided by area of wings--confirmed that two flightless species had significantly higher values than flighted relatives of similar size. Only the estimate for bulky Porphyrio hochstetteri exceeded the "threshold of flightlessness" of Meunier, whereas the value for tiny, flightless Porzana atra was roughly one fourth of the threshold value. The latter indicates the inapplicability of this criterion in taxonomic groups (e.g., Rallidae) in which reductions of the pectoral musculature are critical to flightlessness. Principal component analyses (PCAs) and canonical analyses (CAs) of studyskins provided multidimensional discrimination of species and sexes within key clades with respect to both size and shape. These not only confirmed the variably pronounced reductions in relative wing length and overall size in flightless species indicated by univariate analyses, but revealed that corresponding multivariate shifts were exceptionally great in Porphyrio hochstetteri, Porzana sandwichensis, and Amaurornis ineptus, and that sexual dimorphism was exaggerated in P. hochstetteri, Habroptila wallacii, Gallirallus owstoni, and Cabalus modestus. PCAs of lengths of extracted remiges revealed that flightless species, in addition to differences in overall size, were characterized by disproportionately short (in extreme cases, absent) distal primary remiges (i.e., had more rounded wings). Remiges displayed several important trends associated with flightlessness: reductions in length relative to body size; variably pronounced changes in shape; disproportionate shortening of the distalmost remiges, resulting in comparatively rounded wings; losses of the distalmost one or two remiges primarii and several remiges secundarii (a minority of taxa); and microanatomical reductions in the integrity of margins of vanes ("fringing"). Univariate comparisons confirmed the relative and (in some cases) absolute reductions in lengths of wing elements, and also quantified the reductions in dimensions of elements of the pectoral girdle and widths of appendicular elements. These shifts were accompanied by increased size of the cranium and pelvic apparatus in a number of flightless taxa (e.g., Porphyrio hochstetteri, Gallirallus australis-group, Amaurornis ineptus, and Tribonyx mortierii). Subfossil coots (Fulica chathamensis-group and F. newtoni) largely qualify as allometrically enlarged versions of typical congeners, comparable to two large Andean coots (Fulica cornuta and F. gigantea). Univariate sexual dimorphism was significant in most rallids. However, intersexual differences in bill lengths of several subfossil rails (Diaphorapteryx hawkinsi, Aphanapteryx bonasia, and possibly Cabalus modestus) were exceptionally great and suggestive of intersexual differences in feeding niche. Bivariate correlations within flightless species differed from those for flighted species, notably in the low correlations between most sternal measurements and other osteological variables, a pattern indicative of the virtual disjunction between sternum and other skeletal elements in flightless species. Comparisons of proportions within the pectoral limb revealed that the antebrachium, carpometacarpus, and (to a generally lesser degree) the phalanges were disproportionately short and the brachium was disproportionately long in flightless species. These patterns and the disproportionately robust alulae in flightless rails are consistent with the effects of two largely perpendicular developmental axes acting on both the skeletal and muscular derivatives of the mesoderm in the avian pectoral limb: a primary, proximal-distal growth axis; and a secondary, cranial-caudal growth axis that principally affects the manus. Proportions within the pelvic limb showed a diversity of shifts associated with the loss of flight, one of the most marked being a disproportionate elongation of the pedal digits in highly aquatic Fulica. Ratios of humerus length divided by femur length provided a remarkably robust indicator of flight capacity of rallids (with the exception of natatorial Fulica), with ratios for flighted taxa averaging above 0.90, whereas those for flightless taxa averaged below 0.90. A PCA of detailed matrices of skulls displayed the diversity of size and bill manifested by species of the Rallidae, among which the most extreme bill shapes (and probably foraging modes) were those of several flightless species (e.g., Capellirallus karamu, Diaphorapteryx hawkinsi, Aphanapteryx bonasia, and Erythromachus leguati). Pectoral allomorphosis (intraspecific allometry) displayed higher slopes in many flightless species, consistent with termination of pectoral growth at an earlier stage of skeletal development through heterochrony. CAs of skeletal measurements within clades confirmed relative magnitudes of shifts related to loss of flight that were broadly consistent with those apparent in PCAs, and confirmed significant increases in sexual dimorphism in most flightless lineages. Qualitative changes associated with flightlessness were found in most pectoral elements (especially the humerus and sternum), with many extending to the extinct adzebills (Gruiformes: Aptornithidae), and corroborated homoplasy among flightless species. Tallies of these apomorphies indicated that the most-derived flightless lineages were Porphyrio hochstetteri, Habroptila wallacii, Gallirallus australis-group, Cabalus modestus, Capellirallus karamu, and Diaphorapteryx hawkinsi. Comparisons of the pectoral musculature of rails revealed that reductions in bulk and cranial extents of mm. pectoralis et supracoracoideus were the most conspicuous myological changes. As a percentage of mean body mass, these underwent reductions among flightless taxa as high as 15% (Gallirallus australis and Tribonyx mortierii) and as low as 5-6% (Dryolimnas aldabranus and Gallinula comeri). Also typical of most flightless rails was an increase in the prominence of m. cucullaris capitis pars clavicularis (associated with the caudal regression of the apex carina sterni), attenuation of mm. biceps brachii et humerotriceps, greater distal extent of m. pronator superficialis relative to the underlying (foreshortened) radius, and a corresponding increase in the impressio m. brachialis relative to the ulna. A minority of flightless rails also showed variably pronounced weakening of fibrous portions of m. rhomboideus profundus, m. flexor digitorum superficialis, and m. ulnometacarpalis ventralis, and increased conformational variation in several muscles of the manus (mm. abductor alulae capita dorsale et ventrale, and m. extensor brevis alulae). PCAs of mean muscle measurements indicated greatest morphometric shifts in Gallirallus australis, G. wakensis, Atlantisia rogersi, Porzana palmeri, and Gallinula comeri, patterns not entirely congruent with reductions in breast muscles. A correspondence analysis of ecomorphological variables principally discriminated three groups: small crakes on small, extremely isolated islands (Porzana palmeri and P. atra), large terrestrial species from New Zealand (Porphyrio hochstetteri and Gallirallus australis), and robust, aquatic species from moderately large islands (Habroptila wallacii, Amaurornis ineptus, and Tribonyx mortierii). Most flightless rails manifest variably pronounced increases in size, and in accordance with the substantial literature on giantism, these shifts appear to confer selective advantages related to thermodynamics, procurement of mates, territoriality, capacity for fasting, and interspecific competition. These gains were accompanied by negative implications, including greater total energetic requirements, diminished capacity for stealth, and vulnerability to selected environmental and predatory agents, with the latter contributing to the minority of flightless rails showing dwarfism. Changes in body size are accompanied by allometric changes in numerous, fundamental ecophysiological parameters, among which are several critical to flight capacity. Departures from familial isometry in relative wing size accompany flightlessness in most cases, but in rails reductions in pectoral musculature (and the associated skeleton) appear to be paramount, changes that were associated with variably pronounced changes in the integument, modifications in bill shape, increased sexual dimorphism, energetically efficient reductions in basal metabolic rates, and changes in reproductive and dietary parameters. The latter are consistent with r-K shifts in life histories, and most of the ecological changes are typical of insular birds. Heterochrony, combining pectoral paedomorphosis with (in most taxa) peramorphosis of the axial and pelvic complexes, appears to underlie most anatomical apomorphies related to flightlessness in rails. Morphological and ecological changes in flightless rails provide a strong qualitative analogy with those of vertebrate and invertebrate endemics of caves (troglomorphs). Phylogenetic reconstructions of rallids are replete with morphological homoplasy, apparent irreversibility of the apomorphy associated with flightlessness, and only a few candidates for speciation following the loss of flight. Many rails show metapopulational demographic characteristics, and a number of migratory species show high vagrancy and qualify as consummate colonists of islands. These qualities suggest that a number of flighted rails, especially a core group with high fecundities and longdistance migratory patterns, may maintain dispersal polymorphisms in which a minority of progeny are predisposed to vagrancy and colonization of insular habitats. Insular colonizations occasioned thereby essentially represent "permanent migratory stopovers" followed by evolutionary refinements for year-round residency. The highly convergent morphology of flightless rails indicates a shared, readily triggered, canalized bifurcation in ontogeny that leads to the morphological and physiological changes that result in flightlessness. Conditional advantages of resources redirected in flightless lineages (e.g., conversion of investments in musculature, pectoral skeletons, and metabolic characteristics) are substantial, as indicated by the exorbitant anatomical and physiological requirements of the primary capacity surrendered, migration. The potential for this transformation may be preserved through dispersal polymorphisms and bethedging against overdependence on ephemeral, variable, natal breeding locales. Alternative patterns of dispersal also may be accelerated in some rallids through selectively maintained, environmentally induced plasticity through threshold traits or developmental reactionnorms within small demes subject to founder effects, genetic drift, and population bottlenecks. Distributions of flightless rails are explainable by a complex history of colonizations by flighted ancestors, a scant number of colonizations or nearisland expansions by flightless lineages, and extinctions related to small demes, marginal habitats, earthquakes, volcanoes, El Niño-La Nina events, and (especially) tsunamis of islands during recent millennia. Many flightless rails encountered ecological opportunities beyond those of continental confamilials. Selective advantages under these circumstances were accrued through decreased clutch size, increased egg size, and protracted developmental periods. Flightlessness in rails represents the selectively advantageous, ontogenetically mediated conversion of anatomical and caloric assets of the pectoral apparatus and associated metabolic parameters related to flight toward multiple evolutionary alternatives of intensified selective importance in insular habitats and the adoption of a nonmigratory lifestyle. The evolutionary scenario can be summarized as follows: migration-imposed anatomical and physiological requirements for migration preconditioned key rallids for a conversion of resources; vagrancy (possibly enhanced by polymorphism of dispersal and accelerated cladogenetic capacity maintained among metapopulations) provided opportunities for insular colonization; one or a suite of similar alternative, heterochronic, developmental avenue(s) retained by key rallids (perhaps triggered and hastened as threshold traits or by developmental reaction norms) facilitated the anatomical and physiological transformation to the local optimal, flightless phenotype(s) after colonization; successful colonization may have been advanced by differences in preferred stopover habitats between sexes and ages, and the acceleration of kin-selected altruism among close relatives migrating in concert; concomitant changes in size carried multiple allometrically related changes in physiology and metabolism; and despite a resilience to natural disasters (notably tsunamis), anthropogenic agencies ultimately led to extinction for most flightless lineages effectively by breaching key aspects of insularity essential to their provision of refuge. Accordingly, the "ideal avian colonist" would possess a combination of a capacity to modulate metabolic and physiological parameters; manifest dispersal polymorphism that includes long-distance, gregarious vagrancy as one component tactic; comparatively high sexual dimorphism or a potential for such; and expanded ontogenetic variance and cladogenesis that facilitates evolutionary changes in size and pectoral paedomorphosis.
T HE family Rallidae, containing over 150 living or recently extinct species and having one of the widest distributions of any family of terrestrial vertebrates, has, in proportion to its size and interest, received less study than perhaps any other major group of birds. The only two attempts at a classifi-cation of all of the recent rallid genera are those of Sharpe (1894) and Peters (1934). Although each of these lists has some merit, neither is satisfactory in reflecting relationships between the genera and both often separate closely related groups. In the past, no attempt has been made to identify the more primitive members of the Rallidae or to illuminate evolutionary trends in the family. Lists almost invariably begin with the genus Rdus which is actually one of the most specialized genera of the family and does not represent an ancestral or primitive stock. One of the difficulties of rallid taxonomy arises from the relative homo-geneity of the family, rails for the most part being rather generalized birds with few groups having morphological modifications that clearly define them. As a consequence, particularly well-marked genera have been elevated to subfamily rank on the basis of characters that in more diverse families would not be considered as significant. Another weakness of former classifications of the family arose from what Mayr (194933) referred to as the "instability of the morphology of rails." This "instability of morphology," while seeming to belie what I have just said about homogeneity, refers only to the characteristics associated with flightlessness-a condition that appears with great regularity in island rails and which has evolved many times. I have elsewhere (Olson, 1973) argued that flightlessness in rails is a neotenic condition that is evolved very rapidly, involves little genetic modification, and is without major phylogenetic sig-nificance. Flightlessness and its associated morphology can be used as a taxonomic character in the Rallidae only at the specific or subspecific levels. When this is done, the result is the elimination of much fragmenting of genera that had previously obscured the origins and relationships of many species.
Rallen (Aves, Rallidae) sind recht häufig in miozänen Fundstellen Europas, aber die phylogenetischen Beziehungen zwischen den fossilen Arten und den Arten ist unsicher. Rallen aus dem frühen Miozän des Gebietes um Saint-Gérand-le-Puy in Zentralfrankreich wurden schon im 19. Jahrhundert beschrieben. Zur Zeit werden zwei Arten unterschieden, Palaeoaramides christyi und Paraortygometra porzanoides. Unsere Studien des Fossilmaterials legen dagegen die Existenz von vier, vermutlich gleichzeitig lebenden Arten nahe. Wir zeigen, daß Palaeoaramides eximius, früher mit Palaeoaramides christyi synonymisiert, wahrscheinlich eine eigene Art repräsentiert und beschreiben eine weitere, bisher unerkannte Rallenart, Baselrallus intermedius gen. et sp. nov. Um die verwandtschaftliche Stellung dieser fossilen Rallen einzugrenzen, verglichen wir sie mit einer repräsentativen Auswahl heutiger Rallen und identifizierten plesiomorphe und apomorphe Merkmale der Kronengruppe. Unsere Untersuchungen stützen keine besonders engen verwandtschaftlichen Beziehungen zwischen Palaeoaramides und Aramides oder Paraortygometra und Crex (Ortygometra), und insgesamt ist die Skelettmorphologie dieser fossilen Rallen deutlich ursprünglicher als bisher angenommen. Aufgrund unserer Untersuchungen des bisher nicht beschriebenen Humerus zeigen wir, daß Palaeoaramides außerhalb der Kronengruppen-Rallidae und möglicherweise nahe verwandt mit dem unteroligozänen Taxon Belgirallus ist. Paraortygometra porzanoides zeigt dagegen Übereinstimmungen in einigen Skelettelementen mit Arten der rezenten afrikanischen Gattung Sarothrura, aber es bleibt unsicher, ob die fossile Art einem Monophylum zugeordnet werden kann, welches Sarothrura beinhaltet.
The order Gruiformes, for which even familial composition remains controversial, is perhaps the least well understood avia order from a phylogenetic perspective. The history of the systematics of the order is presented, and the ecological and biogeographi characteristics of its members are summarized. Using cladistic techniques, phylogenetic relationships among fossil and moder genera of the Gruiformes were estimated based on 381 primarily osteological characters; relationships among modern specie of Grues (Psophiidae, Aramidae, Gruidae, Heliornithidae and Rallidae) were assessed based on these characters augmented b 189 characters of the definitive integument. A strict consensus tree for 20,000 shortest trees compiled for the matrix o gruiform genera (length = 967, CI = 0.517) revealed a number of nodes common to the solution set, many of which were robus to bootstrapping and had substantial support (Bremer) indices. Robust nodes included those supporting: a sister relationshi between the Pedionomidae and Turnicidae; monophyly of the Gruiformes exclusive of the Pedionomidae and Turnicidae; a siste relationship between the Cariamidae and Phorusrhacoidea; a sister relationship between a clade comprising Eurypyga and Messelornis and one comprising Rhynochetos and Aptornis; monophyly of the Grues (Psophiidae, Aramidae, Gruidae, Heliornithidae and Rallidae); monophyly of a clade (Gruoidea) comprisin (in order of increasingly close relationship) Psophia, Aramus, Balearica and other Gruidae, with monophyly of each member in this series confirmed; a sister relationship between the Heliornithida and Rallidae; and monophyly of the Rallidae exclusive of Himantornis. Autapomorphic divergence was comparatively high for Pedionomus, Eurypyga, Psophia, Himantornis and Fulica; extreme autapomorphy, much of which is unique for the order, characterized the extinct, flightless Aptornis.
In the species–level analysis of modern Grues, special efforts were made to limit the analytical impacts of homoplasy relate to flightlessness in a number of rallid lineages. A strict consensus tree of 20,000 shortest trees compiled (length = 1232 CI = 0.463) confirmed the interfamilial relationships resolved in the ordinal analysis and established a number of other variably supported groups within the Rallidae. Groupings within the Rallidae included: monophyly of Rallidae exclusive o Himantornis and a clade comprising Porphyrio (including Notornis) and Porphyrula; a poorly resolved, basal group of genera including Gymnocrex, Habroptila, Eulabeornis, Aramides, Canirallus and Mentocrex; an intermediate grade comprising Anurolimnas, Amaurolimnas, and Rougetius; monophyly of two major subdivisions of remaining rallids, one comprising Rallina (paraphyletic), Rallicula, and Sarothrura, and the other comprising the apparently paraphyletic ‘long–billed’ rails (e.g. Pardirallus, Cyanolimnas, Rallus, Gallirallus and Cabalus and a variably resolved clade comprising ‘crakes’ (e.g. Atlantisia, Laterallus and Porzana, waterhens (Amaurornis), moorhens (Gallinula and allied genera) and coots (Fulica). Relationships among ‘crakes’ remain poorly resolved; Laterallus may be paraphyletic, and Porzana is evidently polyphyletic and poses substantial challenges for reconciliation with current taxonomy. Relationships amon the species of waterhens, moorhens and coots, however, were comparatively well resolved, and exhaustive, fine–scale analyse of several genera (Grus, Porphyrio, Aramides, Rallus, Laterallus and Fulica) and species complexes (Porphyrio porphyrio –group,Gallirallus philippensis –group and Fulica americana –group) revealed additional topological likelihoods. Many nodes shared by a majority of the shortest trees under equal weightin were common to all shortest trees found following one or two iterations of successive weighting of characters. Provisiona placements of selected subfossil rallids (e.g. Diaphorapteryx, Aphanapteryx and Capellirallus ) were based on separate heuristic searches using the strict consensus tree for modern rallids as a backbone constraint.
These analyses were considered with respect to assessments of robustness, homoplasy related to flightlessness, challenge and importance of fossils in cladistic analysis, previously published studies and biogeography, and an annotated phylogeneti classification of the Gruiformes is proposed.
A new species of rail is described from a Pleistocene and Holocene cave deposit on the island of Eivissa, Pityusic Islands (western Mediterranean Sea). Rallus eivissensis sp. nov. was an insular relative of the European Water Rail Rallus aquaticus. Compared with the extant Water Rail, the new species was smaller and stouter, had shorter and more robust hind limbs and shorter wings, with probably reduced flight ability. The Pityusics were the only Mediterranean islands with a vertebrate Quaternary fauna lacking terrestrial mammals, and this absence is no doubt related to the Eivissan rail evolution. The chronology of the Rallus eivissensis sp. nov. extinction overlaps broadly with a period of uncertainty for the arrival of humans at Eivissa, suggesting a relationship between the two events.