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Phylogram showing the phylogenetic relationship in Anseriformes based on two mitochondrial genes. The values on nodes indicate the split time and Bayesian posterior probabilities which were calculated by BEAST 1.7.4, "-" indicated that the value was less than 70. Blue bars at nodes show 95% HPD of divergence times. https://doi.org/10.1371/journal.pone.0184529.g002
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The Anseriformes is a well-known and widely distributed bird order, with more than 150 species in the world. This paper aims to revise the classification, determine the phylogenetic relationships and diversification patterns in Anseriformes by exploring the Cyt b, ND2, COI genes and the complete mitochondrial genomes (mito-genomes). Molecular phylo...
Citations
... Furthermore, a recent study proposed that all the duck species living in South America should be placed in the genus Anas to form a monophyletic group. If this reclassification was accepted, the total number of Anas species would increase to 55 [10]. Overall, the deep branches of the genus Anas are still unclear, which makes the definition of the Anas genus ambiguous. ...
... org/ bioco nda/ ucsc-maffi lter), with the -minCol = 100 option. Next, the [10]; B represents the definition of Anas proposed in this study based on the results of this study and the original definition [3,5]; and C represents the strict definition of Anas according to the IOC World Bird List. The tree structure was adopted from [8], and the definition of each group was established according to [6]. ...
Anas, is a genus of dabbling ducks and encompasses a considerable number of species, among which some are the progenitors of domestic ducks. However, the taxonomic position of the Anas genus remains uncertain because several of its species, initially categorized as Anas based on morphological characteristics, were subsequently reclassified and grouped with the South American genus Tachyeres, primarily based on analysis of their mitochondrial gene sequences. Here, we constructed a phylogenetic tree using nine of our recently assembled Anas genomes, two Tachyeres genomes, and one Cairina genome that are publicly available. The results showed that the Northern shoveler (Anas clypeata) and Baikal teal (Anas formosa) clustered with the other Anas species at the whole-genome level rather than with the Steamer ducks (genus Tachyeres). Therefore, we propose to restore the original classification of the Anas genus, which includes the Northern shoveler and Baikal teal species, 47 species in total. Moreover, our study unveiled extensive incomplete lineage sorting and an ancient introgression event from Tachyeres to Anas, which has led to notable phylogenetic incongruence within the Anas genome. This ancient introgression event not only supports the theory that Anas originated in South America but also that it played a significant role in shaping the evolutionary trajectory of Anas, including the domestic duck.
Supplementary Information
The online version contains supplementary material available at 10.1186/s12711-024-00904-8.
... Within Galliformes, the family Phasianidae is most closely related to the family Odontophoridae, followed by the clade leading to the families Numididae, Cracidae, and Megapodiidae. Our results exhibited a topology similar to those of previous studies [37,38]. ...
... Within Galliformes, the family Phasianidae is most closely related to the family Odontophoridae, followed by the clade leading to the families Numididae, Cracidae, and Megapodiidae. Our results exhibited a topology similar to those of previous studies [37,38]. Based on fossil-calibrated species divergence times (Figure 4) ...
The two existing clades of Galloanseres, orders Galliformes (landfowl) and Anseriformes (waterfowl), exhibit dramatically different evolutionary trends. Mitochondria serve as primary sites for energy production in organisms, and numerous studies have revealed their role in biological evolution and ecological adaptation. We assembled the complete mitogenome sequences of two species of the genus Aythya within Anseriformes: Aythya baeri and Aythya marila. A phylogenetic tree was constructed for 142 species within Galloanseres, and their divergence times were inferred. The divergence between Galliformes and Anseriformes occurred ~79.62 million years ago (Mya), followed by rapid evolution and diversification after the Middle Miocene (~13.82 Mya). The analysis of selective pressure indicated that the mitochondrial protein-coding genes (PCGs) of Galloanseres species have predominantly undergone purifying selection. The free-ratio model revealed that the evolutionary rates of COX1 and COX3 were lower than those of the other PCGs, whereas ND2 and ND6 had faster evolutionary rates. The CmC model also indicated that most PCGs in Anseriformes exhibited stronger selective constraints. Our study suggests that the distinct evolutionary trends and energy requirements of Galliformes and Anseriformes drive different evolutionary patterns in the mitogenome.
... Their rostra are decidedly more mediolaterally narrow than Halszkaraptor escuilliei (rostrum width at antorbital fenestra/skull length approximately 0.16 in Halszkaraptor escuilliei and 0.05 in Mergus squamatus). Mergus and its close relatives (Mergini) also represent a relatively recent (< 10 Ma) secondary development of macrocarnivory from herbivorous and filter feeding ancestors [50], further clouding comparisons to a dromaeosaurid whose lineage is generally considered macrocarnivorous. Further investigation is needed into the relationship between platyrostry, feeding ecology, and hydrodynamics. ...
Non-avialan theropod dinosaurs had diverse ecologies and varied skull morphologies. Previous studies of theropod cranial morphology mostly focused on higher-level taxa or characteristics associated with herbivory. To better understand morphological disparity and function within carnivorous theropod families, here we focus on the Dromaeosauridae, ‘raptors’ traditionally seen as agile carnivorous hunters.
We applied 2D geometric morphometrics to quantify skull shape, performed mechanical advantage analysis to assess the efficiency of bite force transfer, and performed finite element analysis to examine strain distribution in the skull during biting. We find that dromaeosaurid skull morphology was less disparate than most non-avialan theropod groups. Their skulls show a continuum of form between those that are tall and short and those that are flat and long. We hypothesise that this narrower morphological disparity indicates developmental constraint on skull shape, as observed in some mammalian families. Mechanical advantage indicates that Dromaeosaurus albertensis and Deinonychus antirrhopus were adapted for relatively high bite forces, while Halszkaraptor escuilliei was adapted for high bite speed, and other dromaeosaurids for intermediate bite forces and speeds. Finite element analysis indicates regions of high strain are consistent within dromaeosaurid families but differ between them. Average strain levels do not follow any phylogenetic pattern, possibly due to ecological convergence between distantly-related taxa.
Combining our new morphofunctional data with a re-evaluation of previous evidence, we find piscivorous reconstructions of Halszkaraptor escuilliei to be unlikely, and instead suggest an invertivorous diet and possible adaptations for feeding in murky water or other low-visibility conditions. We support Deinonychus antirrhopus as being adapted for taking large vertebrate prey, but we find that its skull is relatively less resistant to bite forces than other dromaeosaurids. Given the recovery of high bite force resistance for Velociraptor mongoliensis, which is believed to have regularly engaged in scavenging behaviour, we suggest that higher bite force resistance in a dromaeosaurid taxon may reflect a greater reliance on scavenging rather than fresh kills.
Comparisons to the troodontid Gobivenator mongoliensis suggest that a gracile rostrum like that of Velociraptor mongoliensis is ancestral to their closest common ancestor (Deinonychosauria) and the robust rostra of Dromaeosaurus albertensis and Deinonychus antirrhopus are a derived condition. Gobivenator mongoliensis also displays a higher jaw mechanical advantage and lower resistance to bite force than the examined dromaeosaurids, but given the hypothesised ecological divergence of troodontids from dromaeosaurids it is unclear which group, if either, represents the ancestral condition. Future work extending sampling to troodontids would therefore be invaluable and provide much needed context to the origin of skull form and function in early birds. This study illustrates how skull shape and functional metrics can discern non-avialan theropod ecology at lower taxonomic levels and identify variants of carnivorous feeding.
Supplementary Information
The online version contains supplementary material available at 10.1186/s12862-024-02222-5.
... The phylogenetic position of Coscoroba has not yet been established. Recent molecular phylogeny (Sun et al., 2017) placed the clade of Coscoroba + Cereopsis as the sister group of the clade of Anserini + Cygnini. On the other hand, in many ornithological catalogs (e.g., Gill et al., 2023), Coscoroba is the sister group of the true swans (modern Cygnus). ...
Annakacygna hajimei is an extinct flightless bird described from the marine Miocene (11.5 Ma) of Annaka, Gunma, Japan. Totally 17 prepelvic vertebrae, 12 cervical and 5 free thoracic, included in the holotype of A. hajimei were reexamined here. As a esult, the number of cervical vertebrae of Annakacygna in life totaled 23, and provides a strong reason to identify this genus as a member of Cygnini. The body length (bill-to-tail length) of A. hajimei was reconstructed to about 150 cm. The original description estimated that A. hajimei was about the same length as the black swan (120-130 cm), but this must be corrected. As a result of this simple calculation A. yoshiiensis was found to be a giant bird with a total body length of
nearly 2 meters.
Morphological examination of the prepelvic vertebrae of Annakacygna revealed that the neck of this bird had a unique curve at its base, with a strong kyphosis at the cervical-thoracic boundary (CTB). Because of this kyphotic curve, the clavicular air sac at the base of the neck and the cervical air sac developed in and around the cervical vertebrae may be pushed ventrally below the water surface when the bird was on water. This "floating ring" found at the base of the bird’s neck acts as the fulcrum on the body axis to give the buoyancy and stability to the bird’s body when on the water surface. The thoracic vertebral column is regarded as a flexible "suspension bridge" that absorbed the weight of the chicks on the back. One of the
diagnostic features of Annakacygna, "ribs with unfused uncinate processes'', was nterpreted as an adaptation that ensured flexibility of the entire ribcage. Annakacygna is a good example of "kin selection". We wholeheartedly agree with the recognition of Annakacygna as the "ultimate birds'' to have ever existed.
... and the non-diving dabbling ducks, hereafter referred to as dabblers (Anatini; 5 spp.) (Ingram and Salmon 1941, Schorger 1947, Nilsson 1972, Alexander and Hair 1979. Within these three tribes, diving evolved separately in the sea ducks and the pochards, with sea ducks diverging from the rest of the sub-family Anatinae 3-5 million years before the pochards (McCracken et al. 1999, Gonzalez et al. 2009, Sun et al. 2017. With independent of evolutions of diving in closely related groups, we can investigate whether O 2 storage traits previously associated with diving behavior are altered to a similar degree in two clades of small-bodied diving ducks. ...
... The phylogeny used for the phylogenetic analyses here was constructed from 10 731 overlapping autosomal ddRAD-seq loci that met the filtering criteria (Fig. 1). Our tree differs from other published phylogenies most significantly in its placement of sea ducks and pochards sister to each other, rather than sea ducks representing the more basal split from the rest of the Anatinae (Gonzalez et al. 2009, Sun et al. 2017); this is due to the small number of species included here. Another potential artifact from a smaller taxonomic sampling is the placement of the long-tail duck Clangula hyemalis sister to the harlequin duck rather than sister to the common eider Somateria mollissima as seen in Lavretsky et al. (2021). ...
Breath‐hold diving presents air‐breathing vertebrates with the challenge of maintaining aerobic respiration while exercising underwater. Adaptive increases in the oxygen (O2) storage capacity in the lungs, blood, or muscle tissues can enhance these reserves and greatly extend aerobic foraging time underwater. Here, we report blood‐ and muscle‐O2 storage parameters (blood hemoglobin concentration ([Hb]), hematocrit, and myoglobin concentration ([Mb]) in the pectoralis and gastrocnemius) for 16 species of diving and dabbling ducks found in North America, and investigate which parameters are correlated with the diving behaviors reported in both the sea ducks (Mergini) and the pochards (Aythini). Both [Hb] in the blood and [Mb] in the gastrocnemius, a major leg muscle used in propulsion for these predominantly leg‐propelled divers, were significantly higher in the sea ducks compared to the dabblers (Anatini). The pochards also showed a significant increase in [Hb] and were intermediate between the sea ducks and the dabblers in hematocrit and [Mb] in the gastrocnemius. Among these four variables and total body mass, [Mb] in the gastrocnemius was the most significant predictor of mean species dive time, and these two variables were correlated across the phylogeny. Our results indicate that the observed changes in O2 storage capacity in the blood and muscles are positively correlated with diving behavior in two clades of ducks, such that larger increases are correlated with longer dive times.
... Un estudio filogenético más reciente del orden Anseriformes mostró que A. nyroca es el linaje hermano de A. australis y que ambas a su vez son el linaje hermano del resto de especies del género (Sun et al., 2017). ...
A comprehensive review of the natural history of the Ferruginous duck Aythya nyroca in Spain
... The phylogenetic position of Mionetta as one of the most ancient and best-known anatids in the paleontological record (Mayr, 2017) is of considerable interest for understanding the evolution of the family. Cheneval (1983) assigned the species of this genus to the subfamily Dendrocygninae, the basal group of extant Anatidae (Sun et al., 2017). Livezey and Martin (1988) included Mionetta in the separate subfamily Dendrocheninae, which they placed between Dendrocygninae and Thalassornithidae (the latter including only the genus Thalassornis, which is now also classified with Dendrocygninae). ...
... In the more advanced group Anatini, the evolutionary development of flying abilities was apparently stimulated by the cooling and aridization of the climate in the Late Miocene (see Dufour et al., 2020), which created the preconditions for the appearance of large-scale migrations, which, during subsequent cooling, led to the formation of expressed migrations. According to molecular data, the divergence of Anatini is estimated to be the end of the Middle Miocene (Sun et al., 2017), which corresponds to the end of the Miocene Climatic Optimum, as well as the epoch of large-scale transformations of the natural environment and continental biomes in Eurasia. The oldest known form close to the phylogenetic lineage of Anatini (sensu Dickinson, Remsen, 2013) is Tagayanetta palaeobaikalensis from the upper Lower Miocene of Eastern Siberia, which is considered here as a possible stem member of this tribe. ...
... A generally similar coracoid is also found in the Oligocene Pinpanetta from Australia (Worthy, 2009). However, the elongated humerus of Malacorhynchus corresponds to the phylogenetic proximity of this genus to Anserinae (Burleigh et al., 2015;Sun et al., 2017), which also have an elongated forelimb. Thus, Malacorhynchus and the Miocene Caerulonettion/Mioquerquedula apparently illustrate alternative evolutionary pathways implemented in two groups of anatids (Anserinae and Anatinae) on a common basis of the structure of the shoulder girdle (and, in particular, the coracoid) but aimed at different flight specializations, the characterization of which requires special studies. ...
The results of a taxonomic and morphological revision of Mionetta natator (Milne-Edwards, 1867)from the lower Miocene of Western and Central Europe are presented. It is shown that the collections of smallducks from the Saint-Gérand-le-Puy localities (France) do indeed contain a small species of the genus Mio-netta, which is here described as Mionetta defossa sp. nov. However, Mionetta natator represents a separatetaxon, and is here assigned to the genus Caerulonettion gen. nov., showing morphological similarities withextant Malacorhynchus and fossil Mioquerquedula spp. The first small ducks from the lower Miocene ofKazakhstan are also described (Aral Formation, the Agyspe and Altynshokysu localities; Akzhar Formation,the Golubye Peski locality), tentatively attributed to Mionetta defossa and Mionetta sp. The diversity and rela-tionships of small ducks of the Early and Middle Miocene of Eurasia are discussed.
... The diving ducks are a polyphyletic group in the largest waterfowl sub-family Anatinae, and include the sea ducks (tribe Mergini) and the pochards (tribe Aythyini) [12]. Recent phylogenetic studies based on complete mitochondrial genomes suggested that the sea ducks represent the more basal of these two lineages, branching from the rest of the Anatinae approximately 18−20 Ma, while the pochards branched approximately 15−16 Ma within the Anatinae [13,14]. Diving thus evolved separately in the sea duck and pochard clades, allowing us to investigate whether they have converged on similar diving phenotypes as seen in other aspects of their morphology [15]. ...
... One difference from other waterfowl phylogenies is the placement of sea ducks and pochards sister to each other, diverging 13.5 Ma, instead of the sea ducks representing the more basal split and pochards being sister to dabblers, which is most likely due to the limited number of species included in our tree. Divergence times of 17.5 Ma for sea ducks correlate well with other phylogenies [14]. Within the sea ducks, all species relationships correlate closely with those found by Lavretsky et al. [32], except the long-tail duck and harlequin duck, which our tree shows as sister to each other and the earliest diverging of the sea ducks included here (9.3 Ma). ...
... Within the sea ducks, all species relationships correlate closely with those found by Lavretsky et al. [32], except the long-tail duck and harlequin duck, which our tree shows as sister to each other and the earliest diverging of the sea ducks included here (9.3 Ma). Finally, our phylogeny puts the northern shoveler (Anas clypeata) in a clade with the diving pochards and sea ducks over dabblers, which could be due to the smaller number of species included, as northern shoveler is part of the dabbler clade in other trees with wider taxonomic sampling [14,56]. Preliminary analyses determined that our phylogeny did not yield different results from a phylogeny constrained to previously published topologies [13,14]. ...
Diving animals must sustain high activity with limited O2 stores to successfully capture prey. Studies suggest that increasing body O2 stores supports breath-hold diving, but less is known about metabolic specializations that underlie underwater locomotion. We measured maximal activities of 10 key enzymes in locomotory muscles (gastrocnemius and pectoralis) to identify biochemical changes associated with diving in pathways of oxidative and substrate-level phosphorylation and compared them across three groups of ducks—the longest diving sea ducks (eight spp.), the mid-tier diving pochards (three spp.) and the non-diving dabblers (five spp.). Relative to dabblers, both diving groups had increased activities of succinate dehydrogenase and cytochrome c oxidase, and sea ducks further showed increases in citrate synthase (CS) and hydroxyacyl-CoA dehydrogenase (HOAD). Both diving groups had relative decreases in capacity for anaerobic metabolism (lower ratio of lactate dehydrogenase to CS), with sea ducks also showing a greater capacity for oxidative phosphorylation and lipid oxidation (lower ratio of pyruvate kinase to CS, higher ratio of HOAD to hexokinase). These data suggest that the locomotory muscles of diving ducks are specialized for sustaining high rates of aerobic metabolism, emphasizing the importance of body O2 stores for dive performance in these species.
... The lower bound (minimum age) of the prior distribution is based on the fossil merganser Mergus miscellus Alvarez and Olsen, 1978 from North America (Alvarez & Olsen, 1978), while the upper bound (maximum age) is based on an apparent lack of any fossil representatives of crown Mergini from the Oligocene. This timescale is also consistent with the Miocene smew (Mergellus spp.) and goldeneye (Bucephala spp.) fossils from Hungary (Gal et al., 1998) and previous divergence dates for scaly-sided merganser and common merganser in the mid-late Miocene (Sun et al., 2017). ...
... Our phylogenetic analysis was generally well-resolved and broadly concordant with previous studies of Mergini, taking into account the absence of previously un-sequenced taxa that may change some evolutionary relationships (Livezey, 1995;Gonzalez et al. 2009;Solovyeva & Pearce, 2011;Liu et al. 2012;Sun et al. 2017;Buckner et al. 2018;Lavretsky et al. 2021). ...
Mergansers are riverine and coastal piscivorous ducks that are widespread throughout North America and Eurasia but uncommon in the Southern Hemisphere. One species occurs in South America and at least two extinct species from New Zealand. It has been proposed that Southern Hemisphere mergansers were founded by independent dispersal events from the Northern Hemisphere. However, some morphological and behavioural evidence suggests that Southern Hemisphere mergansers may be closely related to one another. They share several characteristics that differ from Northern Hemisphere mergansers (e.g., non-migratory vs. migratory, sexual monochromatism vs. sexual dichromatism, long vs. short pair bonds). We sequenced complete mitogenomes from the Brazilian merganser and an extinct merganser from New Zealand - the Auckland Island merganser. Our results show the Brazilian and Auckland Island mergansers form a monophyletic clade with the common merganser, and that a sister relationship between Southern Hemisphere mergansers cannot be rejected. We cannot exclude the possibility that the Brazilian and Auckland Island mergansers descend from a single dispersal event from the Northern Hemisphere at least seven million years ago. Nuclear (palaeo)genomic data may help to resolve the relationship between living and extinct mergansers, including merganser fossils from New Zealand that have not been subjected to palaeogenetic analysis.
... The somewhat larger of these forms, "Anas" velox, is actually a diving form, quite similar to the modern Histrionicus histrionicus. There is a similarity with the fossil Manuherikia primadividua, but the morphology of the coracoid and the carpometacarpus precludes an affinity of "Anas" velox with Oxyurinae; the assignment to the stem Mergini seems more likely and is consistent with molecular dates that estimate the divergence of Mergini as the beginning of the middle Miocene (Sun et al., 2017). In absolute size, "A." velox is about five percent smaller than the extant Mergellus albellus (Woelfle, 1967) and is comparable to Oxyura jamaicensis. ...
A revision of small ducks (the size of the modern teal Anas crecca or smaller) from the middle Miocene of France (Sansan locality) and Mongolia (Sharga locality) clarified the taxonomic status and systematic position of the well-known species Anas velox Milne-Edwards, 1868 and Anas soporata Kurochkin, 1976. It is shown that three small members of the family Anatidae are present in the fauna of the Sansan locality: Anas velox is a diving duck, partly similar to modern Histrionicus, but smaller–here this species is transferred to the fossil genus Protomelanitta Zelenkov, 2011 (basal Mergini). A somewhat smaller taxon from Sansan belongs to the ecological group of dabbling ducks, and is identified as Anas soporata, a species that was previ- ously described from Mongolia and here transferred to the genus Mioquerquedula Zelenkov et Kurochkin, 2012. In addition, yet another very small duck of unclear systematic position is present in the fauna of Sansan. New materials on Mioquerquedula soporata comb. nov. and M. minutissima Zelenkov et Kurochkin, 2012 are also described from the middle Miocene of Mongolia.
