Ben Creisler
Some recent non-Mesozoic avian papers with free pdfs:
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Evolutionary variation in ontogeny played a central role in the origin of the avian skull. However, its influence in subsequent bird evolution is largely unexplored. We assess the links between ontogenetic and evolutionary variation of skull morphology in Strisores (nightbirds). Nightbirds span an exceptional range of ecologies, sizes, life-history traits and craniofacial morphologies constituting an ideal test for evo-devo hypotheses of avian craniofacial evolution. These morphologies include superficially âjuvenile-likeâ broad, flat skulls with short rostra and large orbits in swifts, nightjars and allied lineages, and the elongate, narrow rostra and globular skulls of hummingbirds. Here, we show that nightbird skulls undergo large ontogenetic shape changes that differ strongly from widespread avian patterns. While the superficially juvenile-like skull morphology of many adult nightbirds results from convergent evolution, rather than paedomorphosis, the divergent cranial morphology of hummingbirds originates from an evolutionary reversal to a more typical avian ontogenetic trajectory combined with accelerated ontogenetic shape change. Our findings underscore the evolutionary lability of cranial growth and development in birds, and the underappreciated role of this aspect of phenotypic variability in the macroevolutionary diversification of the amniote skull.
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Gerald May, Vanesa De Pietri & R. Paul Scofield (2021)
New bird remains from the early Eocene Nanjemoy Formation of Virginia (USA), including the first records of the Messelasturidae, Psittacopedidae, and Zygodactylidae from the Fisher/Sullivan site.
Historical Biology (advance online publication)
DOI: 10.1080/08912963.2021.1910820
https://www.tandfonline.com/doi/full/10.1080/08912963.2021.1910820Â
We report new avian remains from the early Eocene Nanjemoy Formation of the Fisher/Sullivan site in Virginia, USA. The fossil material includes the first records of the Messelasturidae, Psittacopedidae, and Zygodactylidae from the Nanjemoy Formation, with these taxa being widespread and fairly common in coeval North American and European sites. Psittacopedidae and Zygodactylidae are stem group representatives of the Passeriformes, and a tibiotarsus assigned to the Psittacopedidae is unusual in that it lacks a supratendinal bridge (this bridge is, however, also absent in the psittacopedid taxon Pumiliornis). We further report more material of the Charadriiformes and corroborate a previous tentative referral of a tarsometatarsus to the Parvicuculidae. It is noted that this latter bone is likewise very similar to the tarsometatarsus of the Fluvioviridavidae, which indicates close affinities between the two higher-level clades. Because of the comparatively small extent of the new avian material, it is remarkable that it includes a comparatively high number of fossils that represent previously unknown taxa. This supports the hypothesis that early Eocene avifaunas featured a high taxonomic diversity, but that higher-level clades showed low species richness. We hypothesise that this may indicate low rates of cladogenetic diversification in a rather homogenous paleoenvironment.
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Taiwan accommodates more than 600 avian species, including about 30 endemic ones. As yet, however, no fossil birds have been scientifically documented from Taiwan, so that the evolutionary origins of this diversified avifauna remain elusive. Here we report on the very first fossil bird from Taiwan. This Pleistocene specimen, a distal end of the left tarsometatarsus, shows diagnostic features of the galliform Phasianidae, including an asymmetric plantar articular facet trochlea metatarsi III. Our discovery of a Pleistocene phasianid from Taiwan opens a new perspective on studies of the evolution of the avifauna in Taiwan because the fossil shows that careful search for fossils in suitable localities has the potential of recovering avian remains. In general, East Asia has an extremely poor avian fossil record, especially if terrestrial birds are concerned, which impedes well-founded evolutionary scenarios concerning the arrival of certain groups in the area. The Phasianidae exhibit a high degree of endemism in Taiwan, and the new fossil presents the first physical evidence for the presence of phasianids on the island, some 400,000â800,000 years ago. The specimen belongs to a species the size of the three larger phasianids occurring in Taiwan today (Syrmaticus mikado, Lophura swinhoii, and Phasianus colchicus). Still, an unambiguous assignment to either of these species is not possible due to the incomplete nature of the left tarsometatarsus. Because the former two species are endemic to Taiwan, the fossil has the potential to yield the first data on their existence in the geological past of Taiwan if future finds allow identification on species-level.
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Terry L. Jones, Joan Brenner Coltrain, David K. Jacobs, Judith Porcasi, Simon C. Brewer, Janet C. Buckner, John D. Perrine & Brian F.Codding (2021)
Causes and consequences of the late Holocene extinction of the marine flightless duck (Chendytes lawi) in the northeastern Pacific.
Quaternary Science Reviews 260: 106914
doi:
https://doi.org/10.1016/j.quascirev.2021.106914https://www.sciencedirect.com/science/article/pii/S0277379121001219Highlights
Pre-contact Holocene extinction of Californiaâs flightless duck was highly unusual.
Duckâs stable isotopic profile suggests feeding niche unlike any living duck.
Isotope profile suggests feeding ecology akin to sea otters and harbor seals.
Time series comparisons suggest extinction influenced by human predation and climate.
Duckâs disappearance may have affected changes in nearshore ecology.
Abstract
The extinction of Californiaâs flightless duck, Chendytes lawi, stands out in the faunal history of North America because it involved a marine animal that disappeared in the late Holocene, not in the terminal Pleistocene when humans arrived from Asia, nor with the more recent entry of Europeans and associated resource exploitation. Here we evaluate the duckâs ecology by combining a stable isotopic evaluation of its feeding niche with records of human predation and climatic variation to evaluate (1) alternative influences on the duckâs extinction and (2) possible ecological consequences of its disappearance. Results indicate that a mid-late Holocene increase in human population density coincided with a decrease in mean sea surface temperatures (SST) and an increase in SST variance, all of which were contemporaneous with the demise of the flightless duck ca. 2500 cal BP. Climate appears to be a main exogenous driver of this extinction event by not only negatively impacting flightless duck food availability, but positively impacting one of the duckâs main predators: humans. Isotopic findings indicate the duck had a unique feeding ecology that overlapped equally with analog species reliant mostly on marine invertebrates (sea otters [Enhydra lutris]) and on fish (harbor seals [Phoca vitulina]). This dietary niche overlap suggests the duckâs extinction could have opened foraging opportunities for harbor seals and sea otters. Otter numbers appear to have increased coincident with the duckâs decline which also correlates with a decrease in size and abundance of red abalone (Haliotis rufescens), one of the otterâs preferred prey. These correlations suggest that new feeding opportunities may have emerged for otters in the face of the duckâs extinction, encouraging an increase in otter populations, which then had negative impacts on abalone that also were targeted by humans. Overall findings suggest the possibility of an unanticipated prehistoric precursor to the historic baseline of this nearshore ecosystem.
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George Sangster & Gerald Mayr (2021)
Feraequornithes: a name for the clade formed by Procellariiformes, Sphenisciformes, Ciconiiformes, Suliformes and Pelecaniformes (Aves).
Vertebrate Zoology 71: 49-53
https://doi:10.3897/vz.71.e61728https://vertebrate-zoology.arphahub.com/article/61728/Recent genomic data sets have resolved many aspects of higher-level phylogenetic relationships of birds. Eleven phylogenomic studies provide congruent support for a clade formed by Procellariiformes, Sphenisciformes, Ciconiiformes, Suliformes and Pelecaniformes. This clade is here named 'Feraequornithes' following the rules and requirements of the PhyloCode.
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