And one more avian paper (taxon not named it seems....)
Free pdf:
https://www.nature.com/articles/s41598-020-66149-9.pdf
Passeriformes is the most diverse bird order. Nevertheless, passerines have a remarkably poor early fossil record. In addition, high osteological homoplasy across passerines makes partial specimens difficult to systematically assign precisely. Here we describe one of the few earliest fossil passerines, from the early Oligocene (ca 30âMa) of southern France, and one of the best preserved and most complete. This fossil can be conservatively assigned to Tyrannida, a subclade of the New World Tyranni (Suboscines), i.e. of the Tyrannides. A most probably stem-representative of Tyrannida, the new fossil bears strong resemblance with some manakins (Pipridae), possibly due to plesiomorphy. Furthermore, it yields a new point of calibration for molecular phylogenies, already consistent with the age of the fossil. Tyrannida, and the more inclusive Tyrannides, are today confined to the New World. Therefore, the new fossil calls for scenarios of transatlantic crossing during or near the Oligocene. Later, the European part of the distribution of the Tyrannida disappeared, leading to a relictual modern New World distribution of this clade, a pattern known in other avian clades. The history of Tyrannida somehow mirrors that of the enigmatic Sapayoa aenigma, sole New World representative of the Eurylaimides (Old World Tyranni), with transatlantic crossing probably caused by similar events.
Free pdf:
SÃgolÃne Riamon, Nicolas Tourment & Antoine Louchart (2020)
The earliest Tyrannida (Aves, Passeriformes), from the Oligocene of France.
Scientific Reports 10, Article Â9776
DOI: https://doi.org/10.1038/s41598-020-66149-9
https://www.nature.com/articles/s41598-020-66149-9
The earliest Tyrannida (Aves, Passeriformes), from the Oligocene of France.
Scientific Reports 10, Article Â9776
DOI: https://doi.org/10.1038/s41598-020-66149-9
https://www.nature.com/articles/s41598-020-66149-9
Free pdf:
https://www.nature.com/articles/s41598-020-66149-9.pdf
Passeriformes is the most diverse bird order. Nevertheless, passerines have a remarkably poor early fossil record. In addition, high osteological homoplasy across passerines makes partial specimens difficult to systematically assign precisely. Here we describe one of the few earliest fossil passerines, from the early Oligocene (ca 30âMa) of southern France, and one of the best preserved and most complete. This fossil can be conservatively assigned to Tyrannida, a subclade of the New World Tyranni (Suboscines), i.e. of the Tyrannides. A most probably stem-representative of Tyrannida, the new fossil bears strong resemblance with some manakins (Pipridae), possibly due to plesiomorphy. Furthermore, it yields a new point of calibration for molecular phylogenies, already consistent with the age of the fossil. Tyrannida, and the more inclusive Tyrannides, are today confined to the New World. Therefore, the new fossil calls for scenarios of transatlantic crossing during or near the Oligocene. Later, the European part of the distribution of the Tyrannida disappeared, leading to a relictual modern New World distribution of this clade, a pattern known in other avian clades. The history of Tyrannida somehow mirrors that of the enigmatic Sapayoa aenigma, sole New World representative of the Eurylaimides (Old World Tyranni), with transatlantic crossing probably caused by similar events.
On Wed, Jun 17, 2020 at 12:47 PM Ben Creisler <bcreisler@gmail.com> wrote:
Ben CreislerSome recent avian evolution papers:====
John Peacock, Garth M. Spellman, Nathaniel T. Greene & Daniel J. Tollin (2020)
Scaling of the Avian Middle Ear.
Hearing Research Article 108017 (advance online publication)
doi: https://doi.org/10.1016/j.heares.2020.108017
https://www.sciencedirect.com/science/article/abs/pii/S0378595520302884
Highlights
Columellar length appears to scale isometrically with interaural diameter.
The footplate area, tympanic membrane area, and extracolumellar length show negative allometric scaling.
Columellar morphology shows striking variation across taxa, but the scaling relationships appear consistent.
Abstract
This article presents a comparative study of morphology of the avian middle ear. The general morphology of the columella shows considerable variation across species, yet few studies have attempted to provide quantitative comparisons, and basic anatomical data has not been thoroughly reported. In this study, we examined the middle ear in 49 taxonomically diverse species of bird. We found significant correlations between measurements of several features (columellar length, mass, tympanic membrane area, footplate area) and interaural diameter. While scaling of columellar length with interaural diameter is consistent with isometry, masses and areas showed negative allometry, or a non-proportional scaling with interaural diameter. These observations remained true even for species with unusual middle ear morphology, such as Alcedinidae (Kingfishers) in which the basal struts of the columella form a structure almost resembling a mammalian stapes, or Tytonidae (Barn Owls) which have a highly bulbous footplate. It therefore appears that allometry cannot help explain the morphological variation in the columella.
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Mary Caswell Stoddard, Harold N. Eyster, Benedict G. Hogan, Dylan H. Morris, Edward R. Soucy, and ÂDavid W. Inouye (2020)
Wild hummingbirds discriminate nonspectral colorsl
Proceedings of the National Academy of Sciences (advance online publication)
doi: https://doi.org/10.1073/pnas.1919377117
https://www.pnas.org/content/early/2020/06/09/1919377117
Significance
Birds have four color cone types in their eyes, compared to three in humans. In theory, this enables birds to discriminate a broad range of colors, including many nonspectral colors. Nonspectral colors are perceived when nonadjacent cone types (sensitive to widely separated parts of the light spectrum) are predominantly stimulated. For humans, purple (stimulation of blue- and red-sensitive cones) is a nonspectral color; birds' fourth color cone type creates many more possibilities. We trained wild hummingbirds to participate in color vision tests, which revealed that they can discriminate a variety of nonspectral colors, including UV+red, UV+green, purple, and UV+yellow. Additionally, based on an analysis of â3,300 plumage and plant colors, we estimate that birds perceive many natural colors as nonspectral.
Abstract
Many animals have the potential to discriminate nonspectral colors. For humans, purple is the clearest example of a nonspectral color. It is perceived when two color cone types in the retina (blue and red) with nonadjacent spectral sensitivity curves are predominantly stimulated. Purple is considered nonspectral because no monochromatic light (such as from a rainbow) can evoke this simultaneous stimulation. Except in primates and bees, few behavioral experiments have directly examined nonspectral color discrimination, and little is known about nonspectral color perception in animals with more than three types of color photoreceptors. Birds have four color cone types (compared to three in humans) and might perceive additional nonspectral colors such as UV+red and UV+green. Can birds discriminate nonspectral colors, and are these colors behaviorally and ecologically relevant? Here, using comprehensive behavioral experiments, we show that wild hummingbirds can discriminate a variety of nonspectral colors. We also show that hummingbirds, relative to humans, likely perceive a greater proportion of natural colors as nonspectral. Our analysis of plumage and plant spectra reveals many colors that would be perceived as nonspectral by birds but not by humans: Birdsâ extra cone type allows them not just to see UV light but also to discriminate additional nonspectral colors. Our results support the idea that birds can distinguish colors throughout tetrachromatic color space and indicate that nonspectral color perception is vital for signaling and foraging. Since tetrachromacy appears to have evolved early in vertebrates, this capacity for rich nonspectral color perception is likely widespread.News:
===Panagiotis Kampouridis, Dimitrios Michailidis, Nikolaos Kargopoulos, Socrates Roussiakis & Georgios Theodorou (2020)
First description of an ostrich from the late Miocene of Kerassia (Euboea, Greece): remarks on its cervical anatomy.
Historical Biology (advance online publication)
doi: https://doi.org/10.1080/08912963.2020.1779252
https://www.tandfonline.com/doi/abs/10.1080/08912963.2020.1779252
The present study describes an almost complete cervical region of the fossil ostrich Struthio karatheodoris from the Turolian locality of Kerassia (Euboea, Greece). The material comes from two distinct fossiliferous horizons and consists of twelve cervical vertebrae, ten of which belong to the same individual. These specimens are the first remains of a large flightless bird from Kerassia and represent some of the very few findings of the genus Struthio in the sub-Paratethyan (Balkan-Iranian) bioprovince from the late Miocene. The morphology of the cervical vertebrae implies that the neck of S. karatheodoris had similar biomechanical properties to that of extant ostriches, pointing to similar ecological adaptations, relating to food procurement. However, it probably had a more flexible and stronger neck, which might indicate a somewhat different ecology. Furthermore, considerable intraspecific size and morphological variation of the cervical vertebrae of S. karatheodoris is observed. This signifies that S. karatheodoris was not necessarily larger than S. camelus as previously suspected, but their size ranges in fact overlap significantly.