TheÂ
PrimoptynxÂpaper now has a free pdf:
Gerald Mayr, Philip D. Gingerich & Thierry Smith (2020)
Skeleton of a new owl from the early Eocene of North America (Aves, Strigiformes) with an accipitrid-like foot morphology.
Journal of Vertebrate Paleontology Article: e1769116
doi: https://doi.org/10.1080/02724634.2020.1769116
https://www.tandfonline.com/doi/full/10.1080/02724634.2020.1769116ÂÂ
Skeleton of a new owl from the early Eocene of North America (Aves, Strigiformes) with an accipitrid-like foot morphology.
Journal of Vertebrate Paleontology Article: e1769116
doi: https://doi.org/10.1080/02724634.2020.1769116
https://www.tandfonline.com/doi/full/10.1080/02724634.2020.1769116ÂÂ
On Tue, Jul 28, 2020 at 12:04 PM Ben Creisler <bcreisler@gmail.com> wrote:
More about the Eocene owl:A 55-Million-Year-Old Owl SkeletonOn Tue, Jul 28, 2020 at 7:22 AM Ben Creisler <bcreisler@gmail.com> wrote:Ben CreislerNew avian papers:Free pdf:Alida M. Bailleul, Jingmai OâConnor, Zhiheng Li, Qian Wu, Tao Zhao, Mario A. Martinez Monleon, Min Wang & Xiaoting Zheng (2020)
Confirmation of ovarian follicles in an enantiornithine (Aves) from the Jehol biota using soft tissue analyses.
Communications Biology 3, Article number: 399
DOI: https://doi.org/10.1038/s42003-020-01131-9
https://www.nature.com/articles/s42003-020-01131-9
The remains of ovarian follicles reported in nine specimens of basal birds represents one of the most remarkable examples of soft-tissue preservation in the Early Cretaceous Jehol Biota. This discovery was immediately contested and the structures alternatively interpreted as ingested seeds. Fragments of the purported follicles preserved in an enantiornithine (STM10-12) were extracted and subjected to multiple high-resolution analyses. The structures in STM10-12 possess the histological and histochemical characteristics of smooth muscles fibers intertwined together with collagen fibers, resembling the contractile structure in the perifollicular membrane (PFM) of living birds. Fossilized blood vessels, very abundant in extant PFMs, are also preserved. Energy Dispersive Spectroscopy shows the preserved tissues primarily underwent alumino-silicification, with minor mineralization via iron oxides. No evidence of plant tissue was found. These results confirm the original interpretation as follicles within the left ovary, supporting the interpretation that the right ovary was functionally lost early in avian evolution.
======Primoptynx poliotauros, gen. et sp. nov.Â
Gerald Mayr, Philip D. Gingerich & Thierry Smith (2020)
Skeleton of a new owl from the early Eocene of North America (Aves, Strigiformes) with an accipitrid-like foot morphology.
Journal of Vertebrate Paleontology Article: e1769116
doi: https://doi.org/10.1080/02724634.2020.1769116
https://www.tandfonline.com/doi/full/10.1080/02724634.2020.1769116
We describe a partial skeleton of a large-sized owl from Wasatchian strata of the Willwood Formation (Wyoming, U.S.A.). The holotype of Primoptynx poliotauros, gen. et sp. nov., includes all major postcranial bones and is one of the most substantial Paleogene records of the Strigiformes. The fossil shows that owls exhibited a considerable morphological diversity in the early Eocene of North America and occupied disparate ecological niches. As in the protostrigid taxon Minerva from the late early to early middle Eocene of North America, but unlike in extant owls, the ungual phalanges of the hallux and the second toe of the new species are distinctly larger than those of the other toes. Primoptynx poliotauros gen. et sp. nov., however, does not exhibit the derived tibiotarsus morphology of the Protostrigidae. Even though the new species may well be a stem group representative of protostrigid owls, current data do not allow an unambiguous phylogenetic placement. Concerning the size of the ungual phalanges, the feet of P. poliotauros correspond to those of extant hawks and allies (Accipitridae). We therefore hypothesize that it used its feet to dispatch prey items in a hawk-like manner, whereas extant owls kill prey with their beak. Primoptynx and protostrigid owls were possibly specialized in foraging on prey items that required an accipitrid-like killing strategy, such as larger-sized or more defensive mammals. The extinction of these peculiar owls may have been related to the radiation of accipitrid diurnal birds of prey, which appear to have diversified in the late Eocene and early Oligocene.
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