Ben Creisler
A new paper:
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Manuel PÃrez-Pueyo, Eduardo PuÃrtolas-Pascual, Miguel Moreno-Azanza, PenÃlope Cruzado-Caballero, Josà Manuel Gasca, Carmen NÃÃez-Lahuerta & Josà Ignacio Canudo (2021)
First record of a giant bird (Ornithuromorpha) from the uppermost Maastrichtian of the Southern Pyrenees, northeast Spain.
Journal of Vertebrate Paleontology Article: e1900210
DOI: 10.1080/02724634.2021.1900210
https://www.tandfonline.com/doi/full/10.1080/02724634.2021.1900210
Throughout the evolutionary history of Avialae, several members of this clade have evolved into giant forms, in different time periods and ecological contexts. In Europe, the first birds that show this condition, the Gargantuaviidae, occur during the Late Cretaceous (late Campanianâearly Maastrichtian), but it is during the Paleogene when more groups evolve large forms. However, until now, there was no record of any giant bird during the late Maastrichtian of Europe, close to the K/Pg boundary. Here we describe a cervical vertebra (MPZ 2019/264) from Beranuy (Huesca, NE Spain), which is the first fossil evidence of a giant bird from the late Maastrichtian of Europe, within Chron C29r. The vertebra displays some features, such as a well-marked heterocoelous articulation, lateral pneumatic foramina, ventral carotid processes, and a low neural spine, that support its inclusion within the clade Ornithuromorpha. This phylogenetic assignment is supported by two cladistic analyses. The vertebra is clearly different from the one assigned to Gargantuavis, meaning that it belonged to a distinct taxon. Although the kinship between these two taxa of giant birds is still unclear, this finding demonstrates that large-sized birds were part of the ecological communities of the Ibero-Armorican island from the late Campanian to the Late Maastrichtian, being present during the last hundreds of thousands of years prior to the K/Pg extinction event.
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Also, a full ref for a recent paper already posted:
Unenlagia comahuensis was originally described as a phylogenetic link between nonavian dinosaurs and birds. Later it was interpreted by some authors as belonging to the deinonychosaurian clade Dromaeosauridae, and more recently as phylogenetically closer to birds than to dromaeosaurids. The only known specimen is represented by an incomplete skeleton, including vertebrae, incomplete scapular girdle, pelvis, and limbs, coming from Upper Cretaceous beds of NeuquÃn province, Patagonia, Argentina. The aim of the present paper is to include a detailed anatomical description of Unenlagia (currently only known by preliminary descriptions). Detailed analysis of Unenlagia anatomy resulted in the recognition of one possible additional Unenlagiidae synapomorphy (i.e., the presence of cupâlike iliac articulation on ischium). We recognize derived anatomical traits that Unenlagia and kin share with birds, lending support to the interpretation that unenlagiids are stemâAvialae. Particularly, some appendicular features (e.g., scapula with subtriangular and relatively reduced acromion, poor outward projection of the glenoid and glenoidal lips on the scapula, lateral orientation of scapular glenoid, craniolaterally oriented deltopectoral crest of humerus) may be related to the acquisition of anatomical novelties that in birds are associated with flight. The present contribution on Unenlagia provides new data regarding the early evolution of avian features.
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