Early Eocene birds from La Borie, southern France

The early Eocene locality of La Borie is located in the village of Saint-Papoul, in southern France. These Eocene flu-vio-lacustrine clay deposits have yielded numerous vertebrate remains. Mammalian taxa found in the fossiliferous levels indicate an age near the reference level MP 8–9, which corresponds to the middle Ypresian, early Eocene. Here we provide a detailed description of the avian remains that were preliminarily reported in a recent study of the vertebrate fauna from La Borie. A maxilla, a quadrate, cervical vertebrae, a femur and two tibiotarsi are assigned to the giant ground bird Gastornis parisiensis (Gastornithidae). These new avian remains add to the fossil record of Gastornis, which is known from the late Paleocene to middle Eocene of Europe, early Eocene of Asia and early Eocene of North America. Gastornis parisiensis differs from the North American Gastornis giganteus in several features, including the more ventral position of the narial openings and the slender orbital process of quadrate. Two tibiotarsi and one tarsometatarsus are assigned to a new genus and species of Geranoididae, Galligeranoides boriensis gen. et sp. nov. So far, this family was known only from the early and middle Eocene of North America. The fossils from La Borie constitute the first record of the Geranoididae in Europe. We show that Gastornis coexisted with the Geranoididae in the early Eocene of both Europe (La Borie) and North America (Willwood Formation). The presence of Geranoididae and the large flightless bird Gastornis on either side of the present-day North Atlantic provides further evidence that a high-latitude land connection existed between Europe and North America in the early Eocene

A roller-like bird (Coracii) from the Early Eocene of Denmark

The fossil record of crown group birds (Neornithes) prior to the Cretaceous-Paleogene boundary is scarce and fragmentary. Early Cenozoic bird fossils are more abundant, but are typically disarticulated and/or flattened. Here we report the oldest roller (Coracii), Septencoracias morsensis gen. et sp. nov. (Primobucconidae), based on a new specimen from the Early Eocene (about 54 million years ago) Fur Formation of Denmark. The new fossil is a nearly complete, three-dimensionally preserved and articulated skeleton. It lies at the lower end of the size range for extant rollers. Salient diagnostic features of Septencoracias relative to other Coracii include the proportionally larger skull and the small, ovoid and dorsally positioned narial openings. Our discovery adds to the evidence that the Coracii had a widespread northern hemisphere distribution in the Eocene. Septencoracias is the oldest substantial record of the Picocoraciae and provides a reliable calibration point for molecular phylogenetic studies

Preliminary assessment of bone histology in the extinct elephant bird <i>Aepyornis</i> (Aves, Palaeognathae) from Madagascar

International audienceAepyornis, a giant subfossil ratite from Madagascar, shows a well-preserved bone histology. Hindlimb bones exhibit an extensive histodiversity; the cortex is initially made of fibrolamellar, well-vascularized primary bone that modulates locally into plexiform or laminar patterns. Lines of arrested growth are generally weakly expressed. Haversian reconstruction can be complete. Perimedullar endosteal deposition is variable but can be extensive. The complex causality (phylogenetic, systematic, ontogenetic and functional… factors) involved in the production of the observed data is discussed.Aepyornis, ratite géant subfossile de Madagascar, montre une histologie osseuse bien préservée. Les os longs des pattes présentent une forte diversité histologique ; l’os primaire des corticales est initialement du type général fibrolamellaire, fortement vascularisé selon des patrons plexiformes ou laminaires. Les lignes d’arrêt de croissance sont généralement peu exprimées. Le remaniement haversien peut être complet. Le dépôt endostéal périmédullaire est variable, mais peut être très important. La causalité complexe (facteurs phylogénétiques, systématiques, ontogénétiques, fonctionnels…) pouvant rendre compte des structures observées est abordée

Avian cerebellar floccular fossa size is not a proxy for flying ability in birds

Extinct animal behavior has often been inferred from qualitative assessments of relative brain region size in fossil endocranial casts. For instance, flight capability in pterosaurs and early birds has been inferred from the relative size of the cerebellar flocculus, which in life protrudes from the lateral surface of the cerebellum. A primary role of the flocculus is to integrate sensory information about head rotation and translation to stabilize visual gaze via the vestibulo-occular reflex (VOR). Because gaze stabilization is a critical aspect of flight, some authors have suggested that the flocculus is enlarged in flying species. Whether this can be further extended to a floccular expansion in highly maneuverable flying species or floccular reduction in flightless species is unknown. Here, we used micro computed-tomography to reconstruct “virtual” endocranial casts of 60 extant bird species, to extract the same level of anatomical information offered by fossils. Volumes of the floccular fossa and entire brain cavity were measured and these values correlated with four indices of flying behavior. Although a weak positive relationship was found between floccular fossa size and brachial index, no significant relationship was found between floccular fossa size and any other flight mode classification. These findings could be the result of the bony endocranium inaccurately reflecting the size of the neural flocculus, but might also reflect the importance of the flocculus for all modes of locomotion in birds. We therefore conclude that the relative size of the flocculus of endocranial casts is an unreliable predictor of locomotor behavior in extinct birds, and probably also pterosaurs and non-avian dinosaurs

Tempo and Pattern of Avian Brain Size Evolution

Relative brain sizes in birds can rival those of primates, but large-scale patterns and drivers of avian brain evolution remain elusive. Here, we explore the evolution of the fundamental brain-body scaling relationship across the origin and evolution of birds. Using a comprehensive dataset sampling> 2,000 modern birds, fossil birds, and theropod dinosaurs, we infer patterns of brain-body co-variation in deep time. Our study confirms that no significant increase in relative brain size accompanied the trend toward miniaturization or evolution of flight during the theropod-bird transition. Critically, however, theropods and basal birds show weaker integration between brain size and body size, allowing for rapid changes in the brain-body relationship that set the stage for dramatic shifts in early crown birds. We infer that major shifts occurred rapidly in the aftermath of the Cretaceous-Paleogene mass extinction within Neoaves, in which multiple clades achieved higher relative brain sizes because of a reduction in body size. Parrots and corvids achieved the largest brains observed in birds via markedly different patterns. Parrots primarily reduced their body size, whereas corvids increased body and brain size simultaneously (with rates of brain size evolution outpacing rates of body size evolution). Collectively, these patterns suggest that an early adaptive radiation in brain size laid the foundation for subsequent selection and stabilization

L'avifaune du Paléogène des phosphates du Maroc et du Togo (diversité, systématique et apports à la connaissance de la diversification des oiseaux modernes (Neornithes))

Une nouvelle avifaune du Paléocène supérieur et de l'Eocène inférieur du bassin à phosphates des Ouled Abdoun (Maroc) est décrite ici. Cette avifaune marine représente les plus anciens oiseaux modernes (Neornithes) d'Afrique et comporte un minimum de 10 espèces. Les Odontopterygidae constituent le groupe dominant des Ouled Abdoun et sont parmi les premiers représentants des oiseaux à pseudo-dent (Odontopterygiformes) : Odontopteryx toliapica Owen 1873 (2-3 m d'envergure), également connu dans l'Eocène inférieur du London Clay (Angleterre) ; Odontopteryx gigas sp. nov. (4 m d'envergure) ; Odontoptila inexpectata gen. et sp. nov. (1,6 m d'envergure). Abdounornis marinus gen. et sp. nov. (Abdounornithidae fam. nov.) est une espèce commune (1 m d'envergure). Le prophaethontidé Lithoptila abdounensis Bourdon 2005 (1 m d'envergure) est le plus ancien représentant des phaétons et apparentés (Phaethontiformes nov.). Le seul oiseau continental de l'avifaune des Ouled Abdoun est un échassier d'une taille voisine de celle de Ciconia ciconia. Trois spécimens de l'Eocène moyen du bassin à phosphates de Kpogamé-Hahotoé (Togo) sont attribués à Aequornis traversei gen. et sp. nov. (Pelagornithidae, Odontopterygiformes). Une nouvelle hypothèse phylogénétique concernant les premières divergences au sein des Neognathae est proposée : les Galliformes sont le groupe frère de tous les autres Neognathae. Au sein de ce clade, les Odontoanserae (Anseriformes plus Odontopterygiformes) sont le groupe frère des Neoaves. Trois nouveaux grands clades sont définis au sein des Neoaves : le premier inclut les Procellariiformes et les Phaethontiformes. Le deuxième comprend les Pelecaniformes redéfinis (Steganopodes sensu Cracraft 1985) et les Ardeiformes. Le troisième inclut les Charadriiformes et les Abdounornithidae.LYON1 - UFR Sciences de la terre (692662208) / SudocPARIS-Museum Hist.Naturelle (751052304) / SudocSudocFranceF

Analyse à trois éléments : représentation hiérarchique et traitement des données manquantes et non applicables

Les méthodes qui utilisent des matrices, dont les programmes de parcimonie, représentent et traitent de la même manière les données manquantes, pour lesquelles tout état de caractère est possible, et les données non applicables, pour lesquelles tout état de caractère est impossible. Ce problème vient du fait que la nature hiérarchique des hypothèses d’homologie ne peut pas être représentée dans une matrice taxons–caractères. Nous montrons que la représentation hiérarchique des hypothèses d’homologie utilisée en analyse à trois éléments permet de traiter correctement les données manquantes et non applicables.Matrix-based methods, including parsimony programs, represent and treat missing data in the same way, such that every character-state is possible, and inapplicable data, such that every character state is impossible. This is because the hierarchical nature of homology assessments cannot be represented in taxon–character matrices. We show that the hierarchical representation of hypotheses of homology used in three-item analysis permits the accurate treatment of missing and inapplicable data.</p

The <i>Gastornis</i> (Aves, Gastornithidae) from the late Paleocene of Louvois (Marne, France)

The Late Paleocene locality of Louvois is located about 20 km south of Reims, in the department of Marne (France). These marly sediments have yielded numerous vertebrate remains. The Louvois fauna is coeval with those of the localities of Cernay-les-Reims and Berru and is dated as reference-level MP6, late Thanetian. Here we provide a detailed description of the remains of giant flightless gastornithids that were preliminarily reported in a study of the vertebrate fauna from Louvois. These fragmentary gastornithid remains mainly include a carpometacarpus, several tarsometatarsi, and numerous pedal phalanges. These new avian fossils add to the fossil record of Gastornis, which has been reported from various Early Paleogene localities in the Northern Hemisphere. Tarsometatarsi and pedal phalanges show large differences in size, which may be interpreted as sexual size dimorphism. The specimens from Louvois are morphologically different from those of Gastornis parisiensis and G. russelli, from Cernay and Berru. The Louvois carpometacarpus is also different from that of the North American G. giganteus, and the Louvois pedal phalanges are shorter and stouter than in other species of Gastornis. Moreover, the Louvois tarsometatarsi are more similar to that of the much younger G. sarasini, from Monthelon, reference-level MP 10, late Ypresian. We refrain from assigning the Louvois specimens to a new species of Gastornis and we designate it as Gastornis sp., owing to the fragmentary nature of the material. However, the morphological features of the Louvois material are sufficiently distinct for us to propose that three different forms of Gastornis were present in the Late Paleocene of North-eastern France

Evaluation de la douleur postopératoire en pédiatrie (application à l'amygdalectomie)

PARIS-BIUP (751062107) / SudocSudocFranceF