The petrosal bone and inner ear of Micromeryx flourensianus (Artiodactyla, Moschidae) and inferred potential for ruminant phylogenetics

While petrosal bones have a long research history in artiodactyl phylogenetics, the inner ear embedded in this bone has rarely been investigated. I describe here a set of petrosals and the associated inner ears of the Middle Miocene moschid Micromeryx flourensianus from the German locality Steinheim and compare them to the extant musk deer Moschus moschiferus (Moschidae), the four-horned antelope Tetracerus quadricornis (Bovidae) and the white-tailed deer Odocoileus virginianus (Cervidae). Inner ears were reconstructed using high resolution x-ray computed tomography scans. In phylogenenetic reconstructions built on morphological and molecular data, Moschidae has variously been shown to be a sister taxon to Bovidae or Cervidae. Its position hasn’t reached a consensus yet. Studying the inner ear morphology adds new morphological characters that will help resolving this question. Micromeryx flourensianus is an abundant fossil moschid and I show indeed that its petrosal bone and inner ear share several similarities with that of the extant musk deer such as a ventral basicapsular groove, a well-developed anterior process of the tegmen tympani, or a fossa for the tensor tympani muscle in the musk-deer that may well have evolved from a Micromeryx-like condition. Inner ears share a thick basal cochlear whorl, a bulky vestibule, or a short and thick cochlear aqueduct. This shows that inner ears have a high potential for taxonomy and phylogenetics. Including the inner ear of a fossil skull of Micromeryx flourensianus also from Steinheim, four inner ears are described here and give insights into the morphological variability of this structure at an intraspecific level as well as into the post-natal ontogenetic changes that occur. This contribution is a first step towards a comprehensive understanding of the evolution of the ruminant inner ear

A new primate assemblage from La Verrerie de Roches (Middle Eocene, Switzerland)

Primates reached a great abundance and diversity during the Eocene, favored by warm temperatures and by the development of dense forests throughout the Northern Hemisphere. Here we describe new primate material from La Verrerie de Roches, a Middle Eocene karstic infill situated in the Jura Region (Switzerland), consisting of more than 80 dental remains. The primate assemblage from La Verrerie de Roches includes five different taxa. The best represented primate is Necrolemur aff. anadoni, similar in size and overall morphology to Necrolemur anadoni but resembling in some features the younger species Necrolemur antiquus. Microchoerines are also represented by two species of Pseudoloris, P. pyrenaicus and Pseudoloris parvulus, constituting the unique joint record of these two species known up to now. Remains of Adapiformes are limited to one isolated tooth of a large anchomomyin and another tooth belonging to the small adapine Microadapis cf. sciureus. The studied primate association allows assigning La Verrerie de Roches to the Robiacian Land Mammal Age. More specifically, this site can be confidently situated between the MP15 and MP16 reference levels, although the primate assemblage probably indicates some degree of temporal mixing. This is the first record of P. pyrenaicus and a form closely related to N. anadoni out of the Iberian Peninsula. The identification of these microchoerines in Switzerland gives further support to the connection of NE Spain and Central Europe during the Middle Eocene

Catalogue of the Eocene mammal types of the Natural History Museum Basel

This catalogue presents a list of the Eocene mammalian type specimens held in the collection of the Natural History Museum Basel (Naturhistorisches Museum Basel, hereafter NMB). After a close inspection of the very rich Eocene collection (several tens of thousands of specimens), a total of 51 valid holotypes (plus 16 invalid species) were identified together with 21 valid lectotypes and several hundreds paratypes, paralectotypes and syntypes. These types belong to 123 originally described species, of which 99 are still valid, 30 having been moved to another genus

The tracks and mammal’s footprints of former Oligocene in Viens (Vaucluse)

Deux gisements situés au coeur du bassin d’Apt- Forcalquier (Vaucluse, SE de la France), datés de la base de l’Oligocène inférieur, ont révélé une importante ichnofaune. Le premier site, à Gignac-Viens, a livré quatre types d’ichnites de mammifères : - Ronzotherichnus voconcense Demathieu et al., 1984 ; empreintes attribuables au périssodactyle Ronzotherium Aymard, 1854 ; - Bifidipes velox Demathieu et al., 1984; traces d’artiodactyles de taille moyenne, peut-être de la famille des Gelocidae ; - une nouvelle ichnoespèce pouvant appartenir au grand artiodactyle Entelodon Aymard, 1847 ; - une empreinte indéterminée, probablement de carnivore. Le second site, toujours à Viens, a également livré Ronzotherichnus voconcense, d’autres empreintes de la famille des Rhinoceratichnidae ainsi que des empreintes de périssodactyles indéterminables. L’étude ichnologique, conjuguée avec des données sédimentologiques, atteste d’un environnement ouvert, de type savane, recouvert d’étendues d’eaux lacustres et palustres à niveau variable selon l’évolution du climat. L a mise en évidence d’une direction privilégiée des pistes vers le nord-ouest suggère que les animaux se dirigeaient vers un point d’eau. Enfin, les associations de pistes de périssodactyles témoignent d’une vie en groupe d’au moins quatre individus chez certains des premiers Rhinocérotoïdés d’Europe occidentale.Two localities, within the Apt-Forcalquier basin (Vaucluse, SE France), both dated from the lowermost Oligocene, have yielded an important ichnofauna. The first site, located in Gignac-Viens, yielded four types of mammals’ ichnites : - Ronzotherichnus voconcense Demathieu et al., 1984; footprints that can be ascribed to the Perissodactyla Ronzotherium Aymard, 1854; - Bifidipes velox Demathieu et al., 1984; ichnites of a medium sized Artiodactyla, perhaps a Gelocidae ; - a new ichnospecies probably belonging to the large Artiodactyla Entelodon Aymard 1847 ; - a single undetermined footprint, possibly of a Carnivora The second site, again in Viens, yielded Ronzotherichnus voconcense as well as other undeterminable Perissodactyla tracks. The ichnological study, together with sedimentological data, shows evidence of an open savanna-like environment with lacustrine and paludal pools, whose water level fluctuates following climatic variations. From a paleobiological point of view, the main direction of the trackways toward the Northwest suggests that the animals were heading to the pools. Finally, the association of several Perissodactyla trackways attests of a life in small groups of at least four individuals for some of the first Rhinocerotoidea of Western Europe

A lynx natural brain endocast from Ingarano (Southern Italy; Late Pleistocene). Taphonomic, Morphometric and Phylogenetic approaches

A natural brain endocast from the Late Pleistocene site of Ingarano (Apulia, Southern Italy) has been investigated in detail using CT scanning, image processing techniques and Geometric Morphometrics to obtain information about the taxonomy and taphonomy of the specimen. Based on its characteristically felid shape, we compared several measurements of the endocast with those of the brains of living Felidae, with a special emphasis on Panthera pardus, Lynx lynx and Felis silvestris earlier reported from the same locality. The applied combination of techniques revealed that this specimen is morphometrically closest to the brains of lynxes, and so can be reported as the first natural endocranial cast of Late Pleistocene Lynx sp. In addition, CT scanning of the Ingarano endocast allowed us to reconstruct the early stages of its taphonomy (i.e., the process of infilling of the braincase with the sediment)

Aubenas-les-Alpes (S-E France). Part III – Last and final part of the mammalian assemblage with some comments on the palaeoenvironment and palaeobiogeography

L’étude du nouveau matériel issu d’Aubenas-les-Alpes permet de compléter la liste faunique par des taxa jusqu’alors inconnus dans cette localité (Neurogymnurus cayluxi, Issiodoromys minor, Eomys minor, Pseudocricetodon cf. hausi, Pseudocricetodon aff. philippi). Les nouveaux spécimens de la musaraigne Srinitium marteli améliorent notre connaissance de ce rare insectivore. Les caractéristiques du théridomorphe I. minor confirment, de même que l’ensemble de la faune de rongeurs, la corrélation avec le niveau MP25 (Rupélien supérieur). L’assemblage d’Aubenas- les-Alpes indique un environnement plutôt sec et ouvert, en accord avec le contexte climatique du début de l’Oligocène, mais quelques différences sont également notées par comparaison aux autres localités du même âge. Finalement l’assemblage mammalien suggère la mise en place d’une différentiation biogéographique à l’échelle européenne au cours du Rupélien supérieur.The study of the new material from Aubenas-les-Alpes makes it possible to add to the faunal list taxa hitherto unknown in this locality (Neurogymnurus cayluxi, Issiodoromys minor, Eomys minor, Pseudocricetodon cf. hausi, Pseudocricetodon aff. philippi). New specimens of the shrew Srinitium marteli increase our knowledge of this rare insectivore. The characteristics of the theridomorph I. minor confirm, as does the whole rodent fauna, the correlation with the MP25 level (Late Rupelian). The assemblage of Aubenas-les-Alpes indicates a rather open and dry environment, in accordance with the Early Oligocene climatic context, but some differences compared to other localities of the same age are also noticed. Finally the mammalian assemblage suggests an ongoing biogeographic differentiation at European scale during the Late Rupelian

New discoveries of mammal footprints from Oligocene in the Park of Luberon

Nous présentons de nouvelles découvertes d’empreintes de pas de mammifères réalisées ces dernières années dans les formations oligocènes du Parc naturel régional du Luberon. Au total, cinq nouveaux sites ont livré des empreintes et viennent compléter les trois sites déjà connus. Une nouvelle piste d’une quinzaine de mètres attribuable à un rhinocéros a également été dégagée dans la carrière d’argile de Viens sur une surface qui avait déjà livré des empreintes auparavant. Ces découvertes donnent des informations sur la faune de l’époque et permettent de poursuivre la réflexion engagée sur la classification des traces de vie des mammifères.Here we present new discoveries of mammal footprints from the Oligocene formations of the Natural Regional Park of Luberon. Five new sites yielded footprints and increase the ichnological record which was up to now limited to three published sites. A new 15 meters long trackway that can be ascribed to a rhinoceros was also discovered and excavated in the red clay quarry of the village of Viens. The surface where this trackway occurs was already known previously for another very nicely preserved rhinoceros trackway. These discoveries give information on the Oligocene faunas of the region and are a good opportunity to develop ideas and thinking on the classification of fossil mammal footprints

First digital study of the frontal sinus of stem-Canini (Canidae, Carnivora): evolutionary and ecological insights throughout advanced diagnostic in paleobiology

Introduction: The phylogenetic and ecological importance of paranasal sinuses in carnivorans was highlighted by several previous authors, mostly in extant species. Nevertheless, no specific study on this feature on extant canids, and no one on fossil representatives of the family, has been published up to now. Here, we analyze for the first time the paranasal sinus of extant and fossil canids through computed tomographic techniques to characterize them morphologically and morphometrically, making ecological inferences. Methods: To do so, we applied for the first time an innovative deformation-based morphometric approach. Results: The results obtained for extant species highlight a remarkable correlation between morphology and ecomorphotypes previously defined by some scholars (namely hypercarnivorous group-hunters; small-prey hypercarnivores, mesocarnivores, hypocarnivores). Our results thus support the direct relationship between diet preferences and the development of frontal sinus in canids. Regarding fossil specimens, we reconstructed for the first time the frontal sinus of three Eucyon species and compared it to those of living forms. Discussion: The best-preserved specimen, the only known cranium of Eucyon adoxus dated to the Late Pliocene of Saint-Estève (France), displayed similarities with hypercarnivorous group-hunter canids by the large sinus prominences. Given that the overall craniodental morphology of E. adoxus suggests that it acted as a small prey hypercarnivore-similar to extant Canis simensis-the aforementioned affinities might have evolved independently, in relation to high stresses during feeding. Overall, our study demonstrates that morphological inspection and deformation-based geometric morphometrics complement each other and allow a thorough investigation of sinus shape variability, thus enabling the study of sinus morphology in other fossil carnivorans with the ultimate goal of inferring their ecological preferences