-
A new Barremian (Early Cretaceous) ichthyosaur from Western Russia
-
Located in
Library
/
RBINS Staff Publications
-
Contribution supplémentaire à l’étude de la faune des Prioninae du Laos avec la description d’une nouvelle espèce du genre Aegosoma Audinet-Serville, 1832 (Coleoptera, Cerambycidae, Prioninae)
-
Located in
Library
/
RBINS Staff Publications 2019
-
Description of a new species belonging to the genus Sarmydus Pascoe from Taiwan island, China (Coleoptera, Cerambycidae, Prioninae) (6th contribution to the study of genus Sarmydus Pascoe, 1867)
-
Located in
Library
/
RBINS Staff Publications 2019
-
First virtual endocasts of two Paleocene arctocyonids: a glimpse into the behavior of early placental mammals after the end-Cretaceous extinction
-
Placentals are by far the most diverse group of mammals today, with 6,111 species. They occupy a plethora of ecological niches worldwide and display a broad range of body masses. The vacant niches left by non-avian dinosaurs and other vertebrates after the end-Cretaceous mass extinction provided a crucial opportunity for placentals to diversify; however, intrinsic factors also may have played a role. The general neurosensory organization exhibited by extant mammals has been maintained since the early Mesozoic. Much later, early members of extant placental groups from the Eocene and Oligocene including rodents, primates and artiodactyls—display neurosensory innovations such as a proportionally larger neocortex and higher encephalization quotient compared to their Mesozoic ancestors. However, between these two well-known intervals of mammalian neurosensory evolution, there is a gap: few studies have focused on the brains of the oldest placentals living during the early Paleogene, in the Paleocene. We focus on the ‘Arctocyonidae’, a likely polyphyletic group of ‘condylarths’, including species potentially implicated in the origins of some extant orders. ‘Arctocyonids’ were among the first placentals to diversify after the end-Cretaceous extinction. They have been reconstructed as small-tomedium sized, mainly omnivorous and terrestrial. We obtained cranial and bony labyrinth endocasts for Chriacus baldwini and C. pelvidens from the lower Paleocene of the San Juan Basin, New Mexico, and Arctocyon primaevus from the upper Paleocene of the Paris Basin, France, via high resolution computed tomography. Both share plesiomorphic brain features with previously described early Paleocene mammals. They have small lissencephalic brains with an EQ range of 0.12-0.43 and 0.16-0.31, respectively. The olfactory bulbs and the paraflocculi represent 6% and less than 1% of the total endocranial volume, respectively and the neocortical height ratio represents ~25% of the total endocranial height. Based on cochlear measurements, both taxa had hearing capabilities similar to those of extant wild boars. Agility scores between 2 and 3 were obtained for both taxa, similar to the modern American badger and crab-eating raccoon, suggesting that C. pelvidens and A. primaevus were ambulatory. These results support growing evidence that early placentals had lower EQs and less expanded neocortices compared to Eocene and later taxa, potentially indicating that high intelligence was not key to the placental radiation after the End-Cretaceous extinction. Grant Information: Marie Sklodowska-Curie Actions: Individual Fellowship, European Research Council Starting Grant, National Science Foundation, and Belgian Science Policy Office.
Located in
Library
/
RBINS Staff Publications 2019
-
Paleocene and Eocene bird assemblage from the Southern North Sea Basin
-
Numerous bird bones from the Paleocene and early Eocene of the Belgian and Paris basins have been collected by amateur paleontologists. Four bones from the early-middle Selandian of Maret, Belgium are among the earliest Cenozoic avian remains from Europe and include the oldest temporally well constrained records of the Gastornithidae, as well as tentative records of the paleognathous Lithornithidae and the Ralloidea. Another assemblage from the middle Thanetian of Templeuve, France contains multiple bones of the Lithornithidae as well as a record of the Pelagornithidae. Specimens from the latest Thanetian of Rivecourt-Petit Pâtis, France are tentatively assigned to the Ralloidea and Leptosomiformes. An assemblage of 54 bones from the middle Ypresian of Egem, Belgium represents at least 20 species in more than 11 higher-level taxa. Well-identifiable specimens are assigned to the Odontopterygiformes, Galliformes, Messelornithidae, Apodiformes, Halcyornithidae, Leptosomiformes, and Coraciiformes. Further specimens are tentatively referred to the phaethontiform Prophaethontidae and to the Accipitridae, Masillaraptoridae, and Alcediniformes. These three-dimensionally preserved fossils provide new data on the osteology of taxa that are otherwise mainly known from compression fossils with crushed bones. They also further knowledge of the composition of early Paleogene avifaunas of the North Sea Basin. Paleocene avifaunas of Europe and North America appear to have had different compositions and only a few taxa, such as the paleognathous Lithornithidae, are known from both continents. This suggests that the very similar early Eocene avifaunas of Europe and North America are the result of early Cenozoic dispersal events. The well-represented small galliform species from Egem most closely resembles Argillipes aurorum, an ignored galliform species from the London Clay. The tentatively identified fossils of Accipitridae and Alcediniformes would represent the earliest fossil records of these clades. The birds from Egem include few seabirds (Odontopterygiformes, cf. Prophaethontidae) and is dominated by terrestrial species (Galliformes, Messelornithidae). Arboreal birds (Halcyornithidae, Leptosomiformes, cf. Alcediniformes, Coraciiformes) are less abundant and aerial insectivores (Apodiformes) very scarce, which either indicates a taphonomic bias in the composition of the avifauna or particular paleoenvironmental characteristics of the nearshore habitats in that area of the southern North Sea Basin. Grant Information: Funded by Belgian Science Policy Office (project BR/121/A3/PalEurAfrica).
Located in
Library
/
RBINS Staff Publications 2019
-
Recent advances in heteromorph ammonoid palaeobiology
-
Located in
Library
/
RBINS Staff Publications 2021
-
Review of the New World genus nanium Townes, 1967 (Hymenoptera: Ichneumonidae: Ctenopelmatinae), with two new species from the Neotropical region
-
Located in
Library
/
RBINS collections by external author(s)
-
A fossil heron from the early Oligocene of Belgium : the earliest temporary well-constrained record of the Ardeidae
-
We describe the earliest temporally well-constrained fossil that can be assigned to the Ardeidae (herons), from the lowermost Oligocene (32.0–33.0 million years ago) of Belgium. The specimen, a partial tarsometatarsus, belongs to a small species and is described as Proardea? deschutteri n. sp. It exhibits the characteristic tarsometatarsus morphology found in extant heron species, but a confident assignment to one of the ardeid subclades is not possible and even the assignment of the new fossil species to the crown group (the clade including the extant species) cannot be established. The fossil indicates a divergence of herons from their sister taxon by at least the earliest Oligocene, and current paleontological data suggest that herons arrived in Europe shortly after a major faunal turnover at the Eocene/Oligocene boundary. We consider that dispersal is the likely reason for the sudden appearance of herons in the earliest Oligocene of Europe but it is uncertain from where exactly this took place, with Asia and Africa being among the candidate areas.
Located in
Library
/
RBINS Staff Publications 2018
-
Further records of Odonata from Timor Island, with the first photographs of living Nosoticta impercepta (Odonata: Platycnemididae) and additional records from Rote and Romang Islands
-
Located in
Library
/
RBINS collections by external author(s)
-
Limits of calcium isotopes diagenesis in fossil bone and enamel
-
Diagenesis has been recognized for decades to significantly alter the trace elements biogenic signatures in fossil tooth enamel and bone that are routinely used for paleobiological and paleoenvironmental reconstructions. This signature is modified during diagenesis according to a complex continuum between two main processes, addition and substitution. For an additive-like, or early diagenesis, the trace elements biogenic profiles can be restored by leaching secondary minerals, but this technique is inefficient for a substitutive-like, or extensive diagenesis for which secondary trace elements are incorporated into the biogenic mineral. This scheme is however unclear for Ca, the major cation in tooth enamel and bone hydroxylapatite, whose stable isotope composition (δ44/42Ca) also conveys biological and environmental information. We present a suite of leaching experiments for monitoring δ44/42Ca values in artificial and natural fossil enamel and bone from different settings. The results show that enamel δ44/42Ca values are insensitive to an additive-like diagenesis that involves the formation of secondary Ca- carbonate mineral phases, while bone shows a consistent offset toward 44Ca-enriched values, that can be restored to the biogenic baseline by a leaching procedure. In the context of a substitutive-like diagenesis, bone exhibits constant δ44/42Ca values, insensitive to leaching, and shows a REE pattern symptomatic of extensive diagenesis. Such a REE pattern can be observed in fossil enamel for which δ44/42Ca values are still fluctuating and follow a trophic pattern. We conclude that Ca isotopes in fossil enamel are probably not prone to extensive diagenesis and argue that this immunity is due to the very low porosity of enamel that cannot accommodate enough secondary minerals to significantly modify the isotopic composition of the enamel Ca pool.
Located in
Library
/
RBINS Staff Publications 2023
