Search publications of the members of the Royal Belgian institute of natural Sciences
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Reconstruction of the skeleton of Teilhardina belgica, the oldest European Primate
- Teilhardina belgica is one of the earliest fossil primates ever recovered and the oldest fossil primate from Europe (~ 56 Million years). It was originally described by Teilhard de Chardin (1927) from the MP7 reference level of Dormaal (Belgium), which is situated at the Paleocene-Eocene boundary at the base of the Tienen Formation (Smith & Smith, 1996). Teilhardina is known on all three northern continents in association with the carbon isotope excursion marking the Paleocene–Eocene Thermal Maximum. Relative position within the carbon isotope excursion indicates that Asian Teilhardina asiatica is oldest, European T. belgica is younger, and North American T. brandti and T. americana are, successively, youngest. Analysis of morphological dental characteristics of all four species supports an Asian origin and a westward Asia-to-Europe-to-North America dispersal for Teilhardina. High-resolution isotope stratigraphy indicates that this dispersal happened in an interval of 25,000 years (Smith et al, 2006). Moreover, Teilhardina is one of the most primitive fossil primates known to date and the earliest haplorhine with associated three dimensional postcranials making it relevant to a reconstruction of the ancestral primate morphotype. As such, Teilhardina has often been hypothesized as a basal tarsiiform on the basis of its primitive dental formula with four premolars and a simplified molar cusp pattern. Until recently, little was known concerning its postcranial anatomy with the exception of its well-known tarsals. Here we describe additional postcranial elements for Teilhardina belgica and compare these to other tarsiiforms and to primitive adapiforms. Teilhardina is a small primate with an estimated body mass between 30-60 g, similar to the size of a mouse lemur. Its hindlimb anatomy suggests frequent and forceful leaping with excellent foot mobility and grasping capabilities. It can now be established that it exhibits critical primate postcranial synapomorphies such as a grasping hallux and a tall knee (Gebo et al, 2012), and nailed digits (Rose et al, 2011). This anatomical pattern and behavioral profile is similar to what has been inferred before for other omomyids and adapiforms. The most unusual feature of Teilhardina belgica is its elongated middle phalanges suggesting that this early primate had very long fingers similar to those of living tarsiers. Our phyletic analysis indicates that we can identify several postcranial characteristics shared in common for stem primates as well as note several derived postcranial characters for Tarsiiformes.
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Early Eocene cambaytheres from Indo-Pakistan are the sister group of Perissodactyls
- Cambaytherium, Nakusia, and Kalitherium are closely related early Eocene mammals from the Indo-Pakistan region that have been assigned to Perissodactyla (Laurasiatheria)or Anthracobunidae. The latter have been variously considered artiodactyls or perissodactyls, but more recently are usually placed at the base of the order Proboscidea or of the more inclusive Tethytheria (Afrotheria). We present new evidence from the dentition, skull, and postcranial skeleton of Cambaytherium, from Gujarat, India (ca. 54.5 Ma), that cambaytheres occupy a pivotal position as the sister taxon of Perissodactyla. Cambaytherium was more robust than basal perissodactyls such as ″Hyracotherium″ and Homogalax, and had a body mass of ~25-27 kg based on humeral, radial, and dental regressions. Perissodactyl synapomorphies include a transverse nasal-frontal suture, twinned molar metaconids, and an astragalus with deeply grooved trochlea and a saddleshaped navicular facet. Like perissodactyls, cambaytheres are mesaxonic and have hooflike unguals and a cursorially-adapted skeleton. Plesiomorphic traits compared to basal perissodactyls include bunodont molars with large conules and almost no hint of bilophodonty, unmolarized premolars, sacrum with four vertebrae, humerus with distally extensive pectoral crest and distal articulation lacking a capitular tail, distal radius without discrete scaphoid and lunate fossae, femur with low greater trochanter, calcaneus robust and wide with rounded ectal facet, astragalus wide with moderately long neck and vestigial astragalar foramen, navicular and cuboid short and wide, metapodials short and robust, and Mc I and Mt V present. In most or all of these traits cambaytheres are intermediate between phenacodontid condylarths and perissodactyls but closer to the latter. Our phylogenetic analyses place cambaytheres just outside perissodactyls, and place anthracobunids among primitive perissodactyls. However, similarities between cambaytheres and anthracobunids suggest that they are closely related, and future discovery of skeletal material of anthracobunids will provide a test of this hypothesis. Our results indicate that Anthracobunidae are not Proboscidea or tethytheres, and suggest that the origin of Perissodactyla may have taken place on the drifting Indian plate. How the progenitors of perissodactyls reached India is more problematic but might have involved land connections with Afro-Arabia during the Paleocene. Field work and research supported by the National Geographic Society.
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Focus stacking: Comparing commercial top-end set-ups with a semi-automatic low budget approach. A possible solution for mass digitization of type specimens
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Elementen van de populatiedynamiek van de Oehoe (Bubo bubo) in de Ardennen.
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Eocene stratigraphy of the Wadi Al-Hitan World Heritage Site and adjacent areas (Fayum, Egypt).
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Habitat selection by Red-breasted Geese (Branta ruficollis) wintering in Eastern Europe
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Early Eocene environmental development in the northern Peri-Tethys (Aktulagay, Kazakhstan) based on benthic foraminiferal assemblages and stable isotopes (O, C).
- The Aktulagay section in Kazakhstan provides an expanded northern Tethyan record of the middle Ypresian (calcareous nannoplankton zones NP11-13, ~ 54-50 Ma), including the Early Eocene Climatic Optimum (EECO). The marl sequence features a series of sapropel beds, observed throughout the Peri-Tethys, indicative of the basin-wide occurrence of episodic hypoxic events. In order to unravel the paleoenvironmental evolution at Aktulagay during this period of global warming, we investigated the benthic foraminiferal record by means of a detailed multivariate analysis of the > 63 μm fraction, as well as through stable isotopic (C, O) investigations on excellently preserved benthic foraminiferal specimens. The Alashen Formation (NP11 to lower NP12; ~ 54 to 52.5 Ma), in the lower part of the sequence, contains a diverse assemblage of deep outer neritic (~ 200-250 m) benthic foraminifera, with common Pulsiphonina prima and Paralabamina lunata. The sea-floor conditions are interpreted as initially (54 Ma) well-ventilated and oligo- to mesotrophic, gradually changing to more eutrophic and oxygen-limited, culminating in more permanent low-oxygen conditions and eutrophy in the sapropel-bearing Aktulagay B1 unit (middle NP12; ~ 52.5-52 Ma). The latter conclusion is corroborated by the dominance of Anomalinoides acutus and Bulimina aksuatica and the lower diversity. Also the upward migration of endobenthic species to the sediment-water interface, as suggested by rising δ13Cendobenthic values, supports this interpretation. A transgression, which flooded lowlands, might have caused this development. In the Aktulagay B2 unit (top NP12-NP13; ~ 52-50 Ma), benthic foraminiferal assemblages dominated by Epistominella minuta suggest an oligotrophic environment, with transient pulses of phytodetritus and moderate ventilation. The Aktulagay B2 unit coincides with the peak temperature interval of the EECO, as indicated by its position close to the base of NP13 and rising δ13Cepibenthic values. Large river plumes, episodically reaching the area, in a monsoonal climatic context, might explain this basin development. Although it is not unlikely that some of the observed patterns are related to long-term climate change, it can currently not be excluded that changing paleogeography and variable connections to the Tethys, Atlantic and the Arctic Ocean were responsible for the long-term period with dysoxia and anoxia during deposition of the sapropel beds at the Peri-Tethyan seafloor. The evolution of the basin as observed in Aktulagay shows similarities to the evolution of the North Sea Basin as observed in Denmark, suggesting that these basins were connected during the Early Eocene.
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Satellite tracking of the highly endangered Slender-billed Curlew : why and how ?
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An international conservation project for the Slender-billed Curlew (Numenius tenuirostris) in Greece: the first results.
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A new approach to locating Slender-billed Curlew breeding grounds.
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Overview of the life history of the Slender-billed Curlew.
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In search of the breeding grounds of the Slender-billed Curlew.
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Satellite tracking the Slender-billed Curlew : Why and How ?
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Population viability : an analysis of the Slender-billed Curlew.
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Stratégies de dispersion des jeunes Ouettes d’Egypte (Alopochen aegyptiacus) baguées en Belgique.
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Détermination comparative des Goélands leucophées et pontiques.
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Dynamique d’expansion d’une population exotique d’Ouettes d’Egypte (Alopochen aegyptiacus).
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Supplement to the genus Megobaraliption (Coleoptera, Cerambycidae, Prioninae)
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Hoe werkt een ruiconcentratie van Canadese Ganzen (Branta canadensis) : het geval Meise.
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Paramètres démographiques du Milan royal (Milvus milvus) nicheur en Belgique.
