Dario De Franceschi’s research while affiliated with Sorbonne University and other places

Eight isolated mammal molars were discovered in lower Oligocene deposits of the Bugti Hills, Pakistan (Paali Nala, DB-C2; lower Chitarwata Formation). Because of their unusual morphology, these molars have long remained enigmatic. Extensive comparisons with fossil eutherian and metatherian mammals and the recent description of new paroxyclaenids (Mammalia, Cimolesta) from the lower Eocene (Ypresian) of Europe have highlighted the plausible affinities of these teeth from the Oligocene of Pakistan and suggest a referral to Paroxyclaenidae. The dental morphology of this taxon is singular among Paroxyclaenidae, and as such it allows us to propose here a new species and a new genus: Welcom-moides gurki. The occurrence of a paroxyclaenid in the Oligo-cene of Pakistan remains somewhat unexpected inasmuch as these mammals have so far been known only from the Eocene of Europe. At c. 4.2 kg, W. gurki is the largest paroxyclaenid ever discovered, and is assigned to the subfamily Merialinae, which became extinct in Europe around the Ypresian-Lutetian transition, long before the occurrence of this new taxon from Pakistan. Welcommoides has a suite of unusual characters compared with merialines, suggesting that this South Asian lineage had diverged for some time from its European Ypresian counterparts. Such a hypothesis is supported by the fau-nal similarities between European and Indian subcontinent faunas during the Ypresian. Moreover, our discovery strengthens support for the hypothesis that low latitudes of South Asia were a tropical refugium, at least during the first steps of the global climatic deterioration started at the Eocene-Oligocene transition.

Premise: The rise of angiosperm‐dominated tropical rainforests has been proposed to have occurred shortly after the Cretaceous–Paleogene transition. Paleocene fossil wood assemblages are rare yet provide important data for understanding these forests and whether their wood anatomical features can be used to document the changes that occurred during this transition. Methods: We used standard techniques to section 11 fossil wood specimens of Paleocene‐age, described the anatomy using standard terminology, and investigated their affinities to present‐day taxa. Results: We report here the first middle Paleocene fossil wood specimens from Myanmar, which at the time was near the equator and anchored to India. Some fossils share affinities with Arecaceae, Sapindales (Anacardiaceae, Meliaceae) and Moraceae and possibly Fabaceae or Lauraceae. One specimen is described as a new species and genus: Compitoxylon paleocenicum gen. et sp. nov. Conclusions: This assemblage reveals the long‐lasting presence of these aforementioned groups in South Asia and suggests the early presence of multiple taxa of Laurasian affinity in Myanmar and India. The wood anatomical features of the dicotyledonous specimens reveal that both “modern” and “primitive” features (in a Baileyan scheme) are present with proportions similar to features in specimens from Paleocene Indian localities. Their anatomical diversity corroborates that tropical flora display “modern” features early in the history of angiosperms and that their high diversity remained steady afterward.

Menispermaceae are an angiosperm family of mostly climbing plants distributed throughout tropical regions. The fruits in this family have a strong sclerified endocarp and can be used for reliable species‐level identifications, even in a fossilized form. New Paleocene‐age menispermaceous endocarps have recently been discovered in South America and Asia, while in Europe, they are mostly found in the Eocene. This paper focuses on the study of fossil endocarps belonging to Menispermaceae, found in the Petit‐Pâtis locality, which is one of the few Paleocene localities in Europe. The locality is dated to the late Paleocene (57–56 Ma) and the fossils represent flora and fauna in the Paris Basin before the onset of the Paleocene–Eocene Thermal Maximum. Lignitized fossils were photographed and their morphology was analyzed using computed tomography, scanning electron microscope, and geometric morphometric analysis. The analysis of 36 fossils belonging to Menispermaceae revealed that three genera ( Stephania , Palaeosinomenium , Tinospora ) were present in the late Paleocene of Paris Basin. Differences in internal morphology and a more inflated endocarp base led to a description of a new fossil species— Palaeosinomenium oisensis sp. nov. The occurrence of these genera in the Paleocene of France is consistent with the suggestion that megathermal flora was present in the Paris Basin before the Paleocene–Eocene Thermal Maximum. These three genera are currently the oldest occurrences in Europe, highlighting the connection between paleofloras of the Americas, Europe, and Asia in the Paleocene.

The palaeobotanical record of Myanmar (Burma) is poorly documented despite its importance for understanding the evolution of Asian monsoonal ecosystems through time. Here, we describe 20 taxa of fossil wood from 30 silicified specimens collected in the upper lower to lowermost middle Miocene Natma Formation, central Myanmar. These fossils share affinities with modern Fabaceae, Dipterocarpaceae, Burseraceae, Moraceae and Cupressaceae. They include a great variety of fossil dipterocarps (eight species) as found in today’s Southeast Asian rainforests. The nearest living relatives of this assemblage reflect different ecotones of seasonal forests with coastal, mixed to dry deciduous, and wet evergreen species. This reconstruction implies a wet, warm, and monsoonal climate in Myanmar during the late early Miocene. The presence of fossil dipterocarp species typical of wet evergreen forests contrasts with Burmese Eocene dry dipterocarp assemblages and indicates wetter conditions during the Miocene. Our reconstructions support a long-term change from seasonal to everwet ecosystems for dipterocarp trees.

Selected fruits and seeds preserved as molds and casts in sediments from the Anjou ora of Maine-et-Loire have been reexamined with the aid of X-ray tomography. Virtual casts and surface renderings from micro-CT scanning data reveal external and internal morphological characters that were not visible by standard re ected light microscopy. Application of this methodology leads to a revision of the fruit formerly treated as Juglandicarya. It is a 5-valved capsule of likely sapindalean a nity, and is placed in Vaudoisia gruetii (Vaudois-Miéja) gen. et. comb. nov. A seed with the characteristic rumination of Anonaspermum is also recognized for the rst time, as are capsular fruits of Ericaceae. We note that many disseminules are hidden from optical viewing because they are buried within the hand samples. A more extensive micro-CT scan investigation of more samples, including those showing only fossil leaf impressions at the surface, may be expected to yield a wealth of new information on this classic ora.