Alain Phélizon’s scientific contributions

Saniwa is an extinct genus of varanid squamate from the Eocene of North America and Europe. Up to now, only one poorly known species, Saniwa orsmaelensis Dollo, 1923, has been reported from Europe. Diagnostic material was limited to vertebrae with only preliminary description and no figure provided, except of one dorsal vertebra that was designated as the lectotype. New specimens from the earliest Eocene of Dormaal, Belgium and Le Quesnoy, France, including recently recovered skull material, are described and illustrated here. These fossils representing the oldest varanid squamate allow further comparisons with the type species, Saniwa ensidens Leidy, 1870, from the early and middle Eocene of North America and to propose a new diagnosis for S. orsmaelensis. Its arrival in Europe is probably linked to rapid environmental changes around the Paleocene Eocene Thermal Maximum (PETM). The occurrence of S. orsmaelensis is restricted to the early Eocene of northwest Europe and paleogeographic considerations regarding the distribution of the genus Saniwa Leidy, 1870 suggest an Asian origin, but an African origin cannot be completely excluded.

Here we describe the lizard fauna from the locality of Montchenot (Paris Basin, late Paleocene, MP6). This material can be allocated to five major clades: Scincoidea, Lacertoidea (?Lacertidae), Amphisbaenia, Anguimorpha (?Anguidae and Shinisauridae). The assemblage from Monchenot is dominated by small lizard specimens and appears as highly sorted. Predation could produce such biased assemblages. The composition of the lizard fauna from Monchenot is rather similar to those of Cernay-lès-Reims and Rivecourt, two coeval localities (MP6) in the Paris Basin. However, these faunas sharply contrast (in diversity and composition) with the lizard fauna found in the early Eocene of the same area (Paris Basin and Belgian Basin). These differences highlight the impact of the Paleocene/Eocene transition on the lizard fauna of Europe.

The Paris Basin has delivered important faunas of fossil mammals from the Thanetian. A rich sample of Late Paleocene mammals has recently been collected from the Marnes de Montchenot in the Montagne de Reims (Marne, France). Study of the new fauna and comparisons with collections from other localities (Cernay, Berru) result in the identification of at least four previously undescribed species of eutherian micromammals in the Late Paleocene of the Paris Basin. A new small-sized species of the genus Phakodon, member of the endemic European family Pseudorhyncocyonidae (order Leptictida), is documented from Montchenot and Cernay in addition to the type species P. levei; a third species of large size may be present at Cernay. The genus Adapisorex (Adapisoricidae, Macroscelidea?) is represented at both localities not only by the type species A. gaudryi, but also by a new species about 25% smaller in size. A new species of the Euro-African and possibly Indian family Adapisoriculidae (Euarchonta?) is identified on the basis of new material from Montchenot, Cernay and the Lentille de Berru, including all molar positions and P4. The new taxon is not closely related to Nosella europaea from Tremp (Spain), to which part of the material had previously been assigned, but identified instead as a large species of Afrodon. Finally, a maxillary fragment from Montchenot and isolated upper molars from Cernay are evidence of the first European species of the pantolestid genus Bessoecetor (order Pantolesta), hitherto known only from North America. The new species is the largest known for the genus, and documents an additional case of intercontinental mammalian dispersal from North America to Europe in the Late Paleocene. The newly identified species show that several groups were more diversified in the Late Paleocene of the Paris Basin than previously recognized, and highlight important faunal similarities between Montchenot and Cernay, supporting close correlation of those faunas in age. The authors thank all persons involved in the study of the Montchenot fauna, including C. Argot, E. Gheerbrant, E. Herbomel, E. Zoukouba, B. Marguet, and residents of Villers-Allerand.

We present new species of an enigmatic family of mammals, which is endemic to Europe, the Paroxyclaenidae: Merialus bruneti sp. nov., Fratrodon tresvauxi gen. et sp. nov., Paraspaniella gunnelli gen. et sp. nov., and Sororodon tresvauxae gen. et sp. nov. The fossils described come from six localities of the Ypresian of the Paris Basin (France): Pourcy (MP7), Mutigny, Avenay, Condé-en-Brie (MP8 + 9), Grauves and Prémontré (MP10). They allow the description of three new genera and four new species belonging to the subfamilies Merialinae and Paroxyclaeninae. Two of these new species represent the earliest occurrence of each subfamily. Fossils from Mutigny, Avenay and Condé-en-Brie indicate that merialines were more abundant than paroxyclaenines during the Ypresian. Surprisingly, merialines disappeared from the fossil record at the end of the Ypresian – the youngest records are close to MP10 – while the paroxyclaenines were present in Europe until the end of the middle Eocene. Based on comparison with the data presently available for European mammals during the Ypresian, we suggest the existence of two periods of faunal turnover that must be more extensively studied in the future in order to be fully characterized: the ‘Intra-Ypresian Mammal Turnover’ and the ‘Ypresian–Lutetian Mammal Turnover’. Finally, because the oldest paroxyclaenids appear morphologically closer to cimolestids such as Procerberus than to pantolestans, it is suggested that similarities between paroxyclaenids and pantolestans could be due to convergence.http://zoobank.org/urn:lsid:zoobank.org:pub:8A3B21A0-6945-4CE4-975C-402736E92C51

Saniwa is an extinct genus of varanid lizard from the Eocene of North America and Europe. It is the sister taxon to the crown-group Varanus. Up to now, only one poorly known species is recognized from Europe, Saniwa orsmaelensis from the earliest Eocene of Dormaal, Belgium. This species originally named by Louis Dollo nearly a century ago, is the earliest varanid of Europe. Unfortunately, the material was limited to vertebrae with only preliminary description and no figure provided, except for one dorsal vertebra that later has been designated as the lectotype. Here we describe and illustrate new fossil specimens collected from Dormaal and other early Eocene localities of the Paris Basin, France, including dentary and maxilla fragments as well as skull material, allowing to reassess the validity of the European taxon. These fossils allow further comparisons with the type-species, Saniwa ensidens, from the late early Eocene Bridger and Green River formations of Wyoming and to propose a new diagnosis for S. orsmaelensis. The occurrence of S. orsmaelensis is restricted to the early Eocene of Northwest Europe and its geographic origin is unresolved because the earliest record of Saniwa in North America is also from the earliest Eocene. The brief presence of varanid lizards in the European Paleogene could result from two major climatic events. At the Paleocene Eocene Thermal Maximum, large biotic interchanges occurred in the northern hemisphere allowing new dispersals into Europe. However, at the end of the Eocene, thermophilic lizards disappeared due to cooler conditions. Another hypothesis for their disappearance could be the competition that occurred with other anguimorph lizards. Grant Information: This abstract is a contribution to the Belspo Brain network project BR/121/A3/PalEurAfrica funded by the Belgian Science Policy Office.

Plesiadapid mammals (Eutheria, Euarchonta, Plesiadapiformes) are well represented in the late Paleocene to early Eocene of Europe (reference levels MP6, MP7 and MP8+9), but relationships among the described species and their links to North American plesiadapids remain disputed. To better understand the evolution of the group in Europe, to explore its potential for biochronological dating and to test hypotheses on plesiadapid phylogenies and dispersal patterns between Europe and North America, a morphometric analysis was performed for a succession of plesiadapid assemblages bracketing the Paleocene/Eocene boundary (PEB) in the Paris Basin, including recently made collections from Montchenot (MP6) and Le Quesnoy (MP7). Both dental size and shape were analysed for nearly all positions of the permanent plesiadapid dentition. Size variation at Cernay (MP6) is consistent with the presence of at least two species of Plesiadapis. A morphological succession is found in European large-sized Plesiadapis, continuing beyond the PEB but showing no clear continuity with Eocene Platychoerops. Large-sized Plesiadapis from Berru (MP6) is distinctly different from P. tricuspidens, justifying the definition of a new species, P. berruensis. Species of Plesiadapis confirm the temporal succession of the localities Cernay, Berru, Le Quesnoy and Meudon, allowing definition of a refined biochronology in the Paris Basin, with Montchenot correlated approximately to Cernay. Comparisons between plesiadapids from Europe and North America indicate a separation from at least the terminal Tiffanian, suggesting correlation of the European reference level MP6 with the North American biozones Ti-5b and Ti-6. Convergent evolution in those lineages and in Platychoerops seems to be linked mainly to trends towards folivory.