Interview de Jean-Marc Marion concernant la nouvelle carte géologique de Malmedy qu'il a réalisé, contenant, peut-être, les plus anciennes roches affleurant en Belgique!
We have a new paper just published in Current Biology, dealing with a new pliosaur from the Late Hauterivian of Russia, Luskhan itilensis, and analyzing the ecomorphological convergences among short-necked plesiosaurs.
Quite an important press coverage (see icon below) and some videos interviews as well: www.rtl.be/info/Video/629641.aspx www.rtc.be/video/info/edition-du-26-05-2017_1495279_307.html
Fischer V, Benson RBJ, Zverkov NG, Soul LC, Arkhangelsky MS, Lambert O, Stenshin IM, Uspensky GN, Druckenmiller PS. 2017. Plasticity and convergence in the evolution of short-necked plesiosaurs. Current Biology 27 doi:10.1016/j.cub.2017.04.052.
Plesiosaurs were the longest-surviving group of secondarily marine tetrapods, comparable in diversity to today’s cetaceans. During their long evolutionary history, which spanned the Jurassic and the Cretaceous (201 to 66 Ma), plesiosaurs repeatedly evolved long- and short-necked body plans. Despite this postcranial plasticity, short-necked plesiosaur clades have traditionally been regarded as being highly constrained to persistent and clearly distinct ecological niches: advanced members of Pliosauridae (ranging from the Middle Jurassic to the early Late Cretaceous) have been characterised as apex predators, whereas members of the distantly related clade Polycotylidae (middle–Late Cretaceous) were thought to have been fast-swimming piscivores. We report a new, highly unusual pliosaurid from the Early Cretaceous of Russia that shows close convergence with the cranial structure of polycotylids: Luskhan itilensis gen. et sp. nov. Using novel cladistic and ecomorphological data, we show that pliosaurids iteratively evolved polycotylid-like cranial morphologies from the Early Jurassic until the Early Cretaceous. This underscores the ecological diversity of derived pliosaurids and reveals a more complex evolutionary history than their iconic representation as gigantic apex predators of Mesozoic marine ecosystems suggests. Collectively, these data demonstrate an even higher degree of morphological plasticity and convergence in the evolution of plesiosaurs than previously thought, and suggest the existence of an optimal ecomorphology for short-necked piscivorous plesiosaurs through time and across phylogeny.
Fischer 2016. Taxonomy of Platypterygius campylodon and the diversity of the last ichthyosaurs. PeerJ 4:e2604; DOI 10.7717/peerj.2604. Freely available here: peerj.com/articles/2604/?td=bl
A complex and confusing taxonomy has concealed the diversity dynamics of Cretaceous ichthyosaurs (Reptilia) for decades. The near totality of Albian-Cenomanian remains from Eurasia has been assigned, by default, to the loosely defined entity Platypterygius campylodon, whose holotype was supposed to be lost. By thoroughly examining the Cenomanian ichthyosaur collections from the UK, I redescribe the syntypic series of Platypterygius campylodon. This material, along with a handful of other coeval remains, is diagnostic and seemingly differs from the vast majority of Cretaceous remains previously assigned to this taxon. A lectotype for Platypterygius campylodon is designated and I reassign this species to Pervushovisaurus campylodon nov. comb. The feeding ecology of this species is assessed and conforms to the scenario of an early Cenomanian diversity drop prior to the latest Cenomanian final extinction.
Figure 3 Rostra referred to Pervushovisaurus campylodon (Carter, 1846a). (AD) CAMSM TN282, a partial rostrum possibly from a juvenile specimen. (A) Ventrolateral view. (BC) Details of the teeth. (D) Detail of the premaxillary overbite. (EF) CAMSM B20671a, a partial rostrum of a large specimen. (E) Lateral view. (F) detail of the mid-snout teeth. (G) Detail of the premaxillary overbite. Fischer 2016 PeerJ
Our former PhD student Sébastien Olive just published novel tetrapod remains from the Famenian of Belgium! The publication Olive & al 2016 Palaeontology can be accessed here!
Une carte géologique produite par notre cartographe sénior Jean-Marc Marion et un ancien du labo, Bernard Mottequin, était exposé au Palais Royal (!) pour une exposition sur la cartographie. Détails de l'expo ici www.cartographiae.be
De gauche à droite: Bernard Mottequin, la carte géologique Louveignié-Spa, Valentin Fischer, Isaure Scavezzoni, Julien Denayer, Cyrille Prestianni et Jean-Marc Marion
J'étais invité hier sur le Forum de Midi Première pour discuter de la "nouvelle" époque géologique de l'Anthropocène avec Pr. Edwin Zaccai de l'ULB. Interview à (ré-)écouter ici.
By our former postdoc Sébastien Olive, congrats to him!
Olive, S., Clement, G. Daeschler, E. B. & Dupret, V. 2016. Placoderm Assemblage from the Tetrapod-Bearing Locality of Strud (Belgium, Upper Famennian) Provides Evidence for a Fish Nursery. PLoS ONE 11(8): e0161540. doi:10.1371/journal.pone.0161540
Strud nursery. © Olive et al. 2016.
Congrats to our very own Julien Denayer for securing a competitive 3 years postdoc funding from the F.R.S.–FNRS! (awarded grants can be found here: www.fnrs.be/index.php/candidatures-retenues-en-2016
Julien will lead the DeCoDE project (Devonian Corals Diversity Events), working on the biodiversity and extinction dynamics among Mid-Devonian corals and reefs!
Finally, we might have an answer for that long-standing palaeontological enigma!
Fischer V, Bardet N, Benson RBJ, Arkhangelsky M & Friedman M. 2016. Extinction of fish-shaped marine reptiles associated with reduced evolutionary rates and global environmental volatility. Nature Communications 7:10825. Freely available here and here (combined article + Supp Info) Covered in the several news, including Science, BBC, The European Commission, etc. See also ULg's Reflexion article here.
The last ichthyosaurs. Two ichthyosaurs (Pervushovisaurus bannovkensis) wander through a middle Cenomanian low latitude ecosystem that will prevail for most of the Late Cretaceous: high sea level and sea temperatures, rudist reefs (Ichthyosarcolites, Hippurites), newly radiating neoselacian sharks and acanthomorph fishes (Aipichthyoides). Artwork by © Andrey Atuchin 2016, based on Fischer & al 2016.
Fischer, Arkhangelsky, Stenshin, Uspensky, Zverkov & Benson 2015. Peculiar macrophagous adaptations in a new Cretaceous pliosaurid. Royal Society Open Science.
Open access, downloadable here!
During the Middle and Late Jurassic, pliosaurid plesiosaurs evolved gigantic body size and a series of craniodental adaptations that have been linked to the occupation of an apex predator niche. Cretaceous pliosaurids (i.e. Brachaucheninae) depart from this morphology, being slightly smaller and lacking the macrophagous adaptations seen in earlier forms. However, the fossil record of Early Cretaceous pliosaurids is poor, concealing the evolution and ecological diversity of the group. Here, we report a new pliosaurid from the Late Hauterivian (Early Cretaceous) of Russia. Phylogenetic analyses using reduced consensus methods recover it as the basalmost brachauchenine. This pliosaurid is smaller than other derived pliosaurids, has tooth alveoli clustered in pairs and possesses trihedral teeth with complex serrated carinae. Maximum-likelihood ancestral state reconstruction suggests early brachauchenines retained trihedral teeth from their ancestors, butmodified this feature in a uniqueway, convergent with macrophagous archosaurs or sphenacodontoids. Our findings indicate that Early Cretaceous marine reptile teeth with serrated carinae cannot be unequivocally assigned to metriorhynchoid crocodylomorphs. Furthermore, they extend the known diversity of dental adaptations seen in Sauropterygia, the longest lived clade of marine tetrapods.