Thanks to our very own Benjamin Jentgen, the lab now has a paper in the field of sauropology! Benjamin took care of the bone histology sections.
Verónica Díez Díaz, Géraldine Garcia, Xabier Pereda Suberbiola, Benjamin Jentgen-Ceschino, Koen Stein, Pascal Godefroit, Xavier Valentin. 2018. The titanosaurian dinosaur Atsinganosaurus velauciensis(Sauropoda) from the Upper Cretaceous of southern France: New material, phylogenetic affinities, and palaeobiogeographical implications. Cretaceous Research , in press. don:10.1016/j.cretres.2018.06.015
Paper can be found here
New remains of the titanosaurian sauropod Atsinganosaurus velauciensis from its Upper Cretaceous type horizon and type locality in Velaux-La Bastide Neuve (Bouches-du-Rhône Department, Provence) in southern France are described. This locality is considered to be upper Campanian (Argiles et Grès à Reptiles Formation, Aix-en-Provence Basin). The new material consists of skull fragments, including a partial braincase, isolated teeth, elements of the axial skeleton (cervical, dorsal and caudal vertebrae, ribs), and appendicular bones (scapula, humeri, ulna, metacarpals, ilia, ischia, femur, tibia, metatarsal). Histological investigation shows that the analysed individuals were mature. The emended diagnosis of Atsinganosaurus velauciensis includes a pubic peduncle of the ilium with a posterior concave surface in its distal half, surrounded by two sharp ridges. Equations for predicting body mass and size in sauropods suggest a body size up to 12 m and a body mass of at least 3.5–5 tonnes for the largest individuals.
A phylogenetic analysis including 29 sauropod taxa was performed, with the European titanosaurs Atsinganosaurus, Ampelosaurus, Lirainosaurus, Lohuecotitan, Paludititan(Late Cretaceous) and Normanniasaurus (Early Cretaceous) all scored in the same analysis for the first time. Atsinganosaurus and Ampelosaurus form a clade that is phylogenetically proximal to Lirainosaurus within Lithostrotia – a clade here named Lirainosaurinae nov. – whereas Lohuecotitan and Paludititan form a clade towards the base of Lithostrotia. Normanniasaurus is resolved outside Lithostrotia, but within Titanosauria. From a palaeobiogeographical perspective, the phylogenetic results suggest that European titanosaurs belong to at least three distinct lineages and that two lithostrotian lineages were present during the latest Cretaceous in the European archipelago.
Today sees the publication of our postdoc Julien Denayer's master thesis, a couple of years in the making! It describes very peculiar "rolling reefs" from the Late Devonian, which might result from the onset of the Frasnian-Famennian mass extinction!
Julien Denayer. 2018. From rolling stones to rolling reefs: a Devonian example of highly diverse macroids. Lethaia, https://doi.org/10.1111/let.12278
The upper carbonate member of the Aisemont Formation (Upper Frasnian, Belgium) yielded a surprisingly diverse assemblage of macroids varying in size, shape and composition, from simplest microbial oncoid to complex, polytaxic circumrotatory macroid. A descriptive classification combining composition and geometry of macroids is proposed. It suits for sedimentological and palaeobiological analyses. Five categories forming a continuum are distinguished as follows: (1) simple oncoids, consisting of microbial coating of various nuclei; (2) composite oncoids, involving several encrusting taxa and microbes‐induced precipitates; (3) simple circumrotatory macroids, constructed by one or few different organisms and forming free‐rolling particle; (4) polytaxic circumrotatory macroids, constructed by diverse organisms, usually in sequential coating and form free‐rolling object; and, (5) polytaxic domed macroids, polytaxic assemblage of encrusting organism forming domed or columnar anchored bioconstructions. The dominant (in number and volume) encrusting organisms are the tabulate corals and stromatoporoids that both possessed the ability to attach to any hard substrate. Microbes also contributed to the formation of macroids although the volume they occupy is relatively limited. Skeletal invertebrates likely grew during the good season when environmental conditions were suitable for the growth, then partly or totally died and was colonized by microbes during the bad season. The surface of the macroid (after rolling or not) was subsequently re‐coated with skeletal organisms when suitable conditions re‐established. Final burial of the macroid occurred during the good season as their outermost surface is rarely coated with microbes. Geopetal sediment filling of cavities displays various directions indicating the rolling of the objects during their formation. Periodical rolling or tilting may be related to seasonal storms and the resulting assemblage formed genuine rolling reefs of crucial importance for birth palaeoecological and sedimentological analysis.