José Luis Sanz

The evolution of the bacterial community in an up-flow anaerobic reactor with silicone support, continuously fed with pure glycerol (day 0–293) and c

A new lithostrotian titanosaur, Qunkasaura pintiquiniestra gen. et sp. nov., is described based on a single partial skeleton from the late Campanian-early Maastrichtian fossil-site of Lo Hueco (Cuenca, Spain). This new taxon is supported by an exclusive combination of characters that highlights strong convergences with members of the South American Aeolosaurini. Qunkasaura allows to reorganise the complex phylogenetic relationships of the increasingly diverse finicretaceous sauropods of Europe. Phylogenetic analyses places Qunkasaura within Saltasauridae and possibly Opisthocoelicaudiinae, together with Abditosaurus. A new clade is established, Lohuecosauria, including Saltasaurus, Lohuecotitan, their most recent common ancestor and all its descendants. Two distinct Ibero-Armorican Campanian-Maastrichtian saltasauroid lineages are recognised: (i) Lirainosaurinae that is exclusive from Europe, and (ii) a saltasaurid lineage with possible opisthocoelicaudiine affinities, with a Laurasian distribution. Lirainosaurinae was a relict lineage including possible dwarf forms that evolved in isolation after reaching Europe before the Late Cretaceous through the Apulian route. The occurrence of opisthocoelicaudiines in Europe may be the result of a Late Cretaceous interchange between Europe and Asia. No evidence of insular dwarfism is found in the Ibero-Armorican opisthocoelicaudiines suggesting that they may have been newcomers to the area that arrived before the ‘Maastrichtian Dinosaur Turnover’ in southwestern Europe.

A reactor with silicone tubes as support medium was used for glycerol fermentation. The experimental set-up consisted of three phases. In P1, the applied glycerol loading rate (gly-LR) was in the range of 6–10 g.L⁻¹.d⁻¹ at an influent pH of 7.9 ± 0.4. In P2, gly-LR was kept constant (18.0 ± 1.8 g.L⁻¹.d⁻¹) with different doses of NaHCO₃. Finally in P3, two different gly-LR (9 and 18 g.L⁻¹.d⁻¹) were evaluated, dosing 1 g-NaHCO₃ per g-COD of glycerol. Glycerol consumption was close 90%. The main end-product was 1,3-propanediol (1,3-PDO) (0.40 mol.mol-gly⁻¹), but ethanol was also generated, particularly at pH above 8 and low gly-LR (0.20 mol.mol-gly⁻¹). After 1-year operation with glycerol as the only carbon source, a drastic shift in the bacterial community was observed. The 1,3-PDO producers Lacrimispora and Clostridium became dominant, although non-glycerol-degrading fermentative genera, e.g., Actinomyces and Eubacterium, thrived at the expense of cellular breakdown products. Graphical abstract

The Lower Cretaceous fossil site of Las Hoyas (Cuenca, Spain) has yielded the richest Cretaceous avifauna of the European continent. We describe a new fossil (MUPA-LH-33333) of an enantiornithine bird from this locality. This specimen consists of a partially articulated skeleton preserving portions of the vertebral column, both girdles and limbs, ribs and sternum; it also preserves patches of soft tissues including remigial feathers and integumentary structures belonging to the postpatagium. MUPA-LH-33333 shares dimensions and some anatomical features with the holotype of Concornis lacustris, a species previously described from Las Hoyas. However, the new specimen shows differences especially in the coracoid and the sternum, suggesting the presence of a different morphotype closely related to C. lacustris. Nevertheless, the poor preservation prevents asserting that it represents a new species. Histological evidence from its long bones indicates that is subadult or adult and that early fast rates followed by slower and protracted cyclical phases took place during its growth, a previously unnoticed pattern in Lower Cretaceous enantiornithines. This new finding supports the hypothesis that enantiornithines regularly inhabited the Las Hoyas wetland, making this site a hotspot for enhancing our understanding of the evolution and life history of these Cretaceous birds.