A nothosaur skull recently discovered from the Lower Muschelkalk (early Anisian) locality of Winterswijk, The Netherlands, represents at only 46 mm in length the smallest nothosaur skull known today. It resembles largely the skull morphology of Nothosaurus marchicus. Differences concern beside the size, the straight rectangular and relative broad parietals, the short posterior extent of the maxilla, the skull proportions, and the overall low number of maxillary teeth. In spite of its small size, the skull can not unequivocally be interpreted as juvenile. It shows fused premaxillae, nasals, frontals, and parietals, a nearly co−ossified jugal, and fully developed braincase elements, such as a basisphenoid and massive epipterygoids. Adding the specimen to an existing phylogenetic analysis shows that it should be assigned to a new species, Nothosaurus winkelhorsti sp. nov., at least until its juvenile status can be unequivocally verified. Nothosaurus winkelhorsti sp. nov. represents, together with Nothosaurus juvenilis, the most basal nothosaur, so far.
A new genus and species of a non-cyamodontoid placodont is described on the basis of an incomplete and disarticulated skeleton from Winterswijk, the Netherlands, dated as early Anisian (Lower Muschelkalk). The new taxon is unique in a ventrolateral expansion of the neural arches of the posterior presacral and sacral vertebrae, in which the transverse process is incorporated. It has a round, plate-like pubis and ischium, and the only preserved long bone indicates elongated limbs. The holotype, which is relatively large (>1.35 m) for a basal sauropterygian, has still un-fused halves of neural arches and no distinct neural spine developed yet. The new taxon is assigned to non-cyamodontoid placodonts based on its round girdle elements, the morphology of dorsal-, sacral-, and caudal ribs, the straight medial and mediolateral elements of gastral ribs, and the presence of un-sutured armour plates. In spite of the large size of the holotype, there is evidence that the animal was not yet fully grown, based on the paired neural arches, and general poor ossification of the bones. The un-fused halves of neural arches are interpreted as skeletal paedomorphosis, which is typical for vertebrates with a secondary marine life style. The sacral region seems to be highly flexible.
A pilot study of bioindicators of environmental health was performed in a non-industrial region of Poland in April 2008. Twenty wild-caught northern pike Esox lucius Linnaeus, 1758 were used. Established biomarkers of environmental stress were studied in these fish, including condition factor, macroscopic lesions, morphometry of hepatic melanomacrophage cells, follicular atresia, and histopathology of liver and gonads. Body weight, total body length, and gender were recorded; livers, gonads, and organs with macroscopic lesions were collected for histopathology. H&E-stained paraffin-embedded sections were studied by light microscopy. All fish appeared in good health and had no macroscopic lesions except for two fish with gut trematodes. Microscopic lesions were minimal and included peribiliary fibrosis and cholangitis, focal hepatic necrosis and vasculitis, biliary myxozoanosis, intestinal metazoan parasites, and post-spawning peritonitis. Very low levels of hepatic MMC and ovarian follicular atresia were found. The data constitute the first report of biomarkers of environmental stress in northern pike from northeastern Poland and can be used as a reference for future monitoring of fish health and aquatic pollution in this region.