The present paper describes Chelonarium dominicanum sp. nov., the first fossil representative of the family Chelonariidae (Coleoptera: Byrrhoidea) in Dominican amber. The specimen is characterized by the shape of its body and head, absence of body pubescence, wide profemora and presence of small tubercles covering the abdominal sternites. The size, rounded clypeus with a small, blunt projection at the tip, flat pronotal disc with lateral margins extending over the head and the protibia much wider than the adjacent profemur and mesotibia, separate the present species from previously known members of the family. Since the larvae of Chelonariidae are assumed to be semi-aquatic, there would have been many fresh water habitats for it in the Dominican amber forest.

A compilation of jumping spiders (Araneae: Salticidae) from the Miocene amber of Chiapas, southwestern Mexico is provided. A total of 65 new fossil records are enumerated, of which three are members of the subfamily Lyssomaninae, five of the subfamily Spartaeinae, and 57 of the subfamily Salticinae, including a new record of the subtribe Freyina and 19 new records of the tribe Dendryphantini, ten of which are from the subtribe Marpissina and four of the subtribe Dendryphantina. In addition, based on recent changes in the salticid taxonomy, Maevia eurekaRiquelme & MenéNdez-Acuña, 2017 is transferred to the genus ParamaeviaBarnes, 1955. The fossil record of jumping spiders in Mexico is the earliest known in the southernmost part of North America. Accordingly, the new records help to understand current distribution patterns of the family Salticidae in North America and the Neotropics.

The lithostratigraphy and ammonite biostratigraphy of the Middle Jurassic Opalinuston Formation in the Teufelsloch gorge at Bad Boll (middle Swabian Alb), which is the type locality of this formation and that of its lower member, the Teufelsloch Member, is described. The term Comptum Subzone, formerly well established in SW Germany, is replaced by the Bifidatum Subzone. Additionally, the regional term Comptumbank bed is replaced by Wilflingen-Bank and the local term Costosumbank bed is replaced by Bifidatumbank. Four ammonite biohorizons (opalinum, dilucidum, opaliniforme and hansrieberi biohorizons) of the Opalinum Subzone and three ammonite biohorizons (bifidatum/rieberi, uncinatum and evolutum biohorizons) of the Bifidatum Subzone (formerly “Comptum Subzone”) are described from the type locality. The crassicostatum biohorizon of the Bifidatum Subzone is introduced in the western Swabian Alb. The biostratigraphical boundary between the Opalinum and Murchisonae zones (Lower/Upper Aalenian) is located at the base of the Achdorf Formation. The succession is compared and correlated with other localities in Germany and Europe. The species of the ammonite genus Leioceras are described using a chronospecies concept. Lectotypes are designated for Leioceras partitum (Buckman, 1899) and Leioceras uncinatum (Buckman, 1899). We briefly report on the macrofauna of the Opalinuston Formation. In addition, we provide important petrographical, sedimentological and geochemical information for the understanding of the depositional conditions for some selected layers.

A new extinct species, Karenina cuneiformis sp. nov. (Neuroptera: Mesochrysopidae) is described from the Lower Cretaceous Crato Formation of northeastern Brazil. This new species is similar to K. borschukewitzi (Nel et al., 2005) and K. longicollisMakarkin & Menon, 2005, but differs from those by wing venation and possesses an apparently stout, cuneiform humeral veinlet in the forewing.

The posture of the earliest dinosaurs is thought to be bipedal whereas their pseudosuchian relatives and stem archosaurs are thought to be typically quadrupedal. Therefore, the transition from quadrupedality to bipedality lies somewhere between the origin of Avemetatarsalia (bird-line archosaurs) and Dinosauria. However, studying this transition is hampered by the lack of forelimb fossils from many of the close relatives of dinosaurs and it is not clear if the morphology of the few dinosauromorphs that have forelimb material is unique or represents the plesiomorphic condition. New forelimb fossils of dinosaur relatives and careful assessments of their osteology are sorely needed to help address this knowledge gap. Here we present the first pectoral (left scapulocoracoid) and forelimb (right humerus) bones of an avemetatarsalian from the upper portion of the Chañares Formation of Argentina. We hypothesize that the bones pertain to the important early ornithodiran Lagerpeton chanarensis, but the scapulocoracoid and humerus does not precisely match any non-dinosaurian avemetatarsalian. The bones were prepared from a concretion that only consisted of Lagerpeton chanarensis and the cynodont Massetognathus pascuali. We identify the bones as belonging to Lagerpeton chanarensis because the distal end of the femur possesses an inflated crista tibiofibularis – a lagerpetid character state – and the newly recognized pectoral and forelimb bones are generally similar to those of the lagerpetid Dromomeron romeri and Ixalerpeton polesinensis, with tall and constricted anteroposteriorly narrow scapular blades and a humerus with a highly asymmetrical proximal end. The length of humerus and the proportions of the proximal and distal end in Lagerpeton chanarensis are also more similar to that of Dromomeron romeri. Overall, the scapulocoracoids and humeri of lagerpetids are similar in proportion across taxa, but comparing the length of the forelimbs to the hindlimbs is hampered by the lack of articulated or unambiguously associated individuals of any member of the group. Currently, it is still not clear if the anatomy of the pectoral girdle and forelimb of lagerpetids, and thus posture, is unique for lagerpetids or represents the ancestral condition for ornithodirans.

Antlion-like lacewings (Myrmeleontiformia) have comparably large predatory larvae; most well-known are the larvae of antlions (Myrmeleontidae) and owlflies (Ascalaphidae). Yet, larvae of spoon-winged lacewings (Nemopterinae, also an ingroup of Myrmeleontiformia) are less well studied and differ in their overall habitus, with a broader head and stouter mouthparts. We here review the known record of spoon-winged lacewing larvae and report two new fossil larvae preserved in 99 million-year-old Kachin amber from Myanmar that have some characteristics of spoon-winged lacewing larvae. We quantitatively compare morphological aspects of all these larvae with those from other myrmeleontiformian larvae. Our analyses suggest that one fossil larva may indeed be closely related to extant spoon-winged lacewings, but retains some plesiomorphies shared with Crocinae, the sister group of Nemopterinae. The other larva shows many unique features, but also some similarities to spoon-winged lacewing larvae, hence might be a highly specialised early representative of the lineage. These two larvae are the first potential larvae of Nemopterinae in the fossil record. Therefore, they are important indicators for the structure of the early diversification of lacewings.

A new fern, Cladarastega burmanica gen. et sp. nov. (Dennstaedtiaceae: Polypodiales) is described from a fertile pinnule in Burmese amber. The new species has dentate margins with acute apices, furcated 1 and 2 forked free veins angled toward pinnule apex, elongate, multicellular and glandular hairs on the epidermis, epidermal peltate scales, sori roundish, apical and subapical on abaxial surface of fronds near vein endings and paraphyses. There are both inner and outer cup-shaped indusia. The inner indusium is initially solid but then disintegrates while still attached to the sorus. The sporangium is stalked with a vertical or slightly oblique annulus. The spores are tetrahedral trilete. Related topics discussed are phylogenetic studies on ages pertaining to the origin of the Dennstaedtiaceae in comparison to the age of the fossil, associations with competing angiosperms and insect herbivores of ferns.

Larvae of Brachypsectridae (Texas beetles) have often been considered rare. However, they are known from North America, Asia and Australia in the extant fauna, and from Miocene, Eocene and Cretaceous ambers. We review the overall record of extant and fossil larvae of Brachypsectridae represented in the literature. Furthermore, we present three new specimens, which were all documented via light microscopy. Two of the specimens are from Baltic amber, and the third one is from the Cretaceous amber of Myanmar; the latter was additionally documented via synchrotron radiation micro-computed tomography. The number of known extant specimens, more than 20, is unusually high compared to other small groups of beetles and with respect to the low number of eight formally described species. The number of fossil specimens from the Miocene, Eocene and Cretaceous is low, two to three specimens per time slice. This makes a comparison of morphological diversity difficult. Still such an analysis of overall body shape as well as of the anterior body region revealed no significant quantitatively recognisable changes over time. However, some qualitative changes in the morphology of the antenna and lateral processes from the Cretaceous to younger faunas could be identified.