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Sea spiders (Pycnogonida) are strange arthropods characterized by a unique morphology, including reduced body, egg-carrying appendages and a proboscis. This peculiar body plan dates at least as early as the first undoubted occurrence of the group, 425 million years ago in the Silurian. All extant species belong to the order Pantopoda, characterized by cylindrical legs and an unsegmented abdomen. Palaeozoic fossils are much more diversified and exhibit features very different from pantopod morphology such as a segmented abdomen, limbs specialized to swim, or even a flagellum. The few Mesozoic fossils from the single Jurassic palaeoenvironment of La Voulte-sur-Rhône (south-eastern France) instead have strong affinities to Pantopoda. Here, we investigate the morphology of nine sea spider fossils using a new photographic protocol to document morphology, combining focus stacking and differential colourization. We also describe two new species of fossil pycnogonids from the Late Jurassic of Solnhofen (southern Germany): Colossopantopodus nanus sp. nov. is closely allied to a large species from La Voulte-sur-Rhône, but distinct in its smaller size; the other, ?Eurycyde golem sp. nov., is the first known fossil representative of the extant family Ascorhynchidae. Seven additional specimens, too poorly preserved for taxonomic description, are illustrated. The comparisons reveal that the shallow lagoons of Solnhofen contained a diverse assemblage of pantopods. Altogether with the fauna of La Voulte-sur-Rhône, the results suggest that Pantopoda became the dominant pycnogonid taxon of both deep and shallow marine waters after the Jurassic. [ABSTRACT FROM AUTHOR]

The enigmatic vertebrate taxon Cyrtura temnospondyla is reassessed following the location and reuniting of both counterparts. The specimen, comprising a series of caudal vertebrae from the Tithonian Solnhofen Limestone, has variously been interpreted as derived either from a temnospondyl amphibian, or a turtle, or to be indeterminate. The redescription of this caudal series reveals that the vertebrae have a single centrum, in contrast to previous descriptions. This specimen is here interpreted to be the tail of a turtle more derived than Proganochelys and Meiolania , but is otherwise indeterminate and cannot be associated with any of the diagnosed taxa from the Solnhofen Limestone. C. temnospondyla lacks any diagnostic character and must therefore be considered a nomen dubium. [ABSTRACT FROM AUTHOR]

The Palaeontinidae (Insecta: Cicadomorpha) from the Upper Jurassic Solnhofen Limestone of Bavaria are revised. The diagnostic characters for three monotypic genera Eocicada Oppenheim, 1888, Prolystra Oppenheim, 1888 and Archipsyche Handlirsch, 1906 are reassessed based on newly discovered material. Beloptesis gigantea (Weyenbergh, 1874), B. oppenheimi Handlirsch, 1906, Limacodites mesozoicus Handlirsch, 1906, and Protopsyche braueri Handlirsch, 1906 are considered to be junior synonyms of Prolystra lithographica Oppenheim, 1888. Eocicada lameerei Handlirsch, 1908 is a junior synonym of E. microcephala Oppenheim, 1888. A key to the species of Solnhofen Palaeontinidae is presented. Solnhofen Palaeontinidae and most Cretaceous Palaeontinidae most probably form a monophyletic group based on the following characters: costal area narrow, vein RA branching from stem R basally, vein ScP not fused with vein RA, clavus much reduced and hindwing smaller. Furthermore, Solnhofen Palaeontinidae are probably basal to Cretaceous Palaeontinidae by the mesonotum lacking distinct longitudinal carinae. A fast succession from early to more derived Palaeontinidae took place during Late Jurassic times. Early Palaeontinidae declined sharply in the Late Jurassic, probably owing to the rise of newly evolved insectivorous animals like early birds and mammals. Late Palaeontinidae with better flight ability survived and became a dominant insect group during latest Jurassic times. [ABSTRACT FROM AUTHOR]