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Understanding of the morphological variation and defining characters of the abundant and ubiquitous dendroid stromatoporoid genus Amphipora Schulz has been hindered by the loss of the holotype specimen of the type species, A. ramosa (Phillips). In the absence of a type, the boundaries of the genus Amphipora could only be defined vaguely, yet 12 genera of Amphipora-like fossils have been named to constitute the family Amphiporidae Rukhin, and about 175 species of these genera have been described.

• Read more about Intraspecific variation, diversity, revised systematics and type of the Devonian stromatoporoid, Amphipora

Machaeridians, enigmatic animals widespread in Palaeozoic strata, have been known for approximately 130 years but nevertheless remain a little studied and problematical group. Two species of machaeridians (Lepidocoleus sp. A and Turrilepas sp. A) from the Upper Wenlock of Gotland are described. They occur commonly at Mollbos, with a preservation that allows tentative reconstruction of their morphology and interpretation of the function of the scleritome.

• Read more about Machaeridians from the Upper Wenlock (Silurian) of Gotland

Early Jurassic bakevelliid bivalves from the Canadian Cordillera are examined taxonomically, morphologically, and with respect to their biogeographical affinities. Four Early Jurassic species are recognized, which belong to the genera Bakevellia, Gervillaria and Gervillella. One species, Gervillella leesi, is new. In addition, Gervillaria ashcroftensis (Crickmay) from the Bajocian (Middle Jurassic) of British Columbia and the Lower Jurassic of northern Chile has been included in this study.

• Read more about Palaeobiology of Early Jurassic bakevelliid bivalves from Western Canada

The Shinnel Formation is dominated by over 2 km of quartzose sandstones. It crops out between the Fardingmullach and Orlock Bridge faults, Northern Belt of the Southern Uplands, and is of mid Ashgill age.

• Read more about Conodonts from the Ordovician Shinnel Formation, Southern Uplands, Scotland

The three Retiolites species, R. geinitzianus, R. australis and R. angustidens, may be distinguished only by differences in their dorso-ventral width (both the maximum attained and the rate of increase from the proximal end). Other characters used previously in specific discrimination are septal bar inclination and meshwork density. The former shows considerable intraspecific variation, with no consistent differences between the species. The latter is dependent upon the astogenetic stage of the specimen examined. Whilst R, geinitzianus and R.

• Read more about Revision of the Silurian graptolite genus Retiolites

Differences between zoologists and palaeontologists over high-level bivalve taxonomy reflect the hitherto poorly understood early phylogeny of the class Bivalvia. Recent description of a diverse early Arenig fauna and recognition that explosive radiation of early Ordovician bivalves can be correlated with evolution of the filibranch gill within the palaeotaxodonts, together with parsimonious analysis of early bivalve shell characters, has allowed the production of a modified scheme of high-level taxonomy reflecting phylogeny.

• Read more about The early phylogeny of the class Bivalvia

The Maastrichtian and Danian echinoid fauna of the Mangyshlak Peninsula, Kazakhstan is revised on the basis of new collections from three localities representing both a shallow water calcarenite facies and a deeper water chalk facies. The two chalk sections sampled have no biostratigraphically detectable breaks across the Cretaceous-Tertiary boundary.Sixteen species in 11 genera are recognized, including one new species, Cycluster galei. Of these, 13 species are found only in Maastrichtian strata.

• Read more about All change at the Cretaceous–Tertiary boundary? Echinoids from the Maastrichtian and Danian of the Mangyshlak Peninsula, Kazakhstan

A newly discovered specimen of Astraspis desiderata Walcott from the mid Ordovician Harding Sandstone Formation of Colorado, USA, is described and represents the third, and most complete, articulated specimen of the taxon recorded to date. Astraspis is a pteraspidomorph agnathan with a dorsal headshield formed from polygonal tesserae, and a ventral shield composed of more irregular tesserae. The tesserae are surmounted by star-shaped or smooth, round or ovate tubercles.

• Read more about Astraspis – the anatomy and histology of an Ordovician fish

Three dimensional scales and fragments of the dermal skeleton from a hitherto little known fish have been isolated from the Ordovician Harding Sandstone of the type area around Canon City, Colorado, USA, allowing exoskeletal morphology to be correlated with tissue structure and arrangement. Scales with a small crown sculpted into ridges over an extended base exhibit the same histology as material in bone-bed thin sections previously described as 'Vertebrate indet. A' by Denison (1967) and here formalized as Skiichthys halsteadi gen. et sp. nov.

• Read more about Exoskeletal micro-remains of an Ordovician fish from the Harding Sandstone of Colorado

Mineralized spherical structures within blood vessels of an archosaurian (possibly pterosaurian) limb bone from the Lower Cretaceous of the Isle of Purbeck, Dorset, England, superficially resemble blood corpuscles, but are shown here to be pyrite framboids. Slightly weathered pyrite framboids in which the outer surface has oxidized, probably to goethite, may resemble nucleated cells when viewed in thin section. Previous records of so-called blood corpuscles within dinosaur bones may also be of a purely diagenetic origin and should be re-examined.

• Read more about Small spheres in fossil bones: blood corpuscles or diagenetic products?