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The ecology and population structure of the Recent articulate brachiopod Terebratulina retusa (Linnaeus) are described. The population studied occurs around the margins of a depression of more than 220 m in the Firth of Lome, Scotland, and is predominantly attached to the horse-mussel Modiolus modiolus (Linnaeus). Spawning occurs regularly in late spring and late autumn, and is initiated at temperatures of 10-11°C. The highly synchronized reproductive cycle, from spawning to spatfall, occurs within 3 weeks in nature.

• Read more about Ecology and population structure of the Recent brachiopod Terebratulina from Scotland

The holotype and only recorded specimen of the Carboniferous aistopod amphibian Ophiderpeton nanum Hancock and Atthey 1868 is described in detail and figured for the first time. The vertebrae, ribs, dermal squamation, and premaxilla are characteristic of Ophiderpeton and confirm that O. nanum is a member of that genus. The relationship of O. nanum to other described Ophiderpeton species is obscured by the absence of most of the skull in the holotype and by the apparently sub-adult nature of the specimen.

• Read more about Morphology and relationships of the Upper Carboniferous aïstopod amphibian Ophiderpeton nanum

Important changes in the taxonomy and phylogenetic interpretation of stellate echinoderms were proposed during the 1960s by H. B. Fell; certain of this author's ideas are re-evaluated. Fell argued that the extant west American sea star Platasterias latiradiata Gray is a surviving member of the otherwise Palaeozoic Somasteroidea. The extant family Luidiidae was considered primitive among true asteroids and it was included with the Palaeozoic family Palasteriscidae in the order Platyasterida.

• Read more about Somasteroidea, Asteroidea, and the affinities of Luidia (Platasterias) latiradiata

'Ophiderpeton', a mid-Visean aistopod from the Wardie Shales near Edinburgh is described.

• Read more about A Lower Carboniferous aïstopod amphibian from Scotland

Conodont faunas from the Lower Carboniferous, Courceyan-Holkerian Stages, of Ravenstonedale are described. Three zones, the Taphrognathus, Cloghergnathus, and Cavusgnathus Zones, are recognized in the Chadian-Holkerian strata and one fauna, Fauna A, in the mid-Courceyan. These zones and the Fauna are correlated with the standard British Stages and with the American classic sections.

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A method of describing the whole of the generating curve of a lamellibranch is sought. When lengths and angles are used to describe an outline, much of the outline remains undefined. A curve can be fitted to an outline and the coefficients in the particular approximation employed then define the outline. Reasons are given for fitting a Tchebychev polynominal, rather than a spline, or Fourier series containing both sine and cosine terms. Polar coordinates r and 6 are calculated for each point on a digitized outline.

• Read more about A description of the generating curve of bivalves with straight hinges

Thirty-seven acritarch species in the type Caradoc rocks of south Shropshire are recognized as reworked from strata of Tremadoc and Arenig/Llanvirn age, their distribution reflecting an inverted stratigraphy. These microfossils yield valuable palaeoenvironmental data, their excellent preservation indicating a source on, or adjacent to, the Midland Platform; erosion of the relatively unconsolidated parent sediments occurred in a marine environment. Acritarchs were eroded and redeposited as discrete particles and wave and current action are considered the most likely erosive agents.

• Read more about Reworked acritarchs from the type section of the Ordovician Caradoc Series, Shropshire

Hitherto undescribed specimens of Psittacosaurus mongoliensis from the Oshih Fm., Mongolian Peoples' Republic, include two almost complete skulls and numerous postcranial elements. A rostral bone, present in these and other specimens of Psittacosaurus, is a cranial element otherwise known only in ceratopsians, and its presence indicates a sister group relationship for the Psittacosauridae and Ceratopsia. Each of the two new specimens of Psittacosaurus is a juvenile, and are among the smallest dinosaur specimens yet described.

• Read more about Juvenile specimens of the ornithischian dinosaur Psittacosaurus

The taxonomy of the infaunal holasteroids Infulaster and Hagenowia is revised in the light of new material from the Senonian Chalk of southern England. Investigation of the plating structure in Hagenowia permits a more precise definition of its species, and a better understanding of the evolution of the rostrum. The majority of structural modifications in the Infulaster-Hagenowia lineage were caused directly, or indirectly, by apical elongation and size reduction.

• Read more about The palaeobiology of the Cretaceous irregular echinoids Infulaster and Hagenowia

A history of research on Ordovician bivalves from Pomeroy is given, and their stratigraphic distribution in the Caradoc-Ashgill rocks is outlined. More than thirty taxa are described including five new species: Praenucula dispersa, P. infirma, P. praetermissa, Ambonychia arundinea, and Cleionychia incognita. The rostroconch Hippocardia praepristis (Reed) is illustrated.

• Read more about A revision of late Ordovician bivalves from Pomeroy, Co. Tyrone, Ireland