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The oldest known freshwater crayfish is described here from a nearly complete specimen found in the Chinle Formation of Late Triassic (Late Carnian) age in Petrified Forest National Park, Arizona, USA. It differs significantly from other Triassic crayfish and is placed in Enoplodytia porteri sp. nov. in the family Erymidae (Malacostraca, Decapoda). Except for clam shrimps (Eubranchiopoda) and notostracans E. porteri sp. nov. is the only crustacean that has been described from the non-marine Upper Triassic strata of North America.

• Read more about The oldest freshwater decapod crustacean, from the Triassic of Arizona

Cribrilina puncturata (Wood, 1844) forms small, patch-like colonies encrusting the concave (almost invariably lower) surface of disarticulated bivalve mollusc shells in the Plio-Pleistocene Red Crag of eastern England. The species is restricted to the deeper central part of each shell, away from the margin. Peripheral abrasion of the shell's surface, which might have removed marginal settlement, is rejected as the major agent in producing the observed distribution. A number of larval behaviour mechanisms that might have been responsible are therefore considered.

• Read more about Disarticulated bivalve shells as substrates for encrustation by the bryozoan Cribrilina puncturata in the Plio-Pleistocene Red Crag of eastern England

Open nomenclature plays an important role in taxonomic decisions by palaeontologists, but usage and interpretation of the signs employed vary considerably. Prevailing fashion seems to favour aff. to indicate affinity of a potentially new, as yet undescribed species with a known species, whereas cf. and ? indicate uncertainty. Use of aff., cf., and ? for different degrees of uncertainty, as recommended by some workers, leads to instability in interpretation. Abbreviated taxonomic expressions such as 'Trichiurus cf. lepturus' are unambiguous and are to be preferred to 'Trichiurus cf. T.

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A new specimen of the early Arenig inadunate crinoid Ramseyocrinus shows unequivocally that the genus had a cup composed of four basal and five radial plates, the latter supporting five arms. There are no anal plates in the dorsal cup. The separate familial status of the genus is confirmed and emended diagnoses of the family, and genus, and a revised description of the species R. cambriensis are given.

• Read more about A reinterpretation of the Arenig crinoid Ramseyocrinus

Three new mixodont genera and species from the late Palaeocene of Mongolia, Khaychina elongata, Eomylus zhigdenensis, and Amar aleator are described; 'Mimotona' borealis (late Palaeocene of China) is referred to Eomylus. Also described is Mimotona Hi n. sp. from the middle Palaeocene of China. The dentition of Gomphos elkema is more fully documented by new material, as is that of Rhombomylus and Eurymylus. Gomphos, Rhombomylus, and 'Matutinia' are compared and 'M.' nitidulus referred to Rhombomylus.

• Read more about Palaeocene and Eocene Mixodontia (Mammalia, Glires) of Mongolia and China

We present a new phylogenetic classification of trilobites which can be included in a ptychoparioid suborder Asaphina, considerably extending the range of families included in the group as compared with existing classifications. Much of the group is known to be united by the possession of a distinctive type of inflated and effaced larva termed the asaphoid protaspis. The morphology and occurrence of this kind of protaspis is reviewed.

• Read more about Classification of the trilobite suborder Asaphina

Preliminary sampling of early Ordovician deposits in the Hunjiang region, southern Jilin Province north-east China, yielded generally well-preserved acritarchs, the seven most characteristic species of which are described. The strata form part of the northern margin of the Sino-Korean platform and are dated by graptolite ranging from Tremadoc (= post Rhabdinopora parabola Biozone and excluding early Tremadoc) to lates Tremadoc or earliest Arenig (Adelograptus-Clonograptus, with Kiaerograptus, fauna). The appearance of Rhopaliophora Tappan and Loeblich, 1971 emend.

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Leafy lycophyte shoots preserved as impressions and as material resembling fusain are described from a shale band in the Drybrook sandstone (Upper Visean), Puddlebrook, Forest of Dean. The consistently narrow stems with small terminal strobili bearing megaspore impressions place this material in Selaginellites Zeiller (1906). Fusainized material shows fine surface morphology and anatomy of the leaves and stem. The large number of specimens demonstrates a wide range of morphological variation in the position and shape of attached leaves.

• Read more about A herbaceous lycophyte from the Lower Carboniferous Drybrook Sandstone of the Forest of Dean, Gloucestershire

The braincase of the embolomere Archeria crassidisca from the Lower Permian of Texas is described, and provides much new detail about a primitive tetrapod braincase. It is a solidly ossified unit as in other embolomeres and like them has no separate dorsal ossification of the occipital arch (supraoccipital). It retains evidence of primitive braincase characters (ventral cranial and lateral otic fissures) found in the embryonic stages of recent jawed vertebrates, and seen in the adult stages of primitive fish groups.

• Read more about The braincase of the anthracosaur Archeria crassidisca with comments on the interrelationships of primitive tetrapods

The late Ordovician Foliomena fauna is now known from five palaeocontinents, South China, Avalonia, Baltica, north-west Gondwana, and Laurentia, but has not yet been recorded from the others. New records of the fauna are presented from the Tangtou Formation, South Jiangsu Province, China, and from the Staurocephalus clavifrons Beds in Poland, and illustrated for the first tune from the Crugan Mudstones of North Wales. The occurrences and ages of all known Foliomena faunas are documented and reviewed, and it is concluded that the most typical Foliomena fauna, including true F.

• Read more about A review of the late Ordovician Foliomena brachiopod fauna with new data from China, Wales, and Poland