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The Sibay and Yaman Kasy massive sulphide deposits contain macrofossil assemblages that represent some of the oldest known hydrothermal vent communities. The deposits are hosted respectively by Middle Devonian and Silurian arc-related volcanic rocks in the Ural Mountains of Russia, and formed under the same environmental constraints as modern vent sulphides.

• Read more about Two Palaeozoic hydrothermal vent communities from the southern Ural Mountains, Russia

Taxa assigned to the family Somaliasteridae (Atelostomata: Echinoidea) possess a combination of the characters usually considered diagnostic for placement in either Holasteroida or Spatangoida. Thus, the affinity of the somaliasterids to one or other of these orders has long been a subject of debate. A cladistic analysis of somaliasterid echinoids with unequivocal representatives of both holasteroids and spatangoids using characters that have commonly been applied in traditional evaluations of atelostomate phylogeny demonstrates that the somaliasterids are spatangoids.

• Read more about A reappraisal of the phylogenetic relationships of somaliasterid echinoids

A partial skull of a juvenile hipparionine equid from Ellesmere Island, Canada, is the northernmost fossil record of a horse (78degrees 33minutes N). Biostratigraphical analysis of the associated fossil biota suggests an age of 3.5 to 4 Ma (early Pliocene). Preserved facial characteristics of the equid include a very reduced preorbital fossa located posterior to the infraorbital foramen. The deciduous premolars have low crown heights, complex fossette plications, multiple pli caballins, and oval, isolated protocones.

• Read more about An early Pliocene hipparionine horse from the Canadian Arctic

Studies on graptolite taxonomy and phylogeny in recent years have placed great emphasis on the proximal development of the rhabdosome, particularly the presence or absence of a virgella and early thecal growth patterns. As the prosicula was the earliest part of the graptolite skeleton to be secreted, it may also reveal fundamental information about evolutionary relationships within the Graptoloidea. The prosiculae from a variety of Ordovician taxa ranging in age from Tremadoc to Caradoc have been examined using a combination of light microscopy, SEM and TEM.

• Read more about Structure and secretion of the graptolite prosicula, and its application for biostratigraphical and evolutionary studies

Two plant-like fossil are described from the middle Ordovician of the Prague Basin, Czech Republic. Both fossils bear a strong superficial resemblance to early land plants, but anatomical data indicate an affinity with animals. New evidence on internal structure demonstrates that the putative plant Boiophyton pragense Obrhel is a dendroid graptolite. The relationships of other heavily coalified, branched axes found in associated strata are more obscure.

• Read more about Semblant land plants from the Middle Ordovician of the Prague Basin reinterpreted as animals

A chimaerid holocephalian, Chimaera zangerli sp. nov., is described from both palatine tooth plates, two tooth plate fragments, and part of the chondrocranium in a nodule from the Maastrichtian of Antarctica. Possibly the oldest known chimaerid, C. zangerli sp. nov. exhibits a tooth plate which is a morphological intermediate between that of the Jurassic Ganodus and the Oligocene C. rupeliensis. The presence of C. zangerli sp. nov. before the end of the Cretaceous is evidence of the early evolution of the Chimaeridae, considered the most derived of the chimaeroid fishes.

• Read more about A Late Cretaceous chimaerid (Chondrichthyes, Holocephali) from Seymour Island, Antarctica

More than 300 specimens of the previously rare arthropod Alalcomenaeus cambricus Simonetta have been collected from a new Burgess Shale locality in the Glossopleura Zone on Mount Stephen, British Columbia. This new material provides much more complete information on its morphology. The cephalon was covered by a shield. A pair of pedunculate eyes and three median eyes were followed by a large anterior appendage, the 'great appendage', bearing three long flagella. The two posterior head appendages, like those of the trunk, were biramous.

• Read more about The arthropod Alalcomenaeus cambricus Simonetta, from the Middle Cambrian Burgess Shale of British Columbia

Plesiosaurus tournemirensis Sciau, Crochet and Mattei, based on a nearly complete skeleton with skull from the Upper Toarcian (Lower Jurassic) of Tournemire (Aveyron Department, southern France), is here redescribed and reinterpreted. Comparisons with other plesiosaurs indicate that it belongs to a new genus, Occitanosaurus. O.

• Read more about A new elasmosaurid plesiosaur from the Lower Jurassic of southern France

A computer-based parsimony analysis of Albian heteromorph ammonites from the Tethyan and European faunal provinces is demonstrated. The results indicate that whilst Anisoceratidae, Baculitidae, Scaphitidae and Turrilitidae are monophyletic, Hamitidae is not. Previous studies of ammonite phylogenetics have used the coiling mode, ornamentation of the shell and the suture line as sources of characters.

• Read more about Cladistic analysis of Albian heteromorph ammonites

Study of three upper Ordovician borehole sections from Estonia has revealed abundant and well-preserved scolecodonts representing more than 50 species of jaw-bearing eunicid polychaetes. In this paper, two monotypic families, Conjungaspidae and Tretoprionidae, are introduced, based on two new species (Conjungaspis minutus gen. et sp. nov. and Tretoprion astae gen. et sp. nov.). The most distinctive features of conjungaspids are the small, distally rounded and long-horned carriers, merged with large basal and laeobasal plates, and symmetrical jaw apparatus.

• Read more about Two new polychaete families from the upper Ordovician of Estonia