A new species of the genus Phymorhynchus (Neogastropoda: Raphitomidae) from a hydrothermal vent in the Manus Back-Arc Basin

During an investigation carried out by the Institute of Oceanology, Chinese Academy of Sciences (IOCAS), three living raphitomid specimens were collected from a hydrothermal vent site in the Manus Back-Arc Basin. Observations of the shell, external anatomy and radular morphology reveal that they represent an undescribed species of the genus Phymorhynchus Dall, 1908. In this paper, we describe and illustrate this species as Phymorhynchus oculatus sp. nov. The new species is most similar in general shell shape to Phymorhynchus buccinoides Okutani, Fujikura & Sasaki, 1993, but can be distinguished from it by having spiral cords over the whole shell surface and much longer marginal tooth with a distal barb. A list of species of Phymorhynchus from vent/seep habitats is also given.

A new species of Aleuromarginatus Corbett, 1935 with a key and checklist of Chinese species (Hemiptera, Aleyrodidae)

A new whitefly species, Aleuromarginatus dielsianae Wang & Xu, sp. n. collected from Millettia dielsiana Harms (Rosales: Fabaceae) in Jiangshan (28°40'N, 118°40'E, 512 m) and Xinchang (29°22'N, 120°46'E, 308 m), Zhejiang, China, is described and illustrated. This new species is characterized by the dark brown lateral margin area and a pair of longitudinal furrows extending from the cephalothorax to the vasiform orifice. The submargin has an elongate-oval fold at the base of each marginal tooth and with 3-4 rows of irregular shaped papillae, nine pairs submedian setae and 13 pairs submarginal setae. Thoracic and caudal tracheal folds and pores discernible. An identification key and checklist of species of Aleuromarginatus known from China are provided.

Multiple tooth-rowed captorhinids from the Early Permian fissure fills of the Bally Mountain Locality of Oklahoma

Captorhinids were Paleozoic eureptiles that originated in the Late Pennsylvanian in Laurasia and dispersed across the major landmasses of Pangaea by the Late Permian. Their evolutionary success as omnivorous and herbivorous members of Permian terrestrial communities has been attributed to the evolution of multiple marginal tooth rows. Multiple tooth rows evolved at least twice within Captorhinidae: once in the omnivorous Captorhinus aguti and again in the diverse subfamily of herbivorous moradisaurines. The earliest known moradisaurines co-occured with C. aguti in Lower Permian strata of Texas; however C. aguti is also known from much older fissure fills in the famous Dolese Brothers quarry near Richards Spur, Oklahoma, suggesting that C. aguti preceded any other multiple-rowed captorhinid. Here we report on new material of multiple-rowed captorhinids from the Lower Permian fissure fills of the Bally Mountain locality in Oklahoma, only 35 miles from Richards Spur. Some of this material is referrable to Captorhinikos valensis, which was previously only known from younger strata in Texas, making this species the geologically and phylogenetically oldest moradisaurine. Furthermore, we determined that Ca. valensis co-existed with C. aguti at Bally Mountain and we explore the potential for niche partitioning in these early captorhinids. Lastly, we assess the potential temporal and environmental differences between Bally Mountain and Richards Spur, in order to explain the abundance of herbivorous moradisaurines at Bally Mountain and the complete lack of moradisaurines at the neighbouring Richards Spur locality.

The northernmost occurrence of Prognathodon (Squamata: Mosasauridae) from the Western Interior Seaway of North America

The marine reptile Prognathodon (Squamata: Mosasauridae), a mosasaurine mosasaur exhibiting a characteristically robust skull and dentition, lived during the last two ages of the Late Cretaceous. Fossilized remains of animals assigned to this genus are so far known from North America, Europe, Africa, and New Zealand, indicating their wide geographic ranges and presumed ecological and evolutionary success. Assignable to Prognathodon, a newly discovered partial marginal tooth from Dorothy, Alberta, Canada (51°15′48″N), extends the geographic range of the genus by 190 km northward in the Northern Hemisphere. Coupled with the New Zealand record of this mosasaur, the new discovery indicates that Prognathodon likely ranged anywhere from 60°N to 60°S paleolatitude, and these reptiles may even have been occasional inhabitants of the polar regions.

Description of a new specimen of Ianthasaurus hardestiorum (Eupelycosauria: Edaphosauridae) and a re-evaluation of edaphosaurid phylogeny

Ianthasaurus hardestiorum , a basal edaphosaurid from the Upper Pennsylvanian of Garnett, Kansas, has been described on the basis of two incomplete, juvenile specimens and a series of disarticulated vertebral elements. New skeletal material of this poorly known species includes previously unknown cranial elements, increasing our knowledge of the anatomy and variation in this taxon. The complete ossification of the neural arches and the overall larger size of the vertebrae relative to those previously described indicate that they were part of an adult individual, and marginal tooth morphology resembles more closely that seen in the genus Edaphosaurus . Phylogenetic analysis of edaphosaurid synapsids confirms the hypothesis that Ianthasaurus is a sister-taxon of all other members of the clade. However, the incomplete fossil record of other putative edaphosaurids, such as Lupeosaurus and Glaucosaurus , makes full resolution of their phylogenetic interrelationships difficult to assess.

Danish mosasaurs

Presented are the first formal descriptions of mosasaur remains of Maastrichtian age from the Danish mainland (Jylland, Sjælland); just two taxa are recognised, viz. Mosasaurus cf. hoffmanni and Plioplatecarpus sp. Recent finds include an association of skeletal fragments, inclusive of a single marginal tooth crown, from within 10 metres or so of the K/T boundary near Holtug, Stevns Klint (Sjælland, eastern Denmark), here assigned to Plioplatecarpus sp. A brief review of previous records of Danish mosasaurs is added.

A new genus of rhizodontid (Sarcopterygii, Tetrapodomorpha) from the Lower Carboniferous Horton Bluff Formation of Nova Scotia, and the evolution of the lower jaws in this group

Letognathus gen. nov. is described from the Lower Carboniferous (Tournaisian) Horton Bluff Formation. Included in this genus is the species Letognathus hardingi (Dawson 1868), which was originally assigned toRhizodus and later toStrepsodus, but it is distinct from these genera in tooth morphology and the presence of several more primitive rhizodontid characters. By contrast with these latter more derived genera, the parasymphysial plate contacts the first coronoid; the first coronoid bears a row of lingually deflected teeth, the tooth striations occur around the entire circumference of the crown and are much finer and less regular than those ofStrepsodus, and marginal tooth row reaches anteriorly to the dentary symphysis. Phylogenetic analysis indicates that rhizodontid jaws primitively bear symphysial tusks; slender recumbent teeth; an anterior projection of the dentary over the anteromesial depression for the median symphysial plate and shows the highly derived jaws ofStrepsodus andRhizodus evolved within the Rhizodontida, rather than as primitive characters for the group. This new jaw material supports earlier models of mandibular kinesis and shows that the coronoid fangs were oriented such as to facilitate kinesis. Rhizodontid jaw evolution seems to be marked by parallelisms with tristichopterids and early tetrapods.

The First Tetrapod Finds from the Devonian (Upper Famennian) of Latvia

Ventastega curonica, from the Upper Famennian Ketleri Formation, is the first tetrapod find from the Upper Devonian of Latvia, and only the fourth adequately represented Devonian tetrapod genus to be described. The taxon is represented by disarticulated cranial and postcranial elements from two localities, Ketleri on the Venta River and Pavari on the Ciecere River. A second tetrapod, represented by a single mandibular fragment, appears to be present at Ketleri. The lower jaw of Ventastega is strikingly primitive in retaining fangs on the coronoid series, but shares many characters with those of other known Devonian tetrapods. Some of these features are interpreted as basal tetrapod synapomorphies; they provide a new data set for the identification of isolated tetrapod jaw fragments, and confirm the (previously disputed) tetrapod status of Metaxygnathus. The upper jaw bones of Ventastega are broadly similar to those of Acanthostega, Ichthyostega and Tulerpeton, as is the narial region. The lateral rostral bone is either very small or absent. A preopercular bone is present in the cheek, and the lacrimal is excluded from the orbit. The palate is closed. Palatine and vomer bear fangs which are set in the marginal tooth row. An isolated iliac blade from Pavari, probably attributable to Ventastega, resembles that of Acanthostega but may not have carried a dorsal process. Two clavicles from Pavari and Ketleri which may also belong to Ventastega are of a typical early tetrapod pattern, similar to Greerpeton but with a broader ventral blade. Non-attributable or doubtfully attributable bones from Ketleri include a probable tetrapod postorbital and a possible limb bone. Ventastega appears to be a tetrapod of the same broad `grade' as Ichthyostega and Acanthostega, but is arguably more primitive than either.

The relationships of Uronemus : A Carboniferous dipnoan with highly modified tooth plates

Previous accounts of the dentition of the Carboniferous dipnoan Uronemus have stressed the significance of the scattered small denticles. These, together with the marginal teeth and ridges, have been interpreted as primitive characters of the dipnoan dentition shared with three other genera: the Devonian Uranolophus and Griphognathus and the Carboniferous to Permian Conchopoma . Genera with tooth plates have been considered to be a monophyletic group in which tooth plates are a derived character; Uronemus has been excluded from this group in all previous investigations dealing with the significance of the dentition for determining relationships among dipnoans. The macromorphology of the dentition of Uronemus has been re-examined and correlated with the histology of all the dental tissues. Optical study of thin sections and scanning electron microscope study of the adjacent cut surfaces has shown that the hard, wear-resistant dentine of the teeth and ridges is petrodentine. The arrangement, growth, wear and histology of the dental tissues have been compared with those of denticulated and tooth-plated genera. The arrangement of new teeth relative to the tooth ridge, the pattern of wear along the ridge, and the type of dentine and its growth indicate that the dentition of Uronemus is best interpreted as a tooth plate with one long lingual tooth ridge and reduced lateral tooth rows. Therefore the marginal tooth ridges are not considered to be homologous with those of denticulate dipnoans such as Uranolophus . The presence of petrodentine, a tissue type only found in forms with tooth plates, is consistent with the view that the dentition is derived by modification of a radiate tooth plate. The denticles covering restricted regions of the palate and lower jaw are considered to have been a secondary acquisition. The suggestion that Conchopoma is a close relative of Uronemus is not accepted, and possible new relationships have been proposed. New data on Scaumenacia and Phaneropleuron , two other genera previously compared with Uronemus , are presented. Rhinodipterus , a form with elongate lingual ridges, is also discussed. Phaneropleuron is shown to have radiate tooth plates and not a marginal row of conical teeth as previously described. It is proposed that the tooth plate of Uronemus is derived from a dipterid type of plate. A discussion of some of the other factors involved in determining the relationships of the genus is given. From an examination of the use of the tongue for respiration and feeding by the extant Lepidosiren paradoxa , it is concluded that many features of dipnoan evolution in the tooth-plated lineage result from the adoption of air breathing after an early evolutionary phase of gill respiration, and that Uronemus was adapted for air breathing. The ‘denticulated’ lineage, which included genera such as Uranolophus and Griphognathus , shows none of the skeletal features associated with the presence of a tongue, and presumably did not become air breathing.