Cranial anatomy of ophiderpetontid aïstopods: Palaeozoic limbless amphibians

Oestocephalus , an ophiderpetontid from the Middle Pennsylvanian of both Europe and North America provides the best known basis for evaluating the relationships of the aïstopods. All aïstopods are united by the unique manner of attachment of the skull and the first cervical in which the articulating surface of the occiput is formed by the narrow circular rim of a notochordal pit. As in other aïstopods (but in contrast with all other early tetrapods), the otic-occipital portion of the braincase is ossified as a single element. The palatoquadrate ossification extends from the orbit to the back of the area of jaw articulation. These two characters may be retained from the osteolepiform sarcopterygians. Few, if any, unique derived characters unite aïstopods with other early tetrapods. Their phylogenetic position remains enigmatic.     

SEM studies on vessels in ferns. 11. Ophioglossum

With scanning electron microscopy (SEM), the nature of metaxylem vessel elements and tracheids was examined in Ophioglossum crotalophomides, 0. pendulum subsp. falcatum , and 0. vulgatum roots and rhizomes. Vessels were identified in all species. End walls of vessel elements, which bear perforations, are like lateral wall pitting of those elements in the secondary wall framework and differ only in absence of pit membranes or presence of pit membrane remnants. Some of the perforations contain pit membrane remnants that have large pores, small porosities, or are threadlike or weblike in structure. Dimorphic perforations were found in some vessel elements of rhizomes of 0. pendulum subsp. falcatum. Tracheids are very likely present in addition to vessels in all three species. The secondary wall framework of both tracheids and vessels is basically scalariform, although deviations in pattern are present. Vessel elements of Ophiglossum are entirely comparable to those of leptosporangiate ferns.     

A new species of Cryptolepis (Periplocoideae, Apocynaceae) from Arabia

A new species of Cryptolepis from Yemen, Arabian Peninsula, C. yemenensis is described and figured. It is recognized by the glabrous appearance of the plant, oblong-elliptic to narrowly obovate leaves, small flowers, small follicles and ridged seed. The new species resembles Cryptolepis gillettii Hutch. & E.A. Bruce and C. volubilis (Balf f.) Schwartz to some extent. Their flowers are die, except for size and different corona shapes. However, they differ with regard to the shape and size of the follicles, the texture of the seed coat and the absence or presence of vesture on the plants.     

Postcranial remains of Baphetes and their bearing on the relationships of the Baphetidae (= Loxommatidae)

The first unequivocal postcranial remains of baphetids (= loxommatids) associated with skull roof and lower jaw material are reported from a specimen of Baphetes from the English Upper Carboniferous, Duckmantian. Characters of the mandible, including the incorporation in the symphysis of paired parasymphysial plates, permit the identification of a previously indeterminate jaw from the Langsettian (Westphalian A) of Nova Scotia, as baphetid. The postcranial remains include vertebrae, pectoral and pelvic limb and limb girdle elements that present a combination of unique characters extending the diagnosis of the family Baphetidae, together with plesiomophic and derived characters which suggest that baphetids are primitive stem group tetrapods.     

A cochleosaurid temnospondyl amphibian from the Middle Pennsylvanian of Linton, Ohio, U.S.A.

Two temnospondyl amphibian specimens from the Middle Pennsylvanian locality of Linton, Ohio, USA are described as Adatnanterpeton ohioensis gen. et sp. nov. , a member of the family Cochleosauridae and sister-taxon to the clade comprising the genera Cochleosaurus+Chenoprosopus. A. ohioensis is a very rare component in the large Linton vertebrate assemblage and may have been a relatively terrestrial form, perhaps similar to Cochleosaurus florensis from the contemporaneous lycopsid-trunk locality at Florence, Nova Scotia. An overview of the edopoid and eryopoid adaptive radiations is presented and it is argued that they were sequential radiations, each of monophyletic origin filling the same range of niches.     

The occurrence of the fossil genus Graminidites in the Maastrichtian Scollard Formation,Alberta, Canada,and its palaeoecological and palaeogeographical significance

Fossil grass pollen is common in Late Tertiary sediments and its rare occurrence in the Early Tertiary led to the belief that its presence is restricted to Tertiary sediments. A literature survey shows that rare occurrences of Graminidites spp. have been reported from Campanian–Maastrichtian strata worldwide. All reported Graminidites spp. have been studied by transmitted light microscopes, which are inadequate to resolve their fine exine sculpture. Graminidites sp. occurs in the Maastrichtian Scollard Formation of Alberta, Canada, and is studied here with light microscopy and scanning electron microscopy. A new species, G. ulkapites, occurs at the initiation of a temperate climate in the area. It occurs in post‐dinosaurian beds locally but in pre‐Cretaceous–Tertiary boundary strata, which implies that grasses could also be present in dinosaur inhabitations. Grass phytoliths, reported from dinosaurian coprolites from the Maastrichtian Deccan Intertrappean sediments of India, indicate that grasses were ingested by dinosaurs even if not included in the dinosaurian diet. A plot of worldwide Senonian occurrences of Graminidites spp. on a late Maastrichtian palaeogeographic map demonstrates that the data are inadequate to reveal the place of origin or migratory pattern. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 167 , 235–248.     

Low genetic and morphological differentiation in the European species complex of Rosa sherardii,R. mollis and R. villosa (Rosa section Caninae subsection Vestitae)

The polyploid species complex of Rosa villosa sensu lato (Rosa section Caninae subsection Vestitae) consists of three morphologically similar polyploid species: R. sherardii, R. mollis and R. villosa. Whereas R. sherardii is distributed in central Europe, R. mollis and R. villosa represent a vicariant species pair occurring in northern Europe and in mountains of central and eastern Europe, respectively. In this study we analysed multiple data sets (morphology, cytology, microsatellites, AFLP and plastid DNA sequences) to re‐evaluate the systematics of these species and to examine whether cytological differences are reflected in the taxonomy and geographical distributions. Furthermore, these data sets were used to evaluate hypotheses explaining the vicariant distribution of R. mollis and R. villosa. None of these data sets revealed a clear‐cut differentiation between the species. Cytological and molecular data argued for a discrete taxonomic position of the predominantly pentaploid R. sherardii, but these data did not support a separation between the mostly tetraploid R. mollis and R. villosa. Population genetics revealed that samples of the latter species were assembled according to ploidy, but not to species affiliation or geographical distribution. Thus, we assume that the cytologically polymorphic original species had a continuous range prior to the last glaciation period and survived on nunataks or in non‐glaciated coastal regions in northern Europe, but that it failed to recover its former range after the retreat of the ice sheets. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 174 , 240–256.     

The adductor mandibulae muscle complex in lower teleostean fishes (Osteichthyes: Actinopterygii): comparative anatomy,synonymy, and phylogenetic implications

Bony fishes of the morphologically diverse infraclass Teleostei include more than 31 000 species, encompassing almost one‐half of all extant vertebrates. A remarkable anatomical complex in teleosts is the adductor mandibulae, the primary muscle in mouth closure and whose subdivisions vary in number and complexity. Difficulties in recognizing homologies amongst adductor mandibulae subdivisions across the Teleostei have hampered the understanding of the evolution of this system and consequently its application in phylogenetic analyses. The adductor mandibulae in representatives of all lower teleost orders is described, illustrated, and compared based on broad taxonomic sampling complemented by extensive literature information. Muscle division homologies are clarified via the application of a standardized homology‐driven anatomical terminology with synonymies provided to the myological terminologies of previous studies. Phylogenetic implications of the observed variations in the adductor mandibulae are discussed and new possible synapomorphies are proposed for the Notacanthiformes, Ostariophysi, Cypriniformes, Siluriphysi, Gymnotiformes, and Alepocephaloidei. New characters corroborate the putative monophyly of the clades Albuliformes plus Notacanthiformes (Elopomorpha), Argentinoidei plus Esocoidei plus Salmonoidei (Protacanthopterygii) and Hemiodontidae plus Parodontidae (Characiformes). We further confirm the validity of characters from the adductor mandibulae previously proposed to support the monophyly of the Esocoidei and the gonorynchiform clade Gonorynchoidei plus Knerioidei. © 2014 The Linnean Society of London