A large Eomys antiquus (Aymard, 1853) (Mammalia, Rodentia) from the early Oligocene sedimentary deposits at Bouldnor Cliff (Isle of Wight, England, UK)

A collection of approx. 150 isolated cheek teeth of the eomyid rodent Eomys antiquus which was obtained from a very thin layer in the HamsteadMember of the Bouldnor Formation at Bouldnor Cliff (Isle ofWight, England, UK) is described. The material is post-Grande Coupure, and earliest Oligocene in age. Comparison is made with and new data are given on teeth of Eomys from localities of a similar age situated elsewhere in Europe: Eomys antiquus from Hoogbutsel (Belgium), andMöhren 13, 19, and 20 (Germany), and Eomys aff. antiquus from Montalbán 1D (Spain), and Kocayarma (Turkish Thrace, Turkey). Teeth from Bouldnor Cliff and Hoogbutsel (Mammal Paleogene zone 21) are morphologically close to those from Möhren 13 (Mammal Paleogene zone 22), but tend to be larger. Size decrease in the course of time is also suggested by the smaller size of the teeth from Montalbán 1D (Mammal Paleogene zone 23). The morphological differences observed between the English, Belgian, and German material at the one side, and the Spanish and Turkish material at the other, confirm that the species from Montalbán 1D and Kocayarma is a different, although closely related form. The taxonomic history of Eomys antiquus is reviewed. The species is the commoner of the two oldest European Eomyidae known. General knowledge on the ecology of the eomyids suggests that at the time of deposition of the Eomys-containing layer in the Hampshire Basin forest was close by

Biosynthesis of lanthionine-constrained agonists of G protein-coupled receptors

The conformation with which natural agonistic peptides interact with G protein-coupled receptor(s) (GPCR(s)) partly results from intramolecular interactions such as hydrogen bridges or is induced by ligand-receptor interactions. The conformational freedom of a peptide can be constrained by intramolecular cross-links. Conformational constraints enhance the receptor specificity, may lead to biased activity and confer proteolytic resistance to peptidic GPCR agonists. Chemical synthesis allows to introduce a variety of cross-links into a peptide and is suitable for bulk production of relatively simple lead peptides. Lanthionines are thioether bridged alanines of which the two alanines can be introduced at different distances in chosen positions in a peptide. Thioether bridges are much more stable than disulfide bridges. Biosynthesis of lanthionine-constrained peptides exploiting engineered Gram-positive or Gram-negative bacteria that contain lanthionine-introducing enzymes constitutes a convenient method for discovery of lanthionine-stabilized GPCR agonists. The presence of an N-terminal leader peptide enables dehydratases to dehydrate serines and threonines in the peptide of interest after which a cyclase can couple the formed dehydroamino acids to cysteines forming (methyl)lanthionines. The leader peptide also guides the export of the formed lanthionine-containing precursor peptide out of Gram-positive bacteria via a lanthipeptide transporter. An engineered cleavage site in the C-terminus of the leader peptide allows to cleave off the leader peptide yielding the modified peptide of interest. Lanthipeptide GPCR agonists are an emerging class of therapeutics of which a few examples have demonstrated high efficacy in animal models of a variety of diseases. One lanthipeptide GPCR agonist has successfully passed clinical Phase Ia.</p

Foraging by the stoplight parrotfish Sparisoma viride. 11.:Intake and assimilation of food, protein and energy

Daily food intake by the herbivorous parrotfish Sparisoma viride, as well as assimilation efficiencies of algal food, protein and energy, were quantified through a combination of laboratory feeding trials and field observations. The intake of algal ash-free dry wt (AFDW) per bite increases linearly with fish wet wt (FWW, g) and algal biomass (mg AFDW CM-2), and is further determined by the skeletal density of the limestone substrate. Low-density substrates yield higher amounts of AFDW per bite than do high-density substrates. The percentage of the total food intake that is derived from endolithic and crustose coralline algae increases with the size of the fish, and can be &gt; 70 % depending on the biomass of epilithic algae. The daily pattern of foraging activity is positively correlated with diurnal changes in food quality, while seasonal daylength variations result in 13 % variation in total daily bites taken. Daily number of bites of S. viride in the field decreases with fish size, and is further dependent on life phase and foraging depth. In experiments, fish attained an assimilation efficiency of ca 20 % from a natural diet of low algal biomass and high-density dead coral substrates that predominates in the shallow reef. Assimilation efficiency was ca 70 % from a diet of high algal biomass and low-density substrates that predominates on the deeper reef parts. In spite of lower daily foraging effort, territorial fish, living in deeper parts of the reef, ingest and assimilate higher amounts of AFDW, protein and energy per day than non-territorial fish foraging on the shallow reef. The difference is caused by increased availability of high-yield food and substrate types inside territories compared to the situation on the shallow reef. Daily assimilated energy (kJ d-1) is 0.85 x FWW 0.773 for fish foraging in the shallow reef zone, and 1.22 x FWW0.854 for S. viride foraging inside territories on the deeper reef.</p

Rodent biostratigraphy of the Eocene-Oligocene transitional strata of the Isle of Wight

The Paleogene deposits of the Isle of Wight in the Hampshire Basin have yielded mammalian remains at various levels. The lowest level is situated near the base of the Lower Headon Beds, while the highest level is situated in the Lower Hamstead Beds. The rodent species belonging to the families Pseudosciuridae, Theridomyidae, Cricetidae, Castoridae and Paramyidae are described in detail. One of these, the theridomyid species Isoptychus headonensis, is new. The pseudosciurid species Paradelomys quercyi is subdivided into two subspecies, P. quercyi quercyi and P. quercyi vectisensis n. subsp. The taxonomic value of the genera Paradelomys and Isoptychus is reassessed. A biozonation is inferred from the sequence of rodent associations. The following zones are recognized from below upwards: Isoptychus headonensis Zone, Paradelomys quercyi vectisensis Zone, Paradelomys quercyi quercyi-Suevosciurus palustris Zone, Paradelomys quercyi quercyi-Suevosciurus fraasi Zone, Eetropomys exiguus Zone and Eucricetodon atavus Zone. The Headonian is proposed as a new stage in the chronostratigraphic scale of continental deposits. Correlation of the Headonian with the Priabonian and Lower Tongrian of the marine chronostratigraphic stage succession is suggested

Early and middle Miocene Sciuridae (Mammalia, Rodentia) from Anatolia, Turkey

Isolated cheek teeth of Sciuridae (Mammalia, Rodentia) from fifteen early and middle Miocene localities in Anatolia (Turkey) are described. The localities range in age from local zone B to local zone H, which zones are correlated to European MN zones 1 to 7+8. The material represents the two subfamilies Sciurinae (ground and tree squirrels) and Pteromyinae (flying squirrels). The number of different species found at a single locality ranges from one to four. The Sciurinae found belong to the genera Palaeosciurus, Dehmisciurus (formerly called ?Ratufa), Spermophilinus, Tamias, and Atlantoxerus. Members of the Pteromyinae are Hylopetes, Miopetaurista, Aliveria, Albanensia, and Blackia. The MN 2 locality Harami 1 has yielded the oldest Spermophilinus and Miopetaurista known so far. Atlantoxerus adroveri from Bağiçi and Yenieskihisar (MN 7+8) is the first member of the Xerini tribe in Anatolia. The squirrel from Keseköy (MN 3), described as Palaeosciurus aff. feignouxi, shows close morphological resemblance to early Miocene Protospermophilus kelloggi from North America. This may suggest that European Palaeosciurus and American Protospermophilus are closely related genera. Three MN 7+8 localities (Sarıçay, Bağiçi, and Yenieskihisar) yielded two Spermophilinus species, which shows that Spermophilinus developed, at least locally, along two parallel lines. Similarity between Anatolian and European squirrel assemblages confirms that Anatolia was connected to the European part of the Eurasian continent in early and middle Miocene times. The lacustrine character of the sediments, and the presence of both ground and/or tree and flying squirrels indicate that most of the localities represent a wet, but arboreal environment

Early and middle Miocene Sciuridae (Mammalia, Rodentia) from Anatolia, Turkey

Isolated cheek teeth of Sciuridae (Mammalia, Rodentia) from fifteen early and middle Miocene localities in Anatolia (Turkey) are described. The localities range in age from local zone B to local zone H, which zones are correlated to European MN zones 1 to 7+8. The material represents the two subfamilies Sciurinae (ground and tree squirrels) and Pteromyinae (flying squirrels). The number of different species found at a single locality ranges from one to four. The Sciurinae found belong to the genera Palaeosciurus, Dehmisciurus (formerly called ?Ratufa), Spermophilinus, Tamias, and Atlantoxerus. Members of the Pteromyinae are Hylopetes, Miopetaurista, Aliveria, Albanensia, and Blackia. The MN 2 locality Harami 1 has yielded the oldest Spermophilinus and Miopetaurista known so far. Atlantoxerus adroveri from Bağiçi and Yenieskihisar (MN 7+8) is the first member of the Xerini tribe in Anatolia. The squirrel from Keseköy (MN 3), described as Palaeosciurus aff. feignouxi, shows close morphological resemblance to early Miocene Protospermophilus kelloggi from North America. This may suggest that European Palaeosciurus and American Protospermophilus are closely related genera. Three MN 7+8 localities (Sarıçay, Bağiçi, and Yenieskihisar) yielded two Spermophilinus species, which shows that Spermophilinus developed, at least locally, along two parallel lines. Similarity between Anatolian and European squirrel assemblages confirms that Anatolia was connected to the European part of the Eurasian continent in early and middle Miocene times. The lacustrine character of the sediments, and the presence of both ground and/or tree and flying squirrels indicate that most of the localities represent a wet, but arboreal environment

Are the Rhizomyinae and the Spalacinae closely related? Contradistinctive conclusions between genetics and palaeontology

The reconstruction of the evolutionary history of the Rhizomyinae and the Spalacinae based on the fossil record strongly suggests that these do not share the same murid ancestor and developed separately since the early Oligocene. This conclusion is supported by the difference in evolutionary dynamics between these groups during the Miocene and Pliocene. Molecular genetic studies of extant representatives of the Rhizomyinae, Spalacinae and Myospalacinae, however, suggest that these subfamilies share similarities that distinguish them from all other Muridae. As a result, geneticists unite these subfamilies into the family Spalacidae and consider the Spalacidae and the Muridae to be sister lineages. Until the conflict between the two disciplines is resolved we prefer to maintain the Rhizomyinae and the Spalacinae as two subfamilies within the family Muridae (superfamily Muroidea)

Which shape factor(s) best describe granules?

This study evaluates methods used for granule shape characterization. The aim is to identify an optimal combination of shape factors to measure granule shape and roughness. Granules were prepared from microcrystalline cellulose (MCC), alpha-lactose, microfine cellulose (MFC), and dextrin, using a small-scale high-shear mixer. Granule shapes were analysed by measuring weight, by microscopic analysis, and by sedimentation analysis in olive oil. A comparison was made among (1) the aspect ratio, (2) the circularity, (3) a new projection shape factor defined in this paper, (4) the shape factor e(R), (5) the radial shape factor, (6) One-Plane-Critical-Stability (OPCS), (7) the Stokes' shape factor, and (8) a new mass shape factor defined in this paper. Besides the evaluation of the shape factors, (9) a roughness factor R is defined. When the shape of granules is evaluated, there can be effects of both shape and surface roughness. The scale of scrutiny of the measurement determines whether or not a shape factor is affected by surface roughness. We chose to call a protrusion smaller than 60 mum a roughness, and a larger protrusion a shape effect. The best evaluation of granule shape is obtained when shape and roughness are described by different parameters. The aspect ratio, the mass shape factor, OPCS, e(R) and the radial shape factor could not significantly discriminate between some of the different shapes. The other three shape factors give distinct differences in value for all different shapes used in this study. Of these factors, Stokes' shape factor was rejected because of the high viscosity of the oil needed, which results in a significant temperature dependency. Circularity and the new projection shape factor both work very well for our granules. The combination of the roughness factor with the new projection shape factor will provide a good description of granule shape and roughness. Granule shapes were(C) 2004 Elsevier B.V. All rights reserved