15 research outputs found
A review of the systematic biology of fossil and living bony-tongue fishes, Osteoglossomorpha (Actinopterygii: Teleostei)
The bony-tongue fishes, Osteoglossomorpha, have been the focus of a great deal of morphological, systematic, and evolutionary study, due in part to their basal position among extant teleostean fishes. This group includes the mooneyes (Hiodontidae), knifefishes (Notopteridae), the abu (Gymnarchidae), elephantfishes (Mormyridae), arawanas and pirarucu (Osteoglossidae), and the African butterfly fish (Pantodontidae). This morphologically heterogeneous group also has a long and diverse fossil record, including taxa from all continents and both freshwater and marine deposits. The phylogenetic relationships among most extant osteoglossomorph families are widely agreed upon. However, there is still much to discover about the systematic biology of these fishes, particularly with regard to the phylogenetic affinities of several fossil taxa, within Mormyridae, and the position of Pantodon. In this paper we review the state of knowledge for osteoglossomorph fishes. We first provide an overview of the diversity of Osteoglossomorpha, and then discuss studies of the phylogeny of Osteoglossomorpha from both morphological and molecular perspectives, as well as biogeographic analyses of the group. Finally, we offer our perspectives on future needs for research on the systematic biology of Osteoglossomorpha
4-[(1-Benzyl-1H-1,2,3-triazol-4-yl)methoxy]benzene-1,2-dicarbonitrile: crystal structure, Hirshfeld surface analysis and energy-minimization calculations
In the solid state, the title compound, C18H13N5O, adopts a conformation whereby the phenyl ring and methoxyâbenzene-1,2-dicarbonitrile residue (r.m.s. deviation of the 12 non-H atoms = 0.041â
Ă
) lie to opposite sides of the central triazolyl ring, forming dihedral angles of 79.30â
(13) and 64.59â
(10)°, respectively; the dihedral angle between the outer rings is 14.88â
(9)°. This conformation is nearly 7 kcal molâ1 higher in energy than the energy-minimized structure which has a syn disposition of the outer rings, enabling intramolecular ÏâÏ interactions. In the crystal, methylene-CâH...N(triazolyl) and carbonitrile-N...Ï(benzene) interactions lead to supramolecular chains along the a axis. Supramolecular layers in the ab plane arise as the chains are connected by benzene-CâH...N(carbonitrile) interactions; layers stack with no directional interactions between them. The specified intermolecular contacts along with other, weaker contributions to the supramolecular stabilization are analysed in a Hirshfeld surface analysis
4-[(1-Benzyl-1 H
In the solid state, the title compound, C18H13N5O, adopts a conformation whereby the phenyl ring and methoxyâbenzene-1,2-dicarbonitrile residue (r.m.s. deviation of the 12 non-H atoms = 0.041â
Ă
) lie to opposite sides of the central triazolyl ring, forming dihedral angles of 79.30â
(13) and 64.59â
(10)°, respectively; the dihedral angle between the outer rings is 14.88â
(9)°. This conformation is nearly 7 kcal molâ1 higher in energy than the energy-minimized structure which has a syn disposition of the outer rings, enabling intramolecular ÏâÏ interactions. In the crystal, methylene-CâH...N(triazolyl) and carbonitrile-N...Ï(benzene) interactions lead to supramolecular chains along the a axis. Supramolecular layers in the ab plane arise as the chains are connected by benzene-CâH...N(carbonitrile) interactions; layers stack with no directional interactions between them. The specified intermolecular contacts along with other, weaker contributions to the supramolecular stabilization are analysed in a Hirshfeld surface analysis