On some modern Ostracoda (Crustacea) from the Tibetan Plateau in SW China, with descriptions of three new species

Studies of Holocene ostracods of the Tibetan Plateau have mostly centred around valves and carapaces collected from lake sediments, some at or near the substrate surface and others from short cores. Reports from habitats other than lakes are scarce, and few living species found in this region have appendages described, hindering further taxonomic and phylogenetic work. For this study collections of living ostracods were made in mostly ponds, as well as two rivers and one lake. Six species, including three previously undescribed, were recovered: Tonnacypris estonica (Järvekülg, 1960), Arctocypris edita n. sp., Cypris pubera O.F. Müller, 1776, Potamocypris variegata (Brady & Norman, 1889), Ilyocypris tibeta n. sp., and Fabaeformiscandona monticulus n. sp. Specimens of Tonnacypris estonica include males, previously unknown for this species, and suggesting it is a geographical parthenogen. A revision of the fifth limb morphology of the genus Arctocypris, and a subsequent amended diagnosis of the genus are given. Based on carapace and appendage features, Eucypris mareotica (Fischer, 1855) is transferred to this genus: Arctocypris mareotica (Fischer, 1855) com. nov. There are now ca. 100 ostracod species reported from modern or subsurface sediments on the Tibetan Plateau, but only 19 of those can be confirmed as alive when collected (i.e. had appendages intact). The families Limnocytheridae and Ilyocyprididae are both relatively diverse on the plateau compared with the Palaearctic zoogeographical region generally. About one third of ostracod species reported from the Tibetan Plateau are only known from there, suggesting a potentially very high rate of endemism.

Description of two new Proceroecia species (Ostracoda: Halocyprididae) from neritic waters off South Korea with an insight into the morphological and molecular diversity of the genus

Two new planktonic ostracods of the genus Proceroecia Kock, 1992, P. hwanghaensis sp. nov. and P. joseondonghaensis sp. nov., collected from neritic waters off the south coast of South Korea are described. Morphologically, they are similar to P. microprocera (Angel, 1971), the type species of the genus, but show several clear morphological differences, most prominent being the shape of the male endopodite on the second antenna and the presence of a sensilla on the coxale of the fifth limb. The two new species have subtle differences, such as the length of the frontal organ, number of spines on the comb-like e-seta on the first antenna in males, number of spinules on the b-seta on the second antenna in females, etc. Sequences derived from partial mitochondrial cytochrome oxidase c subunit 1 (mtCOI) for these novel species have been compared with sequences available for other Proceroecia species on GenBank, including P. microprocera. These comparisons suggest that both new species are distinct taxa. They also indicate that one set of sequences on GeneBank previously attributed to P. microprocera and derived from material collected from Chinese waters, belong to P. hwanghaensis, and that another set of sequences of an unidentified Proceroecia species from the South China Sea can be attributable to P. joseondonghaensis. Hence, these new species occur widely in the neritic waters of East Asia. The present study increases the number of the known Proceroecia species to nine, and the numbers of halocyprid ostracod species recorded from Korean waters to six.

Schornikovoecia eugenyi, a novel species and genus of deep benthopelagic halocyprids (Ostracoda, Myodocopa) from the North-west Pacific

Schornikovoecia eugenyi gen. et sp. nov. of the benthopelagic ostracods of the subfamily Bathyconchoeciinae is established and described, based upon samples collected in the deep-sea zones near the Kurile-Kamchatka Trench and in the Sea of Okhotsk (Kurile Hollow). Most of the specimens have been found at depths over 5000 m. The new genus differs sharply from the currently known genera Bathyconchoecia, Scottoecia, Bathyconchoecetta and Septemoecia of this subfamily in numerous ways: the singular sculpture; the form and structure of the glands on the carapace; the masticatory pad on the mandible; the arming of the fifth limb. The new genus is at present monospecific. Descriptions of the new genus and its new species S. eugenyi sp. nov. are presented.

Euphilomedes biacutidens (Ostracoda, Myodocopida, Philomedidae), a new species from China Sea

Ostracods are one of the major groups of marine benthos, inhabiting virtually all oceanic environments worldwide, and a total of 31 species have been recorded in genus Euphilomedes Kornicker, 1967. In the present study, we describe a new species Euphilomedes biacutidens collected from the Taiwan Strait and South China Sea. E. biacutidens sp. nov. differs from the related species of the genus Euphilomedes in having a unique combination of the characteristics of spines on carapace, the filaments on sensory seta, the arrangement of setae on tip of the first antenna, the numbers of setae on appendages, the claws on fifth limb, the teeth on the comb of the seventh limb and furcal claws. It is particularly obvious that it has a bifurcated and pointed ventral corner of the rostrum, two spines on the posterior margin of right valve, a row of teeth along the inner margin of article 3 of the endopod of the second antenna, and some long claws instead of setae on the fifth limb.

Five-Strand versus Four-Strand Hamstring Tendon Graft Technique for Anterior Cruciate Ligament Reconstruction: A Biomechanical Comparison

The aim of this article is to compare diameter and stiffness, displacement, and strain in a five-strand versus four-strand hamstring graft for anterior cruciate ligament reconstruction. Eight matched pairs of lower extremities underwent four-strand or five-strand hamstring graft reconstruction. Diameter was significantly higher in the five-strand versus the four-strand construct (p = 0.002). No significant difference was found between the groups in construct displacement or stiffness. Significantly higher strain was observed in the inner limb versus the outer limb in the four-strand construct (p = 0.001) and in the inner limb versus the fifth limb in the 5-strand construct (p = 0.004). A fifth limb added to a four-strand hamstring graft significantly increased graft diameter but did not significantly change stiffness or displacement, suggesting that attachment of additional graft material via suture did not provide for full incorporation of the added limb into the graft at time zero. The inner limb in both constructs absorbed significantly greater load than did other limbs. The use of suture to attach additional material to a four-strand hamstring graft may not contribute to improved biomechanical qualities of the graft at time zero.

Muscular anatomy of the tail of the western grey kangaroo, Macropus fuliginosus

The western grey kangaroo, Macropus fuliginosus, is a large-bodied kangaroo that engages in pentapedal locomotion at low speeds and bipedal hopping at high speeds. The tail is thought to have functional roles in both of these modes of locomotion. In pentapedal locomotion the tail acts as a ‘fifth limb’ to support the body weight together with the forelimbs while the hind limbs are drawn forward. The tail has also been suggested to have a role as a counterbalance during bipedal hopping. On the basis of these functional roles for the tail in locomotion, the caudal musculature of the western grey kangaroo was dissected and described in this study. The arrangement of the caudal musculature showed particular adaptations for the role of the tail in both pentapedal locomotion and bipedal hopping.

Bathyconchoecia liui n. sp., a new species of ostracod (Myodocopa, Halocyprididae) from the South China Sea

A new species of halocyprid ostracod,Bathyconchoecia liui, from the bathypelagic zone of the Nansha Trough (North-West Borneo Trough, southern South China Sea) is described and illustrated. It is compared with the closely similar speciesB. angeliGeorge, 1977. The present species is easily distinguished fromB. angeliby the structures of the toothed edges of the mandibular basis and coxa, and by the segmentation of the fifth limb.

A Silurian myodocope with preserved soft-parts: cautioning the interpretation of the shell-based ostracod record

Ostracod crustaceans are the most abundant fossil arthropods. The Silurian Pauline avibella gen. et sp. nov., from the Herefordshire Lagerstätte, UK, is an extremely rare Palaeozoic example with soft-part preservation. Based on its soft-part morphology, especially the exceptionally preserved limbs and presence of lateral eyes, it is assigned to the myodocopid myodocopes. The ostracod is very large, with an epipod on the fifth limb pair, as well as gills implying the presence of a heart and an integrated respiratory–circulatory system as in living cylindroleberidid myodocopids. Features of its shell morphology, however, recall halocyprid myodocopes and palaeocopes, encouraging caution in classifying ostracods based on the carapace alone and querying the interpretation of their shell-based fossil record, especially for the Palaeozoic, where some 500 genera are presently assigned to the Palaeocopida.

New subgenus and new species of marine benthic ostracods of genus Doloria (Ostracoda; Myodocopina) from the Southern Ocean

The project ANDEEP was designed to fill gaps in the knowledge of the biodiversity of the Southern Ocean deep sea. Threeoceanographic cruises (ANDEEP I, II and III) were undertaken in 2002 and 2005 in the Atlantic Sector of the SouthernOcean. Hundreds of samples were collected from 40 stations with water depths ranging from 748 to 6,348 m. Investiga-tions were carried out on a broad range of taxa, including bacteria, meio-, macroand megafauna. Approximately 5000ostracods were collected, which included 29 specimens of Doloria (Dolorietta) subgen. nov.The subdivision of the genus Doloria Skogsberg, 1920 into two subgenera, Doloria (Doloria) and the novel subgenusDoloria (Dolorietta), is based on differences in the structures of the fifth limb, the armature of the sensory bristle on the5th segment of the antennula, and the number of bristles on the 4th endite of the sixth limb. Four new species in the newsubgenus were identified from the ANDEEP samples. The new subgenus and the four novel species are described andillustrated. Two of these new species are named Doloria (Dolorietta) antarctica sp. nov. and Doloria (Dolorietta) sextafiliformis sp. nov., but the other two species are left in open nomenclature (i.e. Doloria (Dolorietta) sp. nov. 1 and Doloria(Dolorietta) sp. nov. 2) because only juveniles were found in our material. Keys to the subgenera and species of Doloria are provided.