The Unique Dorsal Brood Pouch of Thermosbaenacea (Crustacea,Malacostraca) and Description of an Advanced Developmental Stage of Tulumella unidens from the Yucatan Peninsula (Mexico), with a Discussion of Mouth Part Homologies to Other Malacostraca

The Thermosbaenacea, a small taxon of crustaceans inhabiting subterranean waters, are unique among malacostracans as they brood their offspring dorsally under the carapace. This habit is of evolutionary interest but the last detailed report on thermosbaenacean development is more than 40 years old. Here we provide new observations on an ovigerous female of Tulumella unidens with advanced developmental stages in its brood chamber collected from an anchialine cave at the Yucatan Peninsula, which is only the third report on developmental stages of Thermosbaenacea and the first for the genus Tulumella. Significant in a wider crustacean context, we report and discuss hitherto unexplored lobate structures inside the brood chamber of the female originating at the first (maxilliped) and second thoracic segments, which are most likely modified epipods, perhaps serving as gills. At the posterior margin of carapace of the female are rows of large spines preventing the developing stages from falling out. The external morphology of the advanced developmental stages is described in much detail, providing information on e.g., carapace formation and early limb morphology. Among the hitherto unknown structures in the advanced developmental stages provided by this study are the presence of an embryonic dorsal organ and rudimentary ‘naupliar processes’ of the second antennae. Since most hypotheses on crustacean (and malacostracan and peracaridan) relationship rest on external limb morphology, we use early limb bud morphology of Tulumella to better establish thermosbaenacean limb homologies to those of other crustaceans, which is a necessary basis for future morphology based phylogenetic considerations.     

<Emphasis Type="Italic">Glyphiteuthis rhinophora</Emphasis> n. sp., a trachyteuthidid (Coleoidea,Cephalopoda) from the Cenomanian (Late Cretaceous) of Mexico

A new vampyropod coleoid from the Cenomanian limestones of Coahuila (Mexico) is described. Glyphiteuthis rhinophora n. sp. is classified as a member of the Trachyteuthididae because of its general gladius morphology. Within the genus Glyphiteuthis, Gl. rhinophora n. sp. is unique by its nose-shaped extension of the anterior median field extremity. The ventral gladius surface reflects the dorsal surface and lacks evidence of a phragmocone, so affiliations with sepiids are unlikely. Gl. rhinophora n. sp. represents the first Cenomanian record of a vampyropod coleoid in the New World and the first evidence of the genus outside the Tethyan and Boreal realm. The paleoenvironment indicates a nektonic lifestyle for Gl. rhinophora n. sp.     

Macrobothridium rhynchobati n. g., n. sp. from the elasmobranch Rhynchobatus granulatus,representing a new family of diphyllidean cestodes,the Macrobothridiidae

Macrobothridium rhynchobati n. g., n. sp. from the guitarfish Rhynchobatus granulatus in Kuwaiti waters in the Arabian Gulf is described and figured. The new genus differs from Echinobothrium in having a short unarmed peduncle and a posterior sucker-like structure in the terminal proglottid. It differs from Ditrachybothridium in having a powerful rostellum with dorsal and ventral groups of hooks and in having unarmed bothridia. A new family, the Macrobothridiidae, assigned to the order Diphyllidea is erected. Larval forms are described and figured.     

Description and Molecular Phylogeny of a Novel Hypotrich Ciliate from the Soil of Marche Region,Italy; Including Notes on the MOSYSS Project

The morphology and morphogenesis during cell division of a new stylonychine hypotrich, Rigidocortex quadrinucleatus n. sp., were investigated using live observation and protargol staining. The new species was isolated from soil samples collected from an organic farm in the Marche Region, Italy, in framework of the MOSYSS project. Rigidocortex quadrinucleatus is characterized as follows: cell size about 180 × 80 μm in vivo; four ellipsoidal macronuclear nodules; 44 adoral membranelles: 18 fronto‐ventral‐transverse cirri consisting of three frontal, four frontoventral, one buccal, three ventral, two pretransverse, and five transverse cirri; dorsal kinety 3 with multiple fragmentation; resting cyst with hyaline ridges. Rigidocortex quadrinucleatus mainly differs from the type species R. octonucleatus in having four (vs. eight) macronuclear nodules. Rigidocortex quadrinucleatus can be easily confused with Sterkiella cavicola since both have a rather similar ventral ciliature; however, they can be separated by the slightly higher number of cirri in the left marginal row that runs along the posterior cell's margin in R. quadrinucleatus. Morphogenesis on the ventral surface is highly similar to that of Sterkiella species, but differs significantly on the dorsal surface (multiple vs. simple fragmentation of dorsal kinety 3). Phylogenetic analyses based on SSU rRNA gene sequences consistently place the new species within the stylonychine oxytrichids, clustering closer to Gastrostyla steinii than to S. cavicola.     

Brood care in a Silurian ostracod

An exceptionally preserved new ostracod crustacean from the Silurian of Herefordshire, England, preserves eggs and possible juveniles within its carapace, providing an unequivocal and unique view of parental brood care in the invertebrate fossil record. The female fossil is assigned to a new family and superfamily of myodocopids based on its soft-part anatomy. It demonstrates a remarkably conserved egg-brooding reproductive strategy within these ostracods over 425 Myr. The soft-tissue anatomy urges extreme caution in classifying 'straight-hinged' Palaeozoic ostracods based on the carapace alone and fundamentally questions the nature of the shell-based Palaeozoic ostracod record.     

Taxonomy, morphology and speciation of the Semicytherura henryhowei group (Crustacea, Ostracoda)

The genus Semicytherura belongs to the family Cytheruridae, and was distinguished from Cytherura on the basis of carapace features. Species of Semicytherura from Japan and adjacent seas can be divided into two groups. One is represented by Semicytherura miurensis Hanai, 1957, characterized by a thin, oval carapace covered with fine reticulation. The other is represented by Semicytherura henryhowei Hanai & Ikeya, 1977, characterized by a thick sub-rectangular carapace in lateral view. Semicytherura henryhowei, which is distributed from Hokkaido to Okinawa in Japan, has been regarded as having several morphotypes distinguishable on outline and reticulation of carapace. However, as a result of detailed observations on the copulatory organ, carapace outline and distributional pattern of pore systems, remarkable differences are shown to exist between the two most frequently occurring morphotypes. In order to recognize S. henryhowei sensu stricto, the carapace of the holotype was re-examined. Consequently, neither of the two morphotypes are considered to belong to S. henryhowei due to differences of carapace outline and distribution of pore systems. The two morphotypes are here regarded as independent taxa, described as new: S. kazahanan. sp. and S. sasameyukin. sp. The geographical distributions of the two new species overlap, but their micro-habitats differ from each other; the former lives on calcareous algae on rocky shores, the latter lives on silty sand bottom within the inner bay. A third new species, S. slipperi sp. nov., is also described. In view of their present geographical distributions and fossil records, the origin of this group of species would appear to be the Japanese islands or adjacent areas in and after the Miocene. This group then migrated to the Arctic Ocean and East Pacific Ocean during or before the middle Pliocene.     

Anatomy and lifestyle of Kunmingella (Arthropoda, Bradoriida) from the Chengjiang fossil Lagerstätte (lower Cambrian; Southwest China)

An updated reconstruction of the body plan, functional anatomy and life attitude of the bradoriid arthropod Kunmingella is proposed, based on new fossil specimens with preserved soft parts found in the lower Cambrian of Chengjiang and Haikou (Yunnan, SW China) and on previous evidence. The animal has a single pair of short antennae pointing towards the front (a setal pattern indicates a possible sensory function). The following set of seven appendages (each composed of a 5-segmented endopod and a leaf-like exopod fringed with setae) is poorly differentiated, except the first three pairs (with possible rake-like endopodial outgrowths, smaller exopods) and the last pair of appendages (endopod with longer and more slender podomeres). The endopods are interpreted as walking legs with a possible role in handling food particles (marginal outgrowth with setae). The leaf-like exopods may have had a respiratory function. The trunk end is short, pointed, flanked with furcal-like rami and projects beyond the posterior margin of the carapace. The attachment of the body to the exoskeleton is probably cephalic and apparently lacks any well-developed adductor muscle system. The inferred life attitude of Kunmingella (e.g. crawling on the surface of the sediment) was that of a dorsoventrally flattened arthropod capped by a folded dorsal shield (ventral gape at least 120°), thus resembling the living ostracode Manawa. The animal was also probably able to close its carapace as a response to environmental stress or to survive unfavourable conditions (e.g. buried in sediment). The anterior lobes of the valves are likely to have accommodated visual organs (possibly lensless receptors perceiving ambient light through the translucent head shield). Preserved eggs or embryos suggest a possible ventral brood care. The presence of Kunmingella in coprolites and its numerical abundance in Chengjiang sediment indicate that bradoriids constituted an important source of food for larger predators. Kunmingella differs markedly from the representatives of the crown group Crustacea (extant and Cambrian taxa) and from the stem group derivatives of Crustacea (exemplified by phosphatocopids and some ‘Orsten’ taxa) in showing no major sign of limb specialization (e.g. related to feeding strategies). Although it resembles other Chengjiang euarthropods in important aspects of its body plan (e.g. uniramous antennae, endopod/exopod configuration), Kunmingella possesses several features (e.g. antennal morphology, post-antennular appendages with 5-segmented endopods) which support the view that bradoriids may be very early derivatives of the stem line Crustacea.     

Morphology,Morphogenesis, and Molecular Phylogeny of Paraparentocirrus sibillinensis n. gen., n. sp., a “Stylonychine Oxytrichidae” (Ciliophora,Hypotrichida) Without Transverse Cirri

A terrestrial oxytrichid ciliate Paraparentocirrus sibillinensis n. gen., n. sp., which was found in soil samples of a beech forest stand within the National Park of Sibillini Mountains, Italy, was investigated using live observation and protargol impregnation. The morphology of interphase, morphogenesis, and molecular phylogeny inferred from SSU rDNA sequences of this ciliate were studied. Paraparentocirrus n. gen., is mainly characterized by a semirigid body, an undulating membrane in the Oxytricha pattern, six fronto‐ventral (FV) rows, the absence of transverse cirri, one right and one left row of marginal cirri, four dorsal kineties, two dorsomarginal rows, and caudal cirri at the end of dorsal kinety 4. During morphogenesis, oral primordia develop through the proliferation of basal bodies from some cirri of FV rows 4 and 5, and FV row 6 takes part in the anlagen formation of the proter. The dorsal morphogenesis was typical of oxytrichids, with simple fragmentation of dorsal kinety 3, and the dorsomarginal rows developed from the right marginal row. Phylogenetic analyses based on the SSU rDNA sequences support the classification of this new genus in the stylonychines.     

江西晚三叠世安源叶肢介属重要分类学特征的发现（英文）

通过扫描电镜重新研究产自江西省萍乡市安源镇三湾上三叠统安源群的近方形安源叶肢介(Anyuanestheria subquadrata Zhang and Chen in Zhang et al., 1976)的模式标本。电镜照相揭示了光学照相无法分辨的重要分类学新特征,其中包括壳瓣背部生长带上的多边形中–大网装饰,以及腹部生长带上的两种装饰类型:每条生长带上部为稀疏纤细的线脊装饰,每条生长带下部中–大网装饰装饰。网状装饰的特征是网壁纤细,网底平浅,印在外膜上表现为彼此濒临的多边形平台。基于以上观察,本文重新修订了安源叶肢介属壳面装饰特征。     

TEM studies on the lattice organs of cirripede cypris larvae (Crustacea, Thecostraca, Cirripedia)

 Lattice organs consist of five pairs of sensory organs situated on the dorsal carapace in cypris larvae of the Crustacea Cirripedia. The lattice organs in cypris larvae of Trypetesa lampas (Acrothoracica) and Peltogaster paguri (Rhizocephala) represent the two main types found in cirripedes, but only minor differences exist at the TEM level. Each lattice organ is innervated by two bipolar, primary receptor cells. The inner dendritic segment of each receptor cell carries two outer dendritic segments. The outer dendritic segments contain modified cilia with a short ciliary segment (9×2+0 structure). Two sheath cells envelop the dendrite except for the distal ends of the outer dendritic segments. This distal end enters a cavity in the carapace cuticle and reaches a terminal pore situated at the far end of the cavity. The cuticle above the cavity is modified. In both species the epicuticle is partly perforated by numerous small pores and the underlying exocuticle is much thinner and less electron dense than the regular exocuticle. Lattice organs very probably have a chemosensory function and are homologous with the sensory dorsal organ of other crustacean taxa. Accepted: 18 August 1998     

A set of possible sensory system preserved in cuticle of Late Devonian thylacocephalan arthropods from Poland

The cuticle of concavicarids (Arthropoda: Thylacocephala) from the early Famennian (Upper Devonian) of the Holy Cross Mountains, Poland was studied with respect to its microstructural details. Investigated laminated cuticle with phosphatic/organic composition, possesses two different kinds of microstructure with assumed sensory functions. The first kind consists of circular depressions, each located in the central area of characteristic polygons forming the carapace exterior ornamentation. These depressions are interpreted as sealed during phosphatisation processes setal lumens. The second kind occurs exclusively in carapace margins. These intracuticular microstructures occur as elongated tubular structures, circular to oval in cross section, penetrating the cuticle interior but not reaching its surface. They form a thin belt with a kind of ‘sensory fields’ on the dorsum and a wider belt in the ventrocaudal part of the carapace. These belts are connected in the rostral and caudal area, forming a continuous sensory zone encompassing each valve. These structures are very similar to crustacean organule canals, and the dorsally situated ‘sensory fields’, suggest some similarity to crustacean sensory dorsal organs. This possible sensory system is the oldest of this kind found in Thylacocephala. Its morphology and presumed canal walls mineralogical composition suggests crustacean affinity of Thylacocephala.     

Responses of dorsal tricorn-type sensilla on Ligia exotica

• 1.1. In order to investigate the function of the dorsal tricorn-type sensilla on Ligia exotica, the morphology and distribution of the setae and neural responses to certain stimulus modalities were studied.
• 2.2. These foraminate sensilla are found to occur over the body surface, except for several appendages and the ventral carapace (sternite); the dorsal carapace (tergite) is covered by only this type of sensilla.
• 3.3. The tricorn-type sensilla located on the dorsal carapace responded to mechanical, gustatory and olfactory stimulation.
• 4.4. The function of the tricorn-type sensilla on the dorsal carapace was discussed.

     

<Emphasis Type="Italic">Terebellides irinae</Emphasis> sp. n., a new species of <Emphasis Type="Italic">Terebellides</Emphasis> (Polychaeta: Terebellidae) from the Arctic Basin

A new polychaete species of the family Terebellidae, Terebellides irinae sp. n., has been described from materials collected in the Canadian Basin by the international Hidden Ocean 2005 expedition on board the US Coast Guard icebreaker (WAGB-20) Healy. The new species differs from other closely related species by its underdeveloped ventral branchial lobes that are at least two times shorter than the dorsal ones, sometimes reduced to barely noticeable cones and in that the aciculum-like neurochaetes of the 6th setigerous segment are curved at a right angle and have a thin capillaceous tip. Specimens of this polychaete worm are small, no more than 15 mm long.     

中国革腹茧蜂属Ascogaster一新种(膜翅目:茧蜂科:甲腹茧蜂亚科)

本记述了中国革腹茧蜂属Ascogaster一新种皱纹革腹茧蜂Ascogaster retis Ji et Chen,sp,nov.,新种主要特征是：体黑色;触角中部稍膨大,头顶具横向网状皱;背面观,上颊约与复眼等长,额与复眼缘之间具纵向网状皱;脸具粗糙网状皱;唇基具中度密集的刻点,端缘中央具一钝突,盾纵沟甚浅,中胸侧板具孔穴状刻点,无基节前沟,并胸腹节具明显的四齿,侧齿大,中齿小;甲壳末端具与体平行的短棘,产卵器鞘较短,不超出腹末,本新种与Ascogaster fullawayi(Baker)相似,但新种额两侧边缘中间与复眼缘之间无角状齿,脸下部的网状皱不形成弱纵脊,脸部毛短且稀疏,宙末端棘短而钝,该新种模式标本保存于福建农林大学益虫研究室。     

Gladioscutum lauriei n.gen. n.sp. (Archaeocopida) from the Middle Cambrian of the Georgina Basin,central Australia

A small crustacean with extremely long anterodorsal spines occurs in the Middle Cambrian of the western part of the Georgina Basin. It is assigned to the new genusGladioscutum (type speciesG. lauriei n. sp.), and is described from a sample collected from the Arthur Creek Formation, in the Huckitta area of the Northern Territory. The carapaces, preserved as flattened, outspread valves on the surface of finely laminated, dark grey micritic limestone, are comparable with those of Archaeocopida and Archaeostraca. On the basis of gross carapace morphology, an archaeocopid relationship is preferred.     

<Emphasis Type="Italic">Prodajus curviabdominalis</Emphasis> n. sp. (Isopoda: Epicaridea: Dajidae), an ectoparasite of mysids,with notes on morphological changes,behaviour and life-cycle

Adults and larvae of a new ectoparasitic isopod, Prodajus curviabdominalis n. sp., are described from the mysid Siriella okadai Ii collected from the Seto Inland Sea, western Japan. The adult female is found within the host marsupium with the cephalon directed posteriorly, whereas the dwarf adult male attaches to the ventral surface of the female pleon. The cryptoniscid larva usually attaches to the second or third abdominal somite of the host, using an oral sucker. Mature adults of the new species are distinguished from all other congeners by: pleon of ovigerous female strongly curved dorsally, with large swellings on ventral side; pereon of ovigerous female narrow; exopods on male uropods present; male pleon short and thick. This is the third record of a member of the Dajidae from Japan. The behaviour of the cryptoniscid larvae of the new species on the host mysid was also observed using a video camera. Larvae moved from the first attachment site, usually the second or third abdominal somite of the host mysid, into the marsupium. When host oostegites were not fully developed, larvae entered beneath the host carapace until her marsupium was fully formed. The host infected by a female P. curviabdominalis moved the oostegites rhythmically, an action which may aid the respiration of the parasite.     

A presumed spelaeogriphacean crustacean from an upper Barremian wetland (Las Hoyas; Lower Cretaceous; Central Spain)

Abstract: A third fossil attributable to the crustacean peracarid order Spelaeogriphacea is described from an Upper Barremian (125 Ma) lacustrine environment in Central Spain. Neither the new taxon, Spinogriphus ibericus gen. et sp. nov., nor the two already described fossil forms can be identified with certainty as crown‐group spelaeogriphaceans. We consider that Schram’s 1974 family Acadiocarididae represents stem‐lineage spelaeogriphaceans and should accommodate these fossil taxa that display very generalised peracaridan features and lack any conspicuous autapomorphies, except for a short carapace, undifferentiated pereiopods, foliaceous pleopods and a tail fan‐like (uropods + telson) caudal structure where the unsegmented uropodal endopod lacks annulation. The zoogeography of the Acadiocarididae is Laurasian in contrast to the modern, crown‐group spelaeogriphaceans (Spelaeogriphidae), which are limited to Gondwanan territories.     

A catshark (Neoselachii, Carcharhiniformes, Scyliorhinidae) from the Late Jurassic of Germany

A new genus and species of catshark (Neoselachii, Carcharhiniformes, Scyliorhinidae) —Bavariscyllium tischlingeri n. gen. n. sp. — is described from the Late Jurassic (Tithonian) Plattenkalke of South Germany. The new taxon is known from a single articulated skeleton having the skull, the trunk and all of the fins preserved. The position of the first dorsal fin in relation to the pelvic fins and the dental morphology shows that the specimen belongs into the neoselachian family Scyliorhinidae. Two isolated tooth crowns from the Kimmeridgian of North Germany are identified asBavariscyllium sp. and represent the oldest unambigious fossil record of the Scyliorhinidae known so far.     

Development of the turtle carapace: Implications for the evolution of a novel bauplan

The chelonian carapace is composed of the endochondral ribs and vertebrae associated with a specialized dermis. The ribs are found in an aberrant position compared to those of all other tetrapods; they are superficial and dorsal to the limb girdles. This morphological arrangement, which constitutes the unique chelonian Bauplan, is examined from a developmental perspective. Embryos of Chelydra serpentina were studied during stages of carapace development. Tissue morphology, autoradiography, and indirect immunofluorescent localization of adhesion molecules indicate that the outgrowth of the embryonic carapace occurs as the result of an epithelial–mesenchymal interaction in the body wall. A carapacial ridge composed of mesenchyme of the dermis and overlying ectoderm is formed dorsal to the ectodermal boundary between somitic and lateral plate mesoderm. It is the anlage of the carapace margin, in which the ribs will eventually terminate. The ectoderm of the carapacial ridge is thickened into a pseudostratified columnar epithelium, which overlies a condensation in the mesenchyme of the dermis. Patterns of cell proliferation and the distribution of N-CAM and fibronectin in the carapacial ridge are consistent with patterns seen in other structures initiated by epithelial–mesenchymal interactions such as feathers and limb buds. Based on an analogy to this developmental mechanism in the development of the limb skeleton, a further analogy with the evolution of the limbs from lateral fin folds is used to form a hypothesis on the evolution of the carapace from elements of the primitive reptilian integument.