Anterodorsal Surface Research Articles

Revision of the plesiosaur Polycotylus sopozkoi from the Southern Urals (Russia) confirms the wide distribution of Polycotylus in the Late Cretaceous of the Northern Hemisphere

Polycotylids are among the most common plesiosaurians of the Late Cretaceous, however, in Eurasia their findings are rare and fragmentary. In 2016, a partial polycotylid skeleton from the Upper Cretaceous of the Izhberda quarry in the Southern Urals region was described by Efimov et al. as a new species, Polycotylus sopozkoi. Here we revise this holotype specimen and show that many features initially proposed to distinguish the species are the result of misinterpretations. However, P. sopozkoi is indeed referable to Polycotylus and is highly similar to its type species, P. latipinnis. Although only one distinctive trait of the species noted by Efimov et al., the protruding basioccipital tubera with deep carotid canals on their anterodorsal surface, is confirmed here, new observations revealed additional features that allow us to substantiate the validity of P. sopozkoi. The presence of Polycotylus in the Upper Cretaceous of North America and Eastern Europe highlights a wide distribution of some plesiosaurian genera and suggests caution in assumptions of ‘endemic’ plesiosaurian taxa in particular regions of the world.

Two new species of Eurydice Leach, 1815 (Crustacea: Isopoda: Cirolanidae) from the Andaman Islands, northern Indian Ocean

ABSTRACT Eurydice andamanensis sp. nov. and Eurydice mohani sp. nov. are described from intertidal sandy beaches of South Andaman, Andaman Islands. Eurydice andamanensis sp. nov. can be identified by the posterior margin of pleotelson being one-fourth of the pleotelson in width, weakly convex with 11 plumose marginal setae and 4 robust setae; appendix masculina 0.8 times as long as endopod, projecting slightly beyond endopod distal margin by one-third of its length, distally broad, widely rounded, curved medially and mesial margin with 4 small acute cuticular scales; Eurydice mohani sp. nov. can be identified by the posterior margin of pleotelson with 6 plumose marginal setae, pleotelson without distinct depression on anterodorsal surface; appendix masculina 0.4 times as long as endopod, projecting beyond mid-region of endopod by 0.02 of its length, lateral margin with a sinuate notch and apex is rounded. http://www.zoobank.org/urn:lsid:zoobank.org:pub:AFF18D66-4CE3-4D73-BAAA-39083D542008

The Effect of Type II Slap Lesions Repair Technique on the Length of Intratendinous Vascular Supply in Long Head of Biceps Tendon: A Cadaveric Injection Study

Reapiring techniques of SLAP lesion effect the vascular supply of long head of biceps tendon. Type II superior labrum anterior and posterior (SLAP) lesions are usually treated with arthroscopic SLAP repair. A vascular supply of proximal long head of biceps tendon (LHBT) passes through soft tissue nearby SLAP repair site. To evaluate intratendinous vascular supply of proximal LHBT resulting from SLAP repair and compare between each SLAP repair techniques. Forty-five fresh cadaveric shoulders were divided into 3 major groups: normal, created SLAP and repaired SLAP group. SLAP lesions were repaired using 3 common techniques: two-anchors with simple sutures, one-anchor with double sutures and one-anchor with horizontal mattress suture. Each group had 9 shoulders. India-ink was injected into acromial branch of thoracoacromial artery. Proximal LHBT was resected for histological cross-sectional study. Intratendinous vascular distance was measured and compared between each groups. The vascular supply of proximal LHBT was seen macroscopically at anterodorsal surface. It derived from soft tissue lying anterior to LHBT origin. In normal shoulder, intratendinous vascular distance was 16.92 ± 1.49 mm (95%CI: 15.78-18.06). There was no significant difference between normal shoulder and created SLAP group (P=0.503). By comparing non-repaired SLAP to each repair technique, the technique using two-anchors with simple sutures showed no significant difference (P=0.716), while the others showed significant difference disruption of blood supply (P=0.0002). There was significant difference between each techniques (P=0.0001). Main vascular supply of proximal LHBT comes from anterior direction. Some techniques of SLAP repair might disrupt the vascularization. The technique using two-anchors with simple sutures, one anchor at 3-mm anterior to anterior boarder and one at posterior boarder of tendon, can preserve vascularization of LHBT.

Oviposition and development in the glass frog Hyalinobatrachium orientale (Anura: Centrolenidae)

Oviposition and development in the glass frog Hyalinobatrachium orientale (Anura: Centrolenidae). Oviposition and external embryonic developmental features are described in the Tobago glass frog, Hyalinobatrachium orientale. Egg clutches are nearly always laid on the undersides of leaves (one exception); usually leaves of Heliconia sp. are used, but Philodendron and palms may be used in the absence of Heliconia. Clutches contain 28.0 ± 5.3 eggs (mean ± SD) and eggs are 1.86 ± 0.11 mm in diameter. The behavior of one amplectant pair was followed for more than five hours; the pair rotated several times around a small area of the leaf depositing eggs in a tight spiral formation. External embryonic features were observed by scanning electron microscopy. Surface ciliation is extensive up to the time of hatching when it is lost; external gills are short and a cement gland is absent. Hatching gland cells were detectable on the anterodorsal surface of the head from Day 4 after deposition and persisted until at least Day 10, and hatching occurred between Days 9 and 16. During this period, progressive development in tail length, surface pigmentation, intestinal coiling, and oral disc features was observed. Post-hatching larvae reared for six weeks grew 37% in length and tripled in weight, but remained at Gosner Stage 25.

Sensory organs of the antenna of two Fannia species (Diptera: Fanniidae)

The latrine fly (Fannia scalaris) and lesser house fly (Fannia canicularis) are ubiquitous fanniid species of forensic and medical importance. The external morphology of sensilla on the antennae is studied using a stereoscopic microscope and scanning electron microscope, and the internal structure of the antennae is revealed by paraffin sections under the light microscope and laser scanning confocal microscope. Only grooved bristles are found on the scape and pedicel. Four major types of surface sensilla are found on the antennal funiculus and are classified as: (a) trichoid sensilla, (b) two subtypes of basiconic sensilla, (c) clavate sensilla, and (d) coeloconic sensilla. Density of each sensilla type of the two species is calculated. A remarkable difference is observed that the higher density of clavate sensilla occurs on the posteroventral surface in F. scalaris, whereas they are on the anterodorsal surface in F. canicularis. Several cuticular depressions that were previously known as "olfactory pits" are observed on the funiculus of both species. Combining with previous studies, they are suggested to be classified into two types: pit and sacculus. Pit is single-chambered and filled with one type of sensilla, whereas the sacculus is a multi-chambered pit organ containing several types of sensilla. Surprisingly, the pits observed in our study are mostly situated at the lateral region of the antennal funiculus, whereas in other flies, they are found on the posteroventral or anterodorsal surface of antennal funiculus. In addition, the sacculus found in our study houses only basiconic-like sensilla, which is remarkably different from other findings. Moreover, observation under light microscope indicates that previous data of the complexity and the number of the "olfactory pits," which are an important type of efficient sensory convergence, could be underestimated. Thus, more precise methods such as paraffin section or transmission electron microscope are suggested for further study.

Description of the Second and Third Instars ofLaccornellus lugubris(Aubé) (Coleoptera: Dytiscidae: Hydroporinae)

ABSTRACT The second and third instars of Laccornellus lugubris (Aube) are described and illustrated for the first time, including detailed morphometric and chaetotaxic analyses of the cephalic capsule, head appendages, legs, last abdominal segment, and urogomphi. Laccornellus Roughley and Wolfe shares with Canthyporus Zimmermann a similar shape and secondary setation of the last abdominal segment, the absence of secondary spine-like setae on the lateral margins of the parietal, and the presence of well-developed spinular pectens on the ventral surface of the femora (this last character also is shared with Laccornis Gozis). On the other hand, larvae of Laccornellus differ from those of Canthyporus, Laccornis, and Hydmvatus Motschulsky in the presence of secondary pores on the ventral surface of the prementum and of secondary setae on the tibia, metatarsus, and anterodorsal surface of femur. The known distributional range of L. lugubris is considerably expanded.

Sensilla on the antennal funiculus of the horse stomach bot fly, Gasterophilus nigricornis

Gasterophilus nigricornis (Loew) (Diptera: Oestridae) is one of the most damaging obligate parasites of equids in Kalamaili, Xinjiang, China. The main olfactory organs of this stomach bot fly are paired antennae that bear microscopic sensillar structures. The external morphology of the antennal funiculus and sensilla of male G. nigricornis were studied using stereopic microscopy and scanning electron microscopy. A cross-sectional view of the funiculus shows it to be triangular, with an anterodorsal surface, a dorsolateral margin and a posteroventral surface. Almost the entire surface of the funiculus is densely covered with microtrichiae. Small patches lacking these microtrichiae appear as depressions or pits in the surface of the funiculus. Six distinct types of sensilla are recorded, including one trichoid, three basiconic, one auriculate and one clavate sensilla. Trichoid sensilla are the most abundant, followed by the basiconic, auriculate and clavate types in descending order. Only auriculate sensilla are found in pits on the funiculus. Distributions of different sensilla types located on the antennal funiculus are provided. These results are compared with equivalent findings in several other fly species. In addition, the possible functions of the various sensilla types are discussed.

Sound Characteristics and Sonic Motor System in the Pineconefish, Monocentris japonica (Beryciformes: Monocentridae)

We investigated sound production and the sonic motor system in the Pineconefish, Monocentris japonica. The hand-held Pineconefish produced one type of sound (main frequencies: 100–600 Hz) in both water and air. The sonic organ consists of the swimbladder and a pair of extrinsic sonic muscles originating from exoccipital of the cranium and supracleithrum and inserting on the anterodorsal surface of the swimbladder and partly on vertebrae. The sonic muscle is innervated by occipital nerve branches, not the spinal nerves. Injections of wheat germ agglutinin-conjugated horseradish peroxidase into the sonic muscle resulted in labeled sonic motor neurons ipsilateral to the injections. The labeled neurons were located in the ventral zone of the caudal medulla oblongata, forming a column of sonic motor neurons (or the sonic motor nucleus) from the level of the vagal nerve root to the rostral part of the third ventral root of the occipital nerve. The total number of motor nerve fibers contained in the right and left sonic nerve branches (standard length = 96 mm) were 363 and 369, respectively. We conclude that the sonic muscles of Monocentris japonica are innervated by approximately 700 sonic motor neurons located only in the caudal medulla oblongata.

Description of the nymphs of Ectemnostega (Ectemnostegella) stridulata (Hungerford 1948) (Hemiptera: Heteroptera: Corixidae)

The egg and the five nymphal instars of Ectemnostega (Ectemnostegella) stridulata are described and illustrated for the first time, with emphasis on the morphometry and chaetotaxy of selected structures. Comparison with the eggs of E. (Ectemnostegella) montana and E. (Ectemnostegella) peruana, and the nymphs of E. montana and E. (Ectemnostega) quadrata, are included. The egg of E. stridulata has a very short stalk like those of E. montana and E. peruana, and the three species differ in the chorionic structure. The nymphs of Ectemnostega share the presence of one dorsal abdominal scent gland on each of the segments IV–V. The number of spines on the profemur on the ventral and posteroventral surfaces distinguishes the nymphs of the subgenus Ectemnostega from the those of the subgenus Ectemnostegella. The nymphal characters most useful in identifying instars I–V of Ectemnostega are: the body length, the number of spines on the posteroventral surface of the mesofemur, setae on the posterodorsal surface and spines on the posteroventral surface of the mesotibia, setae on the posterodorsal surface of the mesotarsus, and the grade of development of the wing pads. The nymphal characters most useful in identifying species of Ectemnostega are: the number of spines on the posteroventral surface of the mesofemur, spines on the anterodorsal surface of the metatibia, and spines and swimming hairs on the anteroventral and posterodorsal surfaces of the metatarsus.

Mojoceratops perifania, a new chasmosaurine ceratopsid from the late Campanian of Western Canada

A new genus of long-horned chasmosaurine ceratopsid is described from the Dinosaur Park Formation (upper Campanian) of Western Canada. Mojoceratops perifania is represented by a skull and a parietal from the Dinosaur Park Formation of Alberta and an isolated parietal from the Dinosaur Park Formation of Saskatchewan. Several other specimens are provisionally referred to this taxon. While Mojoceratops shares many plesiomorphies with Chasmosaurus, the animal lacks the forward-curving parietal epoccipitals and reduced postorbital horns that diagnose the genus Chasmosaurus, and it differs from all other chasmosaurines in exhibiting a prominent sulcus on the anterior margin of the parietal, swellings on the anterodorsal surface of the parietal rami, and a small accessory process on the first parietal epoccipital. Other unusual features include anteriorly extended parietal fenestrae, a broad, heart-shaped frill, and transverse expansion of the postfrontal fontanelle. The type material of “Eoceratops canadensis” and “Chasmosaurus kaiseni” are nondiagnostic and these names are therefore considered nomina dubia, but their morphology is consistent with Mojoceratops and they probably belong to this genus. The frill of Mojoceratops shows marked variation. Some of this variation probably results from intraspecific variation or ontogenetic changes, but because the Dinosaur Park Formation encompasses more than a million years of time, evolution may explain some of these differences. Phylogenetic analysis shows that Mojoceratops forms a clade with Agujaceratops mariscalensis; Chasmosaurus is the most basal member of Chasmosaurinae.

Mojoceratops perifania, a new chasmosaurine ceratopsid from the late Campanian of Western Canada

A new genus of long-horned chasmosaurine ceratopsid is described from the Dinosaur Park Formation (upper Campanian) of Western Canada. Mojoceratops perifania is represented by a skull and a parietal from the Dinosaur Park Formation of Alberta and an isolated parietal from the Dinosaur Park Formation of Saskatchewan. Several other specimens are provisionally referred to this taxon. While Mojoceratops shares many plesiomorphies with Chasmosaurus, the animal lacks the forward-curving parietal epoccipitals and reduced postorbital horns that diagnose the genus Chasmosaurus, and it differs from all other chasmosaurines in exhibiting a prominent sulcus on the anterior margin of the parietal, swellings on the anterodorsal surface of the parietal rami, and a small accessory process on the first parietal epoccipital. Other unusual features include anteriorly extended parietal fenestrae, a broad, heart-shaped frill, and transverse expansion of the postfrontal fontanelle. The type material of “Eoceratops canadensis” and “Chasmosaurus kaiseni” are nondiagnostic and these names are therefore considered nomina dubia, but their morphology is consistent with Mojoceratops and they probably belong to this genus. The frill of Mojoceratops shows marked variation. Some of this variation probably results from intraspecific variation or ontogenetic changes, but because the Dinosaur Park Formation encompasses more than a million years of time, evolution may explain some of these differences. Phylogenetic analysis shows that Mojoceratops forms a clade with Agujaceratops mariscalensis; Chasmosaurus is the most basal member of Chasmosaurinae.

Functional and topographic segregation of glomeruli revealed by local staining of antennal sensory neurons in the honeybee Apis mellifera

In the primary olfactory center of animals, glomeruli are the relay stations where sensory neurons expressing cognate odorant receptors converge onto interneurons. In cockroaches, moths, and honeybees, sensory afferents from sensilla on the anterodorsal surface and the posteroventral surface of the flagellum form two nerves of almost equal thicknesses. In this study, double labeling of the two nerves, or proximal/distal regions of the nerves, with fluorescent dyes was used to investigate topographic organization of sensory afferents in the honeybee. The sensory neurons of ampullaceal sensilla responsive to CO2, coelocapitular sensilla responsive to hygrosensory, and thermosensory stimuli and coeloconic sensilla of unknown function were characterized with large somata and supplied thick axons exclusively to the ventral nerve. Correspondingly, all glomeruli innervated by sensory tract (T) 4 received thick axonal processes exclusively from the ventral nerve. Almost all T1-3 glomeruli received a similar number of sensory afferents from the two nerves. In the macroglomerular complexes of the drone, termination fields of afferents from the two nerves almost completely overlapped; this differs from moths and cockroaches, which show heterogeneous terminations in the glomerular complex. In T1-3 glomeruli, sensory neurons originating from more distal flagellar segments tended to terminate within the inner regions of the cortical layer. These results suggest that some degree of somatotopic organization of sensory afferents exist in T1-3 glomeruli, and part of T4 glomeruli serve for processing of hygro- and thermosensory signals.

Two new catfish species of the genus Pseudecheneis Blyth (Teleostei: Siluriformes) from northeastern India

Two new catfish species of the genus Pseudecheneis, viz., P. ukhrulensis sp. nov. and P. sirenica sp. nov. are described from northeastern India, from streams of Ukhrul district, Manipur (Chindwin basin) and Siren River, Upper Siang District, Arunachal Pradesh (Brahmaputra basin), respectively. The two species can be distinguished from their closest congener P. sulcata in having prominent bony spurs on the anterodorsal surface of the first dorsal-fin pterygiophore (vs. absent), from P. crassicauda in shallower caudal peduncle, from P. serracula in shorter adipose fin base and from P. stenura in deeper caudal peduncle. P. sirenica sp. nov. is distinguished from P. eddsi in its longer pelvic fin and anal fin and from P. ukhrulensis sp. nov. in having longer pectoral fin and caudal peduncle. A key to identification of Pseudocheneis of India and Nepal is given.

Termination profiles of insect chemosensory afferents in the antennal lobe are dependent on their origin on the flagellum

In cockroach antennae, sensory afferents from sensilla on the anterodorsal surface of the flagellum form the anterior antennal nerve, while afferents from the posteroventral surface form the posterior nerve. Anterograde staining was used to investigate afferent termination profiles in the glomeruli of the antennal lobe. The densities of terminal arborizations from the two nerves differed between glomeruli, with groupings of similar glomeruli evident. Individual glomeruli showed heterogeneous distribution of afferent terminals, with posterior nerve afferent terminals occurring near the nerve/glomeruli interface, and anterior nerve afferent terminals occurring on the opposite side. This study demonstrates, for the first time, a correlation between the distribution of primary afferent terminals in the individual glomeruli, and their origin on the surface of the flagellum.

Larval Morphology and Phylogenetic Relationships of Bunites distigma (Brullé) (Coleoptera: Dytiscidae: Colymbetinae: Colymbetini)

Bunites Spangler has been the only member of the tribe Colymbetini for which the larva has been unknown. The first-instar larva of Bunites distigma (Brullé) is described and figured for the first time. Detailed morphometric and chaetotaxic analyses are provided. A phylogenetic analysis based on 41 first-instar larval characters, including members of six genera of Colymbetini, supports the hypothesis of a derived condition of Bunites within this tribe. Monophyly of Bunites Rhantus Dejean (s. lat.) (minus Rhantus orbignyi Balke) Neoscutopterus J. Balfour-Browne Meladema Laporte is suggested by four synapomorphies: an elongate and hair-like seta FE5 on both meso- and metafemur, and the presence of additional anteroventral setae on tibia and tarsus. The clade Bunites Neoscutopterus Meladema is supported by three synapomorphies: the presence of additional setae on the frontoclypeus, dorsal surface of parietal, and urogomphi. Six other character states might also support this group. The clade Bunites Meladema is well supported by four synapomorphies: the presence of additional setae on the lateromedial portion of frontoclypeus, ventral surface of parietal, anterodistal margin of prementum, and anterodorsal surface of tibia. A derived condition of Bunites within the Colymbetini is suggested by two autapomorphies: the presence of one additional seta on the coxa, and additional dorsal pores on the eighth abdominal segment.

Sound characteristics and the sound producing system in silver sweeper, Pempheris schwenkii (Perciformes: Pempheridae)

The sound characteristics and the sound producing system in silver sweeper, Pempheris schwenkii, are described. The main frequency component of the emitted sounds was 100–300 Hz, the mean duration of the sounds being 56 ms. The sounds were produced by paired extrinsic sonic muscles vibrating the swimbladder. The sonic muscles originated on the pterotic bones and extended to the anterodorsal surface of the swimbladder, and were innervated by two branches of the occipital nerves. Moreover significant sexual dimorphism of the sonic muscles was observed, those in males being three times as large as in females.

Developmental origin of the frontoparietal bone in Bombina variegata (Anura: Discoglossidae).

Development of the frontoparietal bone in the European yellow-bellied toad, Bombina variegata, was followed on the basis of histological analysis of transverse serial sections through the larval skulls to recognize early stages of ossification represented by osteoid (uncalcified bone matrix) and on cleared and stained specimens to investigate more advanced stages. Ossification of the frontal begins as three tiny areas of osteoid (F(1), F(2), F(3)) adjoining the dorsal surface of the orbital cartilage, which are separated by areas without osteoid. F(3) is the largest (most advanced). Prior to calcification, F(3) extends to fuse with F(2) and then with F(1), but it does not expand over the prootic fissure posteriorly. As calcification begins the strip of bone is joined posteromedially by F(4). Only then does a single ossification center corresponding to the parietal arise on the anterodorsal surface of the otic capsule. This ossification sequence corresponds to those observed in the Actinopterygii and in caudate amphibians.

Angioarchitectural characteristics of the anterodorsal surface of aging and young rabbit tongue: scanning electron microscopy study

The three-dimensional angioarchitecture of young and aging rabbit tongues were studied using a vascular corrosion cast method. The vascular network of different lingual papillae were observed by scanning electron microscope (SEM). Young animals showed filiform papillae distributed all over considered area, with fungiform ones among them. In comparison to developed specimens, young rabbits demonstrated dense and higher organization of microvascular network.

A nuclear lamin is required for cytoplasmic organization and egg polarity in Drosophila.

Nuclear lamins are intermediate filaments that compose the nuclear lamina--the filamentous meshwork underlying the inner nuclear membrane--and are required for nuclear assembly, organization and maintenance. Here we present evidence that a nuclear lamin is also required for cytoplasmic organization in two highly polarized cell types. Zygotic loss-of-function mutations in the Drosophila gene encoding the principal lamin (Dm(0)) disrupt the directed outgrowth of cytoplasmic extensions from terminal cells of the tracheal system. Germline mutant clones disrupt dorsal-ventral polarity of the oocyte. In mutant oocytes, transcripts of the dorsal determinant Gurken, a transforming growth factor-alpha homologue, fail to localize properly around the anterodorsal surface of the oocyte nucleus; their ventral spread results in dorsalized eggs that resemble those of the classical dorsalizing mutations squid and fs(1)K10. The requirement of a nuclear lamin for cytoplasmic as well as nuclear organization has important implications for both the cellular functions of lamins and the pathogenesis of human diseases caused by lamin mutations.

Functional and positional difference and classification of the fungiform papillae on the rabbit tongue seen in microvascular cast specimens by means of scanning electron microscope

The relationships between the functional and morphological characteristics, the positional difference and classification seen in microvascular cast specimens (MVCS) of the fungiform papillae (FuP) on the anterodorsal surface and both sides of the intermolar eminence (IME) of the rabbit tongue were examined and compared by means of scanning electron microscopy (SEM). The small fungiform papillae (S-FuP), scattered sporadically among the numerous small filiform papillae (SfP), were found to be distributed irregularly over the anterodorsal surface. The large fungiform papillae (L-FuP), distributed in a length-wise line in the anterior to the posterior direction among the SfP, were found to be distributed on both peripheral sides of the IME. FuPs consisted of the ascending and descending capillary loops, forming the central hole on the top of the FuP, resembling a carnation, the petals of which numbered eight to twelve, and were wider and more complex in shape and size than SfPs were morphologically different. S-FuPs can be classified into three types: type I (consisting of eight petals), type II (ten petals) and type III (twelve petals) according to the shape of the FuP and the number of petals, L-FuPs, were larger and wider than S-FuPs and of a more complex shape, classified into two types: type I (consisting of ten petals) and type II (twelve petals) according to the shape of the FuP and the number of petals in the MVCS of FuPs as seen in SEM. These results suggest that the petals in the ascending and descending capillary loops of the FuP expand into flower-like figures, increase on the surface and play an effective role in receiving the taste sense from foods and liquids on the antero-dorsal surface and both peripheral sides of the IME.