Early development of the actinopterygian head. I. External development and staging of the paddlefish Polyodon spathula.

abstract：:The flagellum of the thysanopteran spermatozoon has been examined by electron microscopy and computer-aided image analysis. The flagellum consists of 27 microtubular elements that probably are formed as outgrowths from three separate basal bodies. Nine of the elements are normal microtubular doublets that carry dynein...

journal_title：Journal of morphology

authors： Dallai R,Afzelius BA,Lanzavecchia S,Bellon PL

更新日期：1991-09-01 00:00:00

abstract：:Complete postorbital bars, bony arches that encompass the lateral aspect of the eye and form part of a circular orbit, have evolved homoplastically multiple times during mammalian evolution. Numerous functional hypotheses have been advanced for postorbital bars, the most promising being that postorbital bars function ...

journal_title：Journal of morphology

authors： Heesy CP

更新日期：2005-06-01 00:00:00

abstract：:Bone is a dynamic tissue adapting to loading according to "Wolff's law of bone adaptation." During very early life, however, such a mechanism may not be adequate enough to adapt to the dramatic change in environmental challenges in precocial species. Their neonates are required to stand and walk within hours after bir...

journal_title：Journal of morphology

authors： Gorissen BM,Wolschrijn CF,van Vilsteren AA,van Rietbergen B,van Weeren PR

更新日期：2016-07-01 00:00:00

abstract：:The morphology and probable evolution of the depressor muscles of the lower jaw, innervated by the seventh cranial nerve (VII;M. Ceratomandibularis, M. Depressor Mandibulae), in larval, neotenic, and metamorphosed Urodela were investigated. Observations on innervation and skeletal connections of the muscles were inclu...

journal_title：Journal of morphology

authors： Bauer WJ

更新日期：1997-07-01 00:00:00

abstract：:During ontogeny, the apical and basal components of dicamptodontid teeth exhibit three major developmental stages: nonpedicellate, subpedicellate, and pedicellate. Premetamorphic larvae tend to have nonpedicellate teeth, incompletely or recently metamorphosed individuals tend to have subpedicellate teeth, and fully tr...

journal_title：Journal of morphology

authors： Beneski JT Jr,Larsen JH Jr

更新日期：1989-02-01 00:00:00

abstract：:The hypotheses of relationships within Lari (gulls) are highly unstable, and depend on whether morphological or molecular data are examined. Developmental sequence data are thought to contain phylogenetic information, but have never been applied to the problem of avian systematics. In this article, we describe the oss...

journal_title：Journal of morphology

authors： Maxwell EE,Harrison LB

更新日期：2008-09-01 00:00:00

abstract：:Bristle positions in two rows of bristles on the basitarsus of the second leg of the fruitfly Drosophila melanogaster were analyzed in order to determine the accuracy of bristle placement within these rows. Within each row the positions of the two terminal bristles were found to be approximately equally variable, and ...

journal_title：Journal of morphology

authors： Held LI Jr,Pham TT

更新日期：1983-11-01 00:00:00

abstract：:The orientation of the semicircular canals of the inner ear in the skull of vertebrates is one of the determinants of the capacity of this system to detect a given rotational movement of the head. Past functional studies on the spatial orientation of the semicircular canals essentially focused on the lateral semicircu...

journal_title：Journal of morphology

authors： Coutier F,Hautier L,Cornette R,Amson E,Billet G

更新日期：2017-05-01 00:00:00

abstract：:In Canis and Ursus the largest proportion of attachments of muscles of the shoulder and brachium on the scapula and humerus is direct; fewer attachments are aponeurotic or tendinous. In both genera most attachments can be associated with superficial osteological features (scars or delimitable surfaces); attachments th...

journal_title：Journal of morphology

authors： Bryant HN,Seymour KL

更新日期：1990-10-01 00:00:00

abstract：:The combined techniques of light microscopy, scanning (SEM) and transmission (TEM) electron microscopy were used for the first time to study the structure of unicameral lungs of a Tegu lizard (Tupinambis nigropunctatus). The lungs are prolate spheroid bags with blood supplied by superficial branches of a dorsal pulmon...

journal_title：Journal of morphology

authors： Klemm RD,Gatz RN,Westfall JA,Fedde MR

更新日期：1979-09-01 00:00:00

abstract：:Sipuncula is a clade of unsegmented marine worms that are currently placed among the basal radiation of conspicuously segmented Annelida. Their new location provides a unique opportunity to reinvestigate the evolution and development of segmented body plans. Neural segmentation is clearly evident during ganglionic ven...

journal_title：Journal of morphology

authors： Carrillo-Baltodano AM,Boyle MJ,Rice ME,Meyer NP

更新日期：2019-11-01 00:00:00

abstract：:The morphogenesis and ultrastructure of the epidermis of snake embryos were studied at progressive stages of development through hatching to determine the time and modality of differentiation of the shedding complex. Scales form as symmetric epidermal bumps that become slanted and eventually very overlapped. During th...

journal_title：Journal of morphology

authors： Alibardi L

更新日期：2002-02-01 00:00:00

abstract：:The reproductive process in insects may be affected by several factors, among which environmental temperature is one of the most important because of the poikilothermic condition of insects. To determine the effect of suboptimal temperature on the spermiogenic process of Triatoma infestans, males were exposed to 12°C ...

journal_title：Journal of morphology

authors： Giojalas LC

更新日期：1993-04-01 00:00:00

abstract：:The paired tubular accessory glands in Haemaphysalis longicornis open at the junction of the cervical and the vestibular parts of vagina via short and narrow ducts. The pseudostratified columnar glandular epithelium covered by the muscle layer consists of both secretory and supporting cells. As feeding proceeds, the s...

journal_title：Journal of morphology

authors： Kakuda H,Koga T,Mori T,Shiraishi S

更新日期：1994-07-01 00:00:00

abstract：:The present study examined the morphometric properties of the forelimb, including the inertial properties of the body segments and the morphometric parameters of 21 muscles spanning the shoulder and/or elbow joints of six Macaca mulatta and three M. fascicularis. Five muscle parameters are presented: optimal fascicle ...

journal_title：Journal of morphology

authors： Cheng EJ,Scott SH

更新日期：2000-09-01 00:00:00

abstract：:Odontophoral cartilages are located in the molluscan buccal mass and support the movement of the radula during feeding. The structural diversity of odontophoral cartilages is currently known only from limited taxa, but this information is important for interpreting phylogeny and for understanding the biomechanical ope...

journal_title：Journal of morphology

authors： Golding RE,Ponder WF,Byrne M

更新日期：2009-05-01 00:00:00

abstract：:This study describes the male reproductive cycle of Sibynomorphus mikanii from southeastern Brazil considering macroscopic and microscopic variables. Spermatogenesis occurs during spring-summer (September-December) and spermiogenesis or maturation occurs in summer (December-February). The length and width of the kidne...

journal_title：Journal of morphology

authors： Rojas CA,Barros VA,Almeida-Santos SM

更新日期：2013-02-01 00:00:00

abstract：:The ventral surface of the most proximal tarsomere of each mesothoracic leg of the female black fly, Simulium venustum Say, bears approximately 60 bifurcate sensilla. Externally, a sensillum appears as a hair set into an asymmetric socket and with the distal tip flattened into two flared lobes. A single pore opens int...

journal_title：Journal of morphology

authors： McIver S,Siemicki R,Sutcliffe J

更新日期：1980-07-01 00:00:00

abstract：:Patterns of growth and variation of the appendicular skeleton were examined in Thorius, a speciose genus of minute terrestrial plethodontid salamanders from southern Mexico. Observations were based primarily on ontogenetic series of each of five species that collectively span the range of adult body size in the genus;...

journal_title：Journal of morphology

authors： Hanken J

更新日期：1982-10-01 00:00:00

abstract：:According to the current opinion, lymph-heart striated muscle represents a specialized type of skeletal muscles in frogs. Here, we studied muscle fibers in mechanically damaged lymph hearts during the first postoperative week using electron-microscopic autoradiography. We present evidence that both, the satellite cell...

journal_title：Journal of morphology

authors： Krylova MI,Bogolyubov DS

更新日期：2015-12-01 00:00:00

abstract：:Slender blindsnakes (Leptotyphlopidae) are known to use a unique feeding mechanism that involves rapid flexions of the tooth-bearing lower jaw. However, the morphology of the leptotyphlopid jaw apparatus has remained poorly studied due to the extremely small size of these snakes. Here I present a detailed description ...

journal_title：Journal of morphology

authors： Kley NJ

更新日期：2006-04-01 00:00:00

abstract：:The evolution of viviparity alters the physical relationship between mothers and offspring and the prevalence of viviparity among squamate reptiles presents an opportunity to uncover patterns in the evolution of placental structure. Understanding the breadth of this diversity is limited because studies of placental st...

journal_title：Journal of morphology

authors： Stewart JR,Mendez de la Cruz FR

更新日期：2019-01-01 00:00:00

abstract：:The morphology of the musculature and connective tissues of the arms of Octopus bimaculoides was analyzed with light microscopy. We also studied O. briareus and O. digueti, which possess relatively more elongate and less elongate arms, respectively. The morphology of the arms was found to be remarkably uniform among s...

journal_title：Journal of morphology

authors： Kier WM,Stella MP

更新日期：2007-10-01 00:00:00

abstract：:The vertebrate head as a major novelty is directly linked to the evolutionary success of the vertebrates. Sequential information on the embryonic pattern of cartilaginous head development are scarce, but important for the understanding of its evolution. In this study, we use the oriental fire bellied toad, Bombina ori...

journal_title：Journal of morphology

authors： Lukas P,Olsson L

更新日期：2020-06-01 00:00:00

abstract：:Cetacean middle ears are unique among mammals in that they have an elongated tympanic membrane, a greatly reduced manubrium mallei, and an incudal crus longum that is shorter than the crus breve. Elongation of the tympanic membrane and reduction of the manubrium is thought to be related to an evolutionary rotation of ...

journal_title：Journal of morphology

authors： Kinkel MD,Thewissen JG,Oelschläger HA

更新日期：2001-08-01 00:00:00

abstract：:This study examines the allometric scaling relationships of the cetacean humerus, radius, and ulna. Bone lengths and diameters were measured for 20 species of odontocete and three species of mysticete cetaceans, representing eight of the nine extant cetacean families. The scaling of individual bone proportions (bone l...

journal_title：Journal of morphology

authors： Dawson SD

更新日期：1994-11-01 00:00:00

abstract：:There are remarkable interspecific differences in the sizes of the larvae of Andean frogs of the genus Telmatobius. This size variation seems to be associated with the duration of the larval stage and may affect the hind-limb morphology in Telmatobius. Larval, juvenile, and adult Telmatobius rubigo and T. oxycephalus ...

journal_title：Journal of morphology

authors： Barrionuevo JS

更新日期：2020-12-01 00:00:00

abstract：:The dorsal vessel (DV) in the abdomen of the blood-feeding insect Rhodnius prolixus was divided functionally into two regions, the heart, into which haemolymph entered the DV through four pairs of ostia located in abdominal segment VII, and the aorta, along which the haemolymph was propelled from abdominal segment VI ...

journal_title：Journal of morphology

authors： Chiang RG,Chiang JA,Davey KG

更新日期：1990-04-01 00:00:00

abstract：:Nematocytes containing microbasic mastigophores are intimately associated with accessory cells in the epidermis of Chironex fleckeri. Large microbasic mastigophores may be surrounded by seven to nine such cells. Each accessory cell possesses an apical portion containing secretory droplets and a basal portion which car...

journal_title：Journal of morphology

authors： Rifkin JF,Endean R

更新日期：1988-01-01 00:00:00

abstract：:The femoral or cloacal region of many species of lizards and amphisbaenians exhibits epidermal glands. The pores of these glands are plugged with holocrine solid secretions that serve as semiochemical sources. Many authors assume that these glands are mainly associated with reproduction and demarcation of territory. T...

journal_title：Journal of morphology

authors： Jared C,Antoniazzi MM,Silva JR,Freymüller E

更新日期：1999-09-01 00:00:00