Journal of Morphology

Nicrophorus clypeal membranes exaggerate body size, sometimes more noticeably in males.

Unlike all other anurans, the vocal sac wall of hylodids projects through submandibular musculature. We report three synapomorphies for Hylodidae and a mechanism for unilateral inflation of paired vocal sacs, only observed in these frogs.

A mineralized structure, composed of amorphous calcium phosphates and never reported in vertebrates, was found in the notochord of Acipenser baerii from 2 years onwards. We describe this enigmatic tissue using CT-scan, histological analyses and solid state NMR spectroscopy

The groove was formed by two nonpapillated ridges (R). These ridges divided the lumen of the ascending colon into two compartments: the groove lumen (G) and the large main lumen (MLu). The histochemical analysis revealed significant differences among goblet cells in and out of the colonic groove, being this the first time an abrupt change in the glycosylation pattern of the intestinal tract of L. maximus is described (see dotted lines).

Different selective pressures over males with alternative mating tactics may lead to intraspecific diversity in ejaculates, for example, sneakers sperm aggregation, possibly related to avoiding dilution and slowing spermatozoa release until fertilization.

Evolutionary changes in body elongation in Triturus newts are achieved by increasing the number of vertebrae but not their length. Ontogenetic changes of vertebrae in axial skeleton are proportional in T. dobrogicus, but disproportional in T. karelinii morphotype.

Two types of blastokinesis are found in Dictyoptera: one is the “reversion type” (top) in blattoidean cockroaches and termites, and another the “non-reversion type” (below) in blaberoidean cockroaches and mantises.

A simplified phylogeny demonstrating gross differences in the manus morphology of modern tapirs. Bones with lighter colours (higher specificity %) represent higher levels of morphological difference between species, darker colours represent bones that are misclassified more frequently. Each tapir species is represented by a silhouette diagram demonstrating generalised appearance.

Testis structure of Daphnia magna, showing muscles in red, labeled with Phalloiden, and developing nuclei in blue, labeled with Hoechst.

EM observations on both, intermoult and postmoult stages of Xestoleberis species reveal that the “Xestoleberis-spot” system consists of three elements; two calcified chambers, a vesicle of electron-dense material and an uncalcified procuticle.

Plainfin midshipman females and type II males (an alternative male sexual phenotype) have prominent, horn-like rostral swim bladder extensions which are lacking in nesting type I males, that increase the proximity to the auditory end organs.

Salps are unusual marine plankton with alternating generations. Sexual stages possess three eyes, asexual stages a single horseshoe-shaped eye. Eyes consist of pigment cells and rhabdomeric photoreceptor cells. We suggest that differences evolved as a result of life styles of the two stages.

Pharyngeal jaws of two minnow species.

Germline cysts are composed of cystocytes (Cyst). The PACH oocytes are in the pachytene and early diplotene stages of first prophase, the DIP oocytes are in the diplotene stage. Somatic cells (SC) and degenerating cystocytes (asterisks) are present.

The peculiar tongue of anteaters was investigated with gross anatomical observations, scanning electron microscopy and histological techniques. The morphology observed in the tongues of anteaters reflects the adaptive specialization of the organ for myrmecophagy. Comparing it with that of other xenarthrans, it is possible to infer some aspects about the evolution of the organ in the group. Picture of Tamandua tetradactyla by Karina Molina.

The presence of sesamoids on the skeleton of squamate lizards have been described almost exclusively from the appendicular skeleton. In this article, we report two ossicles in the skull of squamates that fulfill the definition of sesamoid elements: one associated with the quadrate bone, and the other with the braincase, previously described as the element X. The latter bone is widespread among squamates, being present in members of major squamate clades with the exception of snakes. Graphic abstract figure indicates the presence of element X among squamate clades (red branches), illustrated here by three groups where this element was unknown, Gekkota (1. Chondrodactylus angulifer, 2. Paradelma orientalis) and Gymophthalmidae (3. Calyptommatus leiolepis).

Comparative morphology of the empodium and medial projection of distal margin of the apical tarsomere and armature of tarsal claws in leiodids and related taxa indicate a wealth of new diagnostic features and potential synapomorphies for family-groups.

We employ linear measurements and 2D geometric morphometrics to examine how the morphology of the calcaneum, the ‘heel bone’, correlates with locomotion in extant carnivores. We use these correlations to determine the locomotor mode, and hence aspects of the probable palaeobiology, of 47 extinct taxa including members of Carnivora and Creodonta.

Protonymphons have important peculiarities of organization, most notably – their segmentary composition. It is especially clear if compared with nauplius. Although both larvae are externally unsegmented and bear three pairs of homologous appendages, protonymphon body includes a fourth segment of the prospective walking legs, absent in nauplius. 1 – chelar gland, 2 – spinning gland, 3 – proboscis, 4 – gut, 5 – ganglion, 6 – ventral organ

• The curvature and form of the parietal bone does not influence the position of the temporal poles in the human skull
• The size and shape of the parietal bone influences the orientation on the head

E. calabaricus. Detail of ciliated band. Ciliated cells (arrow) show prominent ciliary tufts and contain secretory bodies. Goblet cells (G) show secretory bodies and may contain lamellar bodies. Pneumocytes type 2 (double arrow) contain lamellar bodies, may also contain secretory bodies, and are restricted to the ciliated bands. The subepithelium is a thin layer, appears limited by collagen and contains fibroblasts (F) and granulocytes. External to this area is a thin layer of smooth muscle and a thick striated muscle layer with myelinated and non-myelinated nerve fibers. Scale bar, 5 microns.

The aglossan pipid frog, Pipa pipa, recruits its entire trunk during suction feeding on elusive prey by exploiting novel arrangements of buccopharyngeal dilators.

A three-dimensional articulated gill arch skeleton of a 400-million-year-old placoderm fish is described. This adds to the diversity of feeding and respiratory structures in jawed vertebrate animals and informing hypotheses of gill arch evolution in the first jawed vertebrates.

Two divergent developmental patterns are observed in the presacral pleurocentrum of temnospondyls and stem-amniotes. In the former, the pleurocentrum arose from two dorsally located ossification centers while in stem-amniotes, it developed from two ventrally located ossification centers.

Muscles of left forelimb of chameleon (Chamaeleo calyptratus) in medial view, and inset showing detailed muscle anatomy of distinctive syndactylous manus. Considering the remarkable structural and functional modifications of the distal limb in chameleons, the number and attachments of muscles are surprisingly conservative.

Musculature of right clasper of Rioraja agassizi (AC.UERJ 1113). (A) Dorsal view. (B) Ventral view. Abbreviations: c, compressor; fl, flexor; dd, dilatator dorsalis; dv, dilatator ventralis; el, extensor lateralis.

Petrosal and preserved internal structures of the Oligocene artiodactyl Diplobune minor; left, bony labyrinth with postmortem intralabyrinthine stapes viewed through a translucent rendering of the petrosal; right, bony labyrinth endocast (blue), with nerves (yellow), and veins (violet) of the inner ear.

The pleon-holding structures of Carcinus maenas have different microstructures in juvenile and adult specimens. The sternal button is identical in juveniles of both sexes (top) but changes during ontogy are sex specific (bottom).

In the present study, we perform a quantitative comparison of the development and metamorphosis of the peripheral olfactory system across three anuran species with differing larval and adult lifestyles: the tree frog Hypsiboas pulchellus, the terrestrial toad Rhinella arenarum, and the fully aquatic frog Xenopus laevis. Data analysis revealed that Anurans have well developed dual chemosensory system. Interestingly, species whose postmetamorphic stages are more associated with the aquatic environment showed a bigger vomeronasal organ (VNO) and other “water sensitive structures”; whereas those species with more terrestrial adults showed a larger relative size of the olfactory epithelium (OE) at postmetamorphic stages. Moreover we quantitatively described specialized structures that were not present in all species included in the analysis; some of these structures were only present at the larval stages, as the buccal exposed olfactory epithelium (bexOE) of R. arenarum and H. pulchellus tadpoles; whereas others were specializations of postmetamorphic stages, as the olfactory epithelium at the middle chamber (MCE) of X. laevis or the olfactory recess (OR) of R. arenarum. This initial quantitative survey of the olfactory organs in anurans highlights the significant variation in this system in the group, which appears to be correlated with functional and ecological differences among the species.