scholarly journals Comparative morphology of the musculature of the sting apparatus in Ampulex compressa (Hymenoptera, Ampulicidae) and Sceliphron destillatorium (Hymenoptera, Sphecidae)

2021 ◽  
Vol 68 (1) ◽  
pp. 21-32
Author(s):  
Stefan Graf ◽  
Maraike Willsch ◽  
Michael Ohl
Keyword(s):  
Computed Tomography ◽  
Comparative Morphology ◽  
Micro Computed Tomography ◽  
Ampulex Compressa ◽  
First Time

The sting apparatus of aculeate Hymenoptera is derived from the ovipositor and is their most prominent apomorphy. In contrast to the frequently analysed sclerites of the sting apparatus, the associated musculature has largely been neglected. In this study, we use micro-computed tomography to present a detailed description of the musculature of the sting apparatus of Ampulex compressa (Ampulicidae) and Sceliphron destillatorium (Sphecidae). We found that 12 of 15 muscles corresponding to the sting apparatus are homologous between both species examined and 13 muscles in comparison with Hymenoptera described in the literature. All muscles identified as critical for the act of stinging were found in both species. Moreover, we found the ventral tergum 8-tergum 9 muscle and the tergum 8-tergum 8 muscles in A. compressa and the second valvifer-second valvifer muscle in S. destillatorium. For the first time, we describe the ventral tergum 8-tergum 9 muscle and the second valvifer-second valvifer muscle that interconnects both body sides, in Hymenoptera.

scholarly journals An apparently non-swinging tentorium in the Diplopoda (Myriapoda): comparative morphology of the tentorial complex in giant pill-millipedes (Sphaerotheriida)

ZooKeys ◽  
2018 ◽  
Vol 741 ◽  
pp. 77-91 ◽  
Author(s):  
Leif Moritz ◽  
Thomas Wesener ◽  
Markus Koch
Keyword(s):  
Computed Tomography ◽  
Comparative Morphology ◽  
Head Size ◽  
Micro Computed Tomography ◽  
Posterior Process ◽  
Large Head

The presence of a swinging tentorium is a key apomorphy of Myriapoda, but this character has been studied in detail in only few species. Here the tentorium, i.e., the peristomatic skeleton of the preoral chamber, is comparatively studied in three species of the millipede order Sphaerotheriida Brandt, 1833. Since dissections of the fragile tentorial components proved to be difficult, despite the large head size, they were analysed mainly in situ via micro-computed tomography. Our results confirm previous observations of large differences in the tentorial construction in the giant pill-millipedes compared to chilognathan diplopods. The tentorium of Sphaerotheriida consists of a curved, plate-like epipharyngeal bar with distal projections, an elongate and thin hypopharyngeal bar, and a plate-like triangular posterior process; a transverse bar is absent. Only seven muscles attach at the tentorium in giant pill-millipedes, including two antennal muscles and two muscles of the gnathochilarium. Within the order Sphaerotheriida, the composition of the tentorium and its muscular equipment seems to be conserved, except for some variability in the shape of the epipharyngeal bar. As the transverse bar has been considered essential for the mobility of the tentorium in myriapods, its absence in Sphaerotheriida may indicate that their tentorium is not capable of performing a swing. Loss of tentorial mobility may also pertain to the order Glomerida Brandt, 1833, inferred here from the absence of a posterior process. An apparently immobile tentorium in Glomerida and Sphaerotheriida can straightforwardly be correlated with transformations of the head related to their ability of volvation. The different transformations of the tentorium, here hypothesised to cause immobility, may support current assumptions that the ability of volvation evolved convergently in Glomerida and Sphaerotheriida. This conclusion, however, still requires more detailed studies of the head anatomy in Glomerida and Glomeridesmida Cook, 1895.

A new fossil Eurypinae genus and sexual dimorphism in the representatives of Omineus (Coleoptera: Mycteridae) from Tertiary amber of Europe

Zootaxa ◽  
2020 ◽  
Vol 4820 (3) ◽  
pp. 551-562
Author(s):  
VITALII IGOREVICH ALEKSEEV ◽  
ANDRIS BUKEJS ◽  
DARREN ANDREW POLLOCK
Keyword(s):  
Computed Tomography ◽  
Sexual Dimorphism ◽  
Baltic Amber ◽  
Micro Computed Tomography ◽  
Fossil Species ◽  
X Ray ◽  
Secondary Sexual Characters ◽  
Kaliningrad Region ◽  
First Time ◽  
Secondary Sexual

Europoeurypus inglaeso gen. et sp. nov. is described from Eocene Baltic amber found on the Sambian Peninsula, Kaliningrad Region, Russia. Four additional specimens of mycterid beetles from collections of Baltic amber are reported. The secondary sexual characters and sexual dimorphism in the Eocene representatives of the genus Omineus Lewis, 1895 are documented for the first time and examined using X-ray micro-computed tomography (μCT). The studied Omineus male specimens were attributed to the fossil species Omineus febribilis Alekseev, Pollock & Bukejs, 2019. A key to fossil species of Eurypinae from Eocene ambers is provided and several aspects of the biogeography of the subfamily Eurypinae are discussed.

scholarly journals Skeleton Growth in Guinea Pigs and Humans

2021 ◽  
Vol 9 ◽  
Author(s):  
Zoe Skinner ◽  
Natasha Clark ◽  
Sharon Rutland ◽  
Andrew Dawkins ◽  
Catrin Sian Rutland
Keyword(s):  
Computed Tomography ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Imaging Technique ◽  
Cell Types ◽  
Micro Computed Tomography ◽  
Internal Organs ◽  
Unique Structure ◽  
Different Ages ◽  
First Time

Every animal has a skeleton made up of many different bones. Bones are vital. Without bones we would not be able to move, protect our internal organs, store important minerals, or even make some cell types! When we are young, in addition to growing, our bones must develop into specific shapes. This article describes how and why bones grow and heal in humans and guinea pigs. Using a special imaging technique called micro-computed tomography, we will show you the unique structure of some guinea pig bones and how animals of different ages have important bone variations. We will also discuss how the fascinating discovery of a hole in a bone, called a supratrochlear foramen, was described for the first time in a species. We will also answer questions, such as “how can you keep your bones healthy” and “what happens to astronauts’ skeletons in space?”

scholarly journals A comparative description of the mesosomal musculature in Sphecidae and Ampulicidae (Hymenoptera, Apoidea) using 3D techniques

2020 ◽  
Vol 67 (1) ◽  
pp. 51-67
Author(s):  
Maraike Willsch ◽  
Frank Friedrich ◽  
Daniel Baum ◽  
Ivo Jurisch ◽  
Michael Ohl
Keyword(s):  
Computed Tomography ◽  
Abdominal Segment ◽  
Micro Computed Tomography ◽  
3D Reconstructions ◽  
Anatomy Ontology ◽  
Morphological Studies ◽  
Skeletal Musculature ◽  
Ampulex Compressa ◽  
Comparative Description ◽  
Structural Aspects

Conflicting hypotheses about the relationships among the major lineages of aculeate Hymenoptera clearly show the necessity of detailed comparative morphological studies. Using micro-computed tomography and 3D reconstructions, the skeletal musculature of the meso- and metathorax and the first and second abdominal segment in Apoidea are described. Females of Sceliphron destillatorium, Sphex (Fernaldina) lucae (both Sphecidae), and Ampulex compressa (Ampulicidae) were examined. The morphological terminology provided by the Hymenoptera Anatomy Ontology is used. Up to 42 muscles were found. The three species differ in certain numerical and structural aspects. Ampulicidae differs significantly from Sphecidae in the metathorax and the anterior abdomen. The metapleural apodeme and paracoxal ridge are weakly developed in Ampulicidae, which affect some muscular structures. Furthermore, the muscles that insert on the coxae and trochanters are broader and longer in Ampulicidae. A conspicuous characteristic of Sphecidae is the absence of the metaphragma. Overall, we identified four hitherto unrecognized muscles. Our work suggests additional investigations on structures discussed in this paper.

scholarly journals Computed Tomography elucidates ontogeny within the basal therapsid clade Biarmosuchia

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11866
Author(s):  
Aliénor Duhamel ◽  
Julien Benoit ◽  
Michael Day ◽  
Bruce Rubidge ◽  
Vincent Fernandez
Keyword(s):  
Computed Tomography ◽  
Cranial Sutures ◽  
New Taxon ◽  
Late Permian ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Growth Series ◽  
Bony Labyrinth ◽  
Cranial Ontogeny ◽  
First Time

Biarmosuchia is a clade of basal therapsids that includes forms possessing plesiomorphic ‘pelycosaurian’ cranial characters as well as the highly derived Burnetiamorpha which are characterised by cranial pachyostosis and a variety of cranial bosses. Potential ontogenetic variation in these structures has been suggested based on growth series of other therapsids with pachyostosed crania, which complicates burnetiamorph taxonomic distinction and thus it is essential to better understand cranial ontogeny of the Burnetiamorpha. Here, three new juvenile biarmosuchian skulls from the late Permian of South Africa are described using X-ray micro computed tomography (CT). We found that juvenile biarmosuchians are distinguished from adults by their relatively large orbits, open cranial sutures, and incomplete ossification of the braincase and bony labyrinth. Also, they manifest multiple centres of ossification within the parietal and preparietal bones. CT examination reveals that the holotype of Lemurosaurus pricei (BP/1/816), previously alleged to be a juvenile, shows no evidence of juvenility and is thus probably an adult. This suggests that the larger skull NMQR 1702, previously considered to be an adult L. pricei, may represent a new taxon. This study provides, for the first time, a list of characters by which to recognise juvenile biarmosuchians.

scholarly journals High-resolution X-ray computed tomography of an extant new Donuea (Araneae: Liocranidae) species in Madagascan copal

Zootaxa ◽  
2010 ◽  
Vol 2427 (1) ◽  
pp. 25 ◽  
Author(s):  
JAN BOSSELAERS ◽  
MANUEL DIERICK ◽  
VEERLE CNUDDE ◽  
BERT MASSCHAELE ◽  
LUC VAN HOOREBEKE ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Micro Computed Tomography ◽  
Spider Species ◽  
X Ray ◽  
Fresh Material ◽  
Extant Species ◽  
X Ray Computed ◽  
Area X ◽  
First Time

A new extant Donuea (Liocranidae) species is described from Madagascar, from both alcohol preserved fresh material and also as a subfossil in copal from the Sambava area. X-ray micro computed tomography was used to visualise minute details of the male palp of the copal specimen in order to confirm conspecificity. This is the first time a new spider species discovered in Madagascan copal can immediately be demonstrated as belonging to an extant species.

scholarly journals Skeletal architecture of middle Cambrian spicular radiolarians revealed using micro-CT

2020 ◽  
Vol 39 (1) ◽  
pp. 61-76
Author(s):  
Jiani Sheng ◽  
Sarah Kachovich ◽  
Jonathan C. Aitchison
Keyword(s):  
Computed Tomography ◽  
Structural Analysis ◽  
Basal Layer ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Middle Cambrian ◽  
X Ray ◽  
Detailed Structural Analysis ◽  
First Time ◽  
Internal Architecture

Abstract. X-ray micro-computed tomography (micro-CT) is used to resolve the detailed internal architecture of the siliceous skeletons of two well-preserved middle Cambrian (Miaolingian Series) radiolarians from the Inca Formation of the Georgina Basin, Australia. Digital dissections of specimens of Archeoentactinia incaensis and A. tetractinia reveal for the first time that both are exclusively composed of tetractine spicules. A basal layer consisting of robust spicules together with an interwoven meshwork of smaller spicules is observed in both micro-CT models. Detailed structural analysis with the aid of a digitally inserted artificial sphere shows that the framework spicules are likely to have been added one by one as the radiolarian cell enlarged. The timing of spicule genesis may be an important factor controlling the morphology of different groups of spicular radiolarians. Observation of these fundamental skeletal structures suggests that the type genus of Archeoentactiniidae Archeoentactinia belongs to Echidninidae; thus, Archeoentactiniidae is a junior synonym of Echidninidae.

Cortical and trabecular bone parameters from HR-Pqct images at the Tibia: a local comparison with synchrotron radiation micro-computed tomography

2013 ◽  
Author(s):  
Agnes Ostertag ◽  
Francoise Peyrin ◽  
Sylvie Fernandez ◽  
Jean-Denis Laredo ◽  
Vernejoul Marie-Christine De ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Synchrotron Radiation ◽  
Trabecular Bone ◽  
Micro Computed Tomography ◽  
Bone Parameters ◽  
Local Comparison

Morphology and Affinities of Ampelocissites Seeds (Vitaceae: Ampelopsis clade) from the Paleogene of Texas, USA

2020 ◽  
Vol 45 (3) ◽  
pp. 478-482
Author(s):  
Steven R. Manchester
Keyword(s):  
Computed Tomography ◽  
Cross Sections ◽  
Seed Coat ◽  
Ct Scanning ◽  
Seed Morphology ◽  
Early Eocene ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Fossil Seeds ◽  
Fossil Genus

Abstract—The type material on which the fossil genus name Ampelocissites was established in 1929 has been reexamined with the aid of X-ray micro-computed tomography (μ-CT) scanning and compared with seeds of extant taxa to assess the relationships of these fossils within the grape family, Vitaceae. The specimens were collected from a sandstone of late Paleocene or early Eocene age. Although originally inferred by Berry to be intermediate in morphology between Ampelocissus and Vitis, the newly revealed details of seed morphology indicate that these seeds represent instead the Ampelopsis clade. Digital cross sections show that the seed coat maintains its thickness over the external surfaces, but diminishes quickly in the ventral infolds. This feature, along with the elliptical chalaza and lack of an apical groove, indicate that Ampelocissites lytlensis Berry probably represents Ampelopsis or Nekemias (rather than Ampelocissus or Vitis) and that the generic name Ampelocissites may be useful for fossil seeds with morphology consistent with the Ampelopsis clade that lack sufficient characters to specify placement within one of these extant genera.

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