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1. Macellomenia profundorum n. sp. (Mollusca, Solenogastres, Pholidoskepia) a new abyssal species from the South Atlantic Ocean (Angola Basin)

   Cobo, Maria del ( January 2021 , Iberus)

   null (Ed.)

   A new species of solenogaster (Mollusca, Aplacophora) from the Angola Basin is described: Macellomenia profundorum n. sp. The studied specimen was collected during the DIVA 1 expedition (Latitudinal Gradients of Deep-Sea BioDIVersity in the Atlantic Ocean). The description is based primarily on the sclerites and the internal anatomy (histological study). Macellomenia profundorum n. sp. is the first species of the family to be described from the southern hemisphere and constitutes its deepest record (5400 m deep). Even though only anterior anatomical characters are known, these and especially the radula and mantle sclerites are enough to justify that it is a new species. Amended diagnoses are also provided for the family and genus. 

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2. The first full body diffusible iodine‐based contrast‐enhanced computed tomography dataset and teaching materials for a member of the Testudines

   https://doi.org/10.1002/ar.25282  

   Gray, Jaimi A. ; Gignac, Paul M. ; Stanley, Edward L. ( July 2023 , The Anatomical Record)

   Diffusible iodine‐based contrast‐enhanced Computed Tomography (diceCT) is now a widely used technique for imaging metazoan soft anatomy. Turtles present a particular challenge for anatomists; gross dissection is inherently destructive and irreversible, whereas their near complete shell of bony plates, covered with keratinous scutes, presents a barrier for iodine diffusion and significantly increases contrast‐enhanced CT preparation time. Consequently, a complete dataset visualizing the internal soft anatomy of turtles at high resolution and in three dimensions has not yet been successfully achieved. Here we outline a novel method that augments traditional diceCT preparation with an iodine injection technique to acquire the first full body contrast‐enhanced dataset for the Testudines. We show this approach to be an effective method of staining the soft tissues inside the shell. The resulting datasets were processed to produce anatomical 3D models that can be used in teaching and research. As diceCT becomes a widely employed method for nondestructively documenting the internal soft anatomy of alcohol preserved museum specimens, we hope that methods applicable to the more challenging of these, such as turtles, will contribute toward the growing stock of digital anatomy in online repositories.

    

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3. Safe Casting and Reliable Cusp Reconstruction Assisted by Micro‐Computed Tomographic Scans of Fossil Teeth

   https://doi.org/10.1002/ar.24047  

   O'Hara, Mackie C. ; Le Cabec, Adeline ; Xing, Song ; Skinner, Mark F. ; Guatelli‐Steinberg, Debbie ( January 2019 , The Anatomical Record)

   Dental replicas are frequently utilized in paleoanthropological studies of perikymata and enamel hypoplasia. However, fossil teeth are often fragile and worn, causing two problems: (1) the risk of damage by removing enamel fragments when impression‐making material is separated from the fossil tooth surface, and (2) the need to reconstruct worn portions of the crown to assess perikymata number, distribution, and hypoplasia timing. This study presents the advantages of μCT data of canines and lateral incisors for (1) detecting cracks along the enamel‐dentine junction (EDJ) which could cause damage when casting, and (2) reliably and non‐destructively reconstructing worn or broken cusps. Fragile teeth ofHomo naledi, Miocene, and Pleistocene specimens were μCT‐scanned: 2D virtual sections and 3D models allowed for inspecting crack pattern beyond the external surface and 2D virtual sections were used to digitally reconstruct cusp tips (onlyHomo naledi). Micro‐CT scans allowed cracks running along the EDJ and communicating with radial cracks in the enamel to be identified prior to casting. Cusp reconstructions using μCT data were conducted as precisely as when using thin‐sections or photographs, and with high intra‐ and inter‐observer agreement, while preserving the original specimen and affording numerous planes of virtual section. When available, μCT data should be inspected prior to tooth casting to exclude teeth that show a pattern of cracks that could lead to damage. Virtual sections allow for accessible, reliable, and non‐destructive cusp reconstructions that may be used for developmental (e.g., perikymata and enamel hypoplasia) or enamel thickness studies. Anat Rec, 302:1516–1535, 2019. © 2018 American Association for Anatomy

    

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4. Structural analysis of the female reptile reproductive system by micro-computed tomography and optical coherence tomography

   https://doi.org/10.1093/biolre/ioae039  

   Kircher, Bonnie K. ; McCown, Michaela A. ; Scully, Deirdre M. ; Behringer, Richard R. ; Larina, Irina V. ( April 2024 , Biology of Reproduction)

   Volumetric data provide unprecedented structural insight to the reproductive tract and add vital anatomical context to the relationships between organs. The morphology of the female reproductive tract in non-avian reptiles varies between species, corresponding to a broad range of reproductive modes and providing valuable insight to comparative investigations of reproductive anatomy. However, reproductive studies in reptilian models, such as the brown anole studied here, have historically relied on histological methods to understand the anatomy. While these methods are highly effective for characterizing the cell types present in each organ, histological methods lose the 3D relationships between images and leave the architecture of the organ system poorly understood. We present the first comprehensive volumetric analyses of the female brown anole reproductive tract using two non-invasive, non-destructive imaging modalities: micro-computed tomography (microCT) and optical coherence tomography (OCT). Both are specialized imaging technologies that facilitate high-throughput imaging and preserve three-dimensional information. This study represents the first time that microCT has been used to study all reproductive organs in this species and the very first time that OCT has been applied to this species. We show how the non-destructive volumetric imaging provided by each modality reveals anatomical context including orientation and relationships between reproductive organs of the anole lizard. In addition to broad patterns of morphology, both imaging modalities provide the high resolution necessary to capture details and key anatomical features of each organ. We demonstrate that classic histological features can be appreciated within whole-organ architecture in volumetric imaging using microCT and OCT, providing the complementary information necessary to understand the relationships between tissues and organs in the reproductive system. This side-by-side imaging analysis using microCT and OCT allows us to evaluate the specific advantages and limitations of these two methods for the female reptile reproductive system.

    

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5. Bone microstructure and bone mineral density are not systemically different in Antarctic icefishes and related Antarctic notothenioids

   https://doi.org/10.1111/joa.13537  

   Ashique, Amir M. ; Atake, Oghenevwogaga J. ; Ovens, Katie ; Guo, Ruiyi ; Pratt, Isaac V. ; Detrich, III, H. William ; Cooper, David M. L. ; Desvignes, Thomas ; Postlethwait, John H. ; Eames, B. Frank ( August 2021 , Journal of Anatomy)

   Ancestors of the Antarctic icefishes (family Channichthyidae) were benthic and had no swim bladder, making it energetically expensive to rise from the ocean floor. To exploit the water column, benthopelagic icefishes were hypothesized to have evolved a skeleton with “reduced bone,” which gross anatomical data supported. Here, we tested the hypothesis that changes to icefish bones also occurred below the level of gross anatomy. Histology and micro‐CT imaging of representative craniofacial bones (i.e., ceratohyal, frontal, dentary, and articular) of extant Antarctic fish species specifically evaluated two features that might cause the appearance of “reduced bone”: bone microstructure (e.g., bone volume fraction and structure linear density) and bone mineral density (BMD, or mass of mineral per volume of bone). Measures of bone microstructure were not consistently different in bones from the icefishesChaenocephalus aceratusandChampsocephalus gunnari, compared to the related benthic notothenioidsNotothenia coriicepsandGobionotothen gibberifrons. Some quantitative measures, such as bone volume fraction and structure linear density, were significantly increased in some icefish bones compared to homologous bones of non‐icefish. However, such differences were rare, and no microstructural measures were consistently different in icefishes across all bones and species analyzed. Furthermore, BMD was similar among homologous bones of icefish and non‐icefish Antarctic notothenioids. In summary, “reduced bone” in icefishes was not due to systemic changes in bone microstructure or BMD, raising the prospect that “reduced bone” in icefish occurs only at the gross anatomic level (i.e., smaller or fewer bones). Given that icefishes exhibit delayed skeletal development compared to non‐icefish Antarctic fishes, combining these phenotypic data with genomic data might clarify genetic changes driving skeletal heterochrony.

    

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