Anatomical Record-Advances in Integrative Anatomy and Evolutionary Biology最新文献

Bones of the skull are traditionally categorized as derived from either endochondral or intramembranous bone. In our previous work, we have observed the interaction of different tissue types in growth of the skull. We find the dichotomy of intramembranous and endochondral bone to be too restrictive, limiting our interpretation of sources of biological variation. Here, we advocate for the use of the term ectochondral bone to describe bone that originates from an endochondral model but is directed in its subsequent growth by membranes and other fascial attachments. Growth of the alisphenoid and orbitosphenoid are described as two examples of ectochondral bone, influenced in their shape primarily by the surrounding soft tissues. Ectochondral bone may be an ideal mechanism for rapidly evolving new phenotypes. Instead of evolving novelties by altering morphology of the cartilage template, novel features may be formed by ectochondral ossification, a more direct and rapid mode of osteogenesis than that of the cartilage template.

The Weberian apparatus is a hearing specialization unique to the otophysan fishes, and an unexpected degree of morphological variation exists in species of the Noturus catfishes. Our aim in this study is to investigate relationships between morphological variations and ecology that may drive this variation. Sampling 48 specimens representing 25 species, we investigated morphological diversity and accounted for ecological variables using landmark-based 3D geometric morphometrics and x-ray-based computed tomography (CT) images. We tested five ecological variables using three landmark sets in three focused regions: the tripus, scaphium, and overall shape of the peripheral structures including the complex vertebra. We performed phylogenetic signal tests, and phylogenetic influence is not significant within Noturus in any of the three regions. Among the tested ecological variables, stream velocity and coloration (a proxy for substrate) were found to be significantly associated with the morphology of the tripus and scaphium, the first and the last ossicles of the sound transmitting chain. This eco-morphology connection may be mediated through stream velocity's dominant role in defining the soundscape of aquatic environments and substrate material properties contributing to which sounds are produced and propagated. We conclude that Noturus catfishes could be acoustically adapted to their microhabitats.

Pangolins are the most heavily trafficked mammals in the world, largely because of the high demand for their keratinous scales from the traditional Chinese medicine market. While seizures of pangolin material are largely composed of isolated scales, efficient approaches to reach species-level identification are missing. This mostly originates from the lack of comparative studies on the shape of pangolin scales, resulting in knowledge gaps on the imbricated effects of serial, ontogenetic, and evolutionary variations. Using a large sample of micro-CT scan data, we performed the first quantitative 3D analysis of scale shape variation among the eight species of extant pangolins. Our geometric morphometric approach suggests that pangolins grossly share similar trends of serial variation, with scale shape and size being similarly distinct across the different body regions. Relative elongation is by far the main component of scale shape variation at the intraspecific level, although degree of asymmetry and shape of scale bed area also allow distinction among different body areas, especially in adults. At the evolutionary level, Phataginus is the most distinctive genus, with P. tricuspis having the most elongated scales overall. Scales of the back (dorsum) appear to be the best discriminator between species, providing one of the few scale shape differences recorded between the genera Smutsia and Manis. Our results provide an unprecedented, upstream understanding of broad differentiation patterns across the scaled body of pangolins. Together with other yet-to-be-explored morphological traits (e.g., scale size, ornamentation, and thickness), scale shape could provide a valuable matrix of information for forensic applications.

Hypercanines, or hypertrophied canines, are observed in a wide range of both extinct and extant synapsids. In non-mammaliaform cynodonts, the Permo-Triassic forerunners of mammals, long canines are not uncommon, appearing in several unrelated taxa within the clade. Among them is Trucidocynodon riograndensis, a carnivorous ecteniniid cynodont from the Late Triassic of Brazil, which exhibits a specialized dentition, including spear-shaped incisors, very long and narrow canines, and sectorial postcanines with distally oriented cusps, all of which have finely serrated margins. Recent synchrotron X-ray micro-computed tomography of a large specimen (CAPPA/UFSM 0029; Várzea do Agudo site, Brazil) provides new insights into its lower jaw and dentition, as well as offers the first digital endocast of an ecteniniid. Our study reveals the presence of (i) putatively opened-root canines in the adult stage and the possible presence of unresorbed remnant of an old canine, which may indicate that the specimen stopped replacing its canines; (ii) lower canines that are longer than the upper canines and, in occlusion, were kept inside deep paracanine fossae that perforated the dorsal surface of the rostrum; (iii) a diastema between the incisors and lower canine, which is absent in the holotype; (iv) advanced brain structures, such as the absence of a pineal body, presence of cerebral hemispheres divided by the interhemispheric sulcus and expanded laterally, and a higher encephalization quotient than non-mammaliaform prozostrodonts, reflecting the homoplastic evolution of relative brain sizes observed in Triassic cynodont lineages. Finally, the abundance of carnivorous and omnivorous species at the Várzea do Agudo site, where the specimen was found—including the archosauriforms Dynamosuchus collisensis and Stenoscelida aurantiacus—suggests a diverse predator guild that warrants further investigation from a paleoecological perspective.

Wang, M.-Z., Cai, Y.-F., Fang, Q.-J., Liu, Y.-L., Wang, J., Chen, J.-X., Fu, Y., Wan, B.-Y., Tu, Y., Wu, W., Wan, Y.-G., & Mu, G.-L. (2023). Inhibition of ferroptosis of renal tubular cells with total flavones of Abelmoschus manihot alleviates diabetic tubulopathy. The Anatomical Record, 306(12), 3199–3213. https://doi.org/10.1002/ar.25123

In the originally-published article, author Yi-Gang Wan's affiliation is incorrect. The correct affiliation is:

Yi-Gang Wan^1,3

¹Department of Traditional Chinese Medicine, Nanjing Drum Tower Hospital Clinical College of Nanjing University of Chinese Medicine, Nanjing, China.

³Department of Traditional Chinese Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China.

Figure 7 is incorrect due to image overlap and the representative characteristics of the image being unclear. The correct Figure 7 is included below.

FIGURE 7 The ferroptosis-related changes triggered by AGEs in vitro. (a) The cell viability of the NRK-52E cells cultured in the media with various AGEs concentrations for 24 and 48 h, respectively; (b) The cell viability of the NRK-52E cells cultured in the media with various RSL-3 concentrations for 24 h; (c) FerroOrange staining in the NRK-52E cells (×800). Scale bar = 20 μm; (d) The production of ROS in the NRK-52E cells (×800). Scale bar = 20 μm; (e) The quantification of Fe²⁺ formation fluorescence intensity; (f) The quantification of ROS formation fluorescence intensity. Data are expressed as mean ± SD. **p < 0.01.

Figure 8(f) is incorrect due to an overlapped image. The correct Figure 8 is included below.

FIGURE 8 The effects of TFA and dapagliflozin (Dapa) on ferroptosis-related changes in vitro. (a) The cell viability in the cultured NRK-52E cells exposed to AGEs at 200 μg/mL for 48 h with or without TFA at 5, 10, 20, and 30 μg/mL for 24 h; (b) The cell viability in the cultured NRK-52E cells exposed to AGEs at 200 μg/mL for 48 h with or without Dapa at 10, 20, 50, and 100 μM for 24 h; (c) The cell viability of the NRK-52E cells cultured in the media with various Fer-1 concentrations for 24 h; (d) The cell viability in the cultured NRK-52E cells exposed to AGEs at 200 μg/mL for 48 h with or without Fer-1 at 0.5, 1.0, 1.5, and 2.0 μM for 24 h; (e) FerroOrange staining in the NRK-52E cells (×800). Scale bar = 20 μm; (f) The production of ROS in the NRK-52E cells (×800). Scale bar = 20 μm. Data are expressed as mean ± SD. **p < 0.01.

We apologize for these errors.

The pygmy sperm whale (Kogia breviceps) possesses an exocrine gland associated with its false gill slit pigmentation pattern. The cervical gill slit gland is a compound tubuloalveolar gland that produces a holocrine secretion and displays maturational changes in size and secretory histology. While the morphology of the cervical gill slit gland has been described in detail, to date, the chemical composition of its secretion remains uncharacterized. This study used histochemical staining techniques and quantitative lipid analysis to identify and characterize the constituents expressed in the secretory cells and secretion of the cervical gill slit gland. Results demonstrate that the secretion, like those of terrestrial artiodactyls that function in chemical communication, includes a complex mixture of carbohydrates, proteins, and lipids. Differences in staining intensity across germinal and secretory epithelial layers demonstrate differential expression, or maturation, of mucins and proteins. Additionally, a highly unusual and primary constituent of the secretion is uric acid. Uric acid was identified within the secretion using histochemical stains and polarized light imaging, and chemically verified using scanning electron microscopy with energy dispersive spectrometry. While uric acid is not a common constituent of mammalian exocrine glands, urate-based compounds are abundant in the secretions of marine organisms used in chemical communication. Thus, uric acid may contribute to the chemical message produced by K. breviceps in its marine environment. We hypothesize that the chemical signals produced by the gill slit gland may be shared at close-range by conspecifics, and that the mode of sensory reception is likely gustation.

Diet is one of a limited set of key ecological parameters defining primate species. A detailed understanding of dental functional correlates with primate diet is a key component for accurate dietary inference in fossil primates. Although considerable effort has been devoted to understanding post-canine dental function, incisor function remains poorly understood. Prior analyses have demonstrated that anthropoid incisor mesiodistal (MD) and cervico-incisal (CI) crown curvature correlates with an increased reliance on frugivory and that greater incisor crown curvature functions to increase total crown area and, by extension, crown resistance to normal bending stresses (e.g., compressive and tensile forces). The present study investigates the correlation between incisor basal cross-sectional area at the cementoenamel junction (CA^cej) and the degree to which taxa rely on frugivory to better understand how non-normal forces (e.g., shear) may influence incisor morphology. Results demonstrate that, like resistance to bending stress, resistance to shear stress (as represented by the CA^cej), is positively correlated with an increased reliance on frugivory such that more frugivorous anthropoids have larger CA^cej relative to body mass and therefore greater resistance to shear stress. Likewise, hard-object frugivores have increased shear resistance relative to soft-object frugivores. A more detailed working understanding of the forces acting on primate incisors, and how these crowns resist those forces, will contribute to improving our understanding of how diet influences incisor morphology and the accuracy of dietary inference in fossil anthropoids.

Some animal groups have the right to ask the press for a do-over: “killer” whales, while clearly not vegans, are family-oriented giants who show caring and compassion; guinea “pigs,” while a bit pudgy in appearance, are rodents and in no evolutionary way cousins of pigs; likewise, prairie “dogs” are not related to a human's best friend and are rather cousins of New York City's formidable sewer rats; and the only flying “foxes” are probably the poor critters that were scared to death being hunted by hordes of English nobles, with such animals actually being fruit bats of the order Chiroptera. And, Pseudosuchia is also disrespectfully named, damning a host of varied reptiles to be labeled as some sort of “less than” or “false” relatives of crocodiles when they are not.

First off, a disclaimer: the authors of this editorial were weaned in the study of primates, that is, humans and our kin, monkeys, apes, and all historical relatives. Studying their history is, truthfully, not that difficult. Basically, everything revolves around us and who is most like us. Direct human-like relatives started to come about likely during the Miocene epoch, some 8–10 mya, and all of our primate-like relatives came creeping out from under tree stumps when the non-avian dinosaurs died out and mammals took over around 65 mya in the late Cretaceous. Easy stuff, really.

Now, when it gets to who's who in the world of reptiles and their relatives—that is another story, and one you really have to be “in-the-know” to really know. Reptiles and the varied cousins began their path sometime in the remarkable Triassic period of the Mesozoic era that started some 251 million years ago (mya) at the end of the Permian Period of the Paleozoic Era (for a glimpse into the extraordinary diversity of life forms in the Triassic see the recent Anatomical Record Special Issue, “The Dawn of an Era: New Contributions on Comparative and Functional Anatomy of Triassic Tetrapods,” Pinheiro, Pretto, Kerber, 2024; Laitman & Smith, 2024). The term “Pseudosuchia” was created by German paleontologist Karl Alfred von Zittel in 1887–1890 (see Von Zittel, 1901) and used to identify a grouping of somewhat, or superficially, “crocodile-like” (pseudos meaning false, souchos meaning crocodile in ancient Greek) prehistoric Triassic reptiles of the clade Archosauria. The term Pseudosuchia was used to differentiate these superficially “crocodile-like” archosaurs from the more “bird-like” archosaurs often referred to as Avemetatarsalia. Over the years since the clade was anointed, numerous changes have occurred in fossil reptilian taxonomy and phylogeny. Groups have crept in and swam out; indeed, today, true crocodilians are frequently defined as a subset of Pseudosuchia (for a detailed dining experience on all things crocodilian, see the recent Anatomical Record Special Issue, The Age of Crocodilians and their kin: Their Anatomy

Megantereon was a widespread saber-toothed felid from the Pliocene and Pleistocene of the Old World and North America, but its rarity in the fossil record makes it complicated to restore its life appearance. Lack of complete specimens makes it necessary to combine information from fossils of different individuals to reconstruct their facial anatomy. In this work, we combine the analysis of skulls and mandibles of Megantereon from various fossil sites with the study of extant carnivorans through dissection, 3D scans, and the observation of live individuals. Megantereon combined very elongated upper canines with mandibular flanges that were not deep enough to match the length of the sabers, as well as a wide maxilla combined with narrow incisor rows and mandibular symphysis. Such features are compatible with the presence of exposed canines in life, because the narrow symphysis allows room to accommodate lips and other soft tissues medial to the sabers, while the protrusion of the tips of the upper canines beyond the mental flanges makes it unlikely that they would be enveloped in soft tissue sheaths, which would dangle with the inherent risk of puncture. Megantereon was transitional between saber-toothed felids with covered upper canines, where saber length fits with mental flange depth, and the derived Smilodon where the upper canines are much longer than the flanges and the lips fit between upper canines and mandible, leaving the upper canine crowns largely exposed in life.

Tusks are ever-growing teeth present in mammals of the clade Paenungulata. Unlike the perpetually growing incisors of rodents, tusks are not used in mastication, and in at least some paenungulatans, the tusk is composed of dentin alone in adults. Few studies have provided tissue-level information on tusks of adult paenungulatans with embedding techniques that identify epithelial and other soft tissues. In order to examine the mineralized tissues as well as the cells that form teeth, we studied a single, subadult rock hyrax (Procavia capensis) using microCT and paraffin histology with traditional staining as well as RUNX2 immunohistochemistry, and compared its teeth to scans of adult hyraxes. Three-dimensional reconstructions from microCT volumes revealed that the tusk of this specimen is the only fully erupted replacement tooth, the first adult premolar (P1) is starting to erupt, and the first permanent molar (M1) is fully erupted, whereas all other replacement teeth and M2 remain in crypts. The tusk has a thin layer of enamel on its dorsal side; this is confirmed by histology. All deciduous premolars still possess roots that are in the process of resorption. Amelogenesis has progressed to maturation or nearly so in P1–P3. Notable histological characteristics of replacement premolars include the lack of a stellate reticulum in all except P4, and expression of RUNX2 in ameloblasts, a marker which is expressed by ameloblasts at all stages of amelogenesis. Since the pulp chambers of replacement premolars are relatively large compared to adults, a lengthy time in crypts may be important for dentin production. The results confirm that the hyrax has thin enamel on tusks, supporting the hypothesis that enamel is of limited importance for non-feeding behaviors.