Journal of Morphology最新文献

{"title":"The Influence of Aquaculture and a Natural Environmental Gradient on Shell Landmark Variation of the Mediterranean Mussel (Mytilus galloprovincialis Lamarck, 1819) From the Eastern Adriatic Sea","authors":"Marina Piria,&nbsp;Ivan Špelić,&nbsp;Slađana Nikolić,&nbsp;Rigers Bakiu,&nbsp;Joanna S. Hamilton,&nbsp;Jonathan P. A. Gardner","doi":"10.1002/jmor.70043","DOIUrl":"https://doi.org/10.1002/jmor.70043","url":null,"abstract":"<p>Geometric morphometry is effective in distinguishing bivalve species and populations, including the economically and environmentally important Mediterranean mussel, <i>Mytilus galloprovincialis</i>. Although widely distributed, shell shape variation in <i>M. galloprovincialis</i> along the eastern Adriatic Sea has been infrequently studied. Farming practices and environmental conditions may affect the development of shell shape, as has been reported in the <i>Mytilus</i> genus from numerous locations globally. Building on earlier genetic analyses of mussels collected along a natural environmental gradient, this study aimed to identify shell landmark differentiation between wild and cultured populations and among northern, middle, and southern populations of the eastern Adriatic Sea using a geometric morphometric approach. Samples from 12 sites in Croatia, Montenegro, and Albania, including 4 aquaculture farms, were examined for variation in 9 internal shell landmarks. Wild populations exhibited a more extended posterior adductor muscle scar and a more elongated shape compared to farmed populations. Mussels from low salinity environments in the north and south exhibited an elongated shell shape compared to high salinity environments. Southern populations exhibited an extended posterior adductor muscle scar, along with an elongation of the lateral ligament and ventral umbo orientation that caused a concave shape of the ventral shell border compared to northern populations. The differences in environmental conditions in the Adriatic Sea, such as reduced salinity in Boka Kotorska Bay (Montenegro) in the south and Limski Bay (Croatia) in the north, likely play a role in influencing the variability of shell landmarks. These results may be applied to farming practices so that high-quality spat are collected from source sites with environmental conditions that match the farm site to which the spat are transferred. Overall, these results provide valuable insight into how <i>M. galloprovincialis</i> shell landmarks respond to environmental variation at large (hundreds of kilometres) spatial scale.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"286 4","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.70043","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143707262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Osteology of Dwarfgobies Eviota and Sueviota (Gobiidae: Gobiomorpharia), With Phylogenetic Inferences Within Coral Gobies","authors":"Diego F. B. Vaz,&nbsp;Christopher H. R. Goatley,&nbsp;Luke Tornabene","doi":"10.1002/jmor.70039","DOIUrl":"https://doi.org/10.1002/jmor.70039","url":null,"abstract":"<p><i>Eviota</i> and <i>Sueviota</i> are two genera of cryptobenthic fishes of the family Gobiidae commonly known as dwarfgobies, that collectively contain 142 species. Despite thorough descriptions of the variation of their external morphology, little is known about variations on their skeleton. Combining traditional clearing-and-staining technique with computed scanning microtomography, we examined five species of <i>Sueviota</i> and 40 species of <i>Eviota</i>, representing the two major monophyletic groups in the latter genus, the “branched clade” and “unbranched clade,” named for their pectoral ray morphology. The purpose of this study was to provide generalized descriptions for both genera and highlight potentially phylogenetically informative characters that will aid in future classification of this diverse assemblage of fishes. The posterior portion of the mesethmoid was found to be unossified in eight species of <i>Eviota</i> from the unbranched clade. Twenty-five vertebrae (vs. 26 vertebrae) are present only in species of the unbranched clade of <i>Eviota,</i> and it is considered another potential synapomorphy for this clade. Direct contact between the retroarticular and the anterior edge of the interopercle without the retroarticular-interopercle ligament occurs in all species of <i>Eviota</i> and <i>Sueviota</i>, being interpreted as a potential synapomorphy grouping these two genera. The posterior edge of the interopercle is notched in all species of <i>Eviota</i> and <i>Sueviota</i>, as well as in the closely related genera <i>Bryaninops</i>, <i>Pleurosicya</i>, and <i>Paragobiodon</i>. In species of <i>Sueviota</i> and the branched clade of <i>Eviota</i>, the notch is deep, and there is an additional posteroventral process, forming a wrench-like posterior edge of the interopercle. This wrench-shaped interopercle is a potential synapomorphy, grouping <i>Sueviota</i> with representatives of the branched clade of <i>Eviota</i>. Individual and ontogenetic variations are discussed, including an assessment of the characters previously proposed for characterizing the branched and unbranched clades of <i>Eviota</i>.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"286 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.70039","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Scanning Electron Microscopy Method to Visualise the Copulatory Organ Morphology of Microturbellarian Flatworms: Trigonostomum Schmidt, 1852 as a Case Study","authors":"Laura Vanstraelen,&nbsp;Tom Artois,&nbsp;Thierry Backeljau,&nbsp;Nikol Kmentová,&nbsp;Mare Geraerts,&nbsp;Marlies Monnens","doi":"10.1002/jmor.70040","DOIUrl":"https://doi.org/10.1002/jmor.70040","url":null,"abstract":"<div>\u0000 \u0000 <p>Traditional methods for studying the morphology of microturbellarian flatworms rely on light microscopy, which often lacks the resolution necessary to capture fine structural details. Therefore, we present a protocol to improve the visualisation of structural morphological details in microturbellarians by means of scanning electron microscopy (SEM). We demonstrate this method by imaging the sclerotised copulatory organs of three species of <i>Trigonostomum</i> (Rhabdocoela, Trigonostomidae): <i>T. venenosum</i>, <i>T. setigerum</i>, and <i>T. penicillatum</i>. Additionally, we successfully visualise the bursal appendage of <i>T. penicillatum</i>. SEM imaging offered new morphological insights for the genus, and corrected earlier interpretations made with light microscopy. The method requires precision and careful handling, especially during the isolation of the hard parts. However, it is cost-effective and straightforward to carry out in any standard laboratory setting. Hence, our SEM protocol complements traditional light microscopy and opens new avenues for taxonomical research in microturbellarian taxa with hard parts.</p></div>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"286 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143581823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphology and Volatilomics of the Pre-Pharyngeal and Pharyngeal Glands of Paraponera clavata (Hymenoptera: Paraponerinae) and Pachycondyla crassinoda (Hymenoptera: Ponerinae) Workers","authors":"Erika Vanessa C. C. Sousa,&nbsp;Elane Borba Alves,&nbsp;Ana Paula Pereira Raimundo,&nbsp;Jodieh Oliveira Santana Varejão,&nbsp;Eduardo Vinícius Vieira Varejão,&nbsp;José Eduardo Serrão","doi":"10.1002/jmor.70038","DOIUrl":"https://doi.org/10.1002/jmor.70038","url":null,"abstract":"<div>\u0000 \u0000 <p>Ants occur in a remarkable diversity of species, many of which fulfill essential ecological roles and exhibit complex eusocial behaviors. Among their unique adaptations are specialized exocrine glands, such as the pre-pharyngeal and pharyngeal glands, which produce secretions crucial for physiology and social cohesion. Despite their importance, these glands are poorly studied in Paraponerinae and Ponerinae species. This study examines the morphology and chemical composition of these glands in workers of <i>Paraponera clavata</i> (Paraponerinae) and <i>Pachycondyla crassinoda</i> (Ponerinae). The results document distinct morphological and morphometric differences: the pre-pharyngeal gland in <i>P. clavata</i> is larger, with cells rich in proteins and glycoproteins, whereas in <i>P. crassinoda</i>, the gland has more extensive secretory cells and a higher concentration of lipids. Additionally, the pharyngeal glands in <i>P. clavata</i> are tubular, while in <i>P. crassinoda</i>, they have large lobes with internal cuticular projections. Chemical analyses identified shared hydrocarbons between the species, as well as unique compounds that may reflect specific behavioral and ecological adaptations. These findings suggest that morphological and chemical differences in these ants' glands are potentially associated with dietary habits and behavioral traits.</p></div>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"286 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143571226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Maxillofacial Development of Mice, Mus musculus","authors":"Hiroki Higashiyama,&nbsp;Shunya Kuroda,&nbsp;Akiyasu Iwase,&nbsp;Naoki Irie,&nbsp;Hiroki Kurihara","doi":"10.1002/jmor.70032","DOIUrl":"https://doi.org/10.1002/jmor.70032","url":null,"abstract":"<p>The maxillofacial region is one of the most complex areas in the vertebrate body plan. The homology of the upper jaw bones remain controversial, both between mammals and nonmammalian amniotes and among humans and other mammals, leading to various hypotheses on how this region evolved from ancestral amniotes to humans. As a key mammalian model, the mouse (<i>Mus musculus</i>) is vital for unraveling the evolution and development of the maxillofacial region experimentally. However, limited detailed morphological descriptions of murine cranial development hinder the extrapolation of findings to other species, including humans. Here, we describe the development of the murine face, including the nerves, skeletons, and vasculatures from the pharyngula (9.0 days post-coitum [dpc]) to the late fetal period (18.5 dpc) based on three-dimensional reconstructions of histological sections. The present results confirm that the morphology of the pharyngula stages and developmental process of chondrocranium of mice is highly conserved when compared to nonmammalian tetrapods and humans. We also propose that the Os incisivum, the rostralmost bone in the mammalian upper jaw, consists of septomaxillary and palatine components, supporting our previous hypothesis that the ancestral premaxilla was entirely lost in mammals. The present descriptive study of mice strengthen the anatomical correspondence between mouse and human faces and offers a solid framework for comparative craniofacial studies across vertebrates.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"286 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.70032","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143521760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Morphology of the Rare Beetle Silphopsyllus desmanae (Leiodidae), a Commensal of the Semiaquatic Russian Desman","authors":"Paweł Jałoszyński,&nbsp;Odair M. Meira,&nbsp;Margarita I. Yavorskaya,&nbsp;Alexandr Prokin,&nbsp;Veit Grabe,&nbsp;Rolf G. Beutel","doi":"10.1002/jmor.70031","DOIUrl":"https://doi.org/10.1002/jmor.70031","url":null,"abstract":"<p><i>Silphopsyllus desmanae</i>, a species of the small subfamily Platypsyllinae of Leiodidae, lives in the fur of the semiaquatic Russian desman, and is apparently adapted to this highly specialized life style. Even though the morphology of adults of the species was described almost 70 years ago, we re-examined it with modern methods and documented its external and internal features in detail, and discuss them with respect to phylogeny and function. Our analyses of morphological data place <i>Leptinillus</i> as the sister group of the remaining genera of Platypsyllinae, and <i>Leptinus</i> as the sister group of <i>Silphopsyllus</i> + <i>Platypsyllus</i>. Platypsyllinae are supported by many putative autapomorphies: supraantennal ridges directed mesad but not extending beyond the antennal insertions and not forming a transverse ridge; tentorium without connected laminatentoria anterior to the tentorial bridge; submentum subrectangular; labrum about as wide as the maxillary-labial complex; elongate and posteriorly projecting lateral lobes of the mentum; antennomeres lacking periarticular gutters (and Hamann's organs); cervical sclerites absent; precoxal prosternal region distinctly longer than the coxal rests; mesocoxal cavities situated closer to the body midline than to the lateral mesothoracic margins; metanepisterna fused with the metaventrite; metascutum laterally overlapping the meso- and metapleural regions; procoxae subglobose or only slightly elongate; mesocoxae subglobose. Platypsyllinae are most likely the sister group of Coloninae + Cholevinae. Eight unique apomorphies differentiating <i>Platypsyllus</i> from all the remaining Platypsyllinae are mainly adaptations for living in the fur of beavers. <i>Silphopsyllus</i> is much less adapted to life on a semiaquatic host than <i>Platypsyllus</i>.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"286 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.70031","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143497374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Organization of Lacunar and Muscular Systems of Polyascus polygeneus and Parasacculina pilosella (Rhizocephala: Polyascidae)","authors":"Natalia A. Arbuzova,&nbsp;Anastasia D. Lianguzova,&nbsp;Olga M. Korn,&nbsp;Aleksei A. Miroliubov","doi":"10.1002/jmor.70037","DOIUrl":"https://doi.org/10.1002/jmor.70037","url":null,"abstract":"<div>\u0000 \u0000 <p>Circulatory systems are characteristic of most multicellular animals. In parasitic organisms, which may differ strikingly from their free-living relatives, such systems remain the least studied. Rhizocephala (Pancrustacea: Cirripedia) are among the morphologically most derived parasitic crustaceans. In the adult rhizocephalan female, transport presumably takes place along the lacunar system inside the interna rootlets and the externa. The aim of our study was to visualize and describe the lacunar and muscular systems in the externa of <i>Polyascus polygeneus</i> and <i>Parasacculina pilosella</i> (fam. Polyascidae) using micro-computed tomography and confocal microscopy. The lacunar system in the externae of both species consists of the stalk lumen, mesentery lacuna accompanying the visceral mass and mantle lacunae. These elements of the lacunar system are similar to those previously described in <i>Peltogasterella gracilis</i> (fam. Peltogasterellidae). However, the interposition of these elements differs. The organization of the muscular system mostly corresponds to previous descriptions in other rhizocephalan species, however some unexpected results were obtained. For example, <i>P. polygeneus</i> has an age-related differentiation of mantle musculature, which was not described before for any rhizocephalan species. Obtained data on lacunar and muscular systems organization allow us to assume the change in the externa body axes in the family Polyascidae.</p></div>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"286 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143475404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Fila Olfactoria and the Cribriform Region of the Crocodylia","authors":"Matthew Dille,&nbsp;Michael Cramberg,&nbsp;Hadyn DeLeeuw,&nbsp;Emily Pick,&nbsp;Mary Thompson,&nbsp;Bruce A. Young","doi":"10.1002/jmor.70036","DOIUrl":"https://doi.org/10.1002/jmor.70036","url":null,"abstract":"<p>In mammals the fila olfactoria, fascicles of axons coursing from sensory neurons in the olfactory epithelium to the glomeruli of the olfactory bulb, not only have a topographic projection pattern but also serve as routes for cerebrospinal fluid (CSF) drainage from around the brain. Les is known about the fila olfactoria in nonmammalian taxa. This work explores the fila olfactoria of the American alligator (<i>Alligator mississippiensis</i>) using a combination of gross dissection, histology, Diffusible Iodine-based contrast-enhanced computed tomography, latex corrosion casting, and India ink tracers. In Crocodylians, as in other nonmammalian vertebrates, the fila olfactoria courses through a foramen in the nasal capsule rather than an ethmoidal cribriform plate. In <i>Alligator</i> this foramen is filled by dense connective tissue; prominent perineural spaces extend through the connective tissue, effectively making it perforate like the cribriform plate. Latex or India ink introduced into the cranial CSF pass through the dense connective to reach the submucosa of the olfactory epithelium, suggesting that Crocodylians have the same cranial CSF drainage pattern as mammals. In <i>Alligator</i>, the fila olfactoria is asymmetric, with more fascicles entering the ventral and lateral surfaces of the olfactory bulb than the dorsal or medial surfaces. If individual fascicles of the fila olfactoria are traced in <i>Alligator</i>, a clear topographic projection emerges; with medial and lateral polarity maintained between olfactory epithelium and olfactory bulb, and a rostral-caudal polarity projecting as dorsal-ventral on the olfactory bulb.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"286 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.70036","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143466295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphological Investigation of Superficial Fascia Relationships With the Skin and Underlying Tissues in the Canine Hindlimb","authors":"Oday A. Al-Juhaishi,&nbsp;Zeeshan Akbar,&nbsp;Saad M. Y. Ismail,&nbsp;Smitha Rose Georgy,&nbsp;Christina M. Murray,&nbsp;Helen M. S. Davies","doi":"10.1002/jmor.70033","DOIUrl":"https://doi.org/10.1002/jmor.70033","url":null,"abstract":"<div>\u0000 \u0000 <p>The morphology of the superficial fascia in the canine hindlimb is still poorly understood and incompletely described. The present study aimed to elucidate the macroscopic and microscopic structures of the superficial fascia, thereby clarifying its functional role. Cadavers were investigated for anatomic description (<i>N</i> = 38), ultrasonic scanning (<i>N</i> = 2), and histological analyses (<i>N</i> = 10) of this tissue in the hindlimb. The superficial fascia was identified as a shiny, white fibroelastic layer that adhered to the skin through fibrous septa. It was organized into sublayers enveloping the cutaneous muscle and large blood vessels. In certain areas, superficial fascia fused with the deep fascia or skin, creating fascial bursae. These bursae included the ischiatic bursa, an iliac bursa, a prepatellar subfascial bursa, a prepatellar subcutaneous bursa, and the tarsal fascial bursa. Microscopically, the superficial fascia presented as a layer of dense connective tissue characterized by irregularly arranged collagen and elastic fibers. The superficial fascia was firmly attached to the skin and deep fascia by numerous fibrous tissue strands. Within both, the superficial fascia and fascial bursae, several mechanoreceptors and nerve endings were identified, including Ruffini's corpuscles, Pacinian corpuscles, and Golgi-Mazzoni corpuscles. The organization of the superficial fascia and its attachments suggest a mechanical role in supporting structures and resisting loads during movement. The fibrous septa anchors fascia to the skin, providing stability and resistance against external forces, as well as protecting the nerves and blood vessels that pass towards the skin. Existing fascial bursae probably assist in decreasing pressure and facilitating freedom of movement adjacent to bony prominences. Elasticity and connectivity of the superficial fascia may explain the various responses to multidirectional loading. Furthermore, the presence of free nerve endings and mechanoreceptors within the fascia suggests that it may contribute to proprioception of the hindlimb, enhancing the awareness of body movement.</p></div>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"286 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143466300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hidden Armour: The Passive Protective Function of Caudal Osteoderms in Snakes","authors":"Petra Frýdlová,&nbsp;Jan Dudák,&nbsp;Veronika Tymlová,&nbsp;Jan Žemlička,&nbsp;Jiří Moravec,&nbsp;Daniel Frynta","doi":"10.1002/jmor.70034","DOIUrl":"https://doi.org/10.1002/jmor.70034","url":null,"abstract":"<p>Dermal armour, consisting of bony dermal structures known as osteoderms (ODs), is widespread in squamate reptiles. However, in some limbless taxa such as snakes, ODs are rare, probably due to a trade-off between mechanical protection and the demands of locomotion and consumption of large prey. Recent findings of ODs restricted to the distal body regions of sand boas (<i>Eryx</i>, Erycidae) challenge this paradigm, suggesting they provide passive mechanical protection against aggressive prey without significantly impairing locomotion. Building on these findings, we have continued the search and identified three additional snake species that have well-developed caudal ODs, including the first-ever discovery of ODs in shield-tailed snakes (Uropeltidae). In these fossorial species, which are characterised by their unique tail morphology, ecological adaptations and colouration, the ODs at the tail tip may serve as passive protection against predators. However, an alternative role in locomotion or occasional phragmosis cannot be ruled out. In the Javelin sand boa (<i>Eryx jaculus</i>), the ODs are hypothesised to function as a mechanical defence against aggressive prey. These results highlight the functional and evolutionary plasticity of ODs and emphasise the urgent need for further studies on their specific role and adaptive significance in the ecology and evolution of snakes.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"286 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.70034","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143466297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}