Journal of Morphology最新文献

{"title":"Paleoneurology of stem palaeognaths clarifies the plesiomorphic condition of the crown bird central nervous system","authors":"Klara E. Widrig,&nbsp;Guillermo Navalón,&nbsp;Daniel J. Field","doi":"10.1002/jmor.21710","DOIUrl":"10.1002/jmor.21710","url":null,"abstract":"<p>Lithornithidae, an assemblage of volant Palaeogene fossil birds, provide our clearest insights into the early evolutionary history of Palaeognathae, the clade that today includes the flightless ratites and volant tinamous. The neotype specimen of <i>Lithornis vulturinus</i>, from the early Eocene (approximately 53 million years ago) of Europe, includes a partial neurocranium that has never been thoroughly investigated. Here, we describe these cranial remains including the nearly complete digital endocasts of the brain and bony labyrinth. The telencephalon of <i>Lithornis</i> is expanded and its optic lobes are ventrally shifted, as is typical for crown birds. The foramen magnum is positioned caudally, rather than flexed ventrally as in some crown birds, with the optic lobes, cerebellum, and foramen magnum shifted further ventrally. The overall brain shape is similar to that of tinamous, the only extant clade of flying palaeognaths, suggesting that several aspects of tinamou neuroanatomy may have been evolutionarily conserved since at least the early Cenozoic. The estimated ratio of the optic lobe's surface area relative to the total brain suggests a diurnal ecology. <i>Lithornis</i> may provide the clearest insights to date into the neuroanatomy of the ancestral crown bird, combining an ancestrally unflexed brain with a caudally oriented connection with the spinal cord, a moderately enlarged telencephalon, and ventrally shifted, enlarged optic lobes.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 6","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21710","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140957935","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":"Comparative morphology of male genitalia in antlions (Insecta, Neuroptera, Myrmeleontidae), with emphasis on owlflies (Ascalaphinae) and a possible structural evolutionary scenario","authors":"Yesenia Marquez-López,&nbsp;Caleb C. Martins,&nbsp;Luis M. Guevara-Chumacero,&nbsp;Andrés Ramírez-Ponce,&nbsp;Atilano Contreras-Ramos","doi":"10.1002/jmor.21701","DOIUrl":"10.1002/jmor.21701","url":null,"abstract":"<p>Male genitalia morphology in Myrmeleontidae has traditionally been insufficiently studied, although it has received increased attention for its diagnostic value in recent times. A neutral terminology has generally been applied in standard taxonomic practice, yet knowledge of an equivalent and stable terminology across taxa based on comparative morphology has been missing. Herein a detailed comparative morphology study with examples from most tribes within Myrmeleontidae, including owlflies (Ascalaphinae), attempts to relate external and internal genital structures based on a proposed groundplan for Neuroptera and Myrmeleontidae. We contend that a groundplan based on 10 abdominal segments, plus vestigial structures from an 11th segment, coherently depicts structural components across myrmeleontid taxa. A gonarcus, an element of Neuropterida amply referred in Neuroptera, is supported to represent the pair of abdominal appendages of segment X medially fused, with gonocoxite and gonostylus components. In most myrmeleontid taxa, basal (gonocoxites) and distal (gonostyli) components separate, with gonostyli positioned posteriorly with respect to gonocoxites, still united with translucent, lightly sclerotized tissue, forming a more or less conical structure, a proposed synapomorphy for the family. Ninth gonostyli are generally reduced (pulvini) and have migrated close to the base of gonarcus (10th gonocoxites). A pelta, also a potential synapomorphy for Myrmeleontidae, derives from paired setose surfaces of the 10th gonostyli, medially positioned (still evident in <i>Bubopsis</i>). Three structural types of gonarcus are diagnosed for illustrative purposes, as they may represent convergent constructs.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 5","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21701","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140912496","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":"How to do functional morphology, take 2 or 50 years later","authors":"Susan W. Herring","doi":"10.1002/jmor.21709","DOIUrl":"https://doi.org/10.1002/jmor.21709","url":null,"abstract":"","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 5","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140907120","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":"Finite element analysis of kangaroo astragali: A new angle on the ankle","authors":"Peter J. Murphy,&nbsp;Andre J. Rowe,&nbsp;Emily J. Rayfield,&nbsp;Christine M. Janis","doi":"10.1002/jmor.21707","DOIUrl":"10.1002/jmor.21707","url":null,"abstract":"<p>Using finite element analysis on the astragali of five macropodine kangaroos (extant and extinct hoppers) and three sthenurine kangaroos (extinct proposed bipedal striders) we investigate how the stresses experienced by the ankle in similarly sized kangaroos of different hypothesized/known locomotor strategy compare under different simulation scenarios, intended to represent the moment of midstance at different gaits. These tests showed a clear difference between the performance of sthenurines and macropodines with the former group experiencing lower stress in simulated bipedal strides in all species compared with hopping simulations, supporting the hypothesis that sthenurines may have utilized this gait. The Pleistocene macropodine <i>Protemnodon</i> also performed differently from all other species studied, showing high stresses in all simulations except for bounding. This may support the hypothesis of <i>Protemnodon</i> being a quadrupedal bounder.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 5","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21707","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140891978","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":"Aplacophoran traits in the late Ordovician septemchitonid polyplacophorans","authors":"Jerzy Dzik","doi":"10.1002/jmor.21700","DOIUrl":"10.1002/jmor.21700","url":null,"abstract":"<p>A sample of phosphatized, originally calcareous, mollusk shells from the Katian age uppermost Mójcza Limestone at its type locality yielded a few hundred polyplacophoran plates. The chelodids are very rare among them. Three septemchitonid species dominate. They represent a gradation from underived steep roof-like plates to almost cylindrical ones, leaving only a narrow ventral slit for the foot. Apparently, this represents the first step toward the extremely derived ‘segmented clam’ Bauplan of the Silurian <i>Carnicoleus</i>, with plates completely closed at the venter except for the mouth and anal openings. To enable growth, the plates became thinner and more flexible (or perhaps resorbed) along the dorsum. The tendency toward reduction of the ventral gap of the plates in the early Paleozoic septemchitonid polyplacophorans implies their lack of ability to cling to the substrate with a muscular foot. In compensation, their plates changed toward a more efficient protective function, covering the animal body sides more and more completely. This may explain the origin of the ventral furrow of extant solenogasters hiding the rudimentary foot. An opposite route was chosen by the coeval <i>Acaenoplax</i> lineage, in which the plates did not contact each other, exposing much of the soft body on the dorsum. In both cases the animals appeared to be worm-like, perhaps representing different ways of evolution from the Paleozoic chitons to the extant aplacophorans.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 5","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140876601","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":"Comparative morphology of the oropharyngeal denticles in the order Rhinopristiformes and its functional implications (Chondrichthyes: Batoidea)","authors":"Dhayana C. S. Oliveira,&nbsp;Karla D. A. Soares","doi":"10.1002/jmor.21708","DOIUrl":"10.1002/jmor.21708","url":null,"abstract":"<p>Guitarfishes and sawfishes are included in the order Rhinopristiformes, which currently encompasses five families: Pristidae, Rhinobatidae, Trygonorrhinidae, Rhinidae and Glaucostegidae. Considering the low number of studies focused on oral structures in Rhinopristiformes and the need to better understand their internal morphology, this study aimed to (1) evaluate and describe the morphological variation of the oropharyngeal denticles of guitarfishes and sawfish; (2) evaluate and describe the ontogenetic and sexual variation of the oropharyngeal denticles of <i>Zapteryx brevirostris</i>; (3) propose characters potentially useful for taxonomic and systematic purposes and (4) discuss the possible functions and advantages of these structures. Tissue samples were taken from the oropharyngeal region of specimens preserved in 70% alcohol and then prepared for visualization in scanning electron microscopy. A new method for sampling the pharynx region is proposed herein. Considerable morphological variation between families and genera was observed. However, no variation between conspecifics was found. Regional variations of denticles when examining a single individual were observed in shape, ornamentation, and orientation. In <i>Zapteryx brevirostris</i>, males had a significantly higher density of denticles in the ventral region than females and lower densities were observed in juveniles. The four characters discussed here are based on the presence of keels, number of cusps, distal end elongation and width/length ratio of the oropharyngeal denticles. Among the possible functions and advantages of these structures are the improvement of food adherence, tissue protection against food abrasion and parasitism, and attenuation of hydrodynamic drag in the oropharyngeal cavity during food ingestion.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 5","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140891884","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":"Correlated evolution of beak and braincase morphology is present only in select bird clades","authors":"Xiaoni Xu,&nbsp;Rossy Natale","doi":"10.1002/jmor.21703","DOIUrl":"10.1002/jmor.21703","url":null,"abstract":"<p>Complex morphological structures, such as skulls or limbs, are often composed of multiple morphological components (e.g., bones, sets of bones) that may evolve in a covaried manner with one another. Previous research has reached differing conclusions on the number of semi-independent units, or modules, that exist in the evolution of structures and on the strength of the covariation, or integration, between these hypothesized modules. We focus on the avian skull as an example of a complex morphological structure for which highly variable conclusions have been reached in the numerous studies analyzing support for a range of simple to complex modularity hypotheses. We hypothesized that past discrepancies may stem from both the differing densities of data used to analyze support for modularity hypotheses and the differing taxonomic levels of study. To test these hypotheses, we applied a comparative method to 3D geometric morphometric data collected from the skulls of a diverse order of birds (the Charadriiformes) to test support for 11 distinct hypotheses of modular skull evolution. Across all Charadriiformes, our analyses suggested that charadriiform skull evolution has been characterized by the semi-independent, but still correlated, evolution of the beak from the rest of the skull. When we adjusted the density of our morphometric data, this result held, but the strength of the signal varied substantially. Additionally, when we analyzed subgroups within the order in isolation, we found support for distinct hypotheses between subgroups. Taken together, these results suggest that differences in the methodology of past work (i.e., statistical method and data density) as well as clade-specific dynamics may be the reasons past studies have reached varying conclusions.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 5","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21703","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140891893","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":"Tradeoffs between bite force and gape in Eulemur and Varecia","authors":"Myra F. Laird,&nbsp;Taylor A. Polvadore,&nbsp;Gabrielle A. Hirschkorn,&nbsp;Julie C. McKinney,&nbsp;Callum F. Ross,&nbsp;Andrea B. Taylor,&nbsp;Claire E. Terhune,&nbsp;Jose Iriarte-Diaz","doi":"10.1002/jmor.21699","DOIUrl":"10.1002/jmor.21699","url":null,"abstract":"<p>In 1974, Sue Herring described the relationship between two important performance variables in the feeding system, bite force and gape. These variables are inversely related, such that, without specific muscular adaptations, most animals cannot produce high bite forces at large gapes for a given sized muscle. Despite the importance of these variables for feeding biomechanics and functional ecology, the paucity of in vivo bite force data in primates has led to bite forces largely being estimated through ex vivo methods. Here, we quantify and compare in vivo bite forces and gapes with output from simulated musculoskeletal models in two craniofacially distinct strepsirrhines: <i>Eulemur</i>, which has a shorter jaw and slower chewing cycle durations relative to jaw length and body mass compared to <i>Varecia</i>. Bite forces were collected across a range of linear gapes from 16 adult lemurs (suborder Strepsirrhini) at the Duke Lemur Center in Durham, North Carolina representing three species: <i>Eulemur flavifrons</i> (<i>n</i> = 6; 3F, 3M), <i>Varecia variegata</i> (<i>n</i> = 5; 3F, 2M), and <i>Varecia rubra</i> (<i>n</i> = 5; 5F). Maximum linear and angular gapes were significantly higher for <i>Varecia</i> compared to <i>Eulemur</i> (<i>p</i> = .01) but there were no significant differences in recorded maximum in vivo bite forces (<i>p</i> = .88). Simulated muscle models using architectural data for these taxa suggest this approach is an accurate method of estimating bite force-gape tradeoffs in addition to variables such as fiber length, fiber operating range, and gapes associated with maximum force. Our in vivo and modeling data suggest <i>Varecia</i> has reduced bite force capacities in favor of absolutely wider gapes compared to <i>Eulemur</i> in relation to their longer jaws. Importantly, our comparisons validate the simulated muscle approach for estimating bite force as a function of gape in extant and fossil primates.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 5","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21699","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140876602","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":"An atlas of anatomical variants of the human calcaneus","authors":"Samuel James Cockerill,&nbsp;Matilde Arnay-de-la-Rosa,&nbsp;Emilio González-Reimers","doi":"10.1002/jmor.21706","DOIUrl":"https://doi.org/10.1002/jmor.21706","url":null,"abstract":"<p>The usefulness of anatomical variation is determined by the knowledge of why nonmetric traits appear. Clear descriptions of the traits are a necessary task, due to the risk of confusing anatomical variants and evidence of trauma. Numerous interpretations of the appearance of calcaneal anatomical variants add to the need of an anatomical atlas of calcaneal nonmetric traits. We have analyzed a total of 886 calcanei; 559 belong to different modern and pre-Hispanic samples, and 327 bones were studied from a reference collection from Athens. In this study, we present the anatomical variations that exist on the calcaneus bone, some of which have rarely been mentioned in previous research. The standardization of methods proposed may be useful to experts working in human anatomy, physical anthropology as well as comparative morphology, due to usefulness of this information during surgery, and bioanthropology to observe and study the lifestyle of past populations.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 5","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140826204","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":"Ontogenetic changes in jaw leverage and skull shape in tufted and untufted capuchins","authors":"Megan A. Holmes,&nbsp;Claire E. Terhune,&nbsp;Janine Chalk-Wilayto,&nbsp;Caitlin B. Yoakum,&nbsp;Parker Taylor,&nbsp;Rocio Ramirez,&nbsp;Megan P. Solís,&nbsp;Taylor A. Polvadore,&nbsp;Callum F. Ross,&nbsp;Andrea B. Taylor,&nbsp;Mariana Dutra Fogaca,&nbsp;Myra F. Laird","doi":"10.1002/jmor.21705","DOIUrl":"https://doi.org/10.1002/jmor.21705","url":null,"abstract":"<p>The ontogeny of feeding is characterized by shifting functional demands concurrent with changes in craniofacial anatomy; relationships between these factors will look different in primates with disparate feeding behaviors during development. This study examines the ontogeny of skull morphology and jaw leverage in tufted (<i>Sapajus</i>) and untufted (<i>Cebus</i>) capuchin monkeys. Unlike <i>Cebus</i>, <i>Sapajus</i> have a mechanically challenging diet and behavioral observations of juvenile <i>Sapajus</i> suggest these foods are exploited early in development. Landmarks were placed on three-dimensional surface models of an ontogenetic series of <i>Sapajus</i> and <i>Cebus</i> skulls (<i>n</i> = 53) and used to generate shape data and jaw-leverage estimates across the tooth row for three jaw-closing muscles (temporalis, masseter, medial pterygoid) as well as a weighted combined estimate. Using geometric morphometric methods, we found that skull shape diverges early and shape is significantly different between <i>Sapajus</i> and <i>Cebus</i> throughout ontogeny. Additionally, jaw leverage varies with age and position on the tooth row and is greater in <i>Sapajus</i> compared to <i>Cebus</i> when calculated at the permanent dentition. We used two-block partial least squares analyses to identify covariance between skull shape and each of our jaw muscle leverage estimates. <i>Sapajus</i>, but not <i>Cebus</i>, has significant covariance between all leverage estimates at the anterior dentition. Our findings show that <i>Sapajus</i> and <i>Cebus</i> exhibit distinct craniofacial morphologies early in ontogeny and strong covariance between leverage estimates and craniofacial shape in <i>Sapajus</i>. These results are consistent with prior behavioral and comparative work suggesting these differences are a function of selection for exploiting mechanically challenging foods in <i>Sapajus</i>, and further emphasize that these differences appear quite early in ontogeny. This research builds on prior work that has highlighted the importance of understanding ontogeny for interpreting adult morphology.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 5","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140826208","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}