{"title":"Comparative anatomy of the ossified braincase of legless anguine lizard Pseudopus apodus (Pallas, 1775) (Squamata, Anguimorpha).","authors":"Jozef Klembara, Miroslav Hain","doi":"10.1002/ar.25695","DOIUrl":"https://doi.org/10.1002/ar.25695","url":null,"abstract":"<p><p>The braincase and inner ear of the largest species of legless anguine lizards, Pseudopus apodus, are described in detail based on high-resolution x-ray microcomputed tomography. Here, the ontogeny of its braincase is briefly described. The detailed anatomy of the individual braincase bones of P. apodus is presented and compared with those of the modern anguine species Anguis fragilis and species of Ophisaurus, Dopasia, and Hyalosaurus. Because only the extant species of Anguinae are studied and discussed here, the generic names of modern taxa defined genetically-Ophisaurus (North America), Dopasia (Southeast Asia), and Hyalosaurus (North Africa)-are used here. The shape of the supraoccipital in juveniles was similar for all species found in all three geographic territories. During growth, the shape of the supraoccipital changes significantly in Pseudopus, Dopasia, and Ophisaurus, and its shape is very similar to that in adults of the anguine taxon Ophisauriscus quadrupes from the Middle Eocene of Germany. Instead, the shape of the supraoccipital in the adults of Hyalosaurus and Anguis is very similar to that in the juveniles of Pseudopus, Dopasia, and Ophisaurus. This suggests that paedomorphosis probably played a role in the shape formation of the supraoccipital in Hyalosaurus and Anguis. The morphological and proportional changes in several other braincase structures during ontogeny are also described.</p>","PeriodicalId":520555,"journal":{"name":"Anatomical record (Hoboken, N.J. : 2007)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144130013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gen Nakamura, Hiroko Yamada, Ayumi Hirose, Hikari Maeda, Joy S Reidenberg, Hidehiro Kato, Shinho Park, Yoshihiro Fujise
{"title":"Discovery of sexual dimorphism of the laryngeal sac in the common minke whale Balaenoptera acutorostrata.","authors":"Gen Nakamura, Hiroko Yamada, Ayumi Hirose, Hikari Maeda, Joy S Reidenberg, Hidehiro Kato, Shinho Park, Yoshihiro Fujise","doi":"10.1002/ar.25681","DOIUrl":"https://doi.org/10.1002/ar.25681","url":null,"abstract":"<p><p>Mysticetes, or baleen whales, have an air sac on the ventral surface of the larynx known as the \"laryngeal sac.\" The primary hypothesis regarding this structure's function is that it is involved in sound production. However, several other functions have been proposed, including air recycling, air storage, and even buoyancy control. In this study, we analyzed ontogenetic development and sexual dimorphism of the laryngeal sac with an aim of elucidating the function of this organ. The larynx of 61 (male: n = 40, female: n = 21) common minke whales Balaenoptera acutorostrata, collected from off the Japanese coast were used for present study. We isolated the larynx, situated between the hyoid bone and the trachea, during the flensing process. Seven linear measurements were taken using calipers, and the weight was obtained using a digital weight scale. Allometric equation and proportions to total body length or weight were used to compare laryngeal morphological differences between sexes and maturity. Measurements of laryngeal sac size were significantly larger in sexually mature males. Furthermore, examination of two male individuals of approximately the same body length but different maturities showed the sexually mature male had a larger laryngeal sac, compared to sexually immature male. The thickness of the laryngeal sac's muscle wall and the volume of the sac's lumen may be related to testes development (sexually mature whales have heavier testes). Only the width of the hyoid bone (basihyal and paired thyrohyals) was proportionally constant within all measurement sites, regardless of sex or maturity. We propose that baleen whales utilize their well muscularly developed laryngeal sac in a manner analogous to the human tongue, actively modifying its shape and volume to influence vocal production. Specifically, this structure may function as a resonance filter that creates a formant structure and contributes to the modification of phonemes generated by the U-folds of the larynx. Furthermore, the ability to produce complex vocalizations through this mechanism may have led to the enlargement of the laryngeal sac in males via sexual selection, where it also serves as a signal of their reproductive status.</p>","PeriodicalId":520555,"journal":{"name":"Anatomical record (Hoboken, N.J. : 2007)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144121973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sarah E Freidline, Madison Hubbart, Catherine Shipman, Najielie Burgos, Chiara Villa, Alexandra Schuh
{"title":"Shaping the human face: Periosteal bone modeling across ontogeny.","authors":"Sarah E Freidline, Madison Hubbart, Catherine Shipman, Najielie Burgos, Chiara Villa, Alexandra Schuh","doi":"10.1002/ar.25689","DOIUrl":"https://doi.org/10.1002/ar.25689","url":null,"abstract":"<p><p>Facial morphology is a defining aspect of Homo sapiens that distinguishes our species from fossil ancestors and plays a central role in estimating age, sex, and ancestry in both past and present populations. Understanding how the face develops during postnatal ontogeny is essential for interpreting adult facial variation. Periosteal bone modeling (i.e., patterns of resorption and formation) provides direct evidence of bone growth activity underlying morphological variation. This study quantifies periosteal bone modeling in a cross-sectional ontogenetic sample of individuals ranging from birth to adulthood from three geographical populations: Western Europe, Greenland, and South Africa. Epoxy replicas were analyzed using digital microscopy to quantify bone resorption, and digital maps of the bone modeling patterns were created for each facial region-brow ridge, zygomatic, maxilla, and mandible-and projected onto three-dimensional surface models. In parallel, geometric morphometric and multivariate statistical analyses were used to evaluate ontogenetic patterns. Results highlight a consistent sequence of resorption and deposition during human ontogeny and a strong pattern of covariation between bone modeling and shape for most facial regions. The face is largely resorptive from early ontogeny, with deposition increasing with age; the maxilla is significantly more resorptive than other facial regions. Greater resorption in the midface corresponds to significant facial growth and development in early ontogeny, and a developmental shift around adolescence marks the transition from primarily downward to more forward-oriented growth. Overall, the combined approach underscores the developmental coordination of the face and suggests that the human facial growth pattern reflects the need to maintain a non-projecting face from birth on.</p>","PeriodicalId":520555,"journal":{"name":"Anatomical record (Hoboken, N.J. : 2007)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144096757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}