Anatomical record (Hoboken, N.J. : 2007)最新文献_第6页

The hierarchical nature of mammalian tooth enamel resilience, and a novel measure of decussational strength in human molars. 哺乳动物牙釉质弹性的等级性质，以及人类磨牙讨论强度的新措施。

IF 2.1

Anatomical record (Hoboken, N.J. : 2007) Pub Date : 2026-08-30 DOI: 10.1002/ar.70325

Frederick E Grine, Deming Yang, Carrie S Mongle

{"title":"The hierarchical nature of mammalian tooth enamel resilience, and a novel measure of decussational strength in human molars.","authors":"Frederick E Grine, Deming Yang, Carrie S Mongle","doi":"10.1002/ar.70325","DOIUrl":"https://doi.org/10.1002/ar.70325","url":null,"abstract":"The resilience of mammalian tooth enamel to fatigue and fracture stems from its anisotropic structure, which is manifest at various hierarchical levels from the nanoscale to the macroscale. At the nanoscale level, the alignment trajectories of thin hydroxyapatite nanocrystals and the organic matrix serve to convey anisotropy and deformability. Various prism packing configurations provide additional structural heterogeneity at the microscale level, while at the mesoscale, the angles at which parazonal and diazonal prisms decussate furnish yet more structural incongruity. At the macroscale level, Hunter-Schreger band (HSB) packing patterns appear to conform to masticatory loading mechanics. This study undertakes a quantitative evaluation of the strength of enamel decussation at the mesoscale in human permanent molars by measuring the degree to which prism pitch angle deviates in adjacent diazones and parazones using scanning electron microscopy. While HSB packing tends to be denser in \"functional\" cusps, decussational strength tends to be greater in \"guiding\" cusps, and whereas HSB packing tends to be denser in maxillary molars, decussational strength tends to be greater in mandibular molars. The general lack of concordance between measures of decussation at the mesoscale and macroscale levels may suggest that decussational strength may serve to compensate for lower HSB packing densities in human permanent molars.","PeriodicalId":520555,"journal":{"name":"Anatomical record (Hoboken, N.J. : 2007)","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148868891","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}

引用次数: 0

Secretagogin immunoreactivity in the forebrain, midbrain and pituitary of the three spot gourami, Trichopodus trichopterus (Pallas, 1770). 三点gourami Trichopodus trichopterus前脑、中脑和垂体分泌素免疫反应性（Pallas, 1770）

IF 2.1

Anatomical record (Hoboken, N.J. : 2007) Pub Date : 2026-08-24 DOI: 10.1002/ar.70307

Yashica L Gharad, Vikas G Barsagade, Swati A Koushik, Sandesh P Kamdi

{"title":"Secretagogin immunoreactivity in the forebrain, midbrain and pituitary of the three spot gourami, Trichopodus trichopterus (Pallas, 1770).","authors":"Yashica L Gharad, Vikas G Barsagade, Swati A Koushik, Sandesh P Kamdi","doi":"10.1002/ar.70307","DOIUrl":"https://doi.org/10.1002/ar.70307","url":null,"abstract":"Secretagogin (SCGN), a calcium-binding protein (CBP) implicated in neuroendocrine signaling, was investigated for its spatial distribution in the forebrain, midbrain, and pituitary of the three spot gourami, Trichopodus trichopterus, a representative labyrinthine teleost. Using immunohistochemistry, SCGN-immunoreactive (SCGN-ir) neurons and fibers were comprehensively mapped across forebrain and midbrain regions. In the telencephalon, strong SCGN expression was observed in the olfactory bulb, particularly within the granule cell layer, along with notable labeling in subdivisions of the pallium and subpallium. Distinct SCGN-ir cell populations were identified in the magnocellular preoptic nucleus and the nucleus preopticus periventricularis. In the hypothalamus, SCGN-positive cells were distributed throughout the dorsal, ventral, and caudal regions, with extension into adjacent thalamic structures such as the paraventricular organ. Additionally, dense SCGN-ir fibers were evident in the optic tectum. In the pituitary, intense SCGN immunoreactivity was localized to the rostral and proximal pars distalis, whereas the pars intermedia showed no labeling. This study represents the first detailed neuroanatomical mapping of SCGN in a labyrinthine teleost and reveals a widespread but region-specific pattern of SCGN localization within sensory and neuroendocrine-associated brain regions.","PeriodicalId":520555,"journal":{"name":"Anatomical record (Hoboken, N.J. : 2007)","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148815008","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}

引用次数: 0

The lower deciduous dentition of protodidelphids (Mammalia, Marsupialia) from the Itaboraí Basin (lower Eocene), Brazil, and the validity of "Riolestes capricornicus" (Goin et al., 2009). 巴西Itaboraí盆地（始新世下）原delphids（哺乳类，有袋类）的下乳牙列，以及“Riolestes capricornicus”的有效性（Goin et al., 2009）。

IF 2.1

Anatomical record (Hoboken, N.J. : 2007) Pub Date : 2026-08-23 DOI: 10.1002/ar.70312

Leonardo M Carneiro, Hugo Bampi, João P P Araújo, Marina B Soares, Gustavo R Oliveira

{"title":"The lower deciduous dentition of protodidelphids (Mammalia, Marsupialia) from the Itaboraí Basin (lower Eocene), Brazil, and the validity of \"Riolestes capricornicus\" (Goin et al., 2009).","authors":"Leonardo M Carneiro, Hugo Bampi, João P P Araújo, Marina B Soares, Gustavo R Oliveira","doi":"10.1002/ar.70312","DOIUrl":"https://doi.org/10.1002/ar.70312","url":null,"abstract":"The Itaboraí Basin, Southeastern Brazil, preserved one of the most diverse mammalian faunas from the Paleogene, with Metatheria comprising more than 60% of its diversity. Among identified metatherian clades, it has been argued that Paucituberculata is represented by \"Riolestes capricornicus\". This species was described based on a putative first lower molar (m1). However, its morphological pattern is remarkably similar to that of deciduous third lower premolars (dp3s) recovered in this basin, differing mostly by its more inflated crown. These similarities led to a previous hypothesis that this specimen represents a deciduous tooth. In this contribution, we review the dental anatomy of \"R. capricornicus\" and describe a dp3 of Protodidelphis vanzolinii. To test the hypothesis that \"R. capricornicus\" is a dp3, we performed a principal component analysis (PCA) to distinguish, for the first time, the morphology of deciduous third lower premolars (dp3s) from that of lower molars. Our results indicate that the morphological pattern of the holotype of \"R. capricornicus\" is occlusally compatible with that of an upper deciduous third premolar (DP3) of the protodidelphine Robertbutleria mastodontoidea, confirming its deciduous (dp3) nature and, thus, \"R. capricornicus\" is a junior synonym of Ro. mastodontoidea. Therefore, Paucituberculata is no longer recorded in the Itaboraí Basin, restricting its occurrence during the early Eocene to southern Patagonia (Austral biogeographic zone). Further, an Austral ancestral area for Paucituberculata and Australidelphia is suggested.","PeriodicalId":520555,"journal":{"name":"Anatomical record (Hoboken, N.J. : 2007)","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148809726","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}

引用次数: 0

Neck muscle motoneuron anatomy in woodpeckers: An exploration of morphological specializations linked to extreme beak behavior. 啄木鸟颈部肌肉运动神经元解剖：与喙的极端行为有关的形态学特化的探索。

IF 2.1

Anatomical record (Hoboken, N.J. : 2007) Pub Date : 2026-08-23 DOI: 10.1002/ar.70310

Nicole M Moody, Stephen O Ogunbiyi, Nicole M Meléndez, Marc F Schmidt, Matthew J Fuxjager

{"title":"Neck muscle motoneuron anatomy in woodpeckers: An exploration of morphological specializations linked to extreme beak behavior.","authors":"Nicole M Moody, Stephen O Ogunbiyi, Nicole M Meléndez, Marc F Schmidt, Matthew J Fuxjager","doi":"10.1002/ar.70310","DOIUrl":"https://doi.org/10.1002/ar.70310","url":null,"abstract":"The avian head and neck often work together as a singular unit, where they act as a \"surrogate limb\" to accomplish a variety of ecologically important tasks. Functional diversity of this system can emerge through various anatomical specializations, though details of these specializations remain underexplored. Woodpeckers offer a prime example of unique head and neck behavior, as they drill and drum on hard woody surfaces to forage, excavate nests, and communicate. Here, we investigate neuroanatomical features of the neck that may relate to woodpeckers' highly specialized behavior. Assuming that specialized behavior can be associated with neuroanatomical modifications, we use retrograde tract-tracing to map spinal motoneuron characteristics in downy woodpeckers. We focus on two neck muscles that drive head protraction (longus colli ventralis, LCv) and retraction (longus colli dorsalis, LCd), and we compare motoneuron features for these muscles to those of the scapulohumeralis, a shoulder muscle that is not implicated in drumming. We also perform cross species comparisons with motoneurons in house sparrows, a similarly sized non-drumming bird. Our results show that motor pool size, density, and location for all three muscles tested are consistent between woodpeckers and sparrows. Yet, we find that motoneuron soma size varies by muscle, such that cells innervating neck muscles are smaller on average than those innervating the shoulder, regardless of species. We conclude that specializations for woodpecker drumming and drilling are not explained by simple neuroanatomical differences. Rather, adaptations for motor control of the woodpecker head and neck likely emerge at the physiological level.","PeriodicalId":520555,"journal":{"name":"Anatomical record (Hoboken, N.J. : 2007)","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148809734","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}

引用次数: 0

Pelvic breadth and juvenile locomotor energetics: Implications for the obstetrical dilemma hypothesis across human growth in past and present humans. 骨盆宽度和青少年运动能量学：对过去和现在人类生长中的产科困境假说的影响。

IF 2.1

Anatomical record (Hoboken, N.J. : 2007) Pub Date : 2026-08-23 DOI: 10.1002/ar.70329

Guillermo Zorrilla-Revilla, Olalla Prado-Nóvoa, Kevin P Davy, José Miguel Carretero, Rebeca García-González

{"title":"Pelvic breadth and juvenile locomotor energetics: Implications for the obstetrical dilemma hypothesis across human growth in past and present humans.","authors":"Guillermo Zorrilla-Revilla, Olalla Prado-Nóvoa, Kevin P Davy, José Miguel Carretero, Rebeca García-González","doi":"10.1002/ar.70329","DOIUrl":"10.1002/ar.70329","url":null,"abstract":"The obstetrical dilemma hypothesis (ODH) proposes an evolutionary trade-off between obstetric requirements and locomotor performance. However, whether external pelvic breadth measures influence walking energetics during human growth remains poorly understood. This study quantified gross walking energy expenditure (WalkingEE) in juveniles and examined whether external pelvic breadth measures influence locomotor energetics during growth. Twenty-eight healthy children and adolescents (8-17 years) completed treadmill walking trials at randomized speeds (2-6 km/h). Gross WalkingEE (kcal/24 h) was measured by indirect calorimetry, and anthropometric variables included body mass (BM), height, femur length, tibia length, bi-iliac breadth (BIL), and bi-trochanteric breadth (BITR). Forward stepwise multiple linear regression identified BM, walking speed, and BIL as the only significant predictors of WalkingEE (R2 = 0.89, *p < 0.0001). BM and walking speed were positively associated with energy expenditure, whereas BIL showed a significant negative association, accounting for 43%, 31.5%, and -25.5% of the explained effect, respectively. These findings indicate that greater bi-iliac breadth is associated with lower walking energy expenditure during growth. Moreover, the fact that bi-trochanteric breadth was not retained in the final model, despite being used as a proxy more closely associated with obstetric dimensions, suggests that locomotor energetics and obstetric function may be at least partly independent. Overall, our findings are consistent with a more dynamic interpretation of the obstetrical dilemma hypothesis and provide new empirical support for the view that the human pelvis is a functionally modular structure shaped by multiple selective pressures.","PeriodicalId":520555,"journal":{"name":"Anatomical record (Hoboken, N.J. : 2007)","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148809743","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}

引用次数: 0

A new view of an old enigma: Reassessing Gymnesicolagus gelaberti (Lagomorpha) from the Middle Miocene of Mallorca (Balearic Islands). 一个古老谜团的新观点：重新评估中中新世马略卡岛（巴利阿里群岛）的Gymnesicolagus gelaberti （Lagomorpha）

IF 2.1

Anatomical record (Hoboken, N.J. : 2007) Pub Date : 2026-08-21 DOI: 10.1002/ar.70322

Stanislav Čermák, Zuzana Heřmanová, Blanca Moncunill-Solé, Chiara Angelone

{"title":"A new view of an old enigma: Reassessing Gymnesicolagus gelaberti (Lagomorpha) from the Middle Miocene of Mallorca (Balearic Islands).","authors":"Stanislav Čermák, Zuzana Heřmanová, Blanca Moncunill-Solé, Chiara Angelone","doi":"10.1002/ar.70322","DOIUrl":"https://doi.org/10.1002/ar.70322","url":null,"abstract":"Over 40 years ago, a peculiar fossil lagomorph was described from the Middle Miocene of Mallorca (Balearic Islands, Spain). Gymnesicolagus gelaberti possesses enormous teeth with striking morphological features, making its systematic placement enigmatic. Here we revise the holotype and the currently available type material, and we describe additional, previously unreported specimens. Alongside classical comparative approaches, we performed micro-CT-based 3D reconstructions of selected specimens to investigate internal dental features relevant for taxonomic purposes. Several of the peculiar dental traits of G. gelaberti can be interpreted as insularity-driven modifications consistent with the Island Rule (increased size, hypsodonty/hypselodonty). Other traits provide relevant phylogenetic signals linking G. gelaberti to the European MP30-MN1 stem lagomorphs of the \"Amphilagus antiquus-Titanomys group\". Most notably, a unique and exceptionally rare p3 morphotype discovered in this mainland stock may explain the puzzling p3 morphotype of G. gelaberti as the fixation of a rare character under the founder effect. The evolutionary history of G. gelaberti shows notable similarities to that of Paludotona spp., other endemic insular stem lagomorphs of the western Mediterranean. Both genera are interpreted as deriving from pre-MN2 continental ancestors, are characterized by extended ghost intervals during their early evolutionary histories, and persisted in isolation within fragmented insular domains for several million years.","PeriodicalId":520555,"journal":{"name":"Anatomical record (Hoboken, N.J. : 2007)","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148804778","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}

引用次数: 0

Osteohistology of the northern raccoon (Procyon lotor) reveals unusual prevalence of cortical compacted coarse cancellous bone. 北浣熊的骨组织学显示皮质致密的粗松质骨异常普遍。

IF 2.1

Anatomical record (Hoboken, N.J. : 2007) Pub Date : 2026-08-20 DOI: 10.1002/ar.70323

Christian T Heck, Gwyneth Volkmann, Holly N Woodward

{"title":"Osteohistology of the northern raccoon (Procyon lotor) reveals unusual prevalence of cortical compacted coarse cancellous bone.","authors":"Christian T Heck, Gwyneth Volkmann, Holly N Woodward","doi":"10.1002/ar.70323","DOIUrl":"https://doi.org/10.1002/ar.70323","url":null,"abstract":"Northern raccoons (Procyon lotor) are common throughout North America and have been introduced into other countries through a variety of means. Intraskeletal surveys of northern raccoon bone microstructure are currently absent in the literature despite the prevalence of the northern raccoon throughout North America. To further explore raccoon bone tissue composition, we describe dentary, forelimb, and hindlimb bone microstructure in a female northern raccoon. General cortical organization consisted of an endosteal layer of lamellar bone followed by a mid-cortex of woven-parallel complex bone (WPC), compacted coarse cancellous bone (CCCB), or both WPC and CCCB. An incomplete incipient external fundamental system is found in the outer cortex of appendicular bones, but not the dentary. All sampled bones contained one or two lines of arrested growth, and all growth lines were near the periosteal surface. Bone microstructure composition deviated from most previous descriptions of carnivore cortices due to the extensive intraskeletal presence of CCCB. CCCB in long bone mid-diaphyses of mammals is reported in only a few of the extant vertebrate taxa thus far studied and the causes of the continued persistence of this tissue type remain unknown. Growth marks and the developing external fundamental system align with northern raccoon life history data and degree of epiphyseal fusion in the current sample. These results therefore support bone microstructure analysis as an accurate tool to evaluate individual life histories in northern raccoons. Detailed osteohistological investigations, such as the present study, also contribute to expanding our understanding of the complexities of mammalian bone formation.","PeriodicalId":520555,"journal":{"name":"Anatomical record (Hoboken, N.J. : 2007)","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148805083","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}

引用次数: 0

Evaluating Bergmann's and Allen's rules in the long bones of the eastern gray squirrel. 评价东部灰松鼠长骨中的伯格曼和艾伦法则。

IF 2.1

Anatomical record (Hoboken, N.J. : 2007) Pub Date : 2026-08-19 DOI: 10.1002/ar.70313

Tyler Blake, Habiba Chirchir

{"title":"Evaluating Bergmann's and Allen's rules in the long bones of the eastern gray squirrel.","authors":"Tyler Blake, Habiba Chirchir","doi":"10.1002/ar.70313","DOIUrl":"https://doi.org/10.1002/ar.70313","url":null,"abstract":"Ecogeographical rules predict variation in body size and appendage proportions across climatic gradients, yet intraspecific tests using long bones from wild populations remain limited among small mammals. This study tests the hypothesis that eastern gray squirrels (Sciurus carolinensis) conform to Bergmann's rule, that is, body size increases with latitude, and to Allen's rule, whereby limb bone lengths relative to body size decrease with latitude. A total of 136 skeletally mature individuals were studied, spanning approximately 27°N-46°N latitude. Maximum lengths of the humerus, femur, and tibia were measured, and femoral head diameter was used as a proxy for body size whenever recorded body mass was unavailable. Linear regression analyses were used to evaluate relationships among body size, limb bone length, and latitude. First, we found that femoral head diameter was strongly correlated with recorded body mass (R2 = 0.567, p< 0.0001), supporting its use as a body size proxy. Second, body size increased significantly with latitude (R2 = 0.512, p< 0.0001), consistent with Bergmann's rule. Limb lengths standardized by body size were generally correlated with latitude with negative regression slopes (R2 = 0.13-0.43), largely supporting the prediction of Allen's rule that appendage lengths decrease at higher latitudes, although these relationships were weaker than those observed for body size. These results suggest that climatic gradients are reflected in body size and, to a lesser extent, limb bone lengths within a single, widely distributed rodent species. The results highlight the influence of latitude and climate on skeletal morphology.","PeriodicalId":520555,"journal":{"name":"Anatomical record (Hoboken, N.J. : 2007)","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148805116","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}

引用次数: 0

Brainstem and cerebellar variations in cheetahs (Acinonyx jubatus). 猎豹（非洲豹）的脑干和小脑变异。

IF 2.1

Anatomical record (Hoboken, N.J. : 2007) Pub Date : 2026-08-19 DOI: 10.1002/ar.70324

Joan S Baizer, Chet C Sherwood, Patrick R Hof, Illke B Malungo, Ayanda Ngwenya, Anita Burkevica, Mads F Bertelsen, Paul Manger, James F Baker

{"title":"Brainstem and cerebellar variations in cheetahs (Acinonyx jubatus).","authors":"Joan S Baizer, Chet C Sherwood, Patrick R Hof, Illke B Malungo, Ayanda Ngwenya, Anita Burkevica, Mads F Bertelsen, Paul Manger, James F Baker","doi":"10.1002/ar.70324","DOIUrl":"https://doi.org/10.1002/ar.70324","url":null,"abstract":"The cheetah is a species known for its high-speed hunting, requiring sophisticated visuomotor and vestibulomotor skills. A recent study showed cheetahs have enlarged semicircular canals, suggesting enhanced vestibular information processing. We asked if the semicircular canal specializations might be reflected in the brainstem targets of vestibular input and in related cerebellar structures. We studied blocks of brain tissue with the medulla and pons from five US zoo-bred cheetahs (three different zoos), and one brainstem of an animal from a zoo in Sweden. We compared the cheetah brainstems with each other, and with the brainstem of the domestic cat. We found variations in several structures, most consistently in the cochlear nuclei, in the brains of the US zoo-bred cheetahs. There were differences among these brains in the nature and extent of these variations. Despite the unusual structural characteristics of the cochlear nuclei, no impairments in auditory function had been noted by the home zoos. The brain of the Swedish zoo cheetah did not show these atypical features. We also saw consistent differences between the US cheetahs and cats in the sizes of the cerebellar peduncles, the pyramidal tracts and the medial longitudinal fasciculus. The low genetic diversity of cheetahs, a consequence of one or more population bottlenecks, may underlie the persistence of genetic changes causing atypical brainstem development.","PeriodicalId":520555,"journal":{"name":"Anatomical record (Hoboken, N.J. : 2007)","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148805100","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}

引用次数: 0

New biological insights from osteoderm histology of Venkatasuchus armatum (Pseudosuchia: Aetosauria). 文katasuchus armatum （Pseudosuchia: Aetosauria）骨皮组织学的生物学新见解。

IF 2.1

Anatomical record (Hoboken, N.J. : 2007) Pub Date : 2026-08-19 DOI: 10.1002/ar.70319

Atrayee Haldar, Sanghamitra Ray

{"title":"New biological insights from osteoderm histology of Venkatasuchus armatum (Pseudosuchia: Aetosauria).","authors":"Atrayee Haldar, Sanghamitra Ray","doi":"10.1002/ar.70319","DOIUrl":"https://doi.org/10.1002/ar.70319","url":null,"abstract":"In this contribution, we studied the histology of several selected paramedian and lateral osteoderm(s) of the Late Triassic aetosaur Venkatasuchus armatum, known from the lower part of the Dharmaram Formation of Pranhita-Godavari Basin in India to assess the growth strategy and functional attributes. The sections revealed a typical diploe structure comprising compact outer and basal cortices surrounding a large and cancellous inner core. The osteoderms had an overall slow and punctuated growth strategy based on the predominance of avascular lamellar bone, crossed parallel-fibered bone, and multiple LAGs. Extensive secondary remodeling, in the form of secondary osteons of several generations, is seen in the ornamented outer cortex, especially in the ridges or peaks that contrasted with its absence and uniform histological features in the unornamented and consistently thick basal cortex. Other features included high abundance of dense bundles of Sharpey's fibers or extrinsic fibers that suggested presence of an external covering, possibly a keratinized sheath on the osteoderms. Comparison with other aetosaurs showed that the Indian taxon underwent pronounced bone remodeling, which may be explained by influence of regional or developmental factors and/or related to reproductive activity in an ovulating female. Although crossed parallel-fibered bone tissue differentiates aetosaurian osteoderms from other pseudosuchian osteoderms, there are distinct differences in osteodermal histology and growth strategies among various aetosaurian taxa.","PeriodicalId":520555,"journal":{"name":"Anatomical record (Hoboken, N.J. : 2007)","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148805106","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}

引用次数: 0