Endocranial Surface Research Articles

Age-related changes in the endocranial capacity and surface area of ancient children from the Zaghunluq Cemetery (650-150 BCE) in Xinjiang, Northwestern China.

Early childhood is an important period for the rapid growth of the brain, which is crucial to neural connection and cognitive development. The purpose of this study is to characterize the age changes of endocasts in ancient children in Northwestern China (2600-2100 BP) to enrich our understanding of brain growth. 28 crania of ancient children excavated from the Zaghunluq cemetery were analyzed using endocasts generated from CT images. The endocast features of age-related changes were assessed by comparing the endocranial volume (cranial capacity), the intracranial surface area, and their ratios among different age groups: 2, 3-5, 6-7, 8-10, 12-15, and 17-19 years. The results demonstrated that with the increase of age, the volume and the surface area of children's endocasts seem to increase between age groups. The growth spurt periods of endocranial volume are 3-5 years old and 8-10 years old, and the growth spurt period of endocranial surface area is 3-5 years old, similar to the patterns in modern children. The increase of endocast surface area is smaller than that of volume, resulting in an overall increase in the ratio of endocranial volume to surface area, indicating a trend of gradual globularization of the brain.

Toll-like receptor-2 induced inflammation causes local bone formation and activates canonical Wnt signaling.

It is well established that inflammatory processes in the vicinity of bone often induce osteoclast formation and bone resorption. Effects of inflammatory processes on bone formation are less studied. Therefore, we investigated the effect of locally induced inflammation on bone formation. Toll-like receptor (TLR) 2 agonists LPS from Porphyromonas gingivalis and PAM2 were injected once subcutaneously above mouse calvarial bones. After five days, both agonists induced bone formation mainly at endocranial surfaces. The injection resulted in progressively increased calvarial thickness during 21 days. Excessive new bone formation was mainly observed separated from bone resorption cavities. Anti-RANKL did not affect the increase of bone formation. Inflammation caused increased bone formation rate due to increased mineralizing surfaces as assessed by dynamic histomorphometry. In areas close to new bone formation, an abundance of proliferating cells was observed as well as cells robustly stained for Runx2 and alkaline phosphatase. PAM2 increased the mRNA expression of Lrp5, Lrp6 and Wnt7b, and decreased the expression of Sost and Dkk1. In situ hybridization demonstrated decreased Sost mRNA expression in osteocytes present in old bone. An abundance of cells expressed Wnt7b in Runx2-positive osteoblasts and ß-catenin in areas with new bone formation. These data demonstrate that inflammation, not only induces osteoclastogenesis, but also locally activates canonical WNT signaling and stimulates new bone formation independent on bone resorption.

Vascular microforamina and endocranial surface: Normal variation and distribution in adult humans.

The term craniovascular traits refers to the imprints left by arteries and veins on the skull bones. These features can be used in biological anthropology and archaeology to investigate the morphology of the vascular network in extinct species and past populations. Generally, the term refers to macrovascular features of the endocranial cavity, like those associated with the middle meningeal artery, venous sinuses, emissary foramina, and diploic channels. However, small vascular passages (here called microforamina or microchannels) have been occasionally described on the endocranial surface. The larger ones (generally with a diameter between 0.5 and 2.0 mm) can be detected through medical scanners on osteological collections. In this study, we describe and quantify the number and distribution of these microforamina in adult humans (N = 45) and, preliminarily, in a small sample of children (N = 7). Adults display more microchannels than juvenile skulls. A higher frequency in females is also observed, although this result is not statistically significant and might be associated with allometric cranial variations. The distribution of the microforamina is particularly concentrated on the top of the vault, in particular along the sagittal, metopic, and coronal sutures, matching the course of major venous sinuses and parasagittal bridging veins. Nonetheless, the density is lower in the region posterior to bregma. Beyond oxygenation, these vessels are likely involved in endocranial thermal regulation, infection, inflammation, and immune responses, and their distribution and prevalence can hence be of interest in human biology, evolutionary anthropology, and medicine.

Cranial Vault Suture Obliteration in Relation to Age: An Autopsy-Based Observational Study.

Age is one of the most critical identifiers for both living and dead. Forensic professionals in medical and legal matters are often presented with dismembered, disfigured, putrefied, or skeletal remains for analysis. In such situations, it is essential to identify individuals and estimate their ages. The skull is typically thewell-preserved part of the body in such situations. If an aged person needs their age officially established for employment, superannuation, pension settlements, senior citizen benefits, etc., they may turn to medical professionals for help in making that determination. It has always been controversial to use cranial suture obliteration as a reference for age. Different geographicallocations have been shown to have vastly different patterns of cranial suture closure. Therefore, this study was conceptualized to assess cranial vault sutureobliteration in relation to age in the Meo population. This study was conducted to determine whether obliteration of cranial sutures can be taken into account for the estimation of age in elderly in this region and its reliability along with the influence of other factors such as sexand right and left side differences. A total of 100 cases of more than 20 years of age brought for medicolegal autopsy were analyzed. The coronal, sagittal, and lambdoid sutures were studied ectocranially and endocranially. The degree of obliteration of sutures was scored ectocranially as well as endocranially. Data were analyzed using IBMSPSSStatistics for Windows, Version 21 (Released 2012; IBM Corp., Armonk, New York, United States). Descriptive statistics were evaluated for continuous data in terms of mean and standard deviation, and categorical data were presented by frequency and percentages. An independent t-test was applied to find out the mean difference between the right and left sides of suture closure for ectocranial and endocranial surfaces. The Spearman rank correlation test was carried out to find out the relationship between the age and score of suture closure both ectocranially and endocranially. Ectocranially and endocranially, the overall sagittal suture obliterates early followed by coronal sutures and then lambdoid sutures. On comparing the mean ectocranial and mean endocranial scores of 100 subjects by applying an independent t-test, a highly significant difference was observed in all three sutures. On correlating ectocranial sutures and endocranial sutures and age at death in all the cases through sagittal, right and left coronal, and lambdoid by applying the Spearman rank correlation coefficient, a highly significant correlation was found in all the subjects combined (p-value 0.000). However, no significant correlation (p-value >0.05) was found in ectocranial and endocranial sagittal sutures in individual age groups. We concluded that obliteration on the endocranial surface is more reliable than on the ectocranial surface. No statistically significant difference exists on the obliteration of sutures on the right and left sides of coronal and lambdoid sutures. The lapsed union was evident in all three sutures ectocranially. Endocranial suture obliteration can be used as a corroborative tool for age estimation.

The frequency and macromorphological classification of abnormal blood vessel impressions and periosteal appositions of the dura mater in an early modern osteological collection from Poland

ObjectiveThe macromorphological characteristics and frequency of endocranial abnormal blood vessel impressions (ABVI) and periosteal appositions of dura mater (PADM), and their association with sex, age-at-death and scurvy-like lesions were studied. The possible etiologies of these lesions were discussed. MaterialsA total of 144 adult skulls excavated from an early modern (16th-19th c. CE) cemetery at the Czysty Square in Wrocław (Poland) were examined, most of which were intact. MethodsThe endocranial surface was inspected with an endoscope for the presence, location, and severity of ABVI and PADM. Frequencies of ABVI and PADM were grouped by sex and age-at-death. ResultsA little more than a half (53.5 %) of the examined skulls were affected by ABVI and/or PADM. PADM were more frequent in females. However, both alteration types occurred with similar frequencies across all age-at-death categories. ConclusionsThe high frequency of ABVI and PADM suggests that meningeal infections and/or hemorrhage among inhabitants of early modern Wrocław, especially in females, were common. SignificanceThe paper emphasizes the need for using an endoscope in standard anthropological analysis of intact skulls, as it allows for a nondestructive inspection of the endocranial surface. LimitationsThe endoscope did not allow for an accurate examination of the middle cranial fossa. Suggestions for further researchComparative studies with other historical populations are necessary to better understand the possible etiologies of macromorphological and demographic characteristics of ABVI and PADM.

Hyperostosis frontalis interna: A new perspective in burned individuals' analysis for determining age and sex from archeo‐anthropological and medicolegal contexts

AbstractHyperostosis frontalis interna (HFI) is a benign bone lesion, which is asymptomatic for the most part and is manifested by the accretion of bone on the endocranial surface of the frontal bone.This type of lesion has been discussed in a multitude of publications since the 19th century. Although a consensus has yet to be reached as to its etiology, it would seem generally accepted that hormones play a role, which would explain the high frequency of this disorder among older and postmenopausal women.The objective of this study is to demonstrate the benefit of HFI diagnosis for identifying individuals (estimating their age and determining their sex) in the archeo‐anthropological analysis of ancient cremation burial sites and in medicolegal investigations on burned human remains.Our sample consisted of 82 cremated individuals from the Roman Porta Nocera necropolis in Pompeii (1st century BC–1st century AD). After excluding juveniles under 15 years of age, as HFI primarily affects adult individuals, our sample was reduced to 71 individuals, and the prevalence of HFI was 15.5% (n = 11). A statistically significant difference is observed between women and men, and no individuals previously identified as male displayed HFI. Furthermore, 90.9% of the individuals displayed degenerative conditions in conjunction with HFI, showing a highly significant correlation of this lesion with signs of aging (chi‐square 9.365; p = 0.01). Finally, this disorder boosted diagnostic performance in respect of determining sex, increasing the number of biologically sexed individuals from 46.5% to 53.5%. Therefore, we propose that the HFI diagnosis offers genuine added value in the identification of burned human remains.

Cranial osteology of a juvenile specimen of Acratocnus ye (Mammalia, Xenarthra, Folivora) and its ontogenetic and phylogenetic implications.

The present study comprises a description of the skull and jaw anatomy of a juvenile specimen of the Antillean sloth Acratocnus ye, from the Holocene of Haiti. Detailed descriptions and illustrations are provided of the skull bones and their sutural connections, which normally fuse in adults. Descriptions are also provided for the mandible and ear ossicles, as well as endocranial surfaces and sinuses exposed by breaks. The anatomy of our juvenile A. ye is compared to that of adult A. ye to assess ontogenetic changes in the skull. Several of these ontogenetic features are significant new observations that impact the relationships within Xenarthra as a whole, or between Xenarthrans and other placental mammals, most notably, the presence of a separate mesethmoid element, the presence of alveoli for a lower deciduous canine and anterior incisor, and the presence of separate rostral and caudal entotympanic elements. A full list of such changes are provided. In addition, the specimen provides information on phylogenetically relevant characters, including features unique to the genus Acratocnus, and features of the clade Choloepodini, including Acratocnus, the smaller extinct Antillean sloth Neocnus, and the extant two-toed sloth Choloepus. Contrary to previous studies, Acratocnus shares as many features with Choloepus as it does with its fellow Antillean form Neocnus in the present study, which is consistent with current morphology-based phylogenetic hypotheses regarding the relationships within Choloepodini. The current study highlights the need for further anatomical and phylogenetic investigations of Antillean sloths (Megalocnidae/Megalonychidae), and juvenile sloths in general.

Morphological correspondence between brain and endocranial surfaces in mice exposed to undernutrition during development.

The morphological changes of the brain and the skull are highly integrated as a result of shared developmental pathways and different types of interactions between them. Shared developmental trajectories between these two structures might be influenced by genetic and environmental factors. Although the effect of environmental factors on neural and craniofacial traits has been extensively studied, less is known about the specific impact of stressful conditions on the coordinated variation between these structures. Here, we test the effect of early nutrient restriction on morphological correspondence between the brain and the endocast. For this purpose, mice exposed to protein or calorie-protein restriction during gestation and lactation were compared with a control group in which dams were fed standard food ad libitum. High-resolution images were obtained after weaning to describe brain and endocranial morphology. By magnetic resonance imaging (MRI), brain volumes were obtained and endocasts were segmented from skull reconstructions derived from micro-computed tomography (microCT). Brain and endocranial volumes were compared to assess the correspondence in size. Shape changes were analyzed using a set of landmarks and semilandmarks on 3D surfaces. Results indicated that brain volume is relatively less affected by undernutrition during development than endocast volume. Shape covariation between the brain and the endocast was found to be quite singular for protein-restricted animals. Procrustes distances were larger between the brain and the endocast of the same specimens than between brains or endocasts of different animals, which means that the greatest similarity is by type of structure and suggests that the use of the endocast as a direct proxy of the brain at this intraspecific scale could have some limitations. In the same line, patterns of brain shape asymmetry were not directly estimated from endocranial surfaces. In sum, our findings indicate that morphological variation and association between the brain and the endocast is modulated by environmental factors and support the idea that head morphogenesis results from complex processes that are sensitive to the pervasive influence of nutrient intake.

Tracking down the White Plague. Chapter three: Revision of endocranial abnormally pronounced digital impressions as paleopathological diagnostic criteria for tuberculous meningitis.

Abnormally pronounced digital impressions (APDIs) on the endocranial surface develop secondary to a prolonged rise in the intracranial pressure. This can result from a number of pathological conditions, including hydrocephalus due to tuberculous meningitis (TBM). APDIs have been described with relation to TBM not only in the modern medical literature but also in several paleopathological studies. However, APDIs are not pathognomonic for TBM and their diagnostic value for identifying TBM in past human populations has not been evaluated in identified pre-antibiotic era skeletons. To assess the diagnostic value of APDIs for the first time, a macroscopic investigation was performed on skeletons from the Terry Collection (Smithsonian Institution, Washington, DC, USA). Our material consisted of 234 skeletons with tuberculosis (TB) as the cause of death (TB group) and 193 skeletons with non-tuberculous (NTB) causes of death (NTB group). The macroscopic examination focused on the stage of the prominence and frequency of APDIs in the TB group and NTB group. To determine the significance of difference (if any) in the frequency of APDIs between the two groups, χ2 testing of our data was conducted. We found that APDIs were twice as common in the TB group than in the NTB group. The χ2 comparison of the frequencies of APDIs revealed a statistically significant difference between the two groups. In addition, APDIs with more pronounced stages were recorded more frequently in the TB group. Our results indicate that APDIs can be considered as diagnostic criteria for TBM in the paleopathological practice. With suitable circumspection, their utilization provides paleopathologists with a stronger basis for identifying TB and consequently, with a more sensitive means of assessing TB frequency in past human populations.

Osteolytic lesions on the os petrosum of a Bronze Age individual from La Llana cave (Northern Spain) compatible with a possible case of otitis media. A multifaceted methodological approach

ObjectiveTo encourage the use of different methodological approaches for the identification of paleopathological lesions and to evaluate osteolytic lesions found on a temporal bone from La Llana cave (Spain). MaterialsCranial remains recovered from from La Llana cave (Spain) dated to the Bronze Age, 3300 ± 25 BP (1631−1509 cal BC). MethodsThe cranium underwent macroscopic, microscopic and computed tomography scan examinations. ResultsThe Tegmen tympani of the left temporal bone is present but is missing on the right. Both cochleae are intact. Both the right and left temporal bones display osteolytic lesions, with the left Tegmen tympani displaying deep and profuse pits on the endocranial surface, exposing the ear channel. ConclusionsThe lesions are compatible with otitis media (atticitis). By using different methods of analysis, the presence and effects of infection were identified. SignificanceThis systematically described case contributes to our understanding of disease in the past and describes otitis-related lesions in archeological contexts for comparative purposes. LimitationsThe fragmentary and damaged cranial remains rendered evaluation difficult and diagnosis tentative. Suggestions for Further ResearchThe use of different approaches to diagnose otitis media in archeological skeletal collections is recommended to improve the knowledge of health status and lifestyle of past populations.

Endocranial morphology of the petalichthyid placodermEllopetalichthys scheiifrom the Middle Devonian of Arctic Canada, with remarks on the inner ear and neck joint morphology of placoderms

Petalichthyid and “acanthothoracid” placoderms have taken pivotal positions in the debate on placoderm — and, by extension, jawed vertebrate — relationships owing to perceived similarities with certain jawless vertebrates. Neurocranial characters are integral to current hypotheses of early gnathostome relationships. Here, we describe the three-dimensionally preserved neurocranial anatomy of the petalichthyid placoderm Ellopetalichthys scheii (Kiær, 1915), from the Middle Devonian (early Eifelian) of Ellesmere Island, Canada. Using X-ray computed microtomography, we generated three-dimensional reconstructions of the endocranial surfaces, orbital walls, and cranial endocavity. These reconstructions verify the absence of a crus commune of the skeletal labyrinth and the complex shape of the petalichthyid endolympathic duct. Details of the craniothoracic joint and occipital musculature fossae help resolve the problematic comparative anatomy of the occipital surface of petalichthyids. These new data highlight similarities with arthrodire placoderms, consistent with older hypotheses of a sister-group relationship between petalichthyids and that clade.

Micro-computed Tomography Study of Frontal Bones in Males and Females with Hyperostosis Frontalis Interna.

Hyperostosis frontalis interna (HFI) represents irregular thickening of the endocranial surface of the frontal bone, mostly seen in postmenopausal females. The microarchitecture of this condition is poorly studied. The aim of this cross-sectional autopsy study was to investigate and compare microarchitectural structure of the frontal bone affected with HFI in both sexes and to test whether HFI severity could be distinguished at the microarchitectural level. The sample was taken from human donor cadavers, 19 males (61 ± 15years old) and 17 females (75 ± 15years old). After classification of HFI severity (type A, B, C or D), samples of the frontal bone were taken and scanned using micro-computed tomography. Bone volume fraction was higher and total porosity lower only in the outer table of males with HFI, compared to females with HFI. Mean total sample thickness differed only between males with HFI type A and D. Bone microarchitecture between males and females with corresponding HFI types (e.g., male with type A versus female with type A) differed only in HFI type C regarding the fractal dimension of diploe. The degree of anisotropy differed between HFI subtypes in males, but the post hoc analysis revealed no significant differences between individual groups. Other microarchitectural parameters did not differ among males with different HFI subtypes, as well in females, in any part of the frontal bone. There is no difference in microarchitectural structure of the frontal bone between males and females with HFI, in general aspect and within corresponding HFI subtypes. HFI severity could not be distinguished at the microarchitectural level, neither in males nor in females.

A morphometric comparison of the parietal lobe in modern humans and Neanderthals

The modern human brain and braincase have a characteristic globular shape including parietal and cerebellar bulging. In contrast, Neanderthals, although having similar endocranial volume, displayed more elongated endocrania with flatter parietal and cerebellar regions. Based on endocranial imprints, we compare the parietal lobe morphology of modern humans and Neanderthals, as this brain region is central to several cognitive functions including tool use and visual imaging. In paleoneurology, shape analyses of endocasts are based either on anatomical landmarks that represent endocranial surface features homologous to cortical convolutions (impressions of brain gyri and sulci) or on dense meshes of semilandmarks that capture overall endocranial shape. Previous analyses using the former suggested that modern humans have relatively longer and taller parietal lobes than extinct human species, while the latter emphasized parietal bulging without a significant size difference of parietal regions. In the present study, we combine both anatomical landmarks and surface semilandmarks to investigate the morphological differences of the parietal lobes between modern humans and Neanderthals. Despite limitations by landmark uncertainty, our analyses were able to detect and confirm average different parietal shapes, with modern humans displaying taller and anteroposteriorly extended parietal lobes. We also show mean size differences, with modern humans displaying slightly larger surface areas on the dorsal posterior parietal region, and on a lateral region comprising the supramarginal gyrus, angular gyrus, and intraparietal sulcus. While we observed average differences in the parietal form between the two species, their ranges of distribution overlap, indicating the differences could be a matter of degree. Thus, further analyses on intraspecific variation in parietal lobe morphology within modern human brains should help understand the differences between globular and elongated endocrania. This is crucial because changes to the parietal cortex might affect associative and integrative functions between somatic and visual primary inputs.

Anatomy of the Petrosal and Middle Ear of the Brown Rat, Rattus norvegicus (Berkenhout, 1769) (Rodentia, Muridae)

The anatomy of the petrosal and associated middle ear structures are described and illustrated for the brown rat, Rattus norvegicus (Berkenhout, 1769). Although the middle ear in this iconic mammal has been treated by prior authors, there has not been a comprehensive, well-illustrated contribution using current anatomical terminology. Descriptions are based on specimens from the osteological collections of the Section of Mammals, Carnegie Museum of Natural History, and a CT scanned osteological specimen from the Texas Memorial Museum. The petrosal, ectotympanic, malleus, incus, stapes, and inner ear were segmented from the CT scans.The petrosal of the brown rat is only loosely attached to the cranium, primarily along its posterior border; it is separated from the basisphenoid, alisphenoid, and squamosal by a large piriform fenestra that transmits various neurovascular structures including the postglenoid vein. The extent of the piriform fenestra broadly exposes the tegmen tympani of the petrosal in lateral view. The floor of the middle ear is formed by the expanded ectotympanic bulla, which is tightly held to the petrosal with five points of contact. The surfaces of the petrosal affording contact with the ectotympanic bulla are the rostral tympanic process, the epitympanic wing, the tegmen tympani, two of the three parts of the caudal tympanic process, and the tympanohyal, with the ectotympanic fused to the last. The ectotympanic in turn is fused to the elongate rostral process of the malleus, which is only discoverable through the study of juvenile specimens. In addition to osteology, the major nerves, arteries, and veins of the petrosal are described and illustrated based on the literature and osteological correlates.The petrosal of the brown rat is compared with those of several Eocene rodents to put the extant form in the context of early members of the rodent lineage. Comparisons benefitted from CT scans of the middle Eocene ischromyoid Paramys delicatusLeidy, 1871, from the western United States, affording the first description of the endocranial surface of the petrosal in an Eocene rodent. The petrosals in the Eocene fossils are more tightly held in the cranium, but the ectotympanic contacts the petrosal through the same five points, with some modifications. The most unexpected discovery in Paramys delicatus was the presence of a prominent tentorial process of the parietal in contact with the reduced crista petrosa.

Tracking down the White Plague: The skeletal evidence of tuberculous meningitis in the Robert J. Terry Anatomical Skeletal Collection.

Paleopathological diagnosis of tuberculosis (TB) essentially relies on the identification of macroscopic lesions in the skeleton that can be related to different manifestations of TB. Among these alterations, granular impressions (GIs) on the inner skull surface have been considered as pathognomonic features of tuberculous meningitis (TBM). GIs may be established by pressure atrophy of the tubercles formed on the outermost meningeal layer during later stages of TBM. Although GIs were used as diagnostic criteria for TBM in the paleopathological practice since the late 20th century, their diagnostic value has been questioned. To contribute to strengthening the diagnostic value of GIs, a macroscopic investigation-focusing on the macromorphological characteristics and frequency of GIs-was performed on skeletons of known cause of death from the Terry Collection. The χ2 analysis of our data revealed that GIs were significantly more common in individuals who died of TB than in individuals who died of non-TB causes. Furthermore, GIs were localized on the inner surface of the skull base and of the lower lateral skull vault. The localization pattern and distribution of GIs on the endocranial surface resemble that of the tubercles observed in the affected meninges during the pathogenesis of TBM. Our results strengthen the tuberculous origin of GIs and imply that they can be considered as specific signs of TBM. Therefore, GIs can be used as diagnostic criteria for TBM in the paleopathological practice, and the diagnosis of TBM can be established with a high certainty when GIs are present in ancient human bone remains.

Normal craniovascular variation in two modern European adult populations.

The vascular networks running into the meningeal layers, between the brain and braincase, leave imprints on the endocranial surface. These traces are visible in osteological specimens and skeletal collections, providing indirect evidence of vascular patterns in those cases in which bone remains are the only source of anatomical information, such as in forensic science, bioarchaeology and paleontology. The main vascular elements are associated with the middle meningeal artery, the venous sinuses of the dura mater, and the emissary veins. Most of these vascular systems have been hypothesized to be involved in endocranial thermal regulation. Although these traits deal with macroanatomical features, much information on their variation is still lacking. In this survey, we analyze a set of craniovascular imprints in two European dry skull samples with different neurocranial proportions: a brachycephalic Czech sample (n=103) and a mesocephalic Italian sample (n=152). We analyzed variation and distribution, correlation with cranial metrics, and sex differences in the dominance of the branches of the middle meningeal artery, the patterns of confluence of the sinuses, and the size of the emissary foramina. The descriptive statistics provide a reference to compare specimens and samples from different case studies. When compared with the Italian skulls, the Czech skulls display a greater dominance of the anterior branch of the middle meningeal artery and more asymmetric right-dominance of the confluence of the venous sinuses. There is no sex difference in the middle meningeal vessels, but males show a greater prevalence of the occipito-marginal draining system. Differences in the middle meningeal vessels or venous sinuses are apparently not influenced by cranial dimensions or proportions. The mastoid foramina are larger in larger and more brachycephalic skulls, which increases the emissary potential flow in the Czech sample and males, when compared with the Italian samples and females, respectively. The number of mastoid foramina increases in wider skulls. This anatomic information is necessary to develop further morphological and functional inferences on the relationships between neurocranial bones and vessels at the genetic, ontogenetic, and phylogenetic levels.

Study of sagittal suture closure at autopsy: A three-year prospective study

The skeleton is a principle source of information in age estimation. It is difficult to estimate age after 25 years. Changes in the pubic symphysis, transparency of root and root length measurement have been considered as good parameters to estimate age beyond 25 years. The reliability of skull suture closure alone in age estimation still remains doubtful. Sagittal suture is considered to be the most accurate among the other vault sutures. Hence this study was conducted to check for its reliability in age estimation. It was observed that, sagittal suture closure starts earlier on the endocranial surface than on the ectocranial surface. Ectocranially females showed earlier fusion than males, but endocranial suture closure was earlier in males. Ectocranial fusion started between 20–29 years, with maximum closure occurringby 60 years. Endocranialfusion alsostartedbetween20-29 years and achieved maximum closure by55years.

Determination of age from fusion of skull vault sutures

Background: Cranial suture closure has long been recognized as a character of human development related to aging. For this reason, it has been utilized for various forensic and archaeological studies to determine the age of an unidentified/or skeletonized individuals. Various cadaveric studies have established the role of lambdoid suture in age estimation, but not routinely practiced. Age estimation is an integral part of the biological profile employed by forensic anthropologists in order to assist in achieving an identification of an unknown deceased individual. The main objective of this article is to determine the pattern of cranial vault suture closure in relation to age. Material and methods: Total number of 90 subjects, 25 years and beyond were included in the study, and divided into four groups with an age interval of 10 years. Each individual was subjected to radiological examination of the skull with a view to• study the Sagittal, Coronal and Lambdoid sutures, a special view was evolved by trial in order to get all the basic three sutures in one film. Ectocranial and endocranial closure pattern were studied. Result: A significant difference was observed between the age group and suture closure. Coronal suture was the first to fuse followed by sagittal suture. Lambdoid suture. Endocranially, starts fusing at the age of 25‐30 yrs. Closure was found earlier in females compared to males. Conclusion: Suture obliteration occurs earlier on endocranial surface. Based on endocranial suture fusion, Coronal suture was first to close followed by sagittal suture, lambdoid suture sequentially.

The endocast of StW 573 (“Little Foot”) and hominin brain evolution

One of the most crucial debates in human paleoneurology concerns the timing and mode of the emergence of the derived cerebral features in the hominin fossil record. Given its exceptional degree of preservation and geological age (i.e., 3.67 Ma), StW 573 (‘Little Foot’) has the potential to shed new light on hominin brain evolution. Here we present the first detailed comparative description of the external neuroanatomy of StW 573. The endocast was virtually reconstructed and compared to ten southern African hominin specimens from Makapansgat, Malapa, Sterkfontein and Swartkrans attributed to Australopithecus and Paranthropus. We apply an automatic method for the detection of sulcal and vascular imprints. The endocranial surface of StW 573 is crushed and plastically deformed in a number of locations. The uncorrected and therefore minimum cranial capacity estimate is 408 cm3 and plots at the lower end of Australopithecus variation. The endocast of StW 573 approximates the rostrocaudally elongated and dorsoventrally flattened endocranial shape seen in Australopithecus and displays a distinct left occipital petalia. StW 573 and the comparative early hominin specimens share a similar sulcal pattern in the inferior region of the frontal lobes that also resembles the pattern observed in extant chimpanzees. The presumed lunate sulcus in StW 573 is located above the sigmoid sinus, as in extant chimpanzees, while it is more caudally positioned in SK 1585 and StW 505. The middle branch of the middle meningeal vessels derives from the anterior branch, as in MH 1, MLD 37/38, StW 578. Overall, the cortical anatomy of StW 573 displays a less derived condition compared to the late Pliocene/early Pleistocene southern African hominins (e.g., StW 505, SK 1585).

Primary visual cortex in neandertals as revealed from the occipital remains from the El Sidrón site, with emphasis on the new SD-2300 specimen.

The comparative analysis of the endocranial surface of the El Sidrón new occipital fragment SD-2300 shows meaningful differences in the configuration of the occipital pole region between neandertals and anatomically modern humans (AMH). The particular asymmetries found in neandertals in the venous sinus drainage and the petalial patterns are recognizable in this new specimen as well. In addition, the supra- and infracalcarine fossae of the occipital pole region appear to deviate obliquely from the mid-line when compared with sapiens. Due to the excellent preservation conditions of SD-2300, the main sulci and gyri of the occipital pole area have been identified, this degree of detail being uncommon in a fossil specimen; in general, the gyrification pattern is similar to AMH, but with some notable differences. Particularly interesting is the description of the lunate and the calcarine sulci. The lunate sulcus is located close to the occipital pole, in a similar posterior position to in other Homo species. Regarding the calcarine sulcus, there are significant differences in the primary visual cortex, with the V1 area, or Brodmann area 17, being larger in Homo neanderthalensis than in Homo sapiens. This may lead to greater visual acuity in neandertals than in sapiens.