Three-dimensional geometric morphometric analysis of cranio-facial sexual dimorphism in a Central European sample of known sex

This article presents an approach for estimating the sexual dimorphism of adult crania using three-dimensional geometric morphometric methods. The study sample consisted of 139 crania of known sex (73 males and 66 females) belonging to persons who lived during the first half of the 20th century in Bohemia. The three-dimensional co-ordinates of 82 ecto-cranial landmarks and 39 semi-landmarks covering the midsagittal curve of the cranial vault were digitised using a MicroScribe G2X contact digitiser. The purposes of the investigation were to define the regions of the cranium where sexual dimorphism is most pronounced and to investigate the effectiveness of this method for determining sex from the shape of the cranium. The results demonstrate that it is better to analyse apportionable parts of the cranium rather than the cranium as a whole. Significant sexual differences (significance was determined using multivariate analysis of variance) were noted in the shape of the midsagittal curve of the vault, upper face, the region of the nose, orbits, and palate. No differences were recorded either in the shape of the cranium as a whole or in the regions of the base and the neurocranium. The greatest accuracy in determining sex was found in the region of the upper face (100% of study subjects correctly classified) and the midsagittal curve of the vault (99% of study subjects correctly classified).     

Evidence of pathological conditions in the Florisbad cranium

Palaeopathological studies of the middle Pleistocene cranium from Florisbad (Free State, South Africa) document the presence of extensive cortical lesions and areas of thinning, a widened medullary cavity with destruction of the diploë, orbital roof lesions, a benign ectocranial neoplasm, and evidence for alveolar destruction, resorption, and antemortem tooth loss. Differential diagnosis suggests one or more possible aetiologies, including a haematological disorder, metabolic condition(s), Paget’s disease of bone, or non-specific infection perhaps following trauma. Moreover, if not directly associated with those on the external vault, orbital lesions alone could have been caused by infection or an indeterminable factor such as pressure from an enlarged organ. Multiple parasagittal lesions on the internal vault cortex probably represent expansile lesions left by enlarged arachnoid granulations. A multifactorial model of pathogenesis may be most appropriate to account for dentoalveolar lesions and antemortem tooth loss. Additionally, there are clear indications of diagenetic alteration deep within the vault, as well as multiple signs of degeneration on the cranium. These complicate the assessment of pathological alterations and identification of their possible aetiology. The Florisbad cranium is the latest specimen to join the growing sample of Pleistocene hominin remains with non-fatal and non-trivial pathological disorders adding to understanding of early human ecology and lifestyle.     

The dating of Lantian man and his significance for analyzing trends in human evolution

The Lantian fossil hominid cranium from Southern Shensi Province, China, provides the earliest record of Homo erectus in northern east Asia, and is morphologically the most primitive specimen in the entire world. Importantly, the Kungwangling Lantian cranium (calvarium plus face), with associated stone tools in good geologic and paleontological context, is demonstrably both earlier and more primitive than the Choukoutien I remains. Faunal and palynological evidence support a mid-Mosbachium equivalent age (some 700,000 years). These facts are not recognized in the original Chinese reports. The Chenchiawo Lantian mandible, like the Choukoutien I remains, is attributable to the Holstein-equivalent in China (some 300,000 years ago), and therefore should no longer be temporally associated with the Kungwangling Lantian cranium. However, that the mandible may be morphologically associated with either calls attention to the relative independence of the mandible in human evolution. A comparative study of some modern Mongoloid populations in which very large mandibles may or may not be associated with a scaphoid keel or sagittal elevation depending upon the size and shape of the cranium demonstrates the relative autonomy of the mandible. Continuing selection pressure for a masticatory complex with large jaws provides another point of continuity between East Asian fossil and modern Mongoloid hunting populations such as Eskimos and Aleuts. A number of morphological features of the cranium, especially vault thickness, cranial capacity and reinforcement system, conform to expectation and confirm a general trend of reduction in vault thickness and reinforcement system with increase in cranial capacity over time within the single human species.     

Morphological evolution through integration: a quantitative study of cranial integration in Homo, Pan, Gorilla and Pongo

Morphological integration refers to coordinated variation among traits that are closely related in development and/or function. Patterns of integration can offer important insight into the structural relationship between phenotypic units, providing a framework to address questions about phenotypic evolvability and constraints. Integrative features of the primate cranium have recently become a popular subject of study. However, an important question that still remains under-investigated is: what is the pattern of cranial shape integration among closely related hominoids? To address this question, we conducted a Procrustes-based geometric morphometrics study to quantify and analyze shape covariation patterns between different cranial regions in Homo, Pan, Gorilla and Pongo. A total of fifty-six 3D landmarks were collected on 407 adult individuals. We then sub-divided the landmarks corresponding to cranial units as outlined in the ‘functional matrix hypothesis.’ Sub-dividing the cranium in this manner allowed us to explore patterns of covariation between the face, basicranium and cranial vault, using the two-block partial least squares approach. Our results suggest that integrated shape changes in the hominoid cranium are complex, but that the overall pattern of integration is similar among human and non-human apes. Thus, despite having very distinct morphologies the way in which the face, basicranium and cranial vault covary is shared among these taxa. These results imply that the pattern of cranial integration among hominoids is conserved.     

Investigating histomorphological variations in human cranial bones through ontogeny

Through ontogeny, human cranial vault bones undergo differentiation in terms of their shape, size and tissue maturation. This differentiation is visible at both the macroscopic and microscopic levels. Preliminary data from a histological and compartmentalisation exploratory analysis of individuals with different ages suggest differences in the modelling and remodelling patterns through ontogeny. Child vault bones are primarily composed of avascular lamellar bone (largely vascularised), late juvenile or adolescent bones present the largest extension of mineralised areas (highly remodelled) and the lowest vascularisation (diploe is highly reduced), and the adult present highly vascularised bone in which the diploe is again largely extended. During childhood, the existence of an avascular lamellar bone promotes the sealing of the cranium bones surfaces whereas adult vault bones seem to become opened ectocranially due to the remodelling. We discuss the possibility that both effects could be related with the head thermoregulation.     

Osseous expansion of the cranial vault by craniotasis.

A study of cranial vault lengthening using a custom expandable fixation-distraction (craniotatic) appliance was performed in the young-adult rabbit model. Ten 24-week-old rabbits underwent circumferential suturectomy plus expansion (expanded group), 10 underwent circumferential suturectomy without expansion (sham control group), and 10 served as normal controls. The appliance was lengthened at a rate of 2.5 mm per week for 5 weeks. Serial lateral cephalometry, comparative dry-skull anthropometric measurements, and histologic examinations were performed. The expanded group demonstrated a significantly longer skull, cranial vault, anterior cranial base, posterior face, and orbit as compared with the control groups (p less than 0.05). Callus bone filled the distracted suturectomy and united the frontofacial complex to the posterior cranium. In conclusion, skull lengthening by distraction osteogenesis is possible in the rabbit model and offers a new technique for future investigation in the treatment of coronal synostosis.     

Developmental stress and cranial hypostosis by epigenetic trait occurrence and distribution: an exploratory study on the Italian Neandertals

The occurrence and distribution of 35 cranial epigenetic traits in the Italian Neandertals (Saccopastore 1 and 2, Guattari 1) were examined according to morpho-functional cranial regions and with respect to a distinction between hypostosis (i.e., weak osseous development, arrested morphogenesis, retention of infantile features) and hyperostosis (i.e. excess of ossification, not reaching the pathological condition). The results, expressed ashypostotic scores, showed higher levels of hypostosis in these Neandertal specimens than in recent European samples. The highest expressions of hypostotis were observed in those regions of the Neandertal cranium where disequilibrium between skeletal and cerebral growth factors was expected. These results—interpreted as expression of developmental stress—are consistent with a heterochronic interpretation of the development of the Neandertal cranium; namely, a faster ossification of the cranial vault relative to brain growth rates.     

Engis: preparation damage, not ancient cutmarks

Scratches found on the Engis 2 cranium have been described as perimortem and interpreted as intentional scalping marks by Russell and LeMort (Am. J. Phys. Anthropol. 69:317-323, 1986). These marks are described and compared to damage on other fossil hominids. The Engis marks have been misinterpreted. These marks are sandpaper striae formed during restoration of the vault, moulding striae formed when mold part lines were incised into the fossil and profiling striae formed when craniograms were made with sharp steel instrument tips. None of them have anything to do with prehistoric behavior.     

The Lake Ndutu cranium and early Homo sapiens in Africa

The partial cranium from Lake Ndutu, near Olduvai Gorge in northern Tanzania, has generally been viewed as Homo erectus, although points of similarity to H. sapiens have also been recognized. Bones of the vault are in fact quite thick, and the cranium is small. Length and breadth dimensions are comparable to those of earlier H. erectus from Koobi Fora and Ileret, and the Ndutu individual is more similar in size to O.H. 12 than to O.H. 9. Unfortunately, the facial skeleton and frontal bone are very incomplete, and little useful information can be obtained from these parts of the existing reconstruction. The parietals are also damaged, but the left temporal is more satisfactorily preserved, and the occiput is nearly complete. Occipital morphology, mastoid shape, and characteristics of the glenoid cavity and tympanic plate probably provide the best available guide to affinities of the Ndutu hominid. In many of these features the cranium resembles Broken Hill, Elandsfontein, and other African fossils referred to archaic H. sapiens. There are some similarities to modern humans also, but no ties to the Neanderthals of Europe. Allocation of Ndutu to an African subspecies of H. sapiens seems most appropriate, even if the pattern of relationships between such archaic populations and recent humans is still unclear.     

A large male hominin cranium from Sterkfontein, South Africa, and the status ofAustralopithecus africanus

Stw 505 is the most complete hominin cranium discovered in Sterkfontein Member 4 since Broom's excavations. It was found in situ in Member 4 breccia in 1989 and is larger, on the whole, than any other cranium from Sterkfontein that has comparable parts. Displacement due to breakage, as well as plastic deformation, has affected Stw 505 in several areas, especially the face and the vault. Diagnosticmorphology is nevertheless abundant in the specimen. In several areas-the distinct anterior pillar, the straight inferior border of the zygoma, the pattern of cresting on the naso-alveolar clivus, the basal aspect of the temporal bone-Stw 505 closely matches the morphology of specimens of Australopithecus africanus and is distinct from other hominins. Some isolated characters overlap with other groups, mainly early Homo and/or A. robustus. However, only the hypodigm of A. africanus can accommodate the entire suite of morphology.In some cases, Stw 505 introduces more variation into the Sterkfontein sample. For example, prominent superciliary eminences occupy the medial portions of the supraorbital region and flow medially into a strongly protruding glabellar mound. These characteristics are probably attributable to sexual dimorphism. In many respects, Stw 505 highlights similarities between A. africanus and early Homo. Comparison with other species suggests that males of A. africanus do not show derived features of A. robustus that are not also present in females, and that cranial differences between A. afarensis and A. africanus have, if anything, been understated.     

A newHomo erectus cranium from Sangiran, Java

A newHomo erectus cranium was found on May 18, 1993 by Budi, a local farmer, at Sangiran. It dates from the Middle Pucangan Formation approximately 1.6–1.8 mya. The braincase is essentially complete and as is most of the face. The vault has the typicalH. erectus gable shape. There is a clear sagittal ridge beginning below the middle of the frontal squama and running to mid-parietal. Parasagittal ridges are rounded angulations halfway up the parietals, and coincide with poorly marked temporal lines. In all measurements, this skull is longer and consistently narrower than Trinil. It is chronologically and morphologically similar to the famousH. erectus skull from east Africa, KNMER-3733. Although existing much older, this new specimen is what one would expect a female counterpart to Sangiran 17 to look like.     

Ecological and phylogenetic dimensions of cranial shape diversification in South American caviomorph rodents (Rodentia: Hystricomorpha)

Caviomorph rodents represent an excellent model to explore morphological diversification on a macroevolutionary scale, as they are ecologically and morphologically diverse. We analysed cranial shape variation using geometric morphometrics and phylogenetic comparative methods. Most variation involved the shape of the rostrum, basicranium, and cranial vault, and clearly matched the phylogenetic structure. At the same time, a strong allometric pattern was associated with the length of the rostrum and cranial vault, size of the auditory bulla, and depth of the zygomatic arch. After accounting for size influence, and taking phylogenetic structure into account, shape variation was significantly associated with habitat. Our results highlight the presence of complex relationships between morphological, phylogenetic, and ecological dimensions in the diversification of the caviomorph cranium. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110 , 898–913.     

Volumetric quantification of intracranial and ventricular volume following cranial vault remodeling: a preliminary report

This preliminary study documents preoperative and postoperative changes in cerebral tissue as well as intracranial and ventricular volume in patients who underwent cranial vault remodeling for craniosynostosis. The documentation and calculations were provided from CT data according to a craniofacial protocol. Three-dimensional images were then obtained of the preoperative and postoperative skulls and cerebral tissues. From these data, comparisons of preoperative and postoperative volumes of the cerebral tissue and ventricles could be examined. In one case, a frontal bone advancement combined with anterior cranial vault remodeling was associated with an increase in intracranial volume of 110 cc (8 percent) and a ventricular volume increase of 112 percent. The reported technique should allow more complete evaluation of the preoperative pathology and documentation and prediction of the projected intracranial and ventricular volume changes.     

Rare temporal bone pathology of the Singa calvaria from Sudan

Evidence has recently accumulated that the Singa calvaria from Sudan probably dates from Oxygen Isotope Stage 6 (>130 ka). Morphological studies have indicated a mixture of archaic and more modern human traits, but such analyses are complicated by the possibility that the vault is pathologically deformed, although the exact etiology has not been established. Now computed tomography (CT) has revealed that the right temporal bone lacks the structures of the bony labyrinth. The most likely cause of this rare pathological condition appears to be labyrinthine ossification, in which newly deposited bone obliterates the inner ear spaces following an infectious disease or occlusion of the labyrinthine blood supply. A possible cause of vascular compromise could have been the presence of an expanding acoustic neuroma in the internal acoustic meatus, which is suggested by a significantly wider right meatus compared with the left side. Interestingly, labyrinthine ossification is also consistent with the controversial diagnosis that an anemia caused the characteristic diploic widening at the parietal bosses, because prime etiological factors of ossification are among the common complications of some of these blood diseases. CT examination of the vault and a review of the literature suggest that a blood disorder may well have caused the unusual parietal morphology. Given the nature of these pathological conditions, the Singa individual must have experienced a period of considerable disability. The morphological evidence from the normal bony labyrinth on the left side and from the CT evaluation of the vault is consistent with the interpretation of Singa as a late archaic hominid or an early representative of Homo sapiens drawn from a population which might be directly ancestral to modern humans. Am J Phys Anthropol 107:41–50, 1998. © 1998 Wiley-Liss, Inc.     

Studies on the condition and structure of bone of the Saldanha fossil cranium.

The external surface of the Saldanha cranium shows extensive exfoliation and cracking. In a few places remnants of the probable original bone surfaces can be observed. These are orange-brown in color, contrasting with the nearly white color of exposed deeper layers, and are subdivided into small segments with pits in their centers. Causes of the color differences are uncertain but merit investigation. The surface cracking and exfoliation probably result from weathering before fossilization. This conclusion is based on the observation that the endocranial surfaces show no such effects, despite the scattering of the cranial fragments at the time of discovery. A depressed fracture in the frontal bone indicates a heavy blow at or shortly after the time of death. This blow probably created some of the fragments, but there are also incomplete fracture cracks which may have resulted from the blow. Unresolved taphonomic problems include the manner in which the cranium held together after decay of soft tissues allowed weathering, and the manner in which the fragments were subsequently scattered. Chips from the cranial vault indicate that the outer table was very thick, tending to support recent proposals that the specimen and assoicated fauna and tools are from a considerably earlier time period than originally believed. The surface damage to the brow ridges gives information on the structure of deeper layers. These are lacking orientation, supporting the hypothesis that hominid brow ridges are not primarily a response to masticatory forces, but may afford protection for the eyes.     

Frontal cranioplasty: risk factors and choice of cranial vault reconstructive material

A study of patients with large cranial defects involving the frontal bone, frontal sinus, nose, and orbit does not support the contention that there is a clear superiority of reconstructive material despite a history of previous bone infection. No patient with an isolated cranial reconstruction experienced an infection despite location in the area of the frontal sinus or the use of acrylic material. All patients experiencing infection underwent simultaneous reconstruction of the frontal cranium and nose and three- or four-wall reconstruction of the orbit, where the frontal sinus had previously been eliminated and where a previous bone infection had been present. Risk factors associated with cranioplasty were timing (p = 0.001) and cranial vault reconstruction in communication with previously infected ethmoid sinuses and the nose (p = 0.03). A history of previous bone infection suggests increased risk (p = 0.15). The choice of reconstructive material was not significant, although acrylic cranioplasties did not experience the complications expected from a review of the literature.     

Vertical growth of the anterior face and cranium in inner city Negro children

A longitudinal cephalometric study was conducted on the vertical growth of the cranium and anterior face on 60 inner city American Negro children, an equal number of boys and girls from four to nine years. Three vertical measurements were used for the purpose of this study. The head height was measured from sellion to bregma, bony nasal height from nasion to anterior nasal spine, and lower facial height from anterior nasal spine and lower facial height from anterior nasal spine to menton. The data were analyzed at annual ages and observations made relative to the growth trends. The findings of this study were compared with those on Caucasian children. No significant statistical difference was found in the mean head (cranial vault) height between the Negro and Caucasian children. The mean bony nasal height expressed as a percentage of subnasal height was found to be less in the Negro children. The difference decreased with age. The annual increment of growth in head height was greater from four to seven years than from seven to nine years. The findings are considered to imply that severe malnutrition may influence child growth.     

Primary producers and nutrient loading in Silver Springs,FL, USA

The characteristics and dynamics of primary producer communities of Silver Springs was examined to compare with that observed by Odum [Odum, H.T., 1957. Trophic structure and productivity of Silver Springs, Florida. Ecol. Monogr. 27, 55–112.] as a means of evaluating the impacts of changes that have occurred over time. The Silver Springs ecosystem is considered an ecosystem at risk, where nitrate levels have more than doubled over the past 50 years. The spatial and temporal abundance and distribution of above-sediment primary producers in Silver Springs, FL, USA, was estimated on a system-wide basis using a GIS platform. The results of study suggest that while the Sagittaria component of Silver Springs has remained relatively stable, epiphyte and benthic algal mat community biomass has expanded, particularly benthic forms, like Lyngbya. However, we argue for caution in weighing the significance of long-term comparisons of system-wide biomass in light of considerable spatial heterogeneity in aquatic primary producer communities.