Facial modeling and measurement based upon homologous topographical features.

Measurement of human faces is fundamental to many applications from recognition to genetic phenotyping. While anthropometric landmarks provide a conventional set of homologous measurement points, digital scans are increasingly used for facial measurement, despite the difficulties in establishing their homology. We introduce an alternative basis for facial measurement, which 1) provides a richer information density than discrete point measurements, 2) derives its homology from shared facial topography (ridges, folds, etc.), and 3) quantifies local morphological variation following the conventions and practices of anatomical description. A parametric model that permits matching a broad range of facial variation by the adjustment of 71 parameters is demonstrated by modeling a sample of 80 adult human faces. The surface of the parametric model can be adjusted to match each photogrammetric surface mesh generally to within 1 mm, demonstrating a novel and efficient means for facial shape encoding. We examine how well this scheme quantifies facial shape and variation with respect to geographic ancestry and sex. We compare this analysis with a more conventional, landmark-based geometric morphometric (GMM) study with 43 landmarks placed on the same set of scans. Our multivariate statistical analysis using the 71 attribute values separates geographic ancestry groups and sexes with a high degree of reliability, and these results are broadly similar to those from GMM, but with some key differences that we discuss. This approach is compared with conventional, non-parametric methods for the quantification of facial shape, including generality, information density, and the separation of size and shape. Potential uses for phenotypic and dysmorphology studies are also discussed.

Description and taxonomic assessment of fossil Cercopithecidae from the Pliocene Galili Formation (Ethiopia).

The Mount Galili Formation in the Afar region, Ethiopia, samples a critical time in hominin evolution, 4.4 to 3.8 Ma, documenting the last appearance of Ardipithecus and the origin of Australopithecus. This period is also important in the evolution of cercopithecids, especially the origin of Theropithecus in general and Theropithecus oswaldi lineage in particular. Galili has provided a total of 655 cercopithecid specimens that include crania, mandibles, isolated teeth and postcrania. All the fossils were recovered from the Lasdanan (5.3-4.43 Ma), Dhidinley (4.43-3.9 Ma) and Shabeley Laag (∼3.92-3.8 Ma) Members. Here, we described and analyzed 362 fossils employing both qualitative and quantitative methods. Descriptions of the material were supplemented with dental metrics and cranial shape analysis using three-dimensional geometric morphometrics. Results indicate the presence of at least six cercopithecid taxa: Theropithecus oswaldi serengetensis (n = 28), Theropithecus sp. (n = 2), three non-Theropithecus papionin groups (n = 134) and one colobine-size group (n = 58). The T. o. serengetensis represents the earliest form of the lineage, documented from ∼3.9 Ma Galili sediments. The three Galili papionins include a smaller taxon, a medium-sized taxon comparable to Pliopapio alemui and a large papionin overlapping in size with Soromandrillus, Gorgopithecus and Dinopithecus. The majority of Galili colobines have closest affinities to Kuseracolobus aramisi and some overlap with other taxa. Papionins dominate the Galili cercopithecid collection, although colobines are still fairly common (approximately 25% of the sample). Thus, Galili sample is like Kanapoi (4.2-4.1 Ma) and Gona (5.2-3.9 Ma) localities but distinct from Aramis, suggesting paleoecological similarity to the former sites. On the other hand, Theropithecus is less abundant at Galili than geologically younger Hadar (3.4-3.2 Ma) and Woranso-Mille (3.8-3.6 Ma) sites. Whether this difference is due to sampling, time or landscape variation requires further investigation.

Will you read how I will read? Naturalistic fMRI predictors of emergent reading.

Despite reading being an essential and almost universal skill in the developed world, reading proficiency varies substantially from person to person. To study why, the fMRI field is beginning to turn from single-word or nonword reading tasks to naturalistic stimuli like connected text and listening to stories. To study reading development in children just beginning to read, listening to stories is an appropriate paradigm because speech perception and phonological processing are important for, and are predictors of, reading proficiency. Our study examined the relationship between behavioral reading-related skills and the neural response to listening to stories in the fMRI environment. Functional MRI were gathered in a 3T TIM-Trio scanner. During the fMRI scan, children aged approximately 7 years listened to professionally narrated common short stories and answered comprehension questions following the narration. Analyses of the data used inter-subject correlation (ISC), and representational similarity analysis (RSA). Our primary finding is that ISC reveals areas of increased synchrony in both high- and low-performing emergent readers previously implicated in reading ability/disability. Of particular interest are that several previously identified brain regions (medial temporal gyrus (MTG), inferior frontal gyrus (IFG), inferior temporal gyrus (ITG)) were found to "synchronize" across higher reading ability participants, while lower reading ability participants had idiosyncratic activation patterns in these regions. Additionally, two regions (superior frontal gyrus (SFG) and another portion of ITG) were recruited by all participants, but their specific timecourse of activation depended on reading performance. These analyses support the idea that different brain regions involved in reading follow different developmental trajectories that correlate with reading proficiency on a spectrum rather than the usual dichotomy of poor readers versus strong readers.

The earliest most complete skeleton of Theropithecus.

The middle Pliocene site of Woranso-Mille in the Afar Region of Ethiopia has yielded numerous significant early hominin fossils representing multiple, coexisting taxa. Here we report on another significant discovery, the oldest partial skeleton of the papionin, Theropithecus. The specimen was recovered from the Aralee Issie collection area over multiple field seasons from 2004 through 2019. The specimen was unearthed in situ from the fluvial facies of the Mesgid Dora Tuff dated to 3.66-3.57 Ma. The partial skeleton, ARI-VP-1/26, is that of a subadult male lacking a skull. In the absence of unambiguously associated craniodental remains, the male status of the specimen was established from the dimensions of the long bones in comparison to those of other Theropithecus from Woranso-Mille. ARI-VP-1/26 is noteworthy because it preserves partial hand and foot skeletons, including a complete set of metacarpals from the left side. The theropith status of ARI-VP-1/26 was established based on the detailed anatomy of the postcranial skeleton, especially the proximal and distal humerus, proximal radius, and proximal femur. The morphology of the postcranium of ARI-VP-1/26 is consistent with that of recognized Theropithecus from Woranso-Mille and, specifically, with specimens recognized as Theropithecus oswaldi cf. darti from other sites. The ratio of the lengths of the first metacarpal to metacarpals 2-5 in ARI-VP-1/26 is intermediate between that seen in extant Papio and Theropithecus. In Theropithecus gelada and Theropithecus brumpti, the pairing of pollical and indical metacarpals of near equal length contributes to the species' high opposability index and is associated with a 'manual grazing' feeding habit. Cercopithecids constitute 43% of the identified vertebrates at Aralee Issie, and T. oswaldi cf. darti is the most common mammalian species. The monkeys of Aralee Issie lived in an open shrubland habitat, but the specific reasons for their high prevalence at the site are unclear.

Expanded geographic distribution and dietary strategies of the earliest Oldowan hominins and Paranthropus.

The oldest Oldowan tool sites, from around 2.6 million years ago, have previously been confined to Ethiopia's Afar Triangle. We describe sites at Nyayanga, Kenya, dated to 3.032 to 2.581 million years ago and expand this distribution by over 1300 kilometers. Furthermore, we found two hippopotamid butchery sites associated with mosaic vegetation and a C4 grazer-dominated fauna. Tool flaking proficiency was comparable with that of younger Oldowan assemblages, but pounding activities were more common. Tool use-wear and bone damage indicate plant and animal tissue processing. Paranthropus sp. teeth, the first from southwestern Kenya, possessed carbon isotopic values indicative of a diet rich in C4 foods. We argue that the earliest Oldowan was more widespread than previously known, used to process diverse foods including megafauna, and associated with Paranthropus from its onset.

Biochronology of South African hominin-bearing sites: A reassessment using cercopithecid primates.

Despite recent advances in chronometric techniques (e.g., Uranium-Lead [U-Pb], cosmogenic nuclides, electron spin resonance spectroscopy [ESR]), considerable uncertainty remains regarding the age of many Plio-Pleistocene hominin sites, including several in South Africa. Consequently, biochronology remains important in assessments of Plio-Pleistocene geochronology and provides direct age estimates of the fossils themselves. Historically, cercopithecid monkeys have been among the most useful taxa for biochronology of early hominins because they are widely present and abundant in the African Plio-Pleistocene record. The last major studies using cercopithecids were published over 30 y ago. Since then, new hominin sites have been discovered, radiometric age estimates have been refined, and many changes have occurred in cercopithecid taxonomy and systematics. Thus, a biochronological reassessment using cercopithecids is long overdue. Here, we provide just such a revision based on our recent study of every major cercopithecid collection from African Plio-Pleistocene sites. In addition to correlations based on shared faunal elements, we present an analysis based on the dentition of the abundant cercopithecid Theropithecus oswaldi, which increases in size in a manner that is strongly correlated with geological age (r2 ∼0.83), thereby providing a highly accurate age-estimation tool not previously utilized. In combination with paleomagnetic and U-Pb data, our results provide revised age estimates and suggest that there are no hominin sites in South Africa significantly older than ∼2.8 Ma. Where conflicting age estimates exist, we suggest that additional data are needed and recall that faunal estimates have ultimately proved reliable in the past (e.g., the age of the KBS Tuff).

A novel use for the biodegradable temporizing matrix.

Biodegradable Temporising Matrix (BTM), a skin substitute, has been recently developed as a novel adjunct to the plastic surgeon's reconstructive repertoire. Its use has been described in literature in a variety of settings and complex wounds, including those that previously would have been described as "non-graftable", with favourable outcomes. We present the case of a patient with a wound to the right foot and ankle following extravasation injury. Following surgical debridement, this injury was managed with BTM, which allowed granulation and production of a "neo-dermis". A split-thickness skin graft was subsequently applied. The characteristics of the BTM allowed the resulting skin graft and scar to be pliable, avoiding tendon tethering and joint contracture. To the authors' knowledge, this skin substitute has not been reported in a wound of this aetiology before. It is our hope that this report will provide evidence to colleagues that this is a valuable adjunct that may be used in complex wounds. Level of evidence: Level V, therapeutic study. Supplementary Information: The online version contains supplementary material available at 10.1007/s00238-022-01964-z.

Early Pleistocene large mammals from Maka'amitalu, Hadar, lower Awash Valley, Ethiopia.

The Early Pleistocene was a critical time period in the evolution of eastern African mammal faunas, but fossil assemblages sampling this interval are poorly known from Ethiopia's Afar Depression. Field work by the Hadar Research Project in the Busidima Formation exposures (~2.7-0.8 Ma) of Hadar in the lower Awash Valley, resulted in the recovery of an early Homo maxilla (A.L. 666-1) with associated stone tools and fauna from the Maka'amitalu basin in the 1990s. These assemblages are dated to ~2.35 Ma by the Bouroukie Tuff 3 (BKT-3). Continued work by the Hadar Research Project over the last two decades has greatly expanded the faunal collection. Here, we provide a comprehensive account of the Maka'amitalu large mammals (Artiodactyla, Carnivora, Perissodactyla, Primates, and Proboscidea) and discuss their paleoecological and biochronological significance. The size of the Maka'amitalu assemblage is small compared to those from the Hadar Formation (3.45-2.95 Ma) and Ledi-Geraru (2.8-2.6 Ma) but includes at least 20 taxa. Bovids, suids, and Theropithecus are common in terms of both species richness and abundance, whereas carnivorans, equids, and megaherbivores are rare. While the taxonomic composition of the Maka'amitalu fauna indicates significant species turnover from the Hadar Formation and Ledi-Geraru deposits, turnover seems to have occurred at a constant rate through time as taxonomic dissimilarity between adjacent fossil assemblages is strongly predicted by their age difference. A similar pattern characterizes functional ecological turnover, with only subtle changes in dietary proportions, body size proportions, and bovid abundances across the composite lower Awash sequence. Biochronological comparisons with other sites in eastern Africa suggest that the taxa recovered from the Maka'amitalu are broadly consistent with the reported age of the BKT-3 tuff. Considering the age of BKT-3 and biochronology, a range of 2.4-1.9 Ma is most likely for the faunal assemblage.

Tracking second language immersion across time: Evidence from a bi-directional longitudinal cross-linguistic fMRI study.

Parallel cohorts of Hebrew speakers learning English in the U.S., and American-English speakers learning Hebrew in Israel were tracked over the course of two years of immersion in their L2. We utilised a functional MRI semantic judgement task with print and speech tokens, as well as a battery of linguistic and cognitive behavioural measures prior to and after immersion, to track changes in both L1 and L2 processing. fMRI activation for print tokens produced a similar network of activation in both English and Hebrew, irrespective of L1 or L2 status. Significant convergence of print and speech processing was also observed in both languages across a network of left-hemisphere regions joint for both L1 and L2. Despite significant increases in behavioural measures of L2 proficiency, only a few signs of longitudinal change in L2 brain activation were found. In contrast, L1 showed widespread differences in processing across time, suggesting that the neurobiological footprint of reading is dynamic and plastic even in adults, with L2 immersion impacting L1 processing. Print/speech convergence showed little longitudinal change, suggesting that it is a stable marker of the differences in L1 and L2 processing across L2 proficiency.

The Haskins pediatric atlas: a magnetic-resonance-imaging-based pediatric template and atlas.

BACKGROUND: Spatial normalization plays an essential role in multi-subject MRI and functional MRI (fMRI) experiments by facilitating a common space in which group analyses are performed. Although many prominent adult templates are available, their use for pediatric data is problematic. Generalized templates for pediatric populations are limited or constructed using older methods that result in less ideal normalization. OBJECTIVE: The Haskins pediatric templates and atlases aim to provide superior registration and more precise accuracy in labeling of anatomical and functional regions essential for all fMRI studies involving pediatric populations. MATERIALS AND METHODS: The Haskins pediatric templates and atlases were generated with nonlinear methods using structural MRI from 72 children (age range 7-14 years, median 10 years), allowing for a detailed template with corresponding parcellations of labeled atlas regions. The accuracy of these templates and atlases was assessed using multiple metrics of deformation distance and overlap. RESULTS: When comparing the deformation distances from normalizing pediatric data between this template and both the adult templates and other pediatric templates, we found significantly less deformation distance for the Haskins pediatric template (P<0.0001). Further, the correct atlas classification was higher using the Haskins pediatric template in 74% of regions (P<0.0001). CONCLUSION: The Haskins pediatric template results in more accurate correspondence across subjects because of lower deformation distances. This correspondence also provides better accuracy in atlas locations to benefit structural and functional imaging analyses of pediatric populations.

Ontogenetic allometry and scaling in catarrhine crania.

In studies of ontogenetic allometry, ontogenetic scaling has often been invoked to explain cranial morphological differences between smaller and larger forms of closely related taxa. These scaled variants in shape have been hypothesized to be the result of the extension or truncation of common growth allometries. In this scenario, change in size is the determining factor, perhaps under direct selection, and changes in cranial shapes are byproducts, not under direct selection themselves. However, many of these conclusions are based on studies that used bivariate generalizations of shape. Even among multivariate analyses of growth allometries, there are discrepancies as to the prevalence of ontogenetic scaling among primates, how shared the trajectories need to be, and which taxa evince properties of scaled variants. In this investigation, we use a large, comparative ontogenetic sample, geometric morphometric methods, and multivariate statistical tests to examine ontogenetic allometry and evaluate if differences in cranial shape among closely related catarrhines of varying sizes are primarily driven by size divergence, that is, ontogenetic scaling. We then evaluate the hypothesis of size as a line of least evolutionary resistance in catarrhine cranial evolution. We found that patterns of ontogenetic allometry vary among taxa, indicating that ontogenetic scaling sensu stricto does not often account for most morphological differences and that large and small taxa within clades are generally not scaled variants. The presence of a variety of ontogenetic pathways for the evolution of cranial shapes provides indirect evidence for selection acting directly on the cranial shape, rather than on size alone.

Functional connectivity in the developing language network in 4-year-old children predicts future reading ability.

Understanding how pre-literate children's language abilities and neural function relate to future reading ability is important for identifying children who may be at-risk for reading problems. Pre-literate children are already proficient users of spoken language and their developing brain networks for language become highly overlapping with brain networks that emerge during literacy acquisition. In the present longitudinal study, we examined language abilities, and neural activation and connectivity within the language network in pre-literate children (mean age = 4.2 years). We tested how language abilities, brain activation, and connectivity predict children's reading abilities 1 year later (mean age = 5.2 years). At Time 1, children (n = 37) participated in a functional near infrared spectroscopy (fNIRS) experiment of speech processing (listening to words and pseudowords) and completed a standardized battery of language and cognitive assessments. At Time 2, children (n = 28) completed standardized reading assessments. Using psychophysiological interaction (PPI) analyses, we observed significant connectivity between the left IFG and right STG in pre-literate children, which was modulated by task (i.e., listening to words). Neural activation in left IFG and STG and increased task-modulated connectivity between the left IFG and right STG was predictive of multiple reading outcomes. Increased connectivity was associated later with increased reading ability.

Individual differences in learning the regularities between orthography, phonology and semantics predict early reading skills.

Statistical views of literacy development maintain that proficient reading requires the assimilation of myriad statistical regularities present in the writing system. Indeed, previous studies have tied statistical learning (SL) abilities to reading skills, establishing the existence of a link between the two. However, some issues are currently left unanswered, including questions regarding the underlying bases for these associations as well as the types of statistical regularities actually assimilated by developing readers. Here we present an alternative approach to study the role of SL in literacy development, focusing on individual differences among beginning readers. Instead of using an artificial task to estimate SL abilities, our approach identifies individual differences in children's reliance on statistical regularities as reflected by actual reading behavior. We specifically focus on individuals' reliance on regularities in the mapping between print and speech versus associations between print and meaning in a word naming task. We present data from 399 children, showing that those whose oral naming performance is impacted more by print-speech regularities and less by associations between print and meaning have better reading skills. These findings suggest that a key route by which SL mechanisms impact developing reading abilities is via their role in the assimilation of sub-lexical regularities between printed and spoken language -and more generally, in detecting regularities that are more reliable than others. We discuss the implications of our findings to both SL and reading theories.

Fossil Cercopithecidae from the Early Pliocene Sagantole Formation at Gona, Ethiopia.

The Early Pliocene Sagantole Fm. in the Gona Project area, Afar State, Ethiopia, is noted for discoveries of the early hominin Ardipithecus ramidus. A large series of fossil cercopithecid primates dated to between 4.8 and 4.3 Ma has also been collected from these sediments. In this paper, we use qualitative analysis and standard dental and postcranial measures to systematically describe the craniodental remains and tentatively allocate postcrania to taxa where we are able to. We then use these data to compare these specimens to fossil assemblages from contemporary sites, interpret their paleobiology, and discuss implications for the paleoecology of the Gona Sagantole Fm. We recognize three cercopithecid species in the Gona Sagantole Fm. Pliopapio alemui makes up approximately two-thirds of the identifiable specimens; nearly all of the rest are allocated to Kuseracolobus aramisi, and a single molar indicates the presence of a second, somewhat larger but morphologically distinct papionin. Among the Early Pliocene cercopithecids from Gona are also a number of postcranial elements. None of the postcranial remains are directly associated with any of the cranial material. Nonetheless, some of the distal humeri and proximal femora can be tentatively allocated to either Pl. alemui or K. aramisi based on a combination of size, as the latter is approximately 50% larger than the former, and morphology. If these assignments are correct, they suggest K. aramisi was primarily arboreal and similar to most extant colobines, whereas Pl. alemui was more mixed in its substrate use, being more terrestrially adapted than K. aramisi, but less so than extant Papio or Theropithecus. Thus, we interpret the predominance of Pl. alemui over K. aramisi is consistent with a somewhat more open environment at Gona than at Aramis.

Morphometric analysis of the hominin talus: Evolutionary and functional implications.

The adoption of bipedalism is a key benchmark in human evolution that has impacted talar morphology. Here, we investigate talar morphological variability in extinct and extant hominins using a 3D geometric morphometric approach. The evolutionary timing and appearance of modern human-like features and their contributions to bipedal locomotion were evaluated on the talus as a whole, each articular facet separately, and multiple combinations of facets. Distinctive suites of features are consistently present in all fossil hominins, despite the presence of substantial interspecific variation, suggesting a potential connection of these suites to bipedal gait. A modern human-like condition evolved in navicular and lateral malleolar facets early in the hominin lineage compared with other facets, which demonstrate more complex morphological variation within Homininae. Interestingly, navicular facet morphology of Australopithecus afarensis is derived in the direction of Homo, whereas more recent hominin species such as Australopithecus africanus and Australopithecus sediba retain more primitive states in this facet. Combining the navicular facet with the trochlea and the posterior calcaneal facet as a functional suite, however, distinguishes Australopithecus from Homo in that the medial longitudinal arch had not fully developed in the former. Our results suggest that a more everted foot and stiffer medial midtarsal region are adaptations that coincide with the emergence of bipedalism, whereas a high medial longitudinal arch emerges later in time, within Homo. This study provides novel insights into the emergence of talar morphological traits linked to bipedalism and its transition from a facultative to an obligate condition.

Cercopithecid fossils from Kanapoi, West Turkana, Kenya (2007-2015).

Recent fieldwork at Kanapoi has expanded the sample of fossil cercopithecids, facilitating a re-appraisal of their taxonomy. The assemblage now includes at least one species of cercopithecin, two papionins, and two colobines. The guenon Nanopithecus browni is similar in dental size to extant Miopithecus. We tentatively re-affirm the identification of Parapapio cf. ado and confirm the presence of Theropithecus. The colobines include a small form tentatively attributed to Kuseracolobus and a second larger species. The Kanapoi fossils represent the oldest occurrences of guenons in Africa and of the important genus Theropithecus, the most abundant and widespread primate in the Neogene of Africa. In the assemblage, Parapapio cf. ado is the most abundant form, comprising the majority of specimens. All of the other taxa are comparatively rare. Colobines make up a small part of the Kanapoi fossil assemblage compared to most other contemporary sites, including Allia Bay, Kenya, where, like Kanapoi, Australopithecus anamensis has been found. The presence of Theropithecus is consistent with the presence of some relatively open habitat at Kanapoi. While the ecological preferences of the small cercopithecin are unknown, most guenons are associated with relatively wooded habitats, as are most colobines, suggesting the availability of at least some wooded areas.