The deciduous dentition of Homo naledi: A comparative study Publication date: November 2019 Source: Journal of Human Evolution, Volume 136 Author(s): Shara E. Bailey, Juliet K. Brophy, Jacopo Moggi-Cecchi, Lucas K. Delezene Abstract In 2013, 2014 new hominin remains were uncovered in the Dinaledi chamber of the Rising Star cave system in South Africa. In 2015 Berger and colleagues identified these remains as belonging to a new species Homo naledi (Berger et al., 2015). Subsequent comparative studies of the skull, postcrania and permanent dentition have supported this taxonomic affiliation (Harcourt-Smith et al., 2015; Kivell et al., 2015; Irish et al., 2018). The deciduous teeth can offer unique insights into hominin evolution. Due to their early onset and rapid development their morphology is thought to be under stronger genetic control and less influenced by environment than are the permanent teeth. In this study we compared the H. naledi deciduous teeth from the 2013–2014 excavations to samples representing much of the hominin clade including Australopithecus afarensis, Australopithecus africanus, Paranthropus boisei, Paranthropus robustus, early Homo, Homo antecessor, Homo erectus s.l., Homo floresiensis, Middle Pleistocene Homo, Homo neanderthalensis, early Homo sapiens and recent H. sapiens from Sub-Saharan Africa. By making such a broad morphological comparison, we aimed to contextualize the Dinaledi hominins and to further assess the validity of their taxonomic assignment. Our analysis of the deciduous teeth revealed a unique combination of features that mirror (but also expand) that found in the permanent teeth. This mosaic includes an asymmetrical lower canine with a distal tubercle, an upper first molar with a large hypocone and epicrista associated with a mesial cuspule, a molarized lower first molar resembling Paranthropus, and upper and lower second molars that resemble later Homo in their lack of accessory cusps. The unique combination of deciduous dental characters supports previous studies assigning H. naledi to a new species, although its phylogenetic position vis-à-vis other Homo species remains ambiguous.

Enamel thickness and dental development in Rudapithecus hungaricus Publication date: November 2019 Source: Journal of Human Evolution, Volume 136 Author(s): Tanya M. Smith, Paul Tafforeau, Joane Pouech, David R. Begun Abstract The fossil record of middle and late Miocene Eurasian hominoids has expanded considerably over the past few decades, particularly with the recovery of numerous isolated teeth and jaws. Scholars have turned to assessments of internal tooth structure and growth to make sense of the evolutionary radiations of these primates as well as their affinities to the living great apes (hominids). Here we characterize full-dentition enamel thickness and dental development in several juvenile Rudapithecus hungaricus individuals using multiple imaging modalities. Relative enamel thickness (RET) values for the anterior teeth and premolars of Rudapithecus are broadly akin to those of gorillas and chimpanzees and are thinner than those of orangutans. First molar RET values are most similar to chimpanzees, while posterior molar values are closer to thicker-enameled orangutans. When compared to Miocene hominoids, Rudapithecus shows an intermediate molar RET condition that is especially similar to other dryopithecines. Long-period line periodicity values are comparable to African apes and most Miocene hominoids, and lower than living and fossil orangutans. The mean cuspal daily secretion rate is similar to that of several other Miocene hominoids but is greater than extant great apes. Cusp-specific molar crown formation times generally exceed those of chimpanzees, are lower than those of orangutans, and are broadly like those of other Miocene apes. While Rudapithecus appears to have a somewhat unique pattern of enamel thickness and dental development relative to individual great ape genera, these structural and developmental features are consistent with its designation as a hominid.

Feathers and food: Human-bird interactions at Middle Pleistocene Qesem Cave, Israel Publication date: November 2019 Source: Journal of Human Evolution, Volume 136 Author(s): Ruth Blasco, Jordi Rosell, Antonio Sánchez-Marco, Avi Gopher, Ran Barkai Abstract The presence of fast-moving small game in the Paleolithic archaeological faunal record has long been considered a key variable to assess fundamental aspects of human behavior and subsistence. Birds occupy a prominent place in this debate not only due to their small size and to the difficulties in capturing them (essentially due to their ability to fly and their elusiveness), but also due to their possible role in the symbolic array in regard to non-nutritional elements (feathers, talons, etc.) and as reflectors of complex human–world relationships. In this study, we attempt to contribute to this topic by presenting taphonomical data of bird specimens from Qesem Cave (Israel), dated between 420 and 200 ka. Human-induced damage, including cut marks, peeling and human gnawing, has been identified on wing bones of Cygnus sp., Columba sp., Corvus ruficollis and Sturnus sp. Our evidence suggests that avian exploitation was not limited to food only—either to complement the human diet or as occasional food item—but also presumably for the use of feathers. While the consumption of birds as a dietary source seems to be evident as early as the Early Pleistocene, the non-alimentary use of inedible elements, such as feathers and talons, appears to be a practice from the Middle Paleolithic onwards. We argue that the combined nutritional and symbolic use of birds is one characteristic of the new mode of adaptation practiced already by the late Lower Paleolithic Acheulo-Yabrudian hominins in the Levant starting 400 ka. The Qesem findings point to the possible emergence of new cognitive and behavioral skills, which are followed in later periods in the Old World. Finally, we discuss the possible ontological and cosmological significance of human–bird interactions to illuminate our hypothesis regarding the emergence of a new perception of human relationships with the world as an integral part of the new Acheulo-Yabrudian mode of adaptation.

Femoral neck cortical bone distribution of dryopithecin apes and the evolution of hominid locomotion Publication date: November 2019 Source: Journal of Human Evolution, Volume 136 Author(s): Marta Pina, David M. Alba, Salvador Moyà-Solà, Sergio Almécija Abstract Only a few postcranial remains have been assigned to the Miocene great ape Dryopithecus fontani, leading to uncertainties in the reconstruction of its overall body plan and positional behavior. Here we shed light on the locomotor repertoire of this species through the study of the femoral neck cortical bone (FNCB) distribution of IPS41724, a partial proximal femur from the Abocador de Can Mata locality ACM/C3-Az (11.9 Ma, middle Miocene; Vallès-Penedès Basin, Spain) attributed to this taxon. This specimen was scanned through computed tomography to measure the superior (SUP) and inferior (INF) cortical thicknesses at the middle and the base of the femoral neck. Measurements were compared with a sample of extant primates and the femur IPS18800.29 from the younger great ape Hispanopithecus laietanus from Can Llobateres 2 (9.6 Ma, late Miocene; Vallès-Penedès Basin), previously shown to display a homogeneous FNCB distribution at the midneck section coupled with postcranial adaptations to below-branch suspensory behaviors. Our analyses indicate an asymmetric FNCB distribution for IPS41724 (SUP/INF index = ∼0.4 at the midneck and base of the neck sections), comparable with that of quadrupedal primates and bipedal hominins (including early australopiths), but contrasting with the homogeneous FNCB distribution of Hispanopithecus and extant great apes. An asymmetrical FNCB distribution has been associated with stereotyped loads at the hip joint (as in both quadrupedal and bipedal taxa). Our results therefore support a significant quadrupedal component of the positional behavior of Dryopithecus, thus strengthening the argument that plesiomorphic generalized quadrupedalism was still a major locomotor behavior for Miocene great apes. If that were the case, it could have deep implications for the origins of hominin bipedalism.

A Neanderthal from the Central Western Zagros, Iran. Structural reassessment of the Wezmeh 1 maxillary premolar Publication date: October 2019 Source: Journal of Human Evolution, Volume 135 Author(s): Clément Zanolli, Fereidoun Biglari, Marjan Mashkour, Kamyar Abdi, Hervé Monchot, Karyne Debue, Arnaud Mazurier, Priscilla Bayle, Mona Le Luyer, Hélène Rougier, Erik Trinkaus, Roberto Macchiarelli Abstract Wezmeh Cave, in the Kermanshah region of Central Western Zagros, Iran, produced a Late Pleistocene faunal assemblage rich in carnivorans along with a human right maxillary premolar, Wezmeh 1, an unerupted tooth from an 8 ± 2 year-old individual. Uranium-series analyses of the fauna by alpha spectrometry provided age estimates between 70 and 11 ka. Crown dimensions place the tooth specimen at the upper limits of Late Pleistocene human ranges of variation. Wezmeh 1 metameric position (most likely a P3) remains uncertain and only its surficial morphology has been described so far. Accordingly, we used microfocus X-ray tomography (12.5 μm isotropic voxel size) to reassess the metameric position and taxonomic attribution of this specimen. We investigated its endostructural features and quantified crown tissue proportions. Topographic maps of enamel thickness (ET) distribution were also generated, and semilandmark-based geometric morphometric analyses of the enamel-dentine junction (EDJ) were performed. We compared Wezmeh 1 with unworn/slightly-moderately worn P3 and P4 of European Neanderthals, Middle Paleolithic modern humans from Qafzeh, an Upper Paleolithic premolar, and Holocene humans. The results confirm that Wezmeh 1 represents a P3. Based on its internal conformation and especially EDJ shape, Wezmeh 1 aligns closely with Neanderthals and is distinct from the fossil and extant modern human pattern of our comparative samples. Wezmeh 1 is thus the first direct evidence of Neanderthal presence on the western margin of the Iranian Plateau.

New Sivapithecus specimen from Ramnagar (Jammu and Kashmir), India and a taxonomic revision of Ramnagar hominoids Publication date: October 2019 Source: Journal of Human Evolution, Volume 135 Author(s): Christopher C. Gilbert, Ramesh K. Sehgal, Kelsey D. Pugh, Christopher J. Campisano, Evangeline May, Biren A. Patel, Ningthoujam Premjit Singh, Rajeev Patnaik

A revision of the conductive hearing loss in Cranium 4 from the Middle Pleistocene site of Sima de los Huesos (Burgos, Spain) Publication date: October 2019 Source: Journal of Human Evolution, Volume 135 Author(s): Mercedes Conde-Valverde, Manuel Rosa, Ignacio Martínez, Julio Marchamalo, Ana Pantoja-Pérez, Rolf Quam, Carlos Lorenzo, Ana Gracia-Téllez, Alfredo García-Fernández, Juan Luis Arsuaga, Teresa Rivera-Rodríguez Abstract Pathological conditions have been previously documented in the Middle Pleistocene Sima de los Huesos hominins from northern Spain, and several of these have clear behavioral implications. Within this fossil assemblage, Cranium 4 shows bilateral external auditory exostoses which have been preliminarily interpreted as causing a significant hearing loss in this individual. If confirmed, this would be the oldest recorded case of deafness in human history and could have important implications for the antiquity of this condition, as well as social interactions. To further investigate this case, the current study presents 3D reconstructions of the entire outer and middle ear, based on computed tomography scans of both temporal bones in Cranium 4. We established the degree of stenosis in both external auditory canals, showing that in both cases the degree of stenosis is less than 52% of the original cross-sectional area of each canal. Based on clinical studies in living humans, the buildup of wax due to the degree of stenosis in Cranium 4 is unlikely to have caused frequent external ear infections. In addition, we estimated the pattern of sound power transmission up to 5 kHz in both ears relying on a comprehensive model developed in the bioengineering literature and which has been applied previously to the Sima de los Huesos hominins. The model was modified to account for the peculiar shape of the pathological external ear canals in Cranium 4. The results show that this pathology had little to no influence on the sound power transmission in this individual. Thus, we conclude that the exostoses present in both ears of Cranium 4 did not significantly affect their hearing.

The shift from typical Western European Late Acheulian to microproduction in unit ‘D’ of the late Middle Pleistocene deposits of the Caune de l’Arago (Pyrénées-Orientales, France) Publication date: October 2019 Source: Journal of Human Evolution, Volume 135 Author(s): Deborah Barsky, Anne Marie Moigne, Véronique Pois Abstract Stratigraphic Unit D levels of the Caune de l’Arago (Pyrénées-Orientales, France), situated in the upper part of the depositional sequence of Ensemble Stratigraphique III (ES III), has yielded a rich Acheulian archeopaleontological record dated to the Middle Pleistocene. The site's infill, dated from 690 to 90 ka, encloses a thick cultural sequence comprising some of the oldest evidence of Acheulian documented so far in Western Europe (Unit P levels). The deposits contain successive occupation layers with abundant faunal remains, stone artifacts, and sometimes hominin remains attributed to Homo erectus tautavelensis. The Unit D levels are chronostratigraphically positioned at the top of the ES III sequence, accumulated at the end of Marine Isotope Stage (MIS) 12. The Unit D lithic assemblage shows no evidence of Levallois knapping strategies. Rather, its features indicate a trend towards microproduction that continues into subsequent occupational phases, apparently marking a local expression of the transition from the Lower to the Middle Paleolithic. Remarkably, tiny discoid and multidirectional type cores, predominantly knapped from small-sized quartz pebbles, characterize the Unit D lithic assemblage. Experimental work presented here demonstrates the likelihood that, despite the small size of the cores and the recalcitrant crystalline materials from which they were knapped, flake production can be carried out with free-hand hard hammer techniques. We explore behavioral aspects gleaned from Unit D cultural material, contrasting them with microlithic praxis observed elsewhere in Europe and the Near East in a similar timeframe.

Trabecular bone structure scales allometrically in the foot of four human groups Publication date: October 2019 Source: Journal of Human Evolution, Volume 135 Author(s): Jaap P.P. Saers, Timothy M. Ryan, Jay T. Stock Abstract The human foot is highly derived relative to that of other hominoids and therefore a topic of intense research in paleoanthropology. While trabecular bone is thought to be highly plastic in response to habitual behavior, knowledge of how trabecular structure scale with body size is essential for making functional inferences from trabecular bone morphology. Trabecular bone properties scale with negative allometry in interspecific studies that includes a wide range of body size; however, intraspecific scaling patterns often differ from interspecific trends. In this paper we examine patterns of trabecular bone scaling in the calcaneus, talus, and first metatarsal of four human populations with different subsistence strategies and associated levels of terrestrial mobility. We report Bayesian linear regressions between the natural logarithms of femoral head diameter and five standard trabecular variables calculated in five spherical volumes of interest. We additionally report regressions on population-specific z-scores of femoral head diameter and trabecular variables as a way of placing the four populations on a common scale. Results show that with increasing body size there is no change in bone volume fraction (BV/TV) and trabecular thickness (Tb.Th), a slight increase in trabecular spacing (Tb.Sp), and a sharp decrease in connectivity density (Conn.D). Degree of anisotropy was found to scale with positive allometry in the calcaneus, negative allometry in the talar trochlea, and shows no relationship with femoral head diameter in the talar and first metatarsal heads. These results show that scaling of the degree of anisotropy can vary substantially within and between bones. Degree of anisotropy is often used as a proxy for directionality in joint loading when interpreting variation in trabecular structures of fossils and extant primates. Body size should therefore be an important consideration when trabecular bone structure is used to interpret function from fossil morphology.

Lithic technology, chronology, and marine shells from Wadi Aghar, southern Jordan, and Initial Upper Paleolithic behaviors in the southern inland Levant Publication date: October 2019 Source: Journal of Human Evolution, Volume 135 Author(s): Seiji Kadowaki, Toru Tamura, Katsuhiro Sano, Taiji Kurozumi, Lisa A. Maher, Joe Yuichiro Wakano, Takayuki Omori, Risako Kida, Masato Hirose, Sate Massadeh, Donald O. Henry Abstract The Initial Upper Paleolithic (IUP) temporally overlaps with the range expansion of Homo sapiens populations in various parts of Eurasia and is often considered a key archaeological phase for investigating behavioral changes from the Middle Paleolithic. This paper reports upon new data from IUP occupations at Wadi Aghar, a rock shelter site in the southern Levant. In combining the results of radiometric dates and lithic analyses, we clarify the chronological and cultural position of Wadi Aghar assemblages in the Levantine IUP. As for the records about mobility, on-site activities, and resource procurement behaviors, we present analyses of lithic use-wear, tool-type composition, soil micromorphology, and marine shells. The lithic analyses and the optically stimulated luminescence (and subsidiary radiocarbon) dating of the Wadi Aghar materials suggest their chronocultural position in the IUP (45–40 ka for Layers C–D1; 39–36 ka for Layer B; possibly 50 ka for Layer D2), providing the southernmost location for the IUP in Eurasia. In the Levant, Wadi Aghar represents one of the few IUP sites in the inland areas. The results also indicate that the timing and technological sequences from the IUP to the following bladelet industries differed between the inland and coastal zones, likely reflecting geographically variable adaptive behaviors and/or cultural transmissions. One of the behavioral characteristics of IUP foragers at Wadi Aghar is the procurement of remote resources, represented by the transportation of marine shells from the Red Sea: Canarium fusiforme and Canarium cf. mutabile. Whether it was a direct procurement with increased mobility or a result of intergroup exchanges, it was not part of behavioral repertoires during the late MP in the same area. This can be understood as the expansion of resource procurement range, functioning as additional buffers from risk in the semiarid environments in the inland Levant.