An examination of the cross-sectional geometrical properties of the long bone diaphyses of Holocene foragers from Roonka, South Australia.

OBJECTIVES: This study examines long bone diaphyseal rigidity and shape of hunter-gatherers at Roonka to make inferences about subsistence strategies and mobility of inhabitants of semi-arid southeastern Australia. Roonka is a cemetery site adjacent to the Lower Murray River, which contains over 200 individuals buried throughout the Holocene. Archaeological evidence indicates that populations living near this river corridor employed mobile, risk averse foraging strategies. METHODS: This prediction of lifestyle was tested by comparing the cross-sectional geometric properties of the humerus, radius, ulna, femur, tibia, and fibula of individuals from Roonka to samples of varying subsistence strategies. Bilateral asymmetry of the upper limb bones was also examined. RESULTS: Roonka males and females have moderately high lower limb diaphyseal rigidity and shape. In the upper limb, females have low rigidity and bilateral asymmetry while males have moderately high rigidity and bilateral asymmetry. This pattern is similar to other foraging groups from Australia and southern Africa that have behaviorally adapted to arid and semi-arid environments. DISCUSSION: Lower limb results suggest that populations in the Lower Murray River Valley had relatively elevated foraging mobility. Upper limb rigidity and bilateral asymmetry indicate a sexual division of labor at Roonka. Females resemble other samples that had mixed subsistence strategies that involved hunting, gathering, and processing tasks. Males display a pattern similar to groups that preferentially hunted large game, but that supplemented this source with smaller game and riverine resources.

Risk Minimization and a Late Holocene Increase in Mobility at Roonka Flat, South Australia: An Analysis of Lower Limb Bone Diaphyseal Shape.

OBJECTIVES: The strengthening of the El Niño Southern Oscillation (ENSO) in the mid-Holocene caused significant changes in climate, vegetation, and faunal assemblages in South Australia. The appearance of a light, flexible backed-artifact toolkit ∼4 kya has been interpreted as evidence for changes in foraging behavior in response to this event. Optimal foraging theory supports a risk minimization strategy for South Australian hunter-gatherers in which increased mobility was used to cope with effects of a dryer, unstable environment in the late Holocene. Whether this event caused changes in foraging mobility will be tested by examining lower limb external diaphyseal shape between pre-ENSO and post-ENSO skeletons from Roonka Flat, South Australia. MATERIALS AND METHODS: Anteroposterior and mediolateral diameters were used to construct diaphyseal shape indices for Roonka Flat femora and tibiae. If populations living in South Australia became more mobile over time, then post-ENSO skeletons should exhibit higher shape indices. RESULTS: The pooled-sex post-ENSO sample has significantly higher femoral shape indices than the pre-ENSO sample. Males do not show significant diaphyseal shape differences over time, but females significantly increase. DISCUSSION: These data are consistent with the risk minimization model, indicating that South Australians became more mobile post-ENSO to better exploit a less productive environment by expanding their foraging radii. The temporal shift toward more elliptical diaphyses is more notable in females than males, which is consistent with Aboriginal ethnographies that show both sexes being intensely involved in hunting and capturing game animals. Am J Phys Anthropol 161:94-103, 2016. © 2016 Wiley Periodicals, Inc.

Brief communication: Artificial cranial modification in Kow Swamp and Cohuna.

The crania from Kow Swamp and Cohuna have been important for a number of debates in Australian paleoanthropology. These crania typically have long, flat foreheads that many workers have cited as evidence of genetic continuity with archaic Indonesian populations, particularly the Ngandong sample. Other scientists have alleged that at least some of the crania from Kow Swamp and the Cohuna skull have been altered through artificial modification, and that the flat foreheads possessed by these individuals are not phylogenetically informative. In this study, several Kow Swamp crania and Cohuna are compared to known modified and unmodified comparative samples. Canonical variates analyses and Mahalanobis distances are generated, and random expectation statistics are used to calculate statistical significance for these tests. The results of this study agree with prior work indicating that a portion of this sample shows evidence for artificial modification of the cranial vault. Many Kow Swamp crania and Cohuna display shape similarities with a population of known modified individuals from New Britain. Kow Swamp 1, 5, and Cohuna show the strongest evidence for modification, but other individuals from this sample also show evidence of culturally manipulated changes in cranial shape. This project provides added support for the argument that at least some Pleistocene Australian groups were practicing artificial cranial modification, and suggests that caution should be used when including these individuals in phylogenetic studies.

Patterns in ritual tooth avulsion at Roonka.

Tooth avulsion is the intentional removal of one or more teeth for ritual or aesthetic reasons, or to denote group affiliation. Typically the maxillary incisors are the teeth most often selected for removal. Previous authors have discussed the presence of tooth avulsions in several individuals recovered from Roonka, but those papers did not examine any patterns in those removals that might be present. Analysis of the tooth avulsions at Roonka reveals a change in the practice over time, with the older burials from phase II typically showing removal of both maxillary central incisors with a left side bias when only one tooth is removed, and the more recent phase III burials showing only one incisor avulsed and a right side bias for removal. Frequencies in the practice also changed over time, with avulsions being much more common in the older phase II burials. Historical evidence suggests that any particular regional or social group would have its own particular pattern of tooth avulsion, so these changes in tooth avulsions at Roonka suggest that the site was either used by multiple groups of people for burials, or that there was significant cultural change during the occupation of the site.

Southeast Asian and Australian paleoanthropology: a review of the last century.

A large and diverse body of scholarship has been developed around the fossil evidence discovered in Southeast Asia and Australia. However, despite its importance to many different aspects of paleoanthropological research, Australasia has often received significantly less attention than it deserves. This review will focus primarily on the evidence for the origins of modern humans from this region. Workers like Franz Weidenreich identified characteristics in the earliest inhabitants of Java that bore some resemblance to features found in modern indigenous Australians. More recent work by numerous scholars have built upon those initial observations, and have contributed to the perception that the fossil record ofAustralasia provides one of the better examples of regional continuity in the human fossil record. Other scholars disagree, insteadflnding evidence for discontinuity between these earliest Indonesians and modern Australian groups. These authorities cite support for an alternative hypothesis of extinction of the ancient Javan populations and their subsequent replacement by more recently arrived groups of modern humans. Presently, the bulk of the evidence supports this latter model. A dearth of credible regional characteristics linking the Pleistocene fossils from Java to early Australians, combined with a series offeatures indicating discontinuity between those same groups, indicate that the populations represented by the fossils from Sangiran and Ngandong went extinct without contributing genes to modern Australians.

Artificial cranial deformation in Kow Swamp 1 and 5: a response to Curnoe (2007).

Recently, Curnoe (2007) tested the predictions of competing models of modern human origins using three crania from Australia: Kow Swamp 1 and 5 and Keilor. The Kow Swamp specimens have long been suspected of having been altered through artificial deformation of the skull. Though Curnoe (2007) provided assurances that no evidence of deformation is present in those specimens, the current study retests the hypothesis that these Australian specimens are artificially deformed. The Australian crania are compared to known deformed individuals from New Britian through canonical variates analysis, and the resulting Mahalanobis distances are examined for statistical significance with random expectation statistics. The results show that Kow Swamp 1 and 5 have strong shape similarities to known deformed individuals, and both crania are very different in shape from Keilor. Keilor is statistically significantly different in shape from both Kow Swamp specimens and all of the known deformed specimens. These findings cast doubt on Curnoe's (2007) conclusions of a shared Australian cranial morphology as well as the retention of an archaic suite of morphologies in the Australians.

Mandibular fossa morphology in the Ngandong and Sambungmacan fossil hominids.

There has been debate in recent years concerning the significance of the mandibular fossa morphology in the Ngandong and Sambungmacan hominids. These fossils lack a postglenoid process and their squamotympanic fissure runs along the apex of the fossa for its entire length. This configuration differs from that seen in other fossil and modern humans, which have a prominent postglenoid process and a squamotympanic fissure that takes a more posterior course that does not lie in the apex of the fossa. Some recent studies have suggested that the Ngandong and Sambungmacan hominids are not unique in their expression of these characteristics, and that they can also be found in other fossil crania from Africa and Indonesia. The present study reexamines these morphologies in an effort to better understand their distribution in the hominid fossil record. The results confirm that the lack of a prominent postglenoid process in combination with a squamotympanic fissure that lies wholly in the apex of the mandibular fossa along its entire length is indeed autapomorphic for the Ngandong and Sambungmacan fossils. This finding, in conjunction with work on other nonmetric features in these hominids, suggests that at least two hominid morphs, possibly representing separate species, were present on Java during the Pleistocene. In addition, if this apparent autapomorphy is confirmed, then it is also unlikely that the Ngandong hominids contributed to the gene pool of modern humans.

The enigma of the Sangiran 4 palate revisited.

The Sangiran 4 palate has been controversial since its discovery in the 1930s because it retains a number of more primitive morphologies such as projecting canines and precanine diastemata. These characters have led some workers to question the hominid status of the palate, suggesting that it is both too large and too primitive to belong to the same individual as the Sangiran 4 cranial fragments. The palate has instead been diagnosed as a new species of Pongo. The present study re-evaluates this controversy through the analysis of new metric data and comparisons with more recently published fossil discoveries. This analysis shows that the Sangiran 4 palate is not unique, and shares several of these putative pongid traits with other Javan hominid fossils as well as recently described hominid specimens from Dmanisi, Georgia. These results suggest that the evolution of the earliest Asians was more complex than has previously been appreciated.

Artificial cranial deformation in Pleistocene Australians: the Coobool Creek sample.

Several authors have suggested that some Pleistocene Australian crania have been altered by artificial cranial deformation. The large sample from Coobool Creek has featured prominently in this debate. The present study reevaluates the evidence for artificial cranial deformation in this population using both a larger cranial sample and a more comprehensive set of measurements than those used in earlier work on this subject. Additionally, random expectation statistics are used to calculate statistical significance for these examinations. The results of this study agree with prior work indicating that a portion of this sample shows evidence for artificial deformation of the cranial vault. Many Coobool Creek crania display strong shape similarities with a population of known deformed individuals from New Britain. Coobool Creek crania 1, 41, 65, and 66 show the strongest evidence for deformation, but several other individuals from this sample also show clear evidence for culturally manipulated changes in cranial shape. This project provides added support for the argument that at least some Pleistocene Australian groups were practicing artificial cranial deformation.

The view from down under: a test of the multiregional hypothesis of modern human origins using the basicranial evidence from Australasia.

Proponents of the Multiregional Hypothesis of modern human origins have consistently stated that Australasia provides one of the most compelling examples of regional continuity in the human fossil record. According to these workers, features found in the earliest Homo erectus fossils from Sangiran, Central Java, can be traced through more advanced hominids from Ngandong and are found in fossil and recent Australian Aborigines. In order to test the hypothesis that a close evolutionary relationship exists amongst the fossils from Australasia, this study will examine the cranial base. This region of the skull is considered to be evolutionarily conservative and has relatively good representation and preservation throughout much of the Australasian record. The results of this project highlight a number of features on the cranial base in the Ngandong sample that appear to be unique not only within the region, but in the human fossil sample as a whole. Several of these features, such as the morphology of the foramen ovale, the location of the squamotympanic fissure in the roof of the temporomandibular fossa, and the extreme expression of the postcondyloid tuberosities have been pointed out by workers such as Weidenreich and Jacob in their surveys of this material. The presence of these characters in the Ngandong population, and their apparent lack of expression outside of this group, provides strong evidence of discontinuity in the Australasian fossil record.

A re-evaluation of the metric diversity within Homo erectus.

Previous work by several researchers has suggested that the cranial sample from Zhoukoudian possesses a unique metric pattern relative to the African and Asian specimens assigned to Homo erectus. The current study readdresses this issue with an expanded fossil sample and a larger and more comprehensive set of cranial measurements. To test the patterns present in the assemblage, canonical variates analysis was performed using a covariance matrix generated from the Howells data set. From this, interindividual Mahalanobis distances were computed for the fossils. Random expectation statistics were then used to measure statistical significance of the Mahalanobis distances. The results show that the Zhoukoudian hominids exhibit a unique metric pattern not shared by the African and Indonesian crania sampled. In these tests the Hexian calvaria resembled the African and Indonesian specimens and differed significantly from the craniometric pattern seen in the Zhoukoudian fossils. The Zhoukoudian specimens are characterized by a wide midvault and relatively narrow occipital and frontal bones, while the African and Indonesian crania (including Hexian) have relatively broad frontal and occipital dimensions compared to their midvaults. These results do not suggest that a multiple-species scenario is necessary to encompass the variation present in the sample. Based on the current evidence it is more probable that this variation reflects polytypism influenced by environmental adaptation and/or genetic drift.

Squamotympanic fissure in the Ngandong and Sambungmacan hominids: a reply to Delson et al.

In the present study the course of the squamotympanic fissure of the mandibular fossa is examined in several fossil hominid specimens. While previous work by several authors had found that the course of this fissure was potentially autapomorphic for the Ngandong and Sambungmacan fossil samples from Indonesia, a more recent study performed by Delson et al. (Anat Rec 2001; 262:380--397) reported that a number of other fossils, including OH 9, Sangiran 4 and 17, and KNM WT 15000 were similar to the Ngandong and Sambungmacan specimens in the expression of this feature. To test these findings, those specimens purported to share similarities with Ngandong and Sambungmacan were examined. The results of this study indicate clearly differing morphologies between the Ngandong and Sambungmacan fossils, on the one hand, and the four African and Indonesian fossils named by Delson et al. (2001). Hence, the course of the squamotympanic fissure remains a potentially autapomorphic feature separating the Ngandong and Sambungmacan samples from the remaining specimens allocated to Homo erectus.