Limb Proportions Research Articles

Estimation of body size and physique from hominin skeletal remains

Three methods of measuring stature from skeletal remains are reviewed: the reconstructed skeletal length, the correspondence of long bone length to stature and the regression of stature on long bone length. Each involves problems and difficulties. For the anthropologist, there is the additional problem of applying findings from extant taxa to extinct taxa with potentially different morphologies and limb proportions. Of the various studies involving regression of the stature the findings of Trotter and Gleser are judged the most robust and useful notwithstanding problems and limitations. The lumbar vertebrae are potentially important as stature predictors. Estimation of body mass from the skeleton is also beset with problems. Eight methods are reviewed: Hartwig-Scherer's taxon independent solution, four methods involving measurements from the weight-bearing appendicular skeleton, Ruff's method using the length of the reconstructed skeleton and an estimate of body breadth, estimates from the total skeletal mass and estimates from the body mass index when the stature is known approximately. Lumbar vertebrae provide reasonable estimates of both body mass and stature and thus by derivation the body mass index. At present both forensic scientists and anthropologists lack adequate data and methods to estimate body size and shape from hominin skeletons. A further large and well-designed study using magnetic resonance imaging is required.

New Formulae for Estimating Stature in the Balkans

Recent studies of secular change and allometry have observed differential limb proportions between the sexes, among and within populations. These studies suggest that stature prediction formulae developed from American Whites may be inappropriate for European populations. The purpose of this investigation is to present more appropriate stature prediction equations for use in the Balkans to aid present-day identifications of the victims of genocide. The reference sample totals 545 white males obtained from World War II data. The Eastern European sample totals 177 males and includes both Bosnian and Croatian victims of the recent war. Mean stature for Eastern Europeans was obtained from the literature. Results show that formulae based on Trotter and Gleser systematically underestimate stature in the Balkans. Because Eastern Europeans are taller than American Whites it is appropriate to use this as an "informative prior" that can be applied to future cases. This informative prior can be used in predictive formulae, since it is probably similar to the sample from which the Balkan forensic cases were drawn. Based on Bayes' Theorem new predictive stature formulae are presented for Eastern Europeans.

Most incompetent calf perforating veins are found in association with superficial venous reflux

Purpose: The indications for surgical perforator interruption remain undefined. Previous work has demonstrated an association between clinical status and the number of incompetent perforating veins (IPVs). Other studies have demonstrated that correction of IPV physiology results from abolition of saphenous system reflux. The purpose of this study was to identify which, if any, patterns of venous reflux and obstruction are particularly associated with IPV. Patients and Methods: Two hundred thirty patients and subjects (103 men, 127 women, 308 limbs) with varying grades of venous disease were examined both clinically and with duplex ultrasound scan. The odds ratios (ORs) for the presence of IPVs were calculated for different anatomical distributions of main-stem venous reflux and obstruction. The base group are those with no main-stem venous disease. Results: There were no significant associations between the proportions of limbs demonstrating IPVs and patient age or sex. The ORs for the presence of IPVs in association with other venous disease are as follows (age/sex adjusted): long saphenous vein reflux, OR = 1.86, range = 1.32-2.63; short saphenous vein reflux, OR = 1.36, range = 1.02-1.82; deep system venous reflux, OR = 1.61, range = 1.2-2.15; superficial system reflux, OR = 3.17, range = 1.87-5.4; and deep system obstruction, OR = 1.09, range = 0.51-2.33. The ORs for combinations of venous disorders were calculated. Combinations of disease produced higher odds for the presence of IPVs than those above, the highest being long saphenous vein, short saphenous vein, and deep reflux combined, OR = 6.85 (95% CI, 2.97-15.83; P =.0001). Conclusions: Although the presence of IPVs is associated with venous ulceration, the highest ORs for the presence of IPVs were found in patients with superficial disease alone or in combination with deep reflux. Many of these may be corrected by saphenous surgery alone. (J Vasc Surg 2001;34:774-8.)

Stature, Maturation Variation and Secular Trends in Forensic Anthropology

A twentieth-century trend for increased stature has received considerable attention in the forensic literature with regard to its effects on stature estimation, but a secular trend for earlier maturation has received little attention. Current evidence indicates that within populations with similar climatic adaptation, truncation or extension of the same trajectory of ontogenetic allometry accounts for the secular trend and the within-cohort stature variation, as well as the scaling of limb proportion to stature and intralimb proportions. Since secular increase is small compared to interindividual variation, the Trotter and Gleser formulae are still appropriate as long as the 95% confidence intervals are applied. A secular trend for increasing childhood and adolescent obesity is associated with a trend for accelerated skeletal maturation, but does not predict a consistent direction or a quantitative correction for traditional standards. Secular trends for increased stature and earlier maturation are overshadowed by increasing nonsecular intrapopulational variation.

Limb proportions in climbing and ground-dwelling geckos (Lepidosauria, Gekkonidae): a phylogenetically informed analysis

Biomechanical considerations predict that limb proportions should differ between animals with climbing and ground-dwelling lifestyles. Ground-dwellers should have relatively long, parasagittal hind limbs, with high tibia:femur ratios, and relatively short fore limbs. Climbers should have relatively short limbs, with low tibia:femur ratios, and equally long hind and fore limbs. We tested these predictions using gecko species with different locomotion habits (climbing versus ground-dwelling). We measured snout-vent length and lengths of limb segments in 29 species of geckos and analysed them using both non-phylogenetic statistics (nested analysis of variance and principal component analysis) and phylogenetic statistics (analysis of covariance). Neither approach allowed us to find any consistent relationship between habitat use and the morphometric variables. We conclude that either relative limb lengths and limb proportions in geckos have not evolved in response to the physical demands of the microhabitat, or our understanding of those demands is insufficient.

Patterns of positional behavior in mixed‐species troops ofCallimico goeldii,Saguinus labiatus, andSaguinus fuscicollisin northwestern Brazil

We present the results of a 4-month field investigation of positional behavior, vertical ranging, and species differences in limb proportions and body mass in a mixed-species troop of Saguinus fuscicollis, Saguinus labiatus, and Callimico goeldii in northwestern Brazil. Despite certain similarities in overall positional repertoire, patterns of positional behavior varied significantly between species. Travel in Callimico occurred principally in the lowest levels of the canopy, and was characterized by an exaggerated form of hindlimb-dominated bounding (bounding-hop), and leaping to and from vertical trunks (55.1% of leaps). In contrast, saddle-back tamarins traveled in the lower and middle levels of the canopy, and engaged in a range of leaping behaviors, including stationary leaps (37.3%), acrobatic leaps (31.3%), and trunk-to-trunk leaps (20%). Red-bellied tamarins exploited the highest levels of the arboreal canopy. Travel in this species was dominated by quadrupedal bounding and acrobatic leaps (67% of leaps) that began and ended on thin, flexible supports. Species differences in positional behavior correlated with species differences in limb proportions and locomotor anatomy, and provide a framework for understanding niche partitioning in mixed-species troops of Saguinus and Callimico.

GUT CONTENTS FROM A CRETACEOUS TYRANNOSAURID: IMPLICATIONS FOR THEROPOD DINOSAUR DIGESTIVE TRACTS

Abstract A partial skeleton of Daspletosaurus sp. from the Late Cretaceous (Campanian) Two Medicine Formation of western Montana preserves the first gut contents reported for a tyrannosaurid. Associated remains found with this skeleton consist of acid-etched vertebrae and a fragmentary dentary from juvenile hadrosaur dinosaurs. Hadrosaur bonebed data and comparisons of hadrosaur and tyrannosaurid limb proportions suggest that juvenile hadrosaurs represented both an abundant and accessible food source. The surface corrosion exhibited by the hadrosaur elements matches that produced by stomach acids and digestive enzymes in a wide variety of living vertebrates. Based upon these and other gut contents, and also upon tooth-marked bone studies, it appears that Daspletosaurus and most theropods ingested and digested prey in a manner similar to that of extant archosaurs (crocodilians and birds), employing a two-part stomach with an enzyme-producing proventriculus followed by a thick-walled muscular gizzard. This ...

Gut contents from a Cretaceous Tyrannosaurid: Implications for theropod dinosaur digestive tracts

A partial skeleton of Daspletosaurus sp. from the Late Cretaceous (Campanian) Two Medicine Formation of western Montana preserves the first gut contents reported for a tyrannosaurid. Associated remains found with this skeleton consist of acidetched vertebrae and a fragmentary dentary from juvenile hadrosaur dinosaurs. Hadrosaur bonebed data and comparisons of hadrosaur and tyrannosaurid limb proportions suggest that juvenile hadrosaurs represented both an abundant and accessible food source. The surface corrosion exhibited by the hadrosaur elements matches that produced by stomach acids and digestive enzymes in a wide variety of living vertebrates. Based upon these and other gut contents, and also upon tooth-marked bone studies, it appears that Daspletosaurus and most theropods ingested and digested prey in a manner similar to that of extant archosaurs (crocodilians and birds), employing a two-part stomach with an enzyme-producing proventriculus followed by a thick-walled muscular gizzard. This two-part stomach appears to be an archosaur synapomorphy.

Australopithecus to Homo: Transformations in Body and Mind

▪ Abstract Significant changes occurred in human evolution between 2.5 and 1.8 million years ago. Stone tools first appeared, brains expanded, bodies enlarged, sexual dimorphism in body size decreased, limb proportions changed, cheek teeth reduced in size, and crania began to share more unique features with later Homo. Although the two earliest species of Homo, H. habilis and H. rudolfensis, retained many primitive features in common with australopithecine species, they both shared key unique features with later species of Homo. Two of the most conspicuous shared derived characters were the sizes of the brain and masticatory apparatus relative to body weight. Despite the shared derived characters of H. habilis and H. rudolfensis, one unexpected complication in the transition from australopithecine to Homo was that the postcranial anatomy of H. habilis retained many australopithecine characteristics. H. rudolfensis, however, seems to have had a more human-like body plan, similar to later species of Homo. H. rudolfensis may therefore represent a link between Australopithecus and Homo.

Limb bone proportions, strength and digging in some Lujanian (Late Pleistocene-Early Holocene) mylodontid ground sloths (Mammalia, Xenarthra)

ABSTRACT The mylodontid ground sloths (Xenarthra, Tardigrada) are among the most intriguing components of the Lujanian (Late Pleistocene-Early Holocene) fauna of the Pampean region in South America. Limb proportions and resistance to bending forces were studied in Scelidotherium, Glossotherium and Lestodon to infer their locomotory abilities. Body masses were estimated using scale and computer-generated geometric models. Allometric equations were calculated from humeri, ulnae, radii, femora, tibiae, and the pes, and were used to predict linear dimensions from body mass. Slopes and intercepts were obtained using Model I and II regressions. An indicator of strength was calculated for humeri and femora. Body masses of approximately 850, 1,500 and 4,100 kg were estimated from scale models for Scelidotherium, Glossotherium and Lestodon, respectively. The proportions and capacity to resist bending forces of the limb bones of Scelidotherium and Glossotherium indicate that they were well adapted for strenuous activities in which force is enhanced over velocity, such as digging. We consider these taxa as possible builders of the large Late Cenozoic burrows present in the Pampean region. Although limb proportions of Lestodon are comparable to those of the others, its low strength indicator suggests that its limbs were not as well designed to perform such strenuous activity.

Estimating stature in fossil hominids: which regression model and reference sample to use?

Researchers have long appreciated the significant relationship between body size and an animal's overall adaptive strategy and life history. However, much more emphasis has been placed on interpreting body size than on the actual calculation of it. One measure of size that is especially important for human evolutionary studies is stature. Despite a long history of investigation, stature estimation remains plagued by two methodological problems: (1) the choice of the statistical estimator, and (2) the choice of the reference population from which to derive the parameters.This work addresses both of these problems in estimating stature for fossil hominids, with special reference to A.L. 288-1 (Australopithecus afarensis) and WT 15000 (Homo erectus). Three reference samples of known stature with maximum humerus and femur lengths are used in this study: a large (n=2209) human sample from North America, a smaller sample of modern human pygmies (n=19) from Africa, and a sample of wild-collected African great apes (n=85). Five regression techniques are used to estimate stature in the fossil hominids using both univariate and multivariate parameters derived from the reference samples: classical calibration, inverse calibration, major axis, reduced major axis and the zero-intercept ratio model. We also explore a new diagnostic to test extrapolation and allometric differences with multivariate data, and we calculate 95% confidence intervals to examine the range of variation in estimates for A.L. 288-1, WT 15000 and the new Bouri hominid (Australopithecus garhi).Results frequently vary depending on whether the data are univariate or multivariate. Unique limb proportions and fragmented remains complicate the choice of estimator. We are usually left in the end with the classical calibrator as the best choice. It is the maximum likelihood estimator that performs best overall, especially in scenarios where extrapolation occurs away from the mean of the reference sample. The new diagnostic appears to be a quick and efficient way to determine at the outset whether extrapolation exists in size and/or shape of the long bones between the reference sample and the target specimen.

Theropod forelimb design and evolution

Abstract We examined the relationship between forelimb design and function across the 230-million-year history of theropod evolution. Forelimb disparity was assessed by plotting the relative contributions of the three main limb elements on a ternary diagram. Theropods were divided into five functional groups: predatory, reduced, flying, wing-propelled diving, and flightless. Forelimbs which maintained their primitive function, predation, are similarly proportioned, but non-avian theropods with highly reduced forelimbs have relatively longer humeri. Despite the dramatically different forces imparted by the evolution of flight, forelimb proportions of basal birds are only slightly different from those of their non-avian relatives. An increase in disparity accompanied the subsequent radiation of birds. Each transition to flightlessness has been accompanied by an increase in relative humeral length, which results from relatively short distal limb elements. We introduce theoretical predictions based on five biomechanical and developmental factors that may have influenced the evolution of theropod limb proportions.

Theropod forelimb design and evolution

We examined the relationship between forelimb design and function across the 230-million-year history of theropod evolution. Forelimb disparity was assessed by plotting the relative contributions of the three main limb elements on a ternary diagram. Theropods were divided into five functional groups: predatory, reduced, flying, wing-propelled diving, and flightless. Forelimbs which maintained their primitive function, predation, are similarly proportioned, but non-avian theropods with highly reduced forelimbs have relatively longer humeri. Despite the dramatically different forces imparted by the evolution of flight, forelimb proportions of basal birds are only slightly different from those of their non-avian relatives. An increase in disparity accompanied the subsequent radiation of birds. Each transition to flightlessness has been accompanied by an increase in relative humeral length, which results from relatively short distal limb elements. We introduce theoretical predictions based on five biomechanical and developmental factors that may have influenced the evolution of theropod limb proportions.

MORPHOLOGICAL DIVERSIFICATION AND ADAPTIVE RADIATION: A COMPARISON OF TWO DIVERSE LIZARD CLADES.

We compared the morphological diversity (i.e., the amount of morphological space occupied) of two similar clades, the lizard genera Anolis and Sceloporus. These species-rich monophyletic clades are similar in body size, age of origin, and many aspects of their natural history. We examined a number of morphological traits whose variation is likely to represent adaptation to different aspects of the environment, including body size, limb proportions, head dimensions, and tail length. Examination of the position of species in multidimensional space, based on a principal components analysis, indicates that the morphological diversity of Anolis, which we refer to as disparity, is significantly greater than that of Sceloporus. One potential explanation for this pattern is that morphological diversification in Anolis was facilitated by the evolution of subdigital toe-pads, which allow anoles to use the environment in ways not available to Sceloporus. The geographic location of diversification (tropical and subtropical for Anolis, arid for Sceloporus) may also have been important.

Osteometric variation in the Inuit second metacarpal: a test of Allen's Rule

Bergmann's and Allen's Rules predict a relationship between climate and morphology as a thermoregulatory adaptation. These ecogeographic principles predict/explain change in the ratio of body surface area to body mass in hot and cold climates. With regard to Allen's Rule we would expect short and relatively broad limb proportions. Such adaptation should be observable in skeletal architecture. This paper provides a test of Allen's Rule using osteometric data for the second metacarpal from the Sadlermiut of Southampton Island, Northwest Territories, Canada. Following adjustment for body size, ANOVA by sample and sex shows the Sadlermiut second metacarpal to be shorter, wider at the base and deeper at the distal metacarpophalangeal joint, in comparison to an historic sample of European settlers. This pattern of difference suggests an Inuit hand with a thermally adapted morphology, viz. a large mass relative to surface area. Copyright © 1999 John Wiley & Sons, Ltd.

Brachial and crural indices of European Late Upper Paleolithic and Mesolithic humans

Among recent humans brachial and crural indices are positively correlated with mean annual temperature, such that high indices are found in tropical groups. However, despite inhabiting glacial Europe, the Upper Paleolithic Europeans possessed high indices, prompting Trinkaus (1981) to argue for gene flow from warmer regions associated with modern human emergence in Europe. In contrast, Frayeret al. (1993) point out that Late Upper Paleolithic and Mesolithic Europeans shouldnotexhibit tropically-adapted limb proportions, since, even assuming replacement, their ancestors had experienced cold stress in glacial Europe for at least 12 millennia.This study investigates three questions tied to the brachial and crural indices among Late Pleistocene and recent humans. First, which limb segments (either proximal or distal) are primarily responsible for variation in brachial and crural indices? Second, are these indices reflective ofoveralllimb elongation? And finally, do the Late Upper Paleolithic and Mesolithic Europeans retain relatively and/or absolutely long limbs? Results indicate that in the lower limb, the distal limb segment contributes most of the variability to intralimb proportions, while in the upper limb the proximal and distal limb segments appear to be equally variable. Additionally, brachial and crural indices do not appear to be a good measure of overall limb length, and thus, while the Late Upper Paleolithic and Mesolithic humans have significantly higher (i.e., tropically-adapted) brachial and crural indices than do recent Europeans, they also have shorter (i.e., cold-adapted) limbs. The somewhat paradoxical retention of “tropical” indices in the context of more “cold-adapted” limb length is best explained as evidence for Replacement in the European Late Pleistocene, followed by gradual cold adaptation in glacial Europe.

Modern human, early modern human and Neanderthal limb proportions

The limb proportions of 686 subjects (461 men and 225 women) from five ethnic groups (White, Inuit, Gurkha, Bantu, San) have been compared. Stature, limb and skeletal measurements were taken directly from the subjects by one observer. The brachial and crural indices of the Whites were markedly smaller (lower) than those of the other populations. The crural indices of the Inuit were similar to those of the two African populations, but this may be an artefact from relatively small numbers for the Inuit population. There is no sexual dimorphism for the brachial index, but men have larger (higher) crural indices than women, a finding which probably relates to the relatively broad pelvises and consequently long femurs of women. The two African populations have long limb lengths standardized for height compared to the Gurkha and Inuit populations, with the Whites intermediate. This finding is consistent with Bergmann's thermoregulatory rule. The correlations between distal abbreviation and limb abbreviation for both the upper and lower limbs are poor and negative. Relatively long limbs tend to have smaller distal segments than relatively short limbs and for the legs this may constitute a safeguard for the integrity of the medial and cruciate ligaments of the knee. For these five modern populations distal abbreviation cannot be used as a proxy for limb abbreviation and there is no justification for linking distal abbreviation with climatic selection. Skeletal data relating to nine Neanderthal and 25 early modern humans have also been analysed. The analysis confirms marked limb and distal abbreviation for the Neanderthals compared to early and contemporary modern humans, but this conclusion presupposes that the taxonomic classes are correct and that limb proportions were not used originally as a class discriminant. For these archaic populations there is a moderate positive correlation between lower limb abbreviation and distal abbreviation, but the numbers are small and the confidence intervals very wide. In view of the findings for modern populations, and until more relevant fossils are available, it is probably unwise to use the crural index as a proxy for limb abbreviation in archaic populations. Copyright © 1999 John Wiley & Sons, Ltd.

Ecological Morphology of Caribbean Anoles

Anoles have evolved independently on each island in the Greater Antilles, producing a suite of morphologically-distinct species that utilize different microhabitats. Comparisons among islands indicate that the same set of ecomorphs-distantly related species that are similar in morphology, ecology, and behavior-has evolved on each island. Despite considerable work on anoles over the past three decades, much remains to be learned about evolution of the ecomorphs. In particular, previous studies have focused on external measurements of gross limb proportions, tail length, mass, and number of lamellae. Using a variety of techniques, we examined these char- acters in greater detail and investigated a wide variety of other characters. We found that the ecomorph classes represent distinct entities in morphological space when morphological characters are examined in greater detail (e.g., each limb element was treated separately). In addition, we found that the ecomorphs differ in a variety of characters not previously examined, including toe pad area, pectoral and pelvic girdle dimensions, head dimensions, and tail shape. These differences were apparent regardless of how we defined body size, although comparisons of particular characters were affected by which body size variable was used. This finding indicates that convergence in ecomorph evolutibn extends beyond traits directly linked to habitat use and locomotion. We also examined a number of other taxa that have not traditionally been considered to be members of any ecomorph class. We found that many descendants of ecomorphs living on small islands near the Greater Antilles no longer belong to the ecomorph class of their ancestor. Many Lesser Antillean anoles appear to ibe trunk-crown anoles, whereas others do not belong to any ecomorph class. Montane anoles of the Greater Antilles and Chamaelinorops also do not belong to any ecomorph class, but Chamaeleolis, and possibly Phenacosaurus, are twig anoles.

Two new species of anoles of the Norops crassulus group from Honduras (Reptilia: Sauria: Polychrotidae)

Abstract Two new species of anoles of the Norops crassulus group are described from Honduras. Both are distinguished from all other species of the genus Norops by unique characteristics of scale morphology and meristics, limb proportions, and male dewlap coloration.

Notes on the anatomy and phylogenetic position ofEremias ercoliniiLanza & Poggesi 1975 (Reptilia Lacertidae)

Detailed examination of the only known specimen of Eremias ercolinii Lanza & Poggesi 1975 shows that it has affinities within the Ophisops-Mesalina clade and, on present evidence, is best regarded as a member of Mesalina Gray 1838. However, its exact phylogenetic position will only be confirmed when more material becomes available. Limb proportions and scale form suggest that Mesalina ercolinii probably spends time in low, dense vegetation.