Calcareous grasslands have an outstanding value for biodiversity conservation. However, they are threatened across Europe. The Upright brome (Bromus erectus) is a tall perennial tussock grass, which has increasingly become dominant in calcareous grasslands. Today, its expansion is a major challenge for nature conservation. Here, we studied the drivers and effects of B. erectus encroachment on plant species assemblages across a productivity gradient in semi-dry calcareous grasslands in Germany. Our study revealed, that despite intensified conservation management, the cover of B. erectus increased from 1978-'81 to 2020 in the two most productive types of grasslands (Onobrychido-Brometum typicum and primuletosum) by the factor 1.6 and 2.0, respectively. Across the environmental gradient, B. erectus had its highest cover (mean: 53 %) in plots of the Onobrychido-Brometum typicum, which exhibited an intermediate productivity. Overall, the encroachment of B. erectus has led to a structural and floristic homogenisation. We explain the expansion during the last 40 years particularly by climate change (i.e., milder winters and drier summers) but also nitrogen deposition. The capacity of B. erectus to exploit its habitats even during cool periods of the year is a strong advantage against competitors. This is especially true for deep soils that are enriched in nitrogen due to atmospheric deposition. Summer drought also favours the species. Overall, a higher management frequency is needed to counteract the encroachment of B. erectus. Particularly, grazing in winter and early spring, but also mowing and prescribed burning during that period, are suitable tools.
With the discovery of three almost complete Homo erectus crania, Yunxian is one of the most important early Pleistocene hominin sites in eastern Asia. Yet, the age of the Yunxian fossils has remained debated because of the lack of reliable numerical dating results. Here, we apply the well-established isochron 26Al/10Be burial dating to quartz gravels from two sediment layers of the site. The age results push the Yunxian crania back to 1.77 ± 0.08 million years ago (±1σ internal error), representing the oldest H. erectus fossils discovered in situ in eastern Asia. A much older age assignment to Yunxian supports the model of rapid dispersal and widespread distribution of early H. erectus and contributes to narrowing the chronological gap between the earliest archaeology and hominin paleontology in eastern Asia.
We focus on three researchers-Davidson Black, Franz Weidenreich and Ralph von Koenigswald-who have made major contributions to the recovery of the fossil record of the hominin taxon now known as Homo erectus. Black was responsible for the recognition of Sinanthropus pekinensis and for the recovery of the initial hypodigm from Choukoutien*. Almost all of the original S. pekinensis fossils were lost during the Second World War, but the precise documentation and meticulous descriptions prepared by Franz Weidenreich substantially mitigate their loss. An earlier article in this series focused on Eugène Dubois' recovery of the type specimen of Pithecanthropus erectus from Trinil in Java, and while a few additional specimens from Trinil were recognized, the majority of the Javan hypodigm of P. erectus was recovered thanks to initiatives led or encouraged by Ralph von Koenigswald.
The marine sponge Hyrtios erectus is one of the most widely distributed and extensively studied species worldwide, known for its bioactive compounds. Investigation of the cytotoxic nonpolar fractions of the alcoholic extract of the Red Sea sponge Hyrtios erectus afforded four new natural compounds, erectine A (1), 5-hydroxy-1H-indol-3-carboxamide (2), erectine B (3) and hyrtiosol (4), together with the previously reported compounds 5-hydroxyindole-3-aldehyde (5), hyrtiosine A (6), hyrtiosulawesine (7), heteronemin (8), 3-oxo-12-O-deacetyle-12-epi-scalarin (9), 3-acetylsesterstatin 1 (10), and scalarfuran (11). The chemical structures of the compounds were elucidated using 1D and 2D NMR and HRESIMS. Heteronemin (8) demonstrated outstanding cytotoxic potency with an IC50 value of 0.0419 μg/mL against HCT-116 cells, while other compounds showed weak to moderate activity. To enhance the therapeutic potential of heteronemin, it was successfully encapsulated in lipid nanoformulations. These formulations, designed for high activity against HCT-116, have key features such as negative zeta potential values, nanometer range, and efficient encapsulation. The lipid nanoparticle formulations exhibited potent cytotoxic activity against HCT-116 cells, underscoring their potential as anticancer drug carriers. These findings support the need for additional clinical trials to assess their safety and effectiveness in cancer treatment.
The African Early Pleistocene is a time of evolutionary change and techno-behavioral innovation in human prehistory that sees the advent of our own genus, Homo, from earlier australopithecine ancestors by 2.8-2.3 million years ago. This was followed by the origin and dispersal of Homo erectus sensu lato across Africa and Eurasia between ~ 2.0 and 1.1 Ma and the emergence of both large-brained (e.g., Bodo, Kabwe) and small-brained (e.g., H. naledi) lineages in the Middle Pleistocene of Africa. Here we present a newly reconstructed face of the DAN5/P1 cranium from Gona, Ethiopia (1.6-1.5 Ma) that, in conjunction with the cranial vault, is a mostly complete Early Pleistocene Homo cranium from the Horn of Africa. Morphometric analyses demonstrate a combination of H. erectus-like cranial traits and basal Homo-like facial and dental features combined with a small brain size in DAN5/P1. The presence of such a morphological mosaic contemporaneous with or postdating the emergence of the indisputable H. erectus craniodental complex around 1.6 Ma implies an intricate evolutionary transition from early Homo to H. erectus. This finding also supports a long persistence of small-brained, plesiomorphic Homo group(s) alongside other Homo groups that experienced continued encephalization through the Early to Middle Pleistocene of Africa.
There is a growing need for eco-friendly methods to control disease-carrying insects. The present study aimed to investigate the larvicidal activity of methanolic extracts and their various fractions from a plant, Artemisia arborescens L., and a marine sponge, Hyrtios erectus, against the mosquito, Culex pipiens L. Crude methanolic extracts of A. arborescens and H. erectus were prepared by maceration and successive fractionation were obtained using the liquid-liquid partition of crude extracts. The larvicidal activity of the extracts and their fractions was determined according to the WHO standard method. The results revealed that the n-hexane fraction of A. arborescens exhibited the highest larvicidal activity (LC50 346.74 μg/mL), exceeding the efficacy of the crude extract and other fractions. Furthermore, the sponge's n-hexane (LC50 68.39 μg/mL), chloroform (LC50 63.03 μg/mL), and n-butanol (LC50 71.23 μg/mL) fractions showed a significant 3.9 to 4.5 times increase in the larvicidal potency compared to its crude extract (LC50 = 280.74 μg/mL). The safety of the sponge extracts was tested in the embryos of zebrafish as a non-target organism. In this regard, the crude methanolic extract and n-butanol fraction exhibited weak toxicity and chloroform fraction showed no detectable toxicity. This study suggests the H. erectus sponge as a source for developing safe natural substitutes for use in the battle against Cx. pipiens mosquito, which may help in reducing the spread of mosquito vectors and mosquito-borne diseases.
Conocarpus erectus L. is one of the ornamental shrubs or trees that are utilized in different aspects in landscape (gardens, cities, roads, etc.). Fertilization program is an essential factor affecting the aesthetic characters of this plant species. Pots experiment was conducted in a randomized completed split plot design with the aim to study the effects of NPK fertilizers at the levels of 100%, 75%, and 50% of the suggested doses of 18, 12, and 6 g/plant from ammonium sulfate, calcium superphosphate, and potassium sulfate, respectively, as well as natural extracts as active dry yeast (ADY) at 1 or 3 g L-1, green tea (GT) at 0.2 or 0.5 g L-1, and seaweeds (SW) at 1 or 1.5 mL L-1, and their interaction on the growth and attributes of C. erectus in the 2022 and 2023 seasons. The results indicated that 100% NPK dose produced the highest significant values of plant height, number of branches, primary stem diameter, area/leaf, chlorophyll index, shoots and root fresh and dry weight, percentage of relative water content (in the second season), N, P, K, and total carbohydrates in comparison with 75% and 50% NPK doses in the both seasons. Moreover, 100% NPK increased the activity of peroxidase enzyme, phenol compounds, and antioxidant activity over the 75% and 50% NPK doses. Conversely, 75% NPK recorded a high relative water content (in the first season) and activity of catalase and polyphenol oxidase enzymes over the 100% and 50% NPK doses. All treatments of natural extracts had positive impacts on the studied parameters previously mentioned when compared to untreated control. Among the natural extracts used, 3 g L-1 ADY was the best application to increase the studied traits, except for leaf area and P%, whose higher significant values resulted from treatments with application of SW extract at 1.5 mL L-1 and 1 g L-1 ADY + 0.2 g L-1 GT + 1 mL L-1 SW, respectively. Moreover, the 100% NPK dose combined with 3 gL-1 ADY was the best combination to execute the highest values of the aforementioned traits studied, except the primary stem diameter, P%, and PPO activity, whereas the highest values resulted from treatments with 100% NPK dose + 1.5 mL L-1 SW, 1 g L-1 ADY + 0.2 g L-1 GT + 1 mL L-1 SW, and 75% NPK dose + 3 g L-1 ADY, respectively. Therefore, 100% NPK treatment combined with 3 g L-1ADY is recommended to fertilize C. erectus plants in order to reduce the overuse of chemical fertilizers and to minimize habitat contamination for the maintenance of the whole environment.
Questions about when early members of the genus Homo adapted to extreme environments like deserts and rainforests have traditionally focused on Homo sapiens. Here, we present multidisciplinary evidence from Engaji Nanyori in Tanzania's Oldupai Gorge, revealing that Homo erectus thrived in hyperarid landscapes one million years ago. Using biogeochemical analyses, precise chronometric dating, palaeoclimate simulations, biome modeling, fire history reconstructions, palaeobotanical studies, faunal assemblages, and archeological evidence, we reconstruct an environment dominated by semidesert shrubland. Despite these challenges, Homo erectus repeatedly occupied fluvial landscapes, leveraging water sources and ecological focal points to mitigate risk. These findings suggest archaic humans possessed an ecological flexibility previously attributed only to later hominins. This adaptability likely facilitated the expansion of Homo erectus into the arid regions of Africa and Eurasia, redefining their role as ecological generalists thriving in some of the most challenging landscapes of the Middle Pleistocene.
The timing of Homo erectus and Acheulean emergence in the Early Pleistocene is important to the understanding of the evolution of the genus Homo but is currently insufficiently resolved. Relevant chronologies are often based on a combination of radioisotopic dates and other age indicators such as magnetostratigraphy and biochronology. Here, we report a newly recognized normal magnetozone at ∼1.6 Ma in the Konso Formation, southern Main Ethiopian Rift, Ethiopia. This magnetozone occurs at one of the Konso Fm localities, KGA19, that spans the >1.75- to <1.45-Ma time period otherwise ill-represented in the Formation. We describe the lithostratigraphy and tephrostratigraphy of the KGA19 sedimentary sequence and demonstrate that the Konso Fm Kayle Tuff-1 and the KGA19 Bench Tuff are correlative to the Turkana Basin Orange and Morutot tuffs, respectively. Paleomagnetic analyses of the western sector of KGA19 revealed a normal polarity interval at ∼1.6 Ma, with its age based on 40Ar/39Ar dates and tephrostratigraphic correlations. This suggests that the KGA19 normal magnetozone represents the Gilsá excursion otherwise documented in limited marine cores, Chinese Loess sequences, and few lava flows. A review of these records and sediment accumulation rates of fossil-bearing sequences of eastern Africa suggests that short events such as the Gilsá excursion would be detected if sampling resolution is sufficiently high relative to sedimentation rates. In light of these findings and considerations, evaluation of the Melka Kunture magnetostratigraphy suggests that the age of the Garba IV H. erectus and Acheulean is ∼1.6 Ma, not >1.95 to ∼2 Ma.
In this study, we assess the artiodactyl fossil record of the Homo erectus type locality of Trinil (Indonesia) and explore the paleoenvironmental implications for the site and for our understanding of early hominin paleoecology. Combining ecomorphological analyses on postcranial elements of cervids from Trinil (n = 43) with a range of existing paleobiological and paleoecological data on the bovids and cervids, a holistic reconstruction is made of the ecology of the artiodactyl community. The ecomorphological analyses indicate that the cervid Axis lydekkeri was adapted to relatively open environments with wet substrate. In combination with evidence of the other families, these results are compared in a correspondence analysis with the artiodactyl communities of contemporary Asian nature reserves. Trinil was shown to be similar to a number of Mainland Southeast Asian sites and reconstructed as an open woodland habitat with a wet component, possibly in the form of alluvial grasslands. The paleoenvironmental conditions reconstructed for Trinil indicate that Homo erectus was present in relatively open environments but that it still had a significant degree of environmental flexibility and was able to persist in wet and dry environments, with a vegetation structure ranging from grassland to open woodland.
The present phytochemical investigation of methanol extract from Vietnamese marine sponge, Hyrtios erectus, resulted to the isolation and structure elucidation of five compounds consisting of a new pyridinium-conjugated indole derivative (hyrtiosin, 1), together with four known alkaloids identified as gramine (2), indole-3-carboxaldehyde (3), 3-(methoxymethyl)indole (4) and N-methylnicotinic acid or trigonelline (5). Chemical structures of isolated compounds were established using modern spectroscopic methods including NMR (1H,13C, COSY, HSQC, HMBC), HR-ESIMS, UV and IR. Compound 1 is rare occurrence of natural products with an acetyl moiety linked to N-1. The isolated compounds were tested with inhibitory activity of NO production and growth of bacterial strains. Among them, only compound 1 displayed the weak inhibition of nitric oxide production with an IC50 value of 38.2 μM, others unfortunately have no activity in both of assays. All of them are first report both of isolation, structural elucidation and bioactivities from specie H. erectus.
The Energetic Consequences of Being a Homo erectus Female was published in the American Journal of Human Biology over two decades ago. This paper drew attention to the high body-size-related reproductive costs of an H. erectus female if she retained the same reproductive schedule of smaller-bodied earlier hominins modeled on the schedule for modern Pan. The main conclusion was that the energetic cost per offspring would be significantly reduced by adopting a modern human reproductive schedule with a shorter lactation period and an overall shorter interbirth interval. To make this possible and support the energetic requirements of the larger body size, there would have had to be a fundamental shift in subsistence behavior involving a higher-quality diet and intergenerational cooperation in food acquisition. This paper re-evaluates these conclusions based on recent energetic research developments. Although the modeling parameters have changed, the conclusions are still valid. Their implications are discussed in light of modern research on the increase in body and brain size and the evolution of cooperative subsistence behavior.
This study investigates the impact of vehicular-released heavy metals (Zn, Fe, Pb, Cd, and Ni) on foliar physiological and biochemical parameters of Conocarpus erectus and its relationship with the Air Pollution Tolerance Index (APTI). Leaf samples were collected from six sites along a busy road (Bahawalpur to Rahim Yar Khan, KLP Road) in Punjab, Pakistan, during the spring season, with control samples taken 50 m away from the roadside. Heavy metal concentrations were analyzed using an Atomic Absorption Spectrophotometer (AAS), revealing significantly higher levels of Pb, Cd, Ni, and Cu in leaf dust at polluted sites, particularly in Ahmadpur. Exposure to heavy metal pollution led to notable reductions in shoot length, leaf area, and biomass, with Khanbella exhibiting the most severe declines. Gas exchange parameters were altered, with increased CO2 assimilation and stomatal conductance at Taranda, while transpiration rates decreased across polluted sites. Biochemical responses, including elevated total soluble proteins, free amino acids, and ascorbic acid, indicated adaptive metabolic shifts. Photosynthetic pigments, particularly chlorophyll b and carotenoids, were significantly reduced under pollution stress, whereas antioxidant activity remained stable. Anatomical modifications, such as increased vascular bundle and cortical thickness at Taranda and Iqbalabad, reflected structural resilience. Stomatal density and area were significantly lower at polluted sites, suggesting regulatory adjustments to minimize water loss. APTI values (12.21-9.98) were significantly higher at roadside locations compared to controls, highlighting the strong resilience of C. erectus to pollution. The species high APTI values and capacity to tolerate heavy metal contamination suggest its suitability for urban roadside plantations, where it can mitigate the adverse effects of vehicular emissions and contribute to environmental sustainability.
Seahorse (Hippocampus spp.) is popular in the markets of traditional Chinese medicine, aquarium, and curio. In order to protect wild stocks and still meet the market demand, China attempted the large-scale cultivation of seahorses in the early 21st century and achieved it in the 2010s. However, in recent years, two new issues have gradually emerged in Chinese seahorse cultivation. One is that the juveniles are prone to disease during diet conversion, and the other is that the reproductive performance of broodstocks is significantly reduced. With the aim to provide some measures that can alleviate these issues, in the present study, we used lined seahorse (Hippocampus erectus, a species widely cultured in China) as the experimental subject and Astragalus polysaccharides (APSs) as the immunostimulant to test whether APSs could improve the immune-health status and reproductive performance of seahorses. The measured indices for reproductive performance included ovarian lipid content, assessment time required before mating for paired male and female seahorses, mating success rate, brood size, and newborn body height. The results showed that for juveniles during diet conversion, their body weight, survival rate, plasma immunocytokine contents (interleukin-2, interferon-α, and immunoglobulin M), and alpha diversity indices (Simpson and Pielou's-e) of the intestinal microbiota were significantly higher than those of the control group after dietary APSs. For broodstocks, compared with the control group, the expression of lipid substances in the ovary was significantly upregulated, the assessment time was significantly shortened, and the body height of their newborns was significantly increased in the APS group. These results demonstrate that APSs could indeed improve the immune-health status and reproductive performance of seahorses, providing guidance for addressing existing issues in seahorse cultivation.
The Sima del Elefante cave is one of the archaeopaleontological sites located in the karstic complex of Sierra de Atapuerca (Burgos, Spain), which is a remarkable locality for documenting an extensive sequence of human evidence. Within the stratigraphic sequence of the Sima del Elefante site, Level TE7 has yielded one of the oldest human remains recovered to date in western Europe. A hominin mid-face has recently been discovered (specimen ATE7-1), attributed to Homo aff. erectus. In this study, the fossil amphibian and reptile remains directly associated with this hominin are analyzed, described, and used to perform quantitative paleoecological reconstructions. The resulting herpetofaunal assemblage comprises a total of eight species: five anurans (Alytes gr. Alytes obstetricans/Alytes almogavarii, Pelodytes punctatus, Bufo gr. Bufo bufo, Epidalea calamita, and Rana temporaria), two lizards (small-sized Lacertidae indet. and Anguis fragilis), and two snakes (Coronella cf. Coronella austriaca and Vipera sp.). The paleoecological reconstruction was performed using the Mutual Ecogeographic Range method in conjunction with the Uncertain Distribution Area-Occupied Distribution Area technique to obtain temperature and precipitation estimates, and habitat weighting was used to infer the surrounding environment. The climate of TE7 was reconstructed as cool and humid, with an overall pattern concordant with a present-day continental Mediterranean climate, exhibiting similar temperatures and higher precipitation than today for the Sierra de Atapuerca location. The associated landscape evidenced a more humid environment, primarily made up of woodlands and open humid habitats with aquatic and periaquatic areas. The results obtained provide novel insights into the ecological tolerances of early hominins and thus contribute to the growing body of knowledge regarding their subsistence capabilities and behaviors.
As a flagship taxa for marine ecosystems, seahorses possess a unique reproductive strategy of "male pregnancy". They are severely threatened by marine petroleum-based pollution but the molecular mechanism involved remains unclear. We evaluated the toxic effects and mechanisms of sub-acute exposure to benzo[a]pyrene (BaP), a representative polycyclic aromatic hydrocarbon (PAH), at three environmental related dosages (0.5, 5, and 50 μg/L) on the reproductive organs of sex-role-reversed lined seahorses (Hippocampus erectus). BaP induced ovary, testis and brood pouch tissue damage in a concentration-dependent manner. Transcriptomic results suggested that reproductive organs of the seahorse could undergo biotransformation and detoxification of BaP via the P450 enzyme system; the differential expression of key genes related to these pathways determined the differences in the accumulation of toxic substances in the reproductive organs. Moreover, toxic substances directly induced differential tissue damage in situ by activating tissue-specific signaling pathways: BaP-induced ovarian apoptosis and failure by upregulation of the pro-apoptotic genes, vadc1, traf2b, tnfsf10, and pycard (P < 0.05); inhibition of testicular function through disruption of genes associated with "ECM-receptor interaction", "Tight junction", and "Spermatogenesis" pathways; and interference with brood pouch immune responses, significantly suppressing the expression of ripk1, il-1b, casp3a, apaf1, calr, and canx (P < 0.05), thereby impairing "Apoptosis", "Phagosome", and "Necroptosis" processes, ultimately compromising brood pouch maintenance. Toxic substances exacerbate damage to the reproductive organs in seahorses by disrupting Ca2+ homeostasis. At environmentally-relevant concentrations of BaP, the reproductive efficiency of seahorses may be severely affected, increasing the risk of a decline in the abundance and diversity of wild populations.
Urodeta conocarpi Eiseman, spec. nov. (Lepidoptera: Elachistidae) is described from specimens reared from larvae found mining leaves of Conocarpus erectus L. (Combretaceae) in the Florida Keys. The leaf mine, larva, and pupa are illustrated. Similar leaf mines are reported from elsewhere in southern Florida as well as the Bahamas. This is the first record of Urodeta Stainton from the USA, the second species known from the Neotropical region, and the third to be reared, out of 29 species now known worldwide (of which one remains unnamed).
Caloric restriction (CR) studies have traditionally focused on species with conventional reproductive roles, emphasising female's greater investment in costly gametes and parental care. While the divergent impact of CR on males and females is evident across species, the factors driving this variation, that is, resource allocation to reproductive elements as part of distinct life history strategies, remain unclear. To address this, we investigated the effects of CR on development, gene expression and intestinal microbiota in the lined seahorse Hippocampus erectus, a species with male pregnancy, where fathers invest in offspring through gestation. Juvenile seahorses were subjected to ad libitum (AL) or CR feeding for 5 months. CR stunted male growth and brood pouch development, reflecting the energy demands of this crucial parental care trait. However, condition index declined in CR females but not males, while ovarian weight remained unchanged. Transcriptome analysis demonstrated organ- and sex-specific responses to CR with distinct lipid and energy-related pathways activated in male and female livers, indicative of survival enhancement strategies. CR had minimal impact on genes associated with spermatogenesis, but downregulated lipid metabolic and inflammatory genes in ovaries, emphasising the importance of pre-copulatory resource allocation in female gametes. CR strongly shaped gut microbial composition, creating distinct communities from AL seahorses while also driving sex-specific taxonomic differences. Our research indicates that nutrient limitation's impact on males and females is influenced by their allocation of resources to reproduction and parental investment. We underscore the significance of studying species with diverse reproductive strategies, sex roles and life-history strategies.
Gonadotropin-releasing hormone (GnRH) plays a crucial role in regulating reproductive behavior in vertebrates through the hypothalamus-pituitary-gonad (HPG) axis. Seahorses exhibit unique male pregnancy behavior, making them an interesting subject for investigating the regulatory mechanisms behind this behavior. In this study, we focused on the lined seahorse (Hippocampus erectus) and obtained the full-length cDNA sequences of three GnRH genes: GnRH1, GnRH2, and GnRH3. Notably, we newly identified GnRH1, filling a gap in previous research that had overlooked this subtype. Through a homologous analysis, we found that the core peptide of GnRH1 in lined seahorses is not common in teleosts, while the core peptides of GnRH2 and GnRH3 are conserved. Real-time PCR was performed to determine the tissue expression patterns of these GnRH genes. Our results showed that all three genes were predominantly expressed in the brain, albeit in different regions. Specifically, GnRH1 was mainly expressed in the hypothalamus, GnRH2 in the optic tectum, and GnRH3 in the telencephalon. Expression dynamics indicated a progressive decrease in GnRH2 and a significant surge in GnRH3 during gonadal development, hinting at an alternating regulatory function. Moreover, GnRH1 and GnRH3 expression levels were considerably higher during pregnancy compared to those in pre-pregnancy and post-pregnancy stages, underscoring their critical role in modulating male pregnancy behavior in lined seahorses. Our findings provide insights into the complex interplay of GnRH subtypes in regulating reproductive processes, particularly in the context of male pregnancy behavior in seahorses.
KNM-ER 64061 is a partial skeleton from the upper Burgi Member of the Koobi Fora Formation (2.02-2.06 Ma) associated taphonomically and geochemically with a nearly complete mandibular dentition (KNM-ER 64060) attributed to Homo habilis. The skeleton comprises the clavicle, scapular fragments, both humeri, both ulnae, both radii, and a fragmentary sacrum and os coxae, making this the most complete H. habilis skeleton recovered thus far. The upper limb elements are similar to those of other early Homo specimens. Notably, the humerus is slender with a weakly-projecting lateral epicondyle, a relatively wide capitulum and a narrow trochlea, and the ulna has a relatively large radial notch. Although KNM-ER 64061 does not preserve a lower limb, limited features of the ischium suggest lower limb mechanics more similar to Homo than to australopiths. Brachial index estimates support previous conclusions that H. habilis had a relatively long forearm compared to Homo erectus. All upper limb elements possess strikingly thick cortices, resembling the condition in australopiths and other early Homo fossils. The stature estimate of 160 cm based on humeral length is intermediate between those for H. habilis (OH 62, KNM-ER 3735) and H. erectus (KNM-ER 1808, KNM-WT 15000). The body mass estimate of 30.7-32.7 kg is slightly lower than other H. habilis specimens and noticeably lower than estimates for H. erectus. KNM-ER 64061 indicates that H. habilis retained more primitive proportions and was smaller in stature and mass than H. erectus.