Re-appraisal of the stratigraphy and determination of new U-Pb dates for the Sterkfontein hominin site, South Africa

Sterkfontein Caves is the single richest early hominin site in the world with deposits yielding one or more species of Australopithecus and possible early Homo, as well as an extensive faunal collection. The inability to date the southern African cave sites accurately or precisely has hindered attempts to integrate the hominin fossil evidence into pan-African scenarios about human evolutionary history, and especially hominin biogeography. We have used U-Pb and U-Th techniques to date sheets of calcium carbonate flowstone inter-bedded between the fossiliferous sediments. For the first time, absolute age ranges can be assigned to the fossil-bearing deposits: Member 2 is between 2.8 ± 0.28 and 2.6 ± 0.30 Ma and Member 4 between 2.65 ± 0.30 and 2.01 ± 0.05 Ma. The age of 2.01 ± 0.05 Ma for the top of Member 4 constrains the last appearance of Australopithecus africanus to 2 Ma. In the Silberberg Grotto we have reproduced the U-Pb age of ∼2.2 Ma of for the flowstones associated with StW573. We believe that these deposits, including the fossil and the flowstones, accumulated rapidly around 2.2 Ma. The stratigraphy of the site is complex as sediments are exposed both in the underground chambers and at surface. We present a new interpretation of the stratigraphy based on surface mapping, boreholes logs and U-Pb ages. Every effort was made to retain the Member system, however, only Members 2 and 4 are recognized in the boreholes. We propose that the deposits formally known as Member 3 are in fact the distal equivalents of Member 4. The sediments of Members 2 and 4 consisted of cone-like deposits and probably never filled up the cave. The U-Th ages show that there are substantial deposits younger than 400 ka in the underground cave, underlying the older deposits, highlighting again that these cave fills are not simple layer-cakes.     

U-series and radiocarbon analyses of human and faunal remains from Wajak,Indonesia

Laser ablation U-series dating results on human and faunal bone fragments from Wajak, Indonesia, indicate a minimum age of between 37.4 and 28.5 ka (thousands of years ago) for the whole assemblage. These are significantly older than previously published radiocarbon estimates on bone carbonate, which suggested a Holocene age for a human bone fragment and a late Pleistocene age for a faunal bone. The analysis of the organic components in the faunal material show severe degradation and a positive δ¹³C ratio indicate a high degree of secondary carbonatisation. This may explain why the thermal release method used for the original age assessments yielded such young ages. While the older U-series ages are not in contradiction with the morphology of the Wajak human fossils or Javanese biostratigraphy, they will require a reassessment of the evolutionary relationships of modern human remains in Southeast Asia and Oceania. It can be expected that systematic direct dating of human fossils from this area will lead to further revisions of our understanding of modern human evolution.     

Human cannibalism in the Early Pleistocene of Europe (Gran Dolina, Sierra de Atapuerca, Burgos, Spain).

Human remains belonging to at least six individuals were found in an exploratory excavation made at the site of Gran Dolina (Sierra de Atapuerca, Burgos, Spain). These remains were recovered from the Aurora Stratum of Unit TD6. This stratum has a thickness of approximately 30 cm. The area of the exploratory excavation is about 7 m(2). According to palaeomagnetic analyses, Unit TD6 shows reversed polarity, which is considered to belong to the Matuyama chron. This unit is immediately below TD7, where the Matuyama-Brunhes boundary has been detected, indicating an age of around 780,000 years BP. There is no specific distribution, treatment, or arrangement of the human remains, which were found randomly mixed with abundant faunal remains and stone tools. Most of the faunal and human fossil bones from the Aurora Stratum have human induced damage. Stone tool cutmarks are frequent, and peeling (a type of fracture similar to bending a fresh twig between the hands) provides a specific breakage pattern together with percussion marks and chopmarks. Both nonhuman and human remains show similar intensive exploitation. Slight differences, however, have been observed between fauna and humans (e.g., peeling frequent in humans, rare in fauna), that appear related to different musculature, weight, and bone structure. The characteristics of this fossil assemblage suggest that it is solely the result of consumptive activities as there is no evidence of ritual or other intention. The possibility of distinguishing between dietary vs. survival cannibalism is discussed here.     

A chronological framework for a long and persistent archaeological record: Melka Kunture, Ethiopia

New ⁴⁰Ar/³⁹Ar geochronological data for several volcanic ash horizons from Melka Kunture, Ethiopia, allow for significantly more precise age constraints to be placed upon the lithostratigraphy, archaeology and paleontology from this long record. Ashes from the Melka Kunture Formation at Gombore yielded the most reliable age constraints, from 1.393 ± 0.162 Ma² (millions of years ago) near the base of the section to 0.709 ± 0.013 Ma near the top. Dating the Garba section proved more problematic, but the base of the section, which contains numerous Oldowan obsidian artifacts, may be >1.719 ± 0.199 Ma, while the top is securely dated to 0.869 ± 0.020 Ma. The large ignimbrite from the Kella Formation at Kella and Melka Garba is dated to 1.262 ± 0.034 Ma and pre-dates Acheulean artifacts in the area. The Gombore II site, which has yielded two Homo skull fragments, ‘twisted bifaces,’ and a preserved butchery site, is now constrained between 0.875 ± 0.010 Ma and 0.709 ± 0.013 Ma. Additional ashes from these and other sites further constrain the timing of deposition throughout the section.Integration with previously published magnetostratigraphy has allowed for the first time a relatively complete, reliable timeline for the deposition of sediments, environmental changes, archaeology, and paleontology at Melka Kunture.     

Stratigraphic context and direct dating of the Neandertal mandible from Cova del Gegant (Sitges, Barcelona)

Stratigraphic study of the Cova del Gegant’s sedimentary fill revealed different cycles of accumulation of typical interior cave and delta facies. A precise chronology for these deposits, the faunal remains and stone tools contained therein was obtained by radiocarbon, U-Th and OSL. Our results indicate that the Upper Pleistocene archaeological sequence dates between 49.3 ± 1.8 ka BP, the U-Th age of the overlying flowstone, and 60.0 ± 3.9 ka BP, the OSL age of the basal deposits. We have also directly dated the site’s Neandertal mandible to 52.3 ± 2.3 ka by U-Th.     

Datations SMA et nouveaux regards sur l’archéo-séquence du Rond-du-Barry (Polignac,Haute-Loire)

A series of 36 radiocarbon AMS ages produced from separate bone fragments has prompted a new appraisal of the archaeological sequence of the Rond-du-Barry Cave (Polignac, Haute-Loire). A huge rock-fall of unknown age underlies Unit H, which contains evidence of the oldest human occupation of the site consisting of a Middle Palaeolithic assemblage dated to between 40 and 33 kyr. The first Upper Palaeolithic occupation of the Cave occurred later. In Unit F, three Badegoulian occupation sectors can be identified that are dated to between 20 and 17.5 kyr. The uppermost units, E and D yielded Middle and Upper Magdalenian dates of between 15.4 and 12.4 kyr. Within Unit E, a tephra related layer (E6) is likely to belong to a distal southern lobe of an eruptive event that was centred in the Chaîne des Puys, 100 km to the north. Unit D shows evidence of being re-worked at least during Mesolithic/Neolithic times, circa 6.5/4.9 kyr. The sum of this new evidence demonstrates the existence of a previously unrecognised stratigraphic and spatial complexity within the Rond-du-Barry archaeological deposits, which demands that new investigations be made in this cave.     

Cremated human and animal remains of the Roman period--microscopic method of analysis (Sepkovcica, Croatia)

Human and animal cremated osteological remains from twelve graves of Roman Period from archaeological site Sepkovcica near Velika Gorica (Turopolje region, NW Croatia) were analysed. Beside the content of urns and grave pits, fillings of grave vessels like bowls, pots and amphoras from twentytwo grave samples were included in this study. The preservation of osteological and dental remains of human and animal origin was very poor, majority of fragments hardly reach lengths of 10 mm. Weight of each specimen barely exceeds 100 g per person. Apart from traditional macroscopic methods of analysing cremated remains, microscopic method for determination of age at death was also tested. Fragments of femoral bone diaphysis of eighteen persons whose remains had been found on the site were analysed. Person's age at death was presented in the range of five or ten years, and the long bone fragments of a child (infants) were detected. Taxonomic position for each analysed specimen was determined by microscopic analysis of animal cremated bones. Analysis results confirm validity of microscopic method in determination of age at death for human remains and taxonomic qualification of cremated animal remains from archaeological sites.     

Réexamen du contexte géologique,chrono- et biostratigraphique du site de Moulin Quignon à Abbeville (Vallée de la Somme,France)

The geological context of the discoveries made by Boucher de Perthes at Moulin Quignon in 1863–1864 was examined through the testimonies left by himself, by his detractors, then by geologists and archaeologists who later worked on the alluvial deposits of the Somme at Abbeville. This critical approach has been completed by specific studies, through a restricted excavation performed at Carpentier Quarrya locality known since the end of the 19th century as a sequence analogous to Moulin Quignon, and by a series of new analyses (microvertebrate, malacofauna, dating). The main results of these studies confirm the fluvial nature of the ‘archaeological’ layers at Moulin Quignon that correspond to a high terrace of the Somme River, about 40 m above the current valley incision at Abbeville. Dating results provide an age of 584 ± 48 ka for the fluvial levels at Carpentier Quarry, in good agreement with the available biostratigraphic data, inferred from malacofaunas collected at both Moulin Quignon (Boucher de Perthes collection) and Carpentier Quarry, and from mammals fauna recovered since the end of the 19th century from the white marl at Carpentier Quarry which allow the allocation of these alluvial deposits to an interglacial stage of the second half of the Cromerian, the marine isotopic stage (MIS) 15. From these data and taking into account the identification of the human remains of Moulin Quignon as an anatomically modern man, the contemporaneity of these remains with the alluvial deposits of a high terrace of the Somme River is virtually impossible and supports the hypothesis of a hoax. Besides, it is possible that at least some of the lithic material collected at the time of the discovery by Boucher de Perthes could derive from fluvial levels dated of approximately 600,000 years. They would be then the oldest evidence of a human presence in the Somme Valley.     

New Hydroxyproline Radiocarbon Dates from Sungir,Russia, Confirm Early Mid Upper Palaeolithic Burials in Eurasia

Sungir (Russia) is a key Mid-Upper Palaeolithic site in Eurasia, containing several spectacular burials that disclose early evidence for complex burial rites in the form of a range of grave goods deposited along with the dead. Dating has been particularly challenging, with multiple radiocarbon dates ranging from 19,160±270 to 28,800±240 BP for burials that are believed to be closely similar in age. There are disparities in the radiocarbon dates of human bones, faunal remains and charcoal found on the floor of burials [1], [2], [3]. Our approach has been to develop compound-specific methods using High Performance Liquid Chromatography (HPLC) to separate single amino acids, such as hydroxyproline, and thereby avoid the known human contamination on the bones themselves. Previously, we applied this technique to obtain radiocarbon dates of ∼30,000 BP for Sungir 2, Sungir 3 and a mammoth bone from the occupation levels of the site [4]. The single amino acid radiocarbon dates were in good agreement with each other compared to all the dates previously reported, supporting their reliability. Here we report new hydroxyproline dates for two more human burials from the same site, Sungir 1 and Sungir 4. All five hydroxyproline dates reported are statistically indistinguishable and support an identical age for the group. The results suggest that compound-specific radiocarbon analysis should be considered seriously as the method of choice when precious archaeological remains are to be dated because they give a demonstrably contaminant-free radiocarbon age. The new ages are, together with the previously dated ‘Red Lady of Paviland’ human in the British Isles, the earliest for Mid Upper Palaeolithic burial behaviour in Eurasia, and point to the precocious appearance of this form of rite in Europe Russia.     

Correlation of the KHS Tuff of the Kibish Formation to volcanic ash layers at other sites, and the age of early Homo sapiens (Omo I and Omo II)

Hominin specimens Omo I and Omo II from Member I of the Kibish Formation, Ethiopia are attributed to early Homo sapiens, and an age near 196 ka has been suggested for them. The KHS Tuff, within Member II of the Kibish Formation has not been directly dated at the site, but it is believed to have been deposited at or near the time of formation of sapropel S6 in the Mediterranean Sea. Electron microprobe analyses suggest that the KHS Tuff correlates with the WAVT (Waidedo Vitric Tuff) at Herto, Gona, and Konso (sample TA-55), and with Unit D at Kulkuletti in the Ethiopian Rift Valley. Konso sample TA-55 is older than 154 ka, and Unit D at Kulkuletti is dated at 183 ka. These correlations and ages provide strong support for the age originally suggested for the hominin remains Omo I and Omo II, and for correlation of times of deposition in the Kibish region with formation of sapropels in the Mediterranean Sea. The Aliyo Tuff in Member III of the Kibish Formation is dated at 104 ka, and correlates with Gademotta Unit 15 in the Ethiopian Rift Valley.     

Early Acheulean technology in the Rietputs Formation, South Africa, dated with cosmogenic nuclides

An absolute dating technique based on the build-up and decay of ²⁶Al and ¹⁰Be in the mineral quartz provides crucial evidence regarding early Acheulean hominid distribution in South Africa. Cosmogenic nuclide burial dating of an ancient alluvial deposit of the Vaal River (Rietputs Formation) in the western interior of South Africa shows that coarse gravel and sand aggradation there occurred ca 1.57 ± 0.22 Ma, with individual ages of samples ranging from 1.89 ± 0.19 to 1.34 ± 0.22 Ma. This was followed by aggradation of laminated and cross-bedded fine alluvium at ca 1.26 ± 0.10 Ma. The Rietputs Formation provides an ideal situation for the use of the cosmogenic nuclide burial dating method, as samples could be obtained from deep mining pits at depths ranging from 7 to 16 meters. Individual dates provide only a minimum age for the stone tool technology preserved within the deposits. Each assemblage represents a time averaged collection. Bifacial tools distributed throughout the coarse gravel and sand unit can be assigned to an early phase of the Acheulean. This is the first absolute radiometric dated evidence for early Acheulean artefacts in South Africa that have been found outside of the early hominid sites of the Gauteng Province. These absolute dates also indicate that handaxe-using hominids inhabited southern Africa as early as their counterparts in East Africa. The simultaneous appearance of the Acheulean in different parts of the continent implies relatively rapid technology development and the widespread use of large cutting tools in the African continent by ca 1.6 Ma.     

The dating and interpretation of a Mode 1 site in the Luangwa Valley, Zambia

Flake based assemblages (Mode 1) comprise the earliest stone technologies known, with well-dated Oldowan sites occurring in eastern Africa between ∼ 2.6-1.7 Ma, and in less securely dated contexts in central, southern and northern Africa. Our understanding of the spread and local development of this technology outside East Africa remains hampered by the lack of reliable numerical dating techniques applicable to non-volcanic deposits. This study applied the still relatively new technique of cosmogenic nuclide burial dating (¹⁰Be/²⁶Al) to calculate burial ages for fluvial gravels containing Mode 1 artefacts in the Luangwa Valley, Zambia. The Manzi River, a tributary of the Luangwa River, has exposed a 4.7 m deep section of fluvial sands with discontinuous but stratified gravel layers bearing Mode 1, possibly Oldowan, artefacts in the basal layers. An unconformity divides the Manzi section, separating Mode 1 deposits from overlying gravels containing Mode 3 (Middle Stone Age) artefacts. No diagnostic Mode 2 (Acheulean) artefacts were found.Cosmogenic nuclide burial dating was attempted for the basal gravels as well as exposure ages for the upper Mode 3 gravels, but was unsuccessful. The complex depositional history of the site prevented the calculation of reliable age models. A relative chronology for the full Manzi sequence was constructed, however, from the magnetostratigraphy of the deposit (N>R>N sequence). Isothermal thermoluminescence (ITL) dating of the upper Mode 3 layers also provided consistent results (∼78 ka). A coarse but chronologically coherent sequence now exists for the Manzi section with the unconformity separating probable mid- or early Pleistocene deposits below from late Pleistocene deposits above. The results suggest Mode 1 technology in the Luangwa Valley may post-date the Oldowan in eastern and southern Africa. The dating programme has contributed to a clearer understanding of the geomorphological processes that have shaped the valley and structured its archaeological record.     

Os fossiles humains des grottes Muierii et Cioclovina, Roumanie

This paper presents the cultural and archaeological context of the human fossil bones from Muierii Cave, dated by us to the age of 30 150 ± 800 ¹⁴C years BP (Before Present) or 34 810 ± 927 cal years BP (calibrated years Before Present), and from Cioclovina Cave, dated to the age of 29 000 ± 700 ¹⁴C years BP or 33 540 ± 832 cal years BP, in the Southern Carpathians. These are among the most ancient dated human fossil remains from Central and South-Eastern Europe and are described in conjunction with other sites with Mousterian assemblages of the recent Neanderthal population, and sites with Aurignacian assemblage of early modern humans, from Romanian region, for the interval of time 34,000-26,000, the transitional period from the Middle Paleolithic to the Upper Paleolithic.     

Late Quaternary woolly mammoth (Mammuthus primigenius Blum) remains from southern Transdanubia,Hungary

Six samples of subfossil tusk, bone and tooth remains from the woolly mammoth (Mammuthus primigenius Blum) were discovered in south-western Hungary. The remains are relatively well preserved in a Late Pleistocene loess deposit. The samples have been radiocarbon dated (AMS) and are of Late Weichselian (MIS 2) age (21.8–24.1 ka cal BP). The skull fragments, the tusks and maxillary teeth are in close proximity to associated postcranial remains, indicating that the mammoth died where it was found. The size and characteristics of skeletal elements have allowed us to determine that this was a mature male of about 38 years of age.     

Antiviral, anti-parasitic, and cytotoxic effects of 5,6-dihydroxyindole (DHI), a reactive compound generated by phenoloxidase during insect immune response

Phenoloxidase (PO) and its activation system are implicated in several defense responses of insects. Upon wounding or infection, inactive prophenoloxidase (proPO) is converted to active PO through a cascade of serine proteases and their homologs. PO generates reactive compounds such as 5,6-dihydroxyindole (DHI), which have a broad-spectrum antibacterial and antifungal activity. Here we report that DHI and its spontaneous oxidation products are also active against viruses and parasitic wasps. Preincubation of a baculovirus stock with 1.25 mM DHI for 3 h near fully disabled recombinant protein production. The LC₅₀ for lambda bacteriophage and eggs of the wasp Microplitis demolitor were 5.6 ± 2.2 and 111.0 ± 1.6 ??M, respectively. The toxicity of DHI and related compounds also extended to cells derived from insects that serve as hosts for several of the aforementioned pathogens. Pretreatment of Sf9 cells with 1.0 mM DHI for 4 h resulted in 97% mortality, and LC₅₀ values of 20.3 ± 1.2 ??M in buffer and 131.8 ± 1.1 ??M in a culture medium. Symptoms of DHI toxicity in Sf9 cells included DNA polymerization, protein crosslinking, and lysis. Taken together, these data showed that proPO activation and DHI production is strongly toxic against various pathogens but can also damage host tissues and cells if not properly controlled.     

Effects of experimental stem burial on radial growth and wood anatomy of pedunculate oak

In dendrogeomorphology, abrupt changes in wood anatomy are frequently used to date the exact year of burial and exposure events. However, few studies have addressed the precision and underlying mechanisms of these changes. In a field experiment, performed in a drift-sand area in the Netherlands, we buried the stems of mature pedunculate oak trees (Quercus robur L.) up to a height of 50 cm and analysed the responses in ring width and earlywood-vessel characteristics, while monitoring the course of temperature above and below the soil surface.After 3 years of stem burial, we found no significant differences in ring width and earlywood-vessel characteristics between control and buried trees both above and below the burial level. Burial however strongly reduced temperature amplitude and the occurrence of sub-zero temperatures around the buried stems. All buried trees formed epitropic roots that grew upward into the new sediment layer, but no adventitious roots were formed on the buried stems. Irrespective of the burial treatments, we found that the mean ring width was largest at the original stem base and lowest at breast height. In contrast, vessel sizes were significantly larger at breast height compared with the stem base. Differences in vessel density barely differed between years and heights.In our field experiment on mature pedunculate oak trees, the burial of stems by 50 cm of drift sand did not induce any local growth suppression or detectable changes in wood anatomy. As wood-anatomical changes in response to burial have previously been reported for trees that had formed adventitious roots, we stress the role of adventitious-root formation as a possible trigger behind the local changes in wood anatomy, reflecting a functional change of a buried stem towards a root. Based on our field experiment, it seems unlikely that years of shallow or moderate burial events (≤50 cm) can be reconstructed using the wood structure of buried stems. As epitropic roots develop quickly after burial, dating such roots may potentially yield better estimates of burial events. Further research on the relation between adventitious root and changes in stem anatomy is needed to ascertain the precision of dating sand-burial events using tree rings.     

The Neandertal lower right deciduous second molar from Trou de l'Abîme at Couvin, Belgium

A human lower right deciduous second molar was discovered in 1984 at the entrance of Trou de l'Abîme at Couvin (Belgium). In subsequent years the interpretation of this fossil remained difficult for various reasons: (1) the lack of taxonomically diagnostic elements which would support its attribution to either Homo (sapiens) neanderthalensis or H. s. sapiens; (2) the absence of any reliable chronostratigraphic interpretation of the sedimentary sequence of the site; (3) the contradiction between archaeological interpretations, which attributed the lithic industry to a transitional facies between the Middle and Early Upper Palaeolithic, and the radiocarbon date of 46,820 ± 3,290 BP obtained from animal bone remains associated with the tooth and the flint tools.Thanks to recent progress regarding these three aspects, the tooth from Trou de l'Abîme may now be studied in detail. Analyses of the morphology and enamel thickness of the fossil yielded diagnostic characters consistent with an attribution to Neandertals. Re-examination of the lithic industry of Couvin shows that it corresponds to the late Middle Palaeolithic rather than a transitional facies. Furthermore, a new analysis of the site stratigraphy indicates that the unit situated above the archaeological layer in which the tooth was found is probably a palaeosol of brown soil type. Comparison with the regional cave sequences as well as with the reference sequence from the Belgian loess belt tends to show that the most recent palaeosol of this type is dated between 42,000 and 40,000 BP. This is consistent with both a recently obtained AMS result at 44,500 BP and the published conventional date.     

Matrix/mineral ratio and domain size variation with bone tissue age: A photothermal infrared study

Atomic force microscopy-infrared spectroscopy (AFM-IR) and optical photothermal infrared spectroscopy (O-PTIR), which feature spectroscopic imaging spatial resolution down to ～ 50 nm and ～ 500 nm, respectively, were employed to characterize the nano- to microscale chemical compositional changes in bone. Since these changes are known to be age dependent, fluorescently labelled bone samples were employed. The average matrix/mineral ratio values decrease as the bone tissue matures as measured by both AFM-IR and O-PTIR, which agrees with previously published FTIR and Raman spectroscopy results. IR ratio maps obtained by AFM-IR reveal variation in matrix/mineral ratio-generating micron-scale bands running parallel to the bone surface as well as smaller domains within these bands ranging from ～ 50 to 700 nm in size, which is consistent with the previously published length scale of nanomechanical heterogeneity. The matrix/mineral changes do not exhibit a smooth gradient with tissue age. Rather, the matrix/mineral transition occurs sharply within the length scale of 100–200 nm. O-PTIR also reveals matrix/mineral band domains running parallel to the bone surface, resulting in waves of matrix/mineral ratios progressing from the youngest to most mature tissue. Both AFM-IR and O-PTIR show a greater variation in matrix/mineral ratio value for younger tissue as compared to older tissue. Together, this data confirms O-PTIR and AFM-IR as techniques that visualize bulk spectroscopic data consistent with higher-order imaging techniques such as Raman and FTIR, while revealing novel insight into how mineralization patterns vary as bone tissue ages.     

Synthesis,radioprotective activity and pharmacokinetics characteristic of a new stable nitronyl nitroxyl radical-NIT2011

A new stable nitronyl nitroxyl radical NIT2011 was synthesized and characterized. The radioprotective effect and pharmacokinetics profiles of NIT2011 were investigated. The results showed that when irradiation exposure dose was 6.5 Gy gama radiation, the survival rate in the irradiation-only group was 20% on 30th day. The survival rate was 70%, 80%, and 90% on 30th day when mice were pretreated with 0.25, 0.5 and 1.0 mmol/kg NIT2011, respectively. The pretreatment of NIT2011 increased number of spleen colonies, the numbers of bone marrow cells and protein level in bone marrow cells. Pretreatment with NIT2011 prior to radiation exposure increased the plasma SOD (superoxide dismutase) activity. 24 h after irradiation exposure, level of plasma MDA (malondialdehyde) in irradiation-only mice was 14.8 ± 2.8 nmol/mL, level of plasma MDA in NIT2011 (1 mmol/kg) pretreated mice was 9.8 ± 2.0 nmol/mL. Three days after irradiation exposure, the micronucleus ratio in irradiation-only mice is 40.2 ± 3.6, the micronucleus ratio in NIT2011 (1 mmol/kg) pretreated mice was 11.7 ± 1.2. NIT2011 was easily absorbed in mice after it was oral administrated. Compared with the intraperitoneal injection, the relative oral bioavailability of the NIT2011 was 27.5% in mice. The LD₅₀ of NIT2011 was 1510 mg/kg in mice by oral administration. Thus, NIT2011 has potential in being developed as an oral dosage form, safe and effective radioprotective agent.