Abundance and distribution of elephants in the Luangwa Valley, Zambia

Elephant density over 40 000 km² of the Luangwa Valley was estimated as 2–17 km^-2 to give a population size of around 86 000 in that area, a tally that would probably top 100 000 if unsurveyed areas within the drainage had been included. Seasonal movement is largely restricted to a migration on to the riverine strip during the wet season and reciprocal dispersal across the valley thereafter. The mean annual range of movement is about 25 km.     

Patterns of depletion in a black rhinoceros population in Luangwa Valley, Zambia

Black rhinos in Luangwa Valley, Zambia have been subjected to heavy illegal hunting since the late 1970s. A study population monitored by individual recognition decreased at an instantaneous rate of - 0.29 yr^-1 between 1981 and 1985. Two-thirds of skulls found throughout Luangwa Valley between 1979 and 1985 were axed, indicating death from poaching. All age- and sex-classes of rhino were equally susceptible to being shot, presumably due to the high market-price of rhino horn.     

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.     

Observations of tree growth, woodland structure and elephant damage on Colophospermum mopane in Luangwa Valley, Zambia

Six samples of tagged Colophospermum mopane were monitored for five years in locations with varying soil characteristics but with similar elephant densities. Physiognomic variation among the samples was related to soil differences, which also correlated with different browsing habits by elephants. The impact of elephant browsing further influenced both the physiognomy and demography of C. mopane. Results from this study suggest that the influence of soils and elephants on C. mopane alter successional transitions from grassland to woodland. Soils that promote coppicing of C. mopane yield less stable woodlands when associated with elephants than soils promoting woodlands with large bolus, non-coppicing trees. The dynamics of the latter are determined more by tree recruitment as influenced by such agents as other browsers or frequency and seasonality of bush fires. Implications for forest/elephant management are discussed.     

Early Eocene orthophragminids from the Lower Indus Basin,Pakistan, and their biostratigraphic implication

Orthophragminids are a key biostratigraphic proxy for Paleocene–Eocene sequences in western Tethys, but poorly known in eastern Tethys. The orthophragminids were previously misinterpreted as Paleocene's orbitoidiform foraminifera in the Indus Basin, Pakistan. This study focuses on detailed taxonomy and biostratigraphy of orthophragminids. Nine species/subspecies of orthophragminids are identified, including Discocyclina ranikotensis, D. archiaci bakhchisaraiensis, D. a. ex. interc. staroseliensis bakhchisaraiensis, D. dispansa hungarica, D. d. taurica, D. d. broennimanni and Orbitoclypeus schopeni ramaraoi, and two new species Discocyclina pseudoranikotensis n. sp. and Discocyclina debalensis n. sp. are described. The identified orthophragminid taxa represent the orthophragminid zones OZ2-3, corresponding to the shallow benthic zones SBZ5-7 of early Ypresian (early Eocene), which are correlated with those in western Tethys. However, we found that the first appearances of D. d. hungarica and D. d. taurica occur in the OZ3 or SBZ7 in this study instead of the OZ5 or SBZ10 as in western Tethys. The possible paleoecological setting for the occurrences of recognized species is interpreted as inner to middle shelf.     

The biostratigraphic and palaeoenvironmental significance of Lower Cambrian (Botomian) trilobites from the Ak-Kaya section of the Altai Mountains (southern Siberia,Russia)

The presence of one of the oldest records of polycystine Radiolaria in the Lower Cambrian sedimentary sequence of the Ak-Kaya section (Gorny Altai) requires a biostratigraphic dating. The trilobites found recently a few tens of meters below the radiolarian-bearing level belong to Calodiscus resimus Repina, Serrodiscus fossuliferus Repina and Alacephalus aff. contortus Repina; they suggest that this part of the Shashkunar Formation can be correlated with the lower part of the Botomian stage. The absence of eyes in the two former species suggests a mode of life buried in the fine pelagic sediments. Indications of the presence of a strongly developed musculature on the third species point to a palaeoenvironment characterized by a relatively high hydrodynamic regime.     

The Middle Stone Age archaeology of the Lower Omo Valley Kibish Formation: excavations, lithic assemblages, and inferred patterns of early Homo sapiens behavior

This paper describes the excavation, stratigraphy, and lithic assemblages of Middle Stone Age sites from the Omo Kibish Formation (Lower Omo Valley, southwestern Ethiopia). Three sites were excavated, two in Kibish Member I (KHS and AHS) and one at the base of Member III (BNS). The assemblages are dominated by relatively high-quality raw materials procured as pebbles from local gravels. The principal modes of core preparation are radial/centripetal Levallois and discoidal. Retouched tools are rare. Foliate bifaces are present, as are larger tools, such as handaxes, picks, and lanceolates, but these are more common among surface finds than among excavated assemblages. Middle Stone Age assemblages shed light on the adaptations of the earliest-known Homo sapiens populations in Africa.     

Long-term dynamics of orthopteran assemblages (orthoptera) of the Hissar Valley (Tajikistan)

Results of investigation of the species composition and population density of the orthopteran assemblages, performed in the Hissar Valley in 1935 and 1989 are discussed. The increased anthropogenic press resulted in the drastic changes in the assemblages during 50 years. Two species dominating in the past, Calliptamus italicus (L.) and Dociostaurus maroccanus (Thunb.), are indicators of the integrity of original assemblages (and entire ecosystems of Hissar Valley, which are now completely destroyed) or of their insignificant transformation. The recent mesomorphic assemblages are dominated by Oxya fuscovittata (Marsch.), Duroniella gracilis Uv., Chorthippus biguttulus (L.), Aiolopus thalassinus (Fabr.), and xeromorphic communities, by Calliptamus barbarus (Costa), Dociostaurus tartarus (Stshelk.), Oedipoda miniata (Pall.), and Acrotylus insubricus (Scop.). The predominance and wide distribution of these species points to a significant transformation of ecosystems and destabilization of the environment in the Hissar Valley.     

Lower Cambrian Small Shelly Fossils of northern Sichuan and southern Shaanxi (China), and their biostratigraphic importance

Extensive information has been acquired on the occurrence of Lower Cambrian Small Shelly Fossils (SSF) in the shallow water sediments of the western fringe of the Yangtze Platform (eastern Yunnan and central Sichuan Provinces) during the last two decades. However, less is known on the temporal and spatial distribution of SSFs on the northern margin of the Yangtze Platform. Here we report SSF associations from Kuanchuanpu (Ningqiang County, southern Shaanxi Province), Shatan, and Xinli (both Nanjiang County, northern Sichuan Province) representing the Southwest Shaanxi region and from Sanlangpu, and Xiaowan (Xixiang County, southern Shaanxi Province) of the Southeast Shaanxi - Northwest Hubei region. The thickness of the Lower Cambrian SSF-bearing strata strongly decreases in this region from West to East and the stratigraphic hiatus increases. An earliest Cambrian hiatus is widely distributed on the northern margin of the Yangtze Platform. At the same time, a syngenetic brecciation occurred in wide shallow shelf settings. A tectonic mobilization, possibly related to the assembly of Gondwana following the breakup of Rodinia, may be responsible for this. In sections near Kuanchuanpu (Ningqiang County), the Meishucunian (equivalent to the Nemakit-Daldynian to Tommotian of Siberia) succession comprises ca. 55 m of dark phosphatic carbonates, siltstones, and cherts. The SSF associations are similar to those of East Yunnan and, in ascending order, can be discriminated into the Anabarites trisulcatus - Protohertzina anabarica Zone, the Watsonella yunnanensis Zone (previously mentioned as Heraultipegma yunnanensis Zone), and the Sinosachites flabelliformis - Tannuolina zhangwentangi Zone. The Siphogonuchites triangularis - Paragloborilus subglobosus Zone cannot be unambiguously detected in the Southwest Shaanxi region. The occurrence of embryos and eggs within the Anabarites trisulcatus - Protohertzina anabarica Zone, which has been reported earlier, is remarkable. The previously reconstructed life cycle and taxonomic treatment of Olivooides / Punctatus are re-discussed. The earliest SSF associations (Anabarites trisulcatus - Protohertzina anabarica Zone to Watsonella yunnanesis Zone) are missing in the Southeast Shaanxi - Northwest Hubei region and the Ninella tarimensis - Cambroclavus fangxianensis Assemblage Zone and Rhombocorniculum cancellatum Taxon Range Zone are introduced herein.     

山东早二叠世早期太原组煤核中美丽“鳞木”的解剖构造

描述了山东兖州矿区太原组（早二叠世早期）煤核中一种具叶座的鳞木类茎的解剖构造。叶座呈略不对称的菱形。下侧边略长于上侧边,顶,底角均平截,底角并略呈拖延状;叶座上部突起较强烈,叶痕双凸镜形,叶迹呈宽V字形,叶迹与侧通气束可能都以近水平状在叶座内向外延伸;叶舌穴深,自叶座最内处向外斜伸,开口位于叶痕顶角附近,叶座底部表面具横皱纹。茎可能具管状中柱和薄壁组织的髓,初生木质部外始式,外缘较平滑,仅见有外部皮层,由径向伸长的壁较厚的细胞条带和夹于其间的空腔交替排列构成,空腔内可见弧形或宽V字形叶迹,其凹面朝向内方,周皮较发育,由近等量发育的木栓层和栓内层组成,经比较,当前标本与华夏植物区的印痕-压型化石种美丽鳞木在叶座的形态上非常相似,暂归入该种,由于无论是当前标本还是美丽鳞木的模式标本与狭义的鳞木属都有很大区别,因此美丽{“鳞木‘的确切归属还有待于今后进一步对保存更好的具解剖构造的茎和生殖器官的研究。美丽”鳞木“与欧美植物区几个乔木状鳞木类植物属的茎都不完全相同,具有它们的混合特征,很可能代表了一个新属,美丽”鳞木“是目前华夏植物区研究得最详细的一种具解剖构造的鳞木类的茎,对于研究华夏植物区鳞木类植物的起源和演化具有一定的意义。     

山东早二叠世早期太原组煤核中美丽"鳞木"的解剖构造

描述了山东兖州矿区太原组(早二叠世早期)煤核中一种具叶座的鳞木类茎的解剖构造.叶座呈略不对称的菱形,下侧边略长于上侧边,顶、底角均平截,底角并略呈拖延状;叶座上部突起较强烈,叶痕双凸镜形,叶迹呈宽V字形,叶迹与侧通气束可能都以近水平状在叶座内向外延伸;叶舌穴深,自叶座最内处向外斜伸,开口位于叶痕顶角附近.叶座底部表面具横皱纹.茎可能具管状中柱和薄壁组织的髓.初生木质部外始式,外缘较平滑.仅见有外部皮层,由径向伸长的壁较厚的细胞条带和夹于其间的空腔交替排列构成,空腔内可见弧形或宽V字形叶迹,其凹面朝向内方.周皮较发育,由近等量发育的木栓层和栓内层组成.经比较,当前标本与华夏植物区的印痕--压型化石种美丽鳞木在叶座的形态上非常相似,暂归入该种.由于无论是当前标本还是美丽鳞木的模式标本与狭义的鳞木属都有很大区别,因此美丽"鳞木"的确切归属还有待于今后进一步对保存更好的具解剖构造的茎和生殖器官的研究.美丽"鳞木"与欧美植物区几个乔木状鳞木类植物属的茎都不完全相同,具有它们的混合特征,很可能代表了一个新属.美丽"鳞木"是目前华夏植物区研究得最详细的一种具解剖构造的鳞木类的茎,对于研究华夏植物区鳞木类植物的起源和演化具有一定的意义.     

Pollen evolution and its taxonomic significance in Cuscuta (dodders, Convolvulaceae)

The pollen morphology of 148 taxa (135 species and 13 varieties) of the parasitic plant genus Cuscuta (dodders, Convolvulaceae) was examined using scanning electron microscopy. Six quantitative characters were coded using the gap-weighting method and optimized onto a consensus tree constructed from three large-scale molecular phylogenies of the genus based on nuclear internal transcribed spacer (ITS) and plastid trn-LF sequences. The results indicate that 3-zonocolpate pollen is ancestral, while grains with more colpi (up to eight) have evolved only in two major lineages of Cuscuta (subg. Monogynella and clade O of subg. Grammica). Complex morphological intergradations occur between species when their tectum is described using the traditional qualitative types—imperforate, perforate, and microreticulate. This continuous variation is better expressed quantitatively as “percent perforation,” namely the proportion of perforated area (puncta or lumina) from the total tectum surface. Tectum imperforatum is likely the ancestral condition, while pollen grains with increasingly larger perforation areas have evolved multiple times. The reticulated tectum, unknown in other Convolvulaceae, has evolved in Cuscuta only in two lineages (subg. Monogynella, and clade O of subg. Grammica). Overall, the morphology of pollen supports Cuscuta as a sister to either the “bifid-style” Convolvulaceae clade (Dicranostyloideae) or to one of the members of this clade. Pollen characters alone are insufficient to reconstruct phylogenetic relationships; however, palynological information is useful for the species-level taxonomy of Cuscuta.     

The age of puberty of the hippopotamus (Hippopotamus amphibius Linn.) in the Luangwa River in eastern Zambia

As part of a study of the ecology of a high density hippopotamus population (Hippopotamus amphibius) in the Luangwa river in eastern Zambia, a shot sample of 176 males and 161 females was examined. All animals were classified according to age (0–43 years). The female reproductive organs were removed, dissected, examined, and the lactational status was noted. Ovaries and corpora Iutea were weighed, sliced, and all follicles > 5 mm in diameter were recorded. The testes of the males were dissected and weighed. Indications of puberty and maturity in the female were observed in some animals at an age of about 7 and 8 years respectively; but some animals were still not breeding until 20 years of age and the ages at which 50% of the female population reached puberty and maturity (Laws & Clough, 1966) were 11 and 13 years respectively. In the male, puberty begins at an average age of 6 years and maturity is reached at approximately 8 years of age. The data showed that lactation has no effect on ovarian weight or activity. The weight of the corpus luteum during pregnancy (36–72 ± 2–65 g) is significantly (P < 0–01) greater than that observed in non-pregnant animals (16–64 ± 2–46 g). Multiple ovulation occurs in 8–10% of the animals.     

Pollen morphology and its taxonomic significance in the tribe Gochnatieae (Compositae, Gochnatioideae)

In the context of recent molecular phylogenies of the basal grades of Compositae, we investigated the utility of pollen morphology within the tribe Gochnatieae. The pollen of 64 species of Anastraphia, Cnicothamnus, Cyclolepis, Gochnatia, Pentaphorus, and Richterago was studied using light microscopy and scanning electron microscopy. In addition, three extra-Gochnatieae genera (Ianthopappus, Leucomeris, and Nouelia) were examined as they were traditionally morphologically related to members of the tribe Gochnatieae. Three of the species of Gochnatieae were examined using transmission electron microscopy. Two pollen types, and two new subtypes, have been recognized on the basis of the pollen shape, size, and exine sculpture. The pollen features of Gochnatia sect. Moquiniastrum and G. cordata are similar and distinctive within the genus and support the recently re-circumscribed section Hedraiophyllum. Within the species with echinate pollen surface, the distinctive spine length of Anastraphia supports its recent resurrection as a genus. The identity of Pentaphorus could not be supported by pollen features as was for other morphological characteristics. The pollen features shared across Cyclolepis, Ianthopappus, Leucomeris, Nouelia and Gochnatia sect. Moquiniastrum, as well as those shared by Richterago and Anastraphia could be a result of parallel evolution.     

Pollen characteristics of New Zealand Gnaphalieae (Compositae) and their taxonomic significance II. Tem

Pollen ultrastructure has been investigated in 35 taxa of Gnaphalieae (Compositae), predominantly from New Zealand. Pollen grains of all taxa examined are tectate‐columellate and caveate. The characters regarded as particularly distinctive include variability of columellar form and internal organisation of the columellae. The importance of pollen characters in the classification of the New Zealand Gnaphalieae is discussed. The species of Haastia, characterised by senecioid pollen and internal tecta, do not belong to the Gnaphalieae. In the species with helianthoid pollen and sub‐columellae five different columellae types can be distinguished.