Distinctive Fossil Research Articles

Sequence stratigraphy of the late middle Jurassic open shelf platform of the Tuwaiq Mountain Limestone Formation, central Saudi Arabia

Middle Jurassic (Callovian) strata of Tuwaiq Mountain Limestone Formation, central Saudi Arabia are composed of thin- to thick-bedded, grainy and muddy limestones and dolostones with various skeletal and nonskeletal components. Facies analysis documents low- to high-energy environments, including lagoon, back reef, reef framework, fore-reef and intra-shelf basin lithofacies associations. Because of the narrow lateral distribution of facies and the presence of distinctive fossils, the depositional system likely represents an open marine shelf. Two third-order depositional sequences can be distinguished in the stratigraphic measured section. Transgressive sequences show deepening-upward trends, in which shallow water (lagoonal and back reef) facies are overlain by deeper-water (fore-reef and intra-shelf basin) facies. Regressive sequences show shallowing-upward trends in which deep-water facies are overlain by shallow-water facies. Most sequence boundaries in the study area are of the nonerosional (SB2) type. Correlation of depositional sequences in the studied section reveals that relatively shallow marine conditions predominated in the area.

Late Early Devonian brachiopods from Montys Hut Formation, central Victoria, Australia

Earp, C., December 2015. Late Early Devonian brachiopods from Montys Hut Formation, central Victoria, Australia. Alcheringa 40, xxx–xxx. ISSN 0311-5518A distinctive low-diversity fossil assemblage is reported from the Montys Hut Formation (Walhalla Group; Early Devonian), central Victoria, Australia. The fauna is dominated by two species of chonetoid brachiopods; two other brachiopods also occur in sufficient quantities to warrant description. Taungurungetes gen. nov. (?Devonochonetinae) is created to accommodate the nominate species of the assemblage, T. taggertyensis (Gill) comb. nov., and an additional species is described in open nomenclature from the underlying Norton Gully Sandstone. The other principal chonetoid is Parachonetes sp. cf. P. buchanensis (Gill). Capillate spiriferids from the assemblage were previously reported as Mauispirifer Allan. A redescription of M. hectori Allan shows the Victorian material is not congeneric and it is assigned to Tapongaspirifer melodiae gen. et sp. nov. (Filispiriferidae). The other minor constituent is Mesoleptostrophia belli sp. nov. Other (undescribed) fossils include ammonoids, a placoderm, dacryoconarids and vascular plants. A mid- to late Emsian age is indicated. It is concluded that the assemblage structure is consistent with the well-known high level of endemism in Emsian faunas.C. Earp [omaiosys@yahoo.com.au], 16B Ebony Place, Massey, Auckland 0614, New Zealand.

Diversity of extinct Rheidae (Aves, Palaeognathae): historical controversies and the new taxonomic status of Rhea pampeana Moreno and Mercerat 1891 from the Pleistocene of Argentina

Rhea pampeana Moreno and Mercerat 1891 is an extinct species of Rheidae (Aves, Palaeognathae) from the Pleistocene of Buenos Aires province, Argentina. This taxon has been the subject of different and confusing changes of its taxonomic status, and an adequate description is still lacking. This study re-examines the materials assigned to Rhea pampeana with the objective to evaluate their status as a distinct fossil species. The poor preservation of the materials plus certain osteological features of the tibiotarsus and tarsometatarsus allowed to reassign these materials to the living species Rhea americana.

Icacinaceae from the eocene of Western North America.

The Icacinaceae are a pantropical family of trees, shrubs, and climbers with an extensive Paleogene fossil record. Our improved understanding of phylogenetic relationships within the family provides an excellent context for investigating new fossil fruit and leaf material from the Eocene of western North America. We examined fossils from early and middle Eocene sediments of western Wyoming, northeastern Utah, northwestern Colorado, and Oregon and compared them with extant species of Iodes and other icacinaceous genera as well as previously described fossils of the family. Three new fossil species are described, including two based on endocarps (Iodes occidentalis sp. nov. and Icacinicaryites lottii sp. nov.) and one based on leaves (Goweria bluerimensis sp. nov.). The co-occurrence of I. occidentalis and G. bluerimensis suggests these might represent detached organs of a single species. A new genus, Biceratocarpum, is also established for morphologically distinct fossil fruits of Icacinaceae previously placed in Carpolithus. Biceratocarpum brownii gen. et comb. nov. resembles the London Clay species "Iodes" corniculata in possessing a pair of subapical protrusions. These fossils increase our knowledge of Icacinaceae in the Paleogene of North America and highlight the importance of the Northern Hemisphere in the early diversification of the family. They also document interchange with the Eocene flora of Europe and biogeographic connections with modern floras of Africa and Asia, where Icacinaceae are diverse today. The present-day restriction of this family to tropical regions offers ecological implications for the Eocene floras in which they occur.

Additions to the Eocene Perissodactyla of the Margaret Formation, Eureka Sound Group, Ellesmere Island, Arctic Canada

We describe early Eocene (Wasatchian) occurrences of the isectolophid Homogalax, tapiroids Heptodon posticus, Heptodon cf. H. posticus, and Heptodon sp., as well as early middle Eocene (Bridgerian) fossils of the brontothere Palaeosyops from localities in the Margaret Formation of the Eureka Sound Group on Ellesmere Island, Nunavut, Arctic Canada. Their occurrence on Ellesmere Island considerably extends the geographic range of these taxa, previously known from mid-latitude localities in British Columbia (only Heptodon), the Western Interior of the United States, and Asia (Homogalax, Heptodon, and Palaeosyops). We also place the fossil localities near Bay Fiord on central Ellesmere Island into a refined lithostratigraphic framework based upon data from three measured stratigraphic sections. Our stratigraphic data confirm the presence of two, stratigraphically distinct fossil assemblages — a late Wasatchian-aged lower assemblage and a Bridgerian-aged upper assemblage that were previously hypothesized by others based on faunal differences — that are separated by a 478 m thick stratigraphic gap that appears to lack fossil vertebrates. From a paleoenvironmental perspective, occurrence of the tapiroid Heptodon in the Eocene Arctic corroborates an hypothesis put forward by others that tapiroids are proxies for densely forested habitats, although they were adapted to a range of temperatures including near (or at) freezing temperatures of Eocene Arctic winters. Further, Arctic occurrences of tapiroids and brontotheres imply that these typical mid-latitude ungulate mammals were adapted to Arctic environments, thereby increasing the probability of Trans-Beringian dispersal during early and middle Eocene time.

Ichnology of the Miocene Jaraba Formation, Almazán Basin, NE Spain – Morphological characteristics and paleoenvironmental implications of distinct continental trace fossils

Ichnology of the Miocene Jaraba Formation, Almazán Basin, NE Spain – Morphological characteristics and paleoenvironmental implications of distinct continental trace fossils

Provenance and sediment characteristics of contemporary gravel deposits at Sellicks Beach, eastern shore of Gulf St Vincent, South Australia

Sellicks Beach, located on the eastern shore of Gulf St Vincent, South Australia, is subject to wave-dominated processes and northward longshore transport. During winter, when wave energy is typically vigorous, gravel deposits are exposed across most of the beach, and three step-like berms are well developed. Sand is restricted to a narrow strip that is exposed only at low tide. In contrast, during summer, when wave energy is generally moderate to low, much of the gravel is covered by a thin veneer of sand and only the high berm, on the landward edge of the beach, remains as an obvious feature. Steeply dipping Neoproterozoic to Cambrian strata that outcrop strongly across Sellicks Hill are the original source rocks for the beach gravel; distinctive sedimentary textures, structures and fossils in the cobble-size clasts can be confidently matched with those of the provenance rocks. Much of the sediment entered the modern beach environment as a consequence of coastal erosion of transitional alluvial fan sediments. The oldest alluvial fan sediments are of late Pliocene to earliest Pleistocene age. Mount Terrible Gully provides a conduit for the input of fluvial sediment at the mouth of Cactus Canyon, where clasts as large as boulders accumulate across the beach. Sellicks Beach gravels are subject to longshore transport northwards. Relatively softer clasts, such as those derived from the Heatherdale Shale, are rare beyond Cactus Canyon. In contrast, quartzite clasts are more abundant towards the north. This lithological differentiation is attributed to preferential survivorship of clasts that are physically harder and chemically less reactive. The change in the shapes of clasts northwards, from predominately shingle-like ‘very platy’ and ‘very bladed’ at Cactus Canyon, to more ‘compact’ towards the boat ramp, is in accord with the more massive fabric of the surviving quartzite clasts. At Sellicks Beach, preservation of uplifted, coarse gravels, with entire and comminuted marine molluscan shells, of last interglacial age, provides evidence of neotectonism. At the landward margin of the beach, imbricated gravels in which pore spaces have been infilled with mud, and which show no evidence of modern coastal erosion, may provide evidence of continuing uplift during the recent Holocene. The geological setting, geomorphic framework and modern sedimentary regime at Sellicks Beach combine to provide an exceptionally useful outdoor laboratory for education in field geology.

Neandertal demise: an archaeological analysis of the modern human superiority complex.

Neandertals are the best-studied of all extinct hominins, with a rich fossil record sampling hundreds of individuals, roughly dating from between 350,000 and 40,000 years ago. Their distinct fossil remains have been retrieved from Portugal in the west to the Altai area in central Asia in the east and from below the waters of the North Sea in the north to a series of caves in Israel in the south. Having thrived in Eurasia for more than 300,000 years, Neandertals vanished from the record around 40,000 years ago, when modern humans entered Europe. Modern humans are usually seen as superior in a wide range of domains, including weaponry and subsistence strategies, which would have led to the demise of Neandertals. This systematic review of the archaeological records of Neandertals and their modern human contemporaries finds no support for such interpretations, as the Neandertal archaeological record is not different enough to explain the demise in terms of inferiority in archaeologically visible domains. Instead, current genetic data suggest that complex processes of interbreeding and assimilation may have been responsible for the disappearance of the specific Neandertal morphology from the fossil record.

An illustrated guide to the fossil barnacles (Cirripedia) from the Crags (Plio-Pleistocene) of East Anglia

The Plio-Pleistocene Crag deposits of East Anglia include a wealth of shelly remains, including barnacles, preserved variously as complete shells, their disarticulated plates and trace fossils. Herein, we present a field guide to these distinctive fossils, with diagnoses of all known taxa recorded from the Crags of East Anglia, supported by both line drawings and photographs. The known stratigraphic and geographic distribution within the study area are tabulated. Recognised species include the sessile barnacles Armatobalanus bisulcatus (Darwin), A. dolossus (Darwin), Balanus balanus (Linné), B. crenatus Bruguière, B. inclusus Darwin, Concavus concavus (Bronn), Chirona hameri (Ascanius), Megabalanus tintinnabulum (Linné), Conopea calceola (Ellis), Co. spongicola (Brown), Acasta undulata Darwin, Coronula barbara Darwin, Megatrema anglicum (G.B. Sowerby) and Verruca stroemia (Müller) (=14 species); two pedunculate forms, Scalpellum magnum Darwin and Lepas delicatula Withers; and the boring Rogerella isp. The greatest diversity of species is found in the Coralline Crag and Red Crag formations, both yielding 11 species, although only four are common to both. Barnacles are poorly represented in other Crag deposits.

(2243) Proposal to conserve the name Psaronius against Scitaminites (fossil Pteridophyta: Marattiopsida)

Psaronius Cotta is one of most widespread and well known fossil generic names established for permineralised stems showing anatomical structure (Goppert in Nov. Actorum Acad. Caes. Leop.-Carol. Nat. Cur. 17(Suppl.): 456. 1836; Brongniart, Hist. Veg. Foss. 2: 56. 1837 & in d’Orbigny, Dict. Univ. Hist. Nat. 13: 94. 1849; Schimper, Traite Paleontol. Veg. 1: 716. 1869; Scott, Stud. Foss. Bot., ed. 2, 1: 296. 1908; Seward, Foss. Pl. 2: 412. 1910; Gothan in Potonie, Lehrb. Palaobot., ed. 2: 109. 1919; Hirmer, Handb. Palaobot. 1: 545. 1927; Posthumus, Cat. Foss. Fern Stems: 146. 1931; Darrah, Textb. Palaeobot.: 141. 1939 & Princ. Paleobot.: 96. 1939; Reed in Bot. Gaz. (Crawfordsville) 110: 506. 1948; Stidd in Palaeontographica, Abt. B, Palaophytol. 134: 87. 1971; Mickle in Illinois State Mus. Sci. Pap. 19: 1. 1984; Herbst in Ameghiniana 21: 243. 1985; Rosler in Rev. Palaeobot. Palynol. 108: 55. 2000; Hilton & al. in Geol. Mag. 141: 661. 2004; Taylor & al., Paleobotany: 418. 2009). In addition, the generic name provides the type of a distinct fossil fern family Psaroniaceae F. Unger (in Endlicher, Gen. Pl. Suppl. 2: 4. 1842 (‘Psaronieae’)), order Psaroniales Barthel (in Abh. Staatl. Mus. Miner. Geol. Dresden 24: 37. 1976) and suborder Psaroniineae O. Feistm. (in Palaeontographica 23: 151. 1874 (‘Psaronieae’)) [vide Doweld, Prosyllabus: vii. 2001]. In 1845, after careful studies of original Sternberg’s fossil material, Corda (Fl. Protogaea: 94. 1845) came to conclusion that Scitaminites Sternb. should be synonymized with Psaronius Cotta due to their essential similarity in anatomical structure. Although the priority of Sternberg’s name was obvious even in these earlier times, a consensus was reached to keep the junior name Psaronius Cotta in current use, while recognizing Scitaminites Sternb. as a rejected synonym (Presl in Abh. Bohm. Ges. Wiss., ser. 5, 4: 288. 1847; Goppert in Bronn, Index Palaeontol.: 1050. 1848; Brongniart in d’Orbigny, Dict. Univ. Hist. Nat. 13: 94. 1849; Unger, Gen. Sp. Foss.: 216. 1850; Renault, Cours Bot. Foss. 3: 142. 1883; Kidston in Trans. Geol. Soc. Glasgow 9: 39. 1889; Potonie, Lehrb. Palaobot.: 70. 1899 & in Engler & Prantl, Nat. Pflanzenfam. Abt. 1, 4: 509. 1900). Scitaminites Sternb. was used only three more times in its history (Goppert, l.c. 1836; Brongniart, l.c. 1837; Presl in Sternberg, l.c. 2: 173. 1838) and disappeared completely from the botanical literature from 1845. Therefore, in order to legitimize the established use of Psaronius in current systematic botany, it is proposed to conserve this generic name against Scitaminites Sternb. As an addition to the Taxonomic Literature II database, the exact publication date of the book of Cotta (l.c.) was established via weekly bibliographical lists of all newly published books in German states, Bibliographie von Deutschland oder Wochentliches Verzeichnis aller in Deutschland herauskommenden neuen Bucher, Musikalien und Kunstsachen (Leipzig), no. 5, 10 Mar 1832, p. 35 (# 298), the range of dates reflecting the interval between the issuance of consecutive weekly numbers (3–10 Mar 1832).

Sedimentary Basin Analysis of Sachun Formation in Southwestern Iran: Implication for Sedimentary Environments and Tectonic Setting

The Sachun Formation (Paleocene- Lower Eocene), has been formed in Zagros basin, and has 1415 meters thickness in its type section. Sachun Formation sequence at the southern part of Kuh- E- Mianjangal, in Folded Zagros Zone in southwest of Iran, with a thickness of 580 meters was formed of two members. The Lower Member consists of about 280 meters thin to medium bedded of marl, marlstone and argillaceous, silty and sandy limestone with color of light gray to bluish gray, and associated with gypsum inter- layers, which are repeated continuously upward. In each of the alternations or cycles, the terrigenous grains size increase upward which is due to the depth decreasing in each cycle. The Upper Member consists of about 300 meters alternation of gypsum and marl, light gray to bluish gray associated with inter- layers of argillaceous and silty limestone. Microscopic studies of argillaceous limestone, in both members, have showed micrite and pelmicrite microfacies. No distinct fossils, either microscopic or macroscopic, are found in these members in the studied section. Sachun Formation facies have been deposited in a shallow depositional basin which has been controlled by a permanent sea level changes. Among the marine environments, peritdal environments show the most and the best correlation with the Sachun Formation facies. According to the sedimentary records, Sachun Formation has been deposited in a tectonically instable basin.

Sedimentology and Tectonic Setting of Sachun Formation in Folded Zagros Zone (SW Iran)

The Sachun Formation (Paleocene- Lower Eocene), has been formed in Zagros basin, and has 1415 meters thickness in its type section. Sachun Formation sequence at the southern part of Kuh- E- Mianjangal, in Folded Zagros Zone in southwest of Iran, with a thickness of 580 meters was formed of two members. The Lower Member consists of about 280 meters thin to medium bedded of marl, marlstone and argillaceous, silty and sandy limestone with color of light gray to bluish gray, and associated with gypsum inter- layers, which are repeated continuously upward. In each of the alternations or cycles, the terrigenous grains size increase upward which is due to the depth decreasing in each cycle. The Upper Member consists of about 300 meters alternation of gypsum and marl, light gray to bluish gray associated with inter- layers of argillaceous and silty limestone. Microscopic studies of argillaceous limestone, in both members, have showed micrite and pelmicrite microfacies. No distinct fossils, either microscopic or macroscopic, are found in these members in the studied section. Sachun Formation facies have been deposited in a shallow depositional basin which has been controlled by a permanent sea level changes. Among the marine environments, peritdal environments show the most and the best correlation with the Sachun Formation facies. According to the sedimentary records, Sachun Formation has been deposited in a tectonically instable basin.

Pennsylvanian (Late Carboniferous) calcareous microfossils from Cedro Peak (New Mexico, USA). Part 1: Algae and Microproblematica

At Cedro Peak (Manzanita Mountains, central New Mexico), the Pennsylvanian succession is divided into four formations: Sandia, Gray Mesa, Atrasado, and lower part of Bursum. The sampled limestones of the Gray Mesa and Atravasado formations yielded three age distinctive fossil assemblages: (a) latest Atokan/early Desmoinesian; (b) late early Desmoinesian, and (c) middle Virgilian. The calcareous algae, incertae sedis algae and cyanobacterial-foraminiferal consortia are described here. The following new taxa are named: Epimastoporaceae n. fam.; Anthracoporellopsis novamexicana n. sp.; Tubiphytidae n. fam.; and Latitubiphytes n. gen.

New Macroscopic Problematic Fossil from the Early Cambrian Yanjiahe Biota, Yichang, Hubei, China

Abstract:Yanjiahella gen. nov., a distinctive fossil taxon from the Early Cambrian Yanjiahe Biota in Yichang, Hubei Province, is characterized by: 1) an overall body plan composed of a stalk and a calyx (also arms in some species); 2) a stalk with closely spaced, transverse wrinkles and a medial, longitudinal ridge; and 3) a calyx preserved with three‐dimensional radiating striations, as well as a probable madreporite in some specimens. Three species that can be assigned to this genus, which are Y. ancarpa sp. nov., Y. monocarpa sp. nov., and Y. biscarpa sp. nov. Yanjiahella is comparable to certain echinoderm taxa in terms of morphology and some biological structures, which might indicate the early evolution and diversification of ancestral echinoderm lineages from the early Early Cambrian Yangtze Platform. The discovery of putative echinoderms in the Yanjiahe Biota provides significant clues about the origination and evolution of the deuterostome phylum Echinodermata.

New turtles (Chelonia) from the late Eocene through late Miocene of the Panama Canal Basin

Four distinct fossil turtle assemblages (Chelonia) are recognized from the Panama Canal Basin. The oldest, from the late Eocene–early Oligocene Gatuncillo Formation, is dominated by podocnemidid pleurodires. The early Miocene Culebra Formation includes both podocnemidids and trionychids. The early to middle Miocene Cucaracha Formation includes taxa classified in Geoemydidae (including Rhinoclemmys panamaensis n. sp.), Kinosternidae (represented by Staurotypus moschus n. sp.), large testudinids, trionychids, and podocnemidids, and finally, the late Miocene Gatun Formation records cheloniid sea turtles. These fossils include the oldest known representatives of Rhinoclemmys, the oldest record of kinosternids in Central America with a more extensive southern paleodistribution for Staurotypus and staurotypines in general, early occurrences of giant tortoises in the Neotropics, the oldest occurrence of soft-shell turtles in the tropics, the oldest late Eocene–early Oligocene Neotropical occurrences of podocnemidids. The Panamanian fossil turtles represent clades that are primarily endemic to North America, showing their very early arrival into the Neotropics prior to the complete emergence of the Isthmus of Panama, as well as their first contact with Caribbean-South American pleurodires by the early Miocene.

EVIDENCE FOR MULTIPLE SOURCES OF10Be IN THE EARLY SOLAR SYSTEM

Beryllium-10 is a short-lived radionuclide (t1/2 = 1.4 Myr) uniquely synthesized by spallation reactions and inferred to have been present when the solar system’s oldest solids (calcium–aluminum-rich inclusions, CAIs) formed. Yet, the astrophysical site of 10 Be nucleosynthesis is uncertain. We report Li–Be–B isotope measurements of CAIs from CV chondrites, including CAIs that formed with the canonical 26 Al/ 27 Al ratio of ∼5 × 10 −5 (canonical CAIs) and CAIs with Fractionation and Unidentified Nuclear isotope effects (FUN-CAIs) characterized by 26 Al/ 27 Al ratios much lower than the canonical value. Our measurements demonstrate the presence of four distinct fossil 10 Be/ 9 Be isochrons, lower in the FUN-CAIs than in the canonical CAIs, and variable within these classes. Given that FUN-CAI precursors escaped evaporation–recondensation prior to evaporative melting, we suggest that the 10 Be/ 9 Be ratio recorded by FUN-CAIs represents a baseline level present in presolar material inherited from the protosolar molecular cloud, generated via enhanced trapping of galactic cosmic rays. The higher and possibly variable apparent 10 Be/ 9 Be ratios of canonical CAIs reflect additional spallogenesis, either in the gaseous CAI-forming reservoir, or in the inclusions themselves: this indicates at least two nucleosynthetic sources of 10 Be in the early solar system. The most promising locale for 10 Be synthesis is close to the proto-Sun during its early mass-accreting stages, as these are thought to coincide with periods of intense particle irradiation occurring on timescales significantly shorter than the formation interval of canonical CAIs.

Microfaunal Assemblage of the Sui Main Limestone from Sui Gas Field, Pakistan

Sui Main Limestone (SML) is the best reservoir in the Middle Indus Basin of Pakistan. It is an important reservoir that has produced gas for the last fifty (50) years and continues to produce 600 MMCF per day. The characteristic microfossil assemblages within the SML have been studied from fifty two thin sections of the reservoir rock from four Sui wells for understanding the reservoir architecture and quality. There are two distinctive fossil assemblages within SML Formation. The major lower part (>300m) is a carbonate facies of massive fossiliferous limestone dominated by Nummulites along with Alveolina, Discocyclina and Miliolids. The upper part (20m) consists of argillaceous fossiliferous limestone interbedded with calcareous shale layers, making a transition to the overlying Ghazij shales. Assilina is the characteristic fossil with its associated assemblage

Problematic megafossils in Cambrian palaeosols of South Australia

Abstract: Red calcareous Middle Cambrian palaeosols from the upper Moodlatana Formation in the eastern Flinders Ranges of South Australia formed in well‐drained subhumid floodplains and include a variety of problematic fossils. The fossils are preserved like trace fossil endichnia but do not appear to be traces of burrows or other animal movement. They are here regarded as remains of sessile organisms, comparable with fungi or plants living in place, and are formally named as palaeobotanical form genera under provisions of the International Code of Botanical Nomenclature. Most common are slender (0.5–2 mm) branching filaments flanked by green‐grey reduction haloes within the red matrix of palaeosol surface horizons (Prasinema gracilegen. et sp. nov.). Other axial structures (Prasinema nodosumandP. adunatumgen. et spp. nov.) are larger and show distinctive surface irregularities (short protuberances and irregular striations, respectively). The size and form of these filaments are most like rhizines of soil‐crust lichens. Other evidence of life on land includes quilted spheroids (Erytholus globosusgen. et sp. nov.) and thallose impressions (Fargherasp. indet.), which may have been slime moulds and lichens, respectively. These distinctive fossils in Cambrian palaeosols represent communities comparable with modern biological soil crusts.

Glacial geomorphology and glacial lakes of central Transbaikalia, Siberia, Russia

Please click here to download the map associated with this article. A glacial geomorphological map is presented covering the poorly investigated mountainous region of central Transbaikalia, Russia. Interpretation of geomorphology is achieved using remotely sensed data (SRTM digital elevation model, Landsat 7 ETM+ satellite imagery and Google Maps). Glacially modified terrain is mapped together with moraines, glacial lineations and meltwater channels, in order to provide an estimate of the area affected by glaciation. The glacial landform record varies across the mapped region implying that the character of glaciation was not uniform in the area. Several moraine generations occur in the main valleys and at some places glaciers blocked the drainage routes, which resulted in the formation of glacial lakes. The largest, Glacial Lake Vitim, was dammed by a glacier lobe blocking the Vitim valley in the Kodar Range. A distinct fossil shoreline of Glacial Lake Vitim occurs along a substantial part of the former shore at a level of 840 m a.s.l. A col through which the lake drained to the River Nercha occurs at an elevation consistent with the shoreline level of 840 m a.s.l. The existence of another glacial lake in the Chara basin is inferred from mapped delta surfaces and a probable blockage of the Chara River by advancing valley glaciers. The rich and diverse geomorphology and the sedimentary record of glacial lakes represent a potential for more detailed studies of the glacial and climate history of this remote region.

Charles Darwin and human evolution

No field of biology has been more deeply influenced by Darwin’s notion of evolution than has the science of human origins. Yet while Charles Darwin himself was happy to speculate in the abstract upon the qualities of hypothetical human ancestors, he remained curiously reluctant to engage directly with its tangible fossil record. There appear to have been several reasons for this, including Darwin’s desire to avoid confrontation; the scandal-ridden nature of antiquarianism in the mid-nineteenth century; Darwin’s own abiding qualms about the reliability of the fossil record; and his close colleague Thomas Henry Huxley’s dismissal of the Neanderthal skeleton, the most distinctive hominid fossil known at the time, as merely representing a “barbaric” variety of Homo sapiens. There can be no doubt that human evolution and its implications had been very much on Darwin’s mind in the years leading up to the publication of On the origin of species; but in the end he seems to have made a conscious decision to stay clear of this social and intellectual minefield. Even his vast treatise on The descent of man is more plausibly read as an anti-polygenist, anti-slavery tract, and as an exegesis of sexual selection, than as a serious examination of the actual tangible evidence for the origins of humankind. Nonetheless, while staying safely in the realm of abstract speculation, in this great work Darwin managed to establish many of the themes that still dominate paleoanthropology today, including human descent from a single species of ape-like progenitor, the primacy of upright locomotion in human evolution, the birth of our family in the continent of Africa, and, for better or for worse, “the necessary acquirement of each mental power and capacity by gradation”, the founding mantra of today’s evolutionary psychology.