Evolution of Paleocene to Early Eocene larger benthic foraminifer assemblages of the Indus Basin,Pakistan

Afzal, J., Williams, M., Leng, M.J., Aldridge, R.J. & Stephenson, M.H. 2011: Evolution of Paleocene to Early Eocene larger benthic foraminifer assemblages of the Indus Basin, Pakistan. Lethaia, Vol. 44, pp. 299–320. The Paleocene–Early Eocene carbonate successions of the Indus Basin in Pakistan formed on the northwestern continental shelf margin of the Indian Plate in the eastern Tethys Ocean. Based on larger benthic foraminifera (LBF), eight Tethyan foraminiferal biozones (SBZ1–SBZ8) spanning the Paleocene to Early Eocene interval are identified. The base of the Eocene is identified by the first appearance of Alveolina sp. Other stratigraphically important LBFs that are characteristic of the earliest Eocene are Ranikothalia nuttalli, Discocyclina dispansa and Assilina dandotica. Stable isotope analysis through the Paleocene–Eocene (P–E) boundary interval identifies more positive δ¹³C values for the Late Paleocene (+3.4‰ to +3.0‰) and lower values (+2.7‰ to +1.6‰) for the earliest Eocene. However, there is insufficient sampling resolution to identify the maximum negative δ¹³C excursion of the Paleocene–Eocene Thermal Maximum. During Late Paleocene times LBF assemblages in the Indus Basin were taxonomically close to those of west Tethys, facilitating biostratigraphic correlation. However, this faunal continuity is lost at the P–E boundary and the earliest Eocene succession lacks typical west Tethys Nummulites, while Alveolina are rare; LBFs such as Miscellanea and Ranikothalia continue to dominate in the Indus Basin. The absence of Nummulites from the earliest Eocene of Pakistan and rarity of Alveolina, elsewhere used as the prime marker for the base of the Eocene, may imply biogeographical barriers between east and west Tethys, perhaps caused by the initial stages of India‐Asia collision. Later, at the level of the Eocene SBZ8 Biozone, faunal links were re‐established and many foraminifera with west Tethys affinities appeared in east Tethys, suggesting the barriers to migration ceased. □Biostratigraphy, Eocene, India‐Asia collision, larger benthic foraminifera, palaeoecology, Paleocene.     

New records of archaic ungulates from the Lower Eocene of Sanshui Basin,Guangdong, China

Phenacolophidae is a group of little known archaic ungulates from the Late Paleocene to Middle Eocene of Asia. Its phylogenetic relationships with other altungulates have remained uncertain, partly because most phenacolophids are represented by poorly preserved material. Here we report a new phenacolophid, Sanshuilophus zhaoi gen. et sp. nov., from the Lower Eocene Huayong Formation of the Sanshui Basin, Guangdong, China. Although still fragmentary, the new specimens show that the new taxon is characterised by relatively large body size (except for Zaisanolophus), sub-molariform premolars, relatively higher bilophodont molars that lack the mesostyle, and tooth enamel microstructure with true prisms and typical Hunter-Schreger bands (HSB). With the new specimens and a review of the published phenacolophid material, we are able to provide an alternative identification for the tooth loci for the type specimen of Phenacolophus and further present an emended diagnosis for Phenacolophidae. The tooth morphology and enamel microstructure provide new evidence to support the notion that phenacolophids differ from species of Embrithopoda in having low-crown teeth, considerably slanting lophids, distinct paralophids and lacking the arsinoitheriid radial enamel. Phenacolophidae should not be included in Tethytheria but probably represent a stem group for altungulates, if not for all archaic ungulates.     

Latest Permian palynomorphs from Jharia Coalfield,Damodar Basin,India and their potential for biostratigraphic correlation

The objective of the present work is to palynologically date the samples collected from Jharia Coalfield. The samples have been collected from an outcrop section exposed across the Damodar river near NH 32 enroute from Bokaro to Dhanbad (23° 43′06.93″N and 86° 12′06.90″E) near Jharia Coalfield of Damodar Basin. Palynological analysis of the samples has revealed that the palynomorph assemblage is characterized by high incidence of Densipollenites spp. in association with dominance of striate bisaccates chiefly Striatopodocarpites spp. and Faunipollenites spp. The other stratigraphically significant taxa recorded in the section are Guttulapollenites hannonicus, Klausipollenites schaubergeri, Alisporites spp. Falcisporites spp. and Lunatisporites spp. On the basis of the palynocomposition the section has been assigned a latest Permian age. Age determination for the section has been inferred by comparison with coeval assemblages from previous Gondwana studies from India and across Gondwana which were compared to the biostratigraphically dated palynological records from Australia (oldest APP6 Zone) as it is one of the few areas in Gondwana where the palynological records have been calibrated against adequately dated marine invertebrate zones. However, comparison with the westernmost portion of Gondwana was difficult due to its mid latitudinal position (c. 20°S) during the Lopingian (late Permian) which lead to an early transition from coal-bearing strata to red-bed and evaporitic deposits in some parts.     

Paleogene ostracodes from the Dawenkou Basin,East China and their biostratigraphic significance for the age of mineral resources

The Dawenkou Basin is a Cenozoic terrestrial fault basin in Shandong Province, East China, containing abundant mineral resources, especially gypsum. Recently a borehole was drilled in this basin unearthing the upper and middle members of the Dawenkou Formation. From the upper member, well-preserved ostracodes were discovered, which are entirely non-marine taxa including species of Eucypris, Caspiolla, Candona and Candoniella. Based on the new material, a new species Candona dawenkouensis n. sp. was erected. The ostracode assemblage biostratigraphically indicates an age of middle Eocene to Oligocene of the upper member of the Dawenkou Formation and the strata bearing mineral resources (mainly gypsum) of the middle member of the Dawenkou Formation is likely early Eocene.     

Larger benthic foraminiferal assemblages and their response to Middle Eocene Climate Optimum in the Kohat Basin (Pakistan,eastern Tethys)

The Middle Eocene Climatic Optimum (MECO) at ～40 Ma is a significant global warming event associated with pronounced changes in the hydrosphere, atmosphere, and biosphere. The Kohat Formation in the Kohat Basin (eastern Tethys, Pakistan) is studied for identifying the response of larger benthic foraminifera (LBF) to MECO. The LBF assemblages in the Kohat Formation, covering from the Shallow Benthic Zones (SBZ) 15 to 17, suggest middle Lutetian to early Bartonian in age. Microfacies analyses indicate a lagoonal (inner carbonate ramp facies belt) to open marine (middle carbonate ramp facies belt) paleodepositional environment of the Kohat Formation. A distinct positive δ¹³C shift marks the stratigraphic position of the MECO in this formation. At the Peak-MECO event that is marked by the onset of the positive carbon isotope excursion (CIE), no evident compositional variation in the LBF assemblages is observed. However, significant changes in the LBF assemblages with the local first and last occurrences of some LBF genera can be observed in the Post-MECO and CIE recovery phase. These changes are verified by the sudden disappearance of Alveolina and orthophragminids and initial dominance of larger shell-size Nummulites fabianii, Heterostegina, and Linderina species accompanied by an increase in the species diversity. Here, we argue that the change in the observed LBF assemblages in the uppermost part of the Kohat Formation might be related to a larger foraminiferal turnover occurring during the Post-MECO event and corresponds to the CIE recovery phase.     

Early Eocene Primates from Gujarat, India

The oldest euprimates known from India come from the Early Eocene Cambay Formation at Vastan Mine in Gujarat. An Ypresian (early Cuisian) age of ∼53 Ma (based on foraminifera) indicates that these primates were roughly contemporary with, or perhaps predated, the India-Asia collision. Here we present new euprimate fossils from Vastan Mine, including teeth, jaws, and referred postcrania of the adapoids Marcgodinotius indicus and Asiadapis cambayensis. They are placed in the new subfamily Asiadapinae (family Notharctidae), which is most similar to primitive European Cercamoniinae such as Donrussellia and Protoadapis. Asiadapines were small primates in the size range of extant smaller bushbabies. Despite their generally very plesiomorphic morphology, asiadapines also share a few derived dental traits with sivaladapids, suggesting a possible relationship to these endemic Asian adapoids. In addition to the adapoids, a new species of the omomyid Vastanomys is described. Euprimate postcrania described include humeri, radii, femora, calcanei, and tali, most of which show typical notharctid features and are probably attributable to asiadapines. Anatomical features of the limb elements indicate that they represent active arboreal quadrupedal primates. At least one calcaneus is proximally shorter and distally longer than the others, resembling eosimiids in this regard, a relationship that, if confirmed, would also suggest an Asian or southeast Asian faunal connection. Isolated teeth from Vastan Mine recently attributed to a new eosimiid, Anthrasimias gujaratensis, appear to provide that confirmation. However, their attribution to Eosimiidae is equivocal. They are similar to teeth here tentatively referred to Marcgodinotius, hence A. gujaratensis may be a junior synonym of M. indicus. Corroboration of eosimiids at Vastan requires more compelling evidence. Although definitive conclusions are premature, available evidence suggests that the Vastan adapoids, at least, were derived from western European stock that reached India near the Paleocene-Eocene boundary.     

我国部分地区E1^3—E2^1孢粉属种演变的古气候意义

通过对我国部分地区古新世晚期一始新世早期孢粉植物群演化发展规律的分析研究,结合国内外地层学研究的新进展,提出我国古新世晚期气候以暖湿为特征,且暖期的结束与始新世/古新世界限相吻合或接近,因此可以本次暖期的结束作为古新世的顶界。     

Calcareous nannofossil biostratigraphic framework for middle Eocene sediments from ODP Hole 1260A, Demerara Rise

Ocean Drilling Program (ODP) Site 1260 recovered a near-continuous and expanded (187-m thick) middle Eocene carbonate sequence at mid-bathyal depths on Demerara Rise off Suriname, South America. A calcareous nannofossil biostratigraphic framework has been established for the sequence to aid multi-proxy cyclostratigraphic analyses. The diversity of calcareous nannofossils is reasonably high and preservation moderate throughout most of the section, and the proximity to the continent is indicated by the occurrence of braarudosphaerids in the lower three quarters of the section. The species richness of sphenoliths is particularly high, and our data confirm the occurrence of new sphenoliths during the middle Eocene as shown recently by Bown and Dunkley Jones (2006). In particular we corroborate the occurrences of Sphenolithus strigosus and S. runus that these authors found in their Zone NP16 Tanzania sediments, however we extend the ranges of these taxa down into Zone NP15 (CP13). Moreover we document the occurrence of Bramletteius serraculoides in Zone NP15 (CP13b) and the occurrence of Sphenolithus predistentus in NP16 (CP14a), extending their known ranges down column.     

Anthracobunids from the Middle Eocene of India and Pakistan Are Stem Perissodactyls

Anthracobunidae is an Eocene family of large mammals from south Asia that is commonly considered to be part of the radiation that gave rise to elephants (proboscideans) and sea cows (sirenians). We describe a new collection of anthracobunid fossils from Middle Eocene rocks of Indo-Pakistan that more than doubles the number of known anthracobunid fossils and challenges their putative relationships, instead implying that they are stem perissodactyls. Cranial, dental, and postcranial elements allow a revision of species and the recognition of a new anthracobunid genus. Analyses of stable isotopes and long bone geometry together suggest that most anthracobunids fed on land, but spent a considerable amount of time near water. This new evidence expands our understanding of stem perissodactyl diversity and sheds new light on perissodactyl origins.     

Ectomycorrhizas from a Lower Eocene angiosperm forest

The development of mycorrhizal associations is considered a key innovation that enabled vascular plants to extensively colonize terrestrial habitats. Here, we present the first known fossil ectomycorrhizas from an angiosperm forest. Our fossils are preserved in a 52 million-yr-old piece of amber from the Tadkeshwar Lignite Mine of Gujarat State, western India. The amber was produced by representatives of Dipterocarpaceae in an early tropical broadleaf forest. The ectomycorrhizas were investigated using light microscopy and field emission scanning electron microscopy. Dissolving the amber surrounding one of the fossils allowed ultrastructural analyses and Raman spectroscopy. Approx. 20 unramified, cruciform and monopodial-pinnate ectomycorrhizas are fossilized adjacent to rootlets, and different developmental stages of the fossil mycorrhizas are delicately preserved in the ancient resin. Compounds of melanins were detectable in the dark hyphae. The mycobiont, Eomelanomyces cenococcoides gen. et spec. nov., is considered to be an ascomycete; the host is most likely a dipterocarp representative. An early ectomycorrhizal association may have conferred an evolutionary advantage on dipterocarps. Our find indicates that ectomycorrhizas occurred contemporaneously within both gymnosperms (Pinaceae) and angiosperms (Dipterocarpaceae) by the Lower Eocene.     

Omomyid primates (Tarsiiformes) from the Early Middle Eocene at South Pass,Greater Green River Basin,Wyoming

Recent fieldwork in the Gardnerbuttean (earliest Bridgerian) sediments along the northeastern edge of the Green River Basin at South Pass, Wyoming, has yielded a large and diverse sample of omomyid (tarsiiform) primates. This assemblage includes two species each of Artimonius gen. nov., Washakius, and Omomys, one species of Anaptomorphus, Trogolemur and Uintanius, and a new, primitive species of the rare omomyine genus,Utahia. Utahia is known elsewhere only from its type locality in the Uinta Basin and its phylogenetic position is poorly understood. Utahia carina sp. nov. allows for re-evaluation of the affinities of this genus relative to other omomyines. In most characters, such as a lesser degree of molar trigonid compression, more widely open talonid notches, and a lack of molar talonid crenulation, the new species is more primitive than U. kayi. The dental anatomy of U. carina also indicates that Utahia is morphologically intermediate between washakiins and omomyins, although the balance of anatomical features places Utahia as the sister taxon to a broadly defined "Ourayini" clade. Morphological similarity between U. carina, Loveina zephyri, and primitive Washakius suggests that while the omomyin and washakiin clades may have diverged by the middle Wasatchian, substantial morphological distinctions are first evidenced only in the early Bridgerian. This may be due either to a lack of appropriate faunal samples from older sediments, or, more likely, because ecological circumstances in the early Bridgerian favored omomyine diversification and subsequent replacement of previously occurring taxa. This hypothesis is further supported by the stratigraphic co-occurrence of U. carina, W. izetti, and a primitive variant of W. insignis at South Pass, a marginal area. Basin margins have been hypothesized to provide heterogeneous habitats conducive to the production of evolutionary innovation. Basin margin samples have also been cited as evidence that anaptomorphines were relegated to upland refugia as omomyine taxa began to appear in the later part of the early Eocene. Another possible explanation for the unusual co-occurrence of species at South Pass relates to fluctuating lake levels in the Green River Basin, which intermittently would have made lowland environments inhospitable for arboreal fauna. This would have created a situation whereby species which would normally be allopatric become sympatric at South Pass.     

Length–weight relationships of Wallago attu and Sperata sarwari from the Indus River, southern Punjab, Pakistan

The present study describes the length–weight parameters of Wallago attu and Sperata sarwari from the Indus River, southern Punjab, Pakistan with W  = 0.001698  L ^3.27 for W. attu and W  = 0.001698  L ^3.28 for S. sarwari . The values of the slope b are significantly higher than b  = 3.0, which shows that the weight grows more rapidly as compared to the cube of the length. Thus it was concluded that body proportions changed as fish grew in size.     

Mustelids from Sackdilling Cave (Bavaria,Germany) and their biostratigraphic significance

Sackdilling Cave is a karst fissure filled with a fossiliferous breccia including abundant fossil remains, mostly snails and small mammals. The taxonomic status of mustelid remains from this cave was previously regarded as controversial and, consequently, different authors listed different species from the locality. A detailed revision of the material shows the presence of five mustelid species: Meles sp., Martes vetus, Mustela strandi, Mustela palerminea, and Mustela praenivalis. Among them, especially noteworthy is the presence of the type specimen of Martes vetus. The Sackdilling holotype resembles Martes foina and differs from that of Martes martes in a short and broad viscerocranium; wide and less extended forward incisor row; compressed, short and wide temporal region; large, strongly inflated and convex tympanic bullae; and narrow P3 with weak lingual bulge. Some dental characters are specific for Martes vetus and show some intermediate values between Martes foina than Martes martes. Among them are the P4 protocone length and the M1 trigon length. The revised material from Sackdilling Cave of Mustela palerminea and Mustela praenivalis was compared with that from other Early and early Middle Pleistocene sites of Europe and showed the presence of intermediate characters. Subsequently, based on the entire mustelid assemblage and other faunal elements (mainly rodents), the age of this fauna was estimated as ca. 0.9–0.7 Ma.     

Attockicetus praecursor, A New Remingtonocetid Cetacean from Marine Eocene Sediments of Pakistan

A new early-to-middle Eocene cetacean from the Kala Chitta Hills of northern Pakistan is described: Attockicetus praecursor new genus and species. It is based on fragmentary cranial material, including a rostral fragment, P3–M3, endocast, and ectotympanic. Attockicetus is the first remingtonocetid from northern Pakistan, and the oldest member of its family. Attockicetus praecursor is smaller than the species of the other remingtonocetid genera, Remingtonocetus, Andrewsiphius, and Dalanistes. It is also more primitive in the retention of large protocones on the upper molars and the anterior position of the orbit. Known material for Attockicetus is fragmentary, but the taxon is important because it extends the geographic and temporal range of remingtonocetids, is one of the few remingtonocetids in which toothcrowns are preserved, and because it is probably the most plesiomorphic remingtonocetid.     

Biogeography of Eocene bryozoans from the St Vincent Basin, South Australia

The first extensive and stratigraphically detailed taxonomic study of the Middle to Late Eocene Bryozoa of the St Vincent Basin has identified more than 200 species of Cheilostomata and 50 species of Cyclostomata. There are three biogeographic groups: basin endemic, Australian and global. Two-thirds (116) of the cheilostome species and seven genera are currently considered endemic to this basin. Most species are endemic to Australia and similar to those found in the Oligo-Miocene of Victoria. The Cellariidae are a common component of most Australian Cainozoic deposits, but the species are highly dissimilar, with 13 of the 17 species here being new. The global component indicates that biogeographic links with regions outside Australia still existed in the Eocene. The cyclostome genus Reticrescis is only known from the Australian and Antarctic Eocene. Ten genera have their first occurrence in the Eocene St Vincent Basin. The Phidoloporidae and Smittinidae represent the most diverse and ubiquitous groups at a geological time close to their time of origination. Contemporaneous sediments in Antarctica, eastern Europe and North America also have a diverse fauna of this family, pointing to a strong Tethyan link. Rhamphosmittina lateralis (MacGillivray) is still extant in New Zealand, having an exceptionally long time range of 40 million years. Overall, the fauna has a distinct Late Cretaceous character. A new genus of Onychocellidae appears similar to genera that were common in Cretaceous Tethyan faunas but rare during the Cainozoic. This similarity ends in the Oligocene, after which the Australian bryozoan became endemic     

Diversity starts early: notharctid primates from the Sandcouleean (Early Eocene) of the Powder River Basin,Wyoming, USA

Abstract

Abundant specimens, mostly isolated teeth, of the Primate family Notharctidae occur in the Early Eocene rocks of the Powder River Basin of northeastern Wyoming, USA. Very early in the North American history of the family, the notharctid species diversified and this diversity may have been widespread, and not restricted to more southerly areas in the Rocky Mountains. The diversity is shown by detailed analysis of the molar dentition. Two new genera are established: Megaceralemur with Megaceralemur trigonodus as its type and Megaceralemur matthewi sp. nov. as a Sandcouleean species and Pinolophus, with Pinolophus meikei sp. nov. as its type, for a form with an entoconid notch on lower molar 1. Megaceralemur has a prominent nannopithex-fold which dominates the posterior cingulum of upper molars 1–2 and a cristid obliqua on lower molar 1 which attaches to the metaconid, not the metalophid as it does in Cantius and other genera. A small species, Cantius lohseorum sp. nov., is named for a derived lineage the size of Cantius torresi.

urn:lsid:zoobank.org:pub:066DC515-A2DD-40AF-AD8A-3834E2AFD0FB     

Eocene siliceous sponges from the Ebro Basin (Catalonia, Spain)

The Eocene (Bartonian) marls of the La Guixa Member and Gurb Member, Vic Marls Formation (Ebro Basin, Catalonia, Spain), contain a very rich and diversified siliceous sponge fauna. The fauna is dominated by hexactinellids; lithistids and other demosponges are rare. It consists of 16 species representing 16 genera. Eleven new species and two new genera are proposed for these sponges: Reguantella cavernosa nov. gen. nov. sp., Regadrella concinna nov. sp. (both Hexactinellida, Lyssacinosa), Eurete clava nov. sp., Pleuroguettardia iberica nov. sp., Aphrocallistes almeriae nov. sp., Hexactinella informis nov. sp. (all Hexactinellida, Hexactinosa), Brachiolites munterensis nov. sp., Centrosia viquensis nov. sp., Callicylix eocenicus nov. sp., Rhizocheton robustus nov. sp. (all Hexactinellida, Lychniscosa), Propetrosia pristina nov. gen. nov. sp. (Demospongia, Haplosclerida). Some genera of sponges in this fauna are still extant, but, in general, the predominant ones are very close in morphology, and, without doubt, closely related to the Late Cretaceous sponges. This fauna also differs considerably, in terms of composition, from most other described faunas of Tertiary sponges from the Mediterranean region, which are dominated by lithistid sponges. Lithistid sponges are rare in this investigated assemblage, which seems most similar to an as yet undescribed Eocene fauna from Italy. There is ecological differentiation in the proportions of particular sponges in various outcrops and/or stratigraphical levels that is clearly associated with water-depth-related controlling factor(s): Munter, Tona and Sta. Cecilia represent the deepest facies, Gurb is intermediate, and St. Roc and Vespella are the most shallow. The exact bathymetric position of the sponge fauna is difficult to estimate, but it seems that 100 m (but probably 200 m and more in the case of the deepest parts) of water depth may be inferred for this facies.     

Length‐weight relationships of Notopterus notopterus and introduced Oreochromis niloticus from the Indus River,southern Punjab,Pakistan

This study describes the length–weight relationships (LWRs) for Oreochromis niloticus and Notopterus notopterus, collected in 2006 and 2009 respectively from the Indus River, southern Punjab, Pakistan, with W = 0.0393 L^2.72 for O. niloticus and W = 0.0121 L^2.87 for N. notopterus. Negative allometric growth is indicated for both species.     

Early Paleogene decapod crustaceans from the Sulaiman and Kirthar Ranges,Pakistan

A set of Paleocene and Eocene decapod crustaceans is described from the Sulaiman and Kirthar Ranges of Pakistan. The fossil crabs Proxicarpilius planifrons Collins and Morris, 1978 and Pakicarcinus orientalis (Collins and Morris, 1978), already known in the Eocene of northern Pakistan, are reported for the first time in the Paleocene of southern Pakistan, enlarging the stratigraphic and the palaeobiogeographical ranges of these species. The callianassid genus Calliax de Saint Laurent, 1973 is reported for the first time in the Paleocene of southern Pakistan; this is the oldest record for the genus.     

Two Eocene fossil fruits from the Changchang Basin of Hainan Island,China

Two types of fossil fruit, one belonging to Palaeocarya sp. (Juglandaceae) and the other to Acer cf. A. miofranchetii Hu et Chaney (Aceraceae), are found in the Eocene coal-bearing series from the Changchang Basin of Hainan Island, China. This is the first fossil record of Palaeocarya and Acer in a tropical area of China. These fossils provide evidence for an investigation of the phytogeographic history of these two genera. Since their extant relative genera are distributed mostly in northern temperate or tropical–subtropical mountainous regions, I propose that the Changchang Basin of Hainan Island was close to a mountainous region in the Eocene; the plants bearing these fruits were growing at a mid-high altitude with a relatively cool climate, and the fruits were not preserved in situ but transported to the fossil site. The characters of other associated fossil plants and palynological data also support this hypothesis.