Duboiss Antelope

Dubois's antelope (Duboisia santeng) is an extinct antelope known from fossil deposits in Java and Malaysia (Louys et al. 2007). At various times this species has been referred to the genera Bos, Anoa and Capra (see Brongersma (1936) for a discussion on the history of this species), and as such is likely to have shared certain similarities in ecology with these genera. In particular, as a close relative of the extant antelopes, it is likely to have subsisted as a grazer, although this inference...

Causes of mass extinction at the KPg boundary A case study

Elewa and Ahmed M. Dakrory 11.2 Material and 11.3 Quantitative 11.3.1 Cluster 11.3.2 Principal coordinate 11.4 Qualitative 11.5 Discussion and 12 Patterns and causes of mass extinction at the K Pg boundary Planktonic foraminifera from the North African Plate 149 Ashraf M. T. Elewa and Ahmed M. Dakrory 12.2.1 Sudr 12.2.2 Dakhla 12.3 Material and 12.4 Results and 13 Quaternary extinctions in Southeast 13.2 The Quaternary megafauna 13.2.1 What are 13.2.2 The...

JiiiiiiL

Woods 3 'intermediate species' that frequent both habitats and 4 'pasture specialists' that includes species almost exclusively found in this habitat. It was found that among the categories of specialization the most affected by the restriction of the habitat are 'pasture specialists', which declined and 'forest specialists' that increased. The other categories remained more or less unaffected although exhibited some variation. Within each category the member species were also variously...

Abu Qada Formation

In general, more calm late infralittoral to late circalittoral environments than those of Raha Formation, where individuals more developed. Oyster accumulations suggest bars on shoal environment while bioturbation and flat bedding reflects subtidal facies. The faunal groups attain thus gigantic forms. Consistent occurrence of vascoceratid ammonites, tylostomatiid gastropodas and regular echinoids indicates open marine conditions with open circalattoral (a worldwide transgressive phase spanning...

Acknowledgements

The authors are much indebted to Prof. Dr. Hanspeter Luterbacher of the Museum of Paleontology, Barcelona University, Spain for his continuous help as well as reading the first draft of this paper. We would also thank Prof. Dr. Koebrel of the Institute of Geochemistry, University of Vienna, Austria, for doing the rare earth elements analysis in his lab. A special word of thanks is due to Prof. Dr. Satir of the Institute and Museum of Paleontology, Tuebingen University, Germany, for isotope...

Ammonites

No ammonites defined before the late Cenomanian except the Stoliczkaia sp., which represented by small fragments occurred at the lower part of Raha Formation, This suggests a very shallow marine deposition for early-middle Cenomanian. Shell fragments of ammonites collected from the study area, occasionally at late Albian and at the Coniacian-Santonian, are related to agitated wave conditions and characterize infralittoral environment at episode of fast subsidence. The consistent occurrence of...

Asian Gazelle

Although not identified to the species level, the Asian gazelle (genus Gazella sp. indet.) is recorded from Southern China and Burma during the Early Pleistocene (Louys et al. 2007). Although Corbet and Hill (1992) do not record the occurrence of the Asian gazelle in China, the goitered gazelle (Gazella subgutturosa) is recorded in the faunal list of Bogdhad Mountain Biosphere Reserve (Information Centre for the Environment 2007), a reserve situated in the far northwest of China (44 00'N 83...

Biostratigraphy

Biostratigraphic subdivision of the interval considered here was based mainly on, Ammonite, Bivalvia and, to a lesser extent Gastropoda and Echinoidea. Due to the differential thickness of Upper Cretaceous strata in the studied sections the results are presented as a composite biochronological scheme that represent a comprehensive interpretation of the macrofaunal data in a regional sense. Several ammonite-bearing horizons occur within the uppermost Albian-Santonian succession of the study...

Carbon isotope stratigraphy

The Ireviken, Mulde and Lau events were all associated with changes in the global carbon cycle that were of equal or even greater magnitude than those related to the end-Ordovician and end-Devonian mass extinctions. Hence, the perturbations in the ocean-atmosphere system during the intervening Silurian events are fully comparable to those during the major five mass extinction events. This is an important observation since it clearly indicates that the series of comparable perturbations in the...

Causes of current insect extinction

Many authors have emphasized that our knowledge on the composition of insect faunas is fragmentary and incomplete. As a result the documentation of insect extinctions is very difficult unless we are willing to spend more time and money in order to study and document them (Dunn 2005). Samways (2006) in supporting the use of strategic indicators of species at risk says that the South African odonate insects Pseudagrion citricola and Metacnemis angusta changed conservation status when the methods...

Coextinctions

Co-extinctions are more widespread than it was previously thought. In all paragraphs of this chapter it is explicitly stated that any action on the species of a local community affects many species. The number of affected species is strongly dependent on the connectivity of the community and the degree of its packing (Koh et al. 2004) while in some cases extinction is inevitable as is the case of the specialized parasites of an extinct host. The term co-extinction was initially coined to...

Correlation of diversity and preservation

Before entering into the details of faunal abundance and diversities, a few significant characteristics of Late Cretaceous macroinvertebrates need to mention. Macroinvertebrates are highly susceptible to selective dissolution, both before and after burial in the sediment but especially during late digenesis and deep burial. (The extent of preservation of macroinvertebrates assemblages therefore is strongly dependent on the digenetic microenvironment. In general terms, well-preserved samples are...

Dakhla Formation

The term Dakhla Formation was introduced by Said (1961). Its type locality is located at the north of Mut, the main village of the Dakhla Oasis in the Western Desert of Egypt. Its type section was described by Said (1961) as composed of thin bone beds, phosphatic bands, and allochthonous limestones at the base, grading upward into massive shales. The total thickness of this section is 230 m. In the study area, the Dakhla Formation is of late Maastrichtian to early Paleocene ages, and consists...

Early discoveries

The perhaps most drastic extinction of the entire Silurian, the near total extinction of the graptolites in the middle Silurian, was known in some detail already at the turn of the last century when British paleontologists identified substantial biodiversity changes among these pelagic colonies. It was not until the end of the 20th century, however, that the scale of this extinction event was fully appreciated among researchers. Similarly, the worldwide crisis among the conodonts in the Early...

Echinoidea

Extensive occurrence for this group started with lower boundary of Raha Formation. Hemiaster dominated from the bigining but the oldest one is somewhat badly preserved and well withered and hence they obscure and scratched in almost cases, whoever in progress many individuals preserved well. Specimen test affected by the type of sediments buried in, the yellowish ones found in sandy substrata, the gray shale give the gray tone to the imbedded shells. Dark shells collected from organic rich beds...

Ecological preferences

Paleoecology of the Late Cretaceous macrofauna is formally established. The macrofaunal categories employed to infer paleoenvironmental conditions. The methods of establishment of the optimum conditions for the paleoecology is more precisely approaches by analyzed the association grouply. Substantial efforts of the past decade have resulted in a large database of macroinvertebrate ecology and several attempts of interpretations (i.e. Hallam 1967 Nereaudeau 1995 Huber, 1995 Neraudeau et al. 1997...

Fast or slow The changing face of the Ordovician glaciation

During the next twenty years, there was a great deal of research concerning the timing of the glacial onset as well as how long the glacial period lasted. Originally, the glaciation was thought to have started in the Caradoc and continued into the Silurian. However, this estimated glacial duration met with a fair degree of contention. The Caradoc had originally been established as the onset of glaciation because of faunal assemblages found in glacial sequences in the Sahara (Hambrey 1985)....

Foreword

Department of Geological Sciences, Indiana University, Bloomington, IN 47405, USA, pdpolly indiana.edu Only 200 years ago, extinction was a radical new idea. Fossils were known, but their identity as the remains of species that no longer lived on the face of the Earth was not yet firmly established in the scientific world. Arguments that these organic-looking objects from the rocks were merely bizarre mineralizations or that they were the remains of species still living in unexplored regions of...

Future work

The Ordovician mass extinction event is a unique time period that offers a great deal of research opportunities in all fields of geology. The question of the forcing mechanism for the end Ordovician glacial period is still a matter of debate, but Melott et al. (2004) have provided an interesting new way of viewing the extinction event. Future research could focus on testing patterns of extinction in greater detail within the context of a GRB scenario to see if these patterns are indeed...

Sealevel change and sedimentary facies

The majority of the Phanerozoic extinction events are associated with some degree of sea-level change (Hallam and Wignall 1999), although the extinctions not necessarily are caused by the sea-level change. It is strikingly that the Silurian events are in the majority of investigated places associated with pronounced facies shifts, deviating, or even peculiar, sedimentary facies (Kaljo et al. 1995). Some of these facies are difficult to explain by sea-level change and may be the result of more...

Giant

An understanding of the ecology of the Asian giant ape (Gigantopithecus) has advanced considerably since it was interpreted as a hunter of large ungulates who apparently dragged his prey back to the cave (Livingstone 1964 1284). However, direct interpretations of this fascinating ape's environment have been limited, due largely to the paucity of the fossil material available for study. Ciochon et al.'s (1990) study remains one of a few which deal with this subject matter. Opal phytoliths...

Giant Hyena

The giant hyena (Pachycrocuta brevirostris, formally Hyaena brevirostris) is the largest of the true hyenas (Turner and Anton 1996). The postcranial skeleton of the giant hyena indicates that it was not built for running and although it was only slightly taller at the shoulder than the spotted hyena (Crocuta crocuta), it was longer, and its skull was larger and more powerful (Turner and Anton 1996). It is hypothesised as having been an occasional hunter and aggressive scavenger, preying on...

Groups affected

The Ireviken Event is characterized by a survival ratio among conodonts of merely twelve out of about sixty globally known species (Aldridge et al. 1993 Jeppsson 1997a). Conodont diversity never recovered during the remaining Silurian and stayed at about twenty taxa. Also the graptolites went through a profound extinction reducing the global fauna by 80 (the Cyrtograptus murchisoni Event of Melchin et al. 1998 Noble et al. 2006). Chitinozoans display a significant turnover in assemblages and...

Insect extinctions induced by changes in succession status

There are many sites where the probability of extinction is very high. In these places species are lost at a constant rate and local communities very soon become poor (Colinvaux 1973). The widespread farming of the earth surface causes many species extinctions not only through the species area effect. According to many authors plough is a contributing factor more important even from thermonuclear weapons. It keeps communities at an early stage of the ecological succession. At this stage the...

Introduction

Humans are responsible for the worst spate of extinctions since the dinosaurs and must make unprecedented extra efforts to reach a goal of slowing losses by 2010 This sentence was mentioned in the UN report dated 3 21 2006. However, are the causes same as those resulted in the five major mass extinctions of the fossil record The answer is, of course, no. Then, what are the causes led to mass extinctions in the fossil record We herein try to answer this question through the study of the K Pg...

Iil

Dendrogram resulting from cluster analysis of forty samples across the K Pg boundary of the four studied sections The established results led to the following conclusions 1. The extraterrestrial bolide impact played an important role in the foraminiferal extinction in section Hiala (in the south) than the other three sections. 2. Sections El Seig, Sahaba and Yelleq faced gradual foraminiferal extinction earlier below the boundary due to the change in environmental and climatic...

Late Triassic extinction events

The Late Triassic was a time of elevated extinction rates and low origination rates in many biotic groups (e.g. Banmbach et al. 2004 Kiessling et al. 2007). Thus, as noted by many workers, the Late Triassic was a time interval marked by a series of discrete extinction events (Fig. 8). One of the most dramatic was the Carnian crisis at about the early-middle Carnian boundary, which included major extinctions of crinoids (especially the Encrinidae), echinoids, some bivalves (scallops), bryozoans,...

Malayan Tapir

The Malayan tapir (Tapirus indicus) is the only extant species of tapir found outside of South America. It favours well-watered environments with dense forest vegetation (Novarino et al. 2005 Lekagul and McNeely 1988). Although Lekagul and McNeely (1988) suggest they inhabit only primary forests, recent research by Novarino et al. (2005) suggest they actually prefer dense secondary forests. They are generally solitary and most of their activity is tied to rivers and wetlands they are excellent...

Material and methods

For the purpose of the present study, we selected thirty samples across the K Pg boundary of three surface sections from Sinai in Egypt. One section is located in Northern Sinai (section Sahaba) and two sections are located in west Central Sinai (sections Hiala and El Seig) (Fig. 1). These three sections have been selected for geochemical analyses because of their suitability for such analyses through well-preserved faunal assemblages as well as containing the most complete record of the K Pg...

Orangutan

The orang-utan is the only extant species of ape (apart from humans) endemic to Southeast Asia. It has a solitary and arboreal lifestyle, although it has been known to descend from the trees. It subsists largely on a diet of fruits, although fungus, leaves, bark honey and insects are sometimes included (Galdikas 1988). Currently restricted to the rainforests of Sumatra and Borneo, like the panda and stegodons, it was much more widely distributed during the Pleistocene (Louys et al. 2007).

Pigs

Two species of pig are listed by Louys et al. (2007) as becoming extinct in more than one country, the bearded pig (Sus barbatus) and Lydekker's pig (Sus lydekkeri). Pigs subsist in a wide variety of habitats, but prefer those where there is some vegetative cover is available (Nowak 1999). Lekagul and McNeely (1988) noted that they are more common in wet forests, and during the dry season are usually found in riparian environments. They are omnivorous, eating anything from carrion to green...

References

Arbey, Tamain (1971) Existence d'une glaciation siluro-ordovicienne en Sierra Morena (Espagne) Acad Sci Comptes 272 1721-1723 Berner RA (1990) Atmopsheric carbon dioxide levels over Phanerozoic time. Science 249 1382-1386 Berner RA (1992) Palaeo-CO2 and climate, Nature 358 114 Berry WBN, Boucot AJ (1973) Glacio-Eustatic Control of Late Ordovician-Early Silurian Platform Sedimentation and Faunal Changes. Geological Society of America Bulletin 84 (1) 275-284 Beuf S, Biju-Duval B, DeCharpal O,...

Repopulation

The populations of most Cenomanian survivors dramatically decline in the early Turonian and never recover. Some Cenomanian species, however, thrive after the mass extinction of tropical and subtropical species and the decline of the ecological generalist survivors. Because of the absence of ecological competition as a result of the mass extinction and decline of survivor species, and prior to the establishment of the newly evolving Turonian assemblages the faunal assemblages during the early...

Structure of the Silurian global events

This section aims to give a brief overview of the general structure of the Silurian global events and their similarities and differences with some of the major five mass extinction events with regard to biodiversity, stable isotopes and sea-level change. The temporal development for each event is shown in Figures 6, 8, 10. It has commonly been assumed that the Silurian global events had little effect on vagrant and sessile benthic faunas. This is not true for the low latitudes were diverse...

Results and discussion

Most palaeontologists favor a multiple-cause explanation for the end-Cretaceous extinctions, though nonpaleontological geologists continue to favor the bolide impact model (Macleod in press). From the works of Macleod and other geologists, it is clear that the patterns and causes of the K Pg mass extinction are still debated. In the present paper we could successfully investigate the patterns of the K Pg planktonic foraminiferal mass extinction in North and west Central Sinai, which belongs to...

Ringer

Elewa Minia University Fac. Science Dept. Geology Minia 61519 Egypt ISBN 978-3-540-75915-7 e-ISBN 978-3-540-75916-4 Library of Congress Control Number 2007938882 2008 Springer-Verlag Berlin Heidelberg This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilm or in any other way, and storage in data...

Species invasions introductions

Many invasions have resulted in alteration of local faunas by eliminating some species and reshuffling the remaining ones. The same holds for introductions, which differ from invasions only in the agent of the transfer. Whereas in invasions the agent is ultimately the biological species itself armed with its adaptations, in introductions the agent is the man and always the introduced organism bears an economic benefit. This benefit ranges from simple ornamental or agricultural plants to...

Species extinctions

One hundred and eighty species with high individual density examined. Most species disappear at the C T boundary, A total of 6.6 of Cenomanian species range well into the early Turonian and are considered as survivors as discussed below. Thus, we consider 76.4 of species as extinct at or near the C T boundary (Vascocears cauvini Pseudoaspidoceras flexosum Zone). The combined relative abundance of all ammonites genera average less than 50 of the total Turonian assemblage (Tables 3, 4). The great...

Stratigraphic position

The Ireviken Event starts close below the Llandovery-Wenlock epoch boundary. In shelly sequences this corresponds to the zonal boundary between the Pterospathodus amorphognathoides and the Lower Pseudooneotodus bicornis conodont zones (Fig. 6). The end of the event in shelly sequences is put at the top of the Lower Kockelella ranuliformis conodont Zone (Jeppsson 1997b). In terms of graptolite biostratigraphy this corresponds to the upper part of the Cyrtograptus lapworthi graptolite Zone...

Sudr Chalk

Ghorab (1961) introduced the term Sudr Chalk for the snow-white chalk and argillaceous limestone sequence exposed in Wadi Sudr, west Central Sinai. He further subdivided it into the lower Markha Member and the upper Abu Zenima Member and assigned a Campanian age to the Markha Member and a Maastrichtian age to the Abu Zenima Member. In our study area, the Sudr Chalk is distributed in the lowlands between the prominent structural highs. It conformably overlies the Matulla Formation and underlies...

Survivors

Only four groups with species-level survivors include Ammonites (Occasionally Vascoceratriides) epifaunal Bivalvia (Neithea, Inoceramus, Plicatula), and globular Gastropoda (Tylostoma) irregular Echinoidea (Hemiaster ' if we consider Hemiaster herberti as a survivor'), percent survivors among these groups is 42.2 , 33.3 , 25 and 20 respectively (Table 5). Obviously, the C T event had a substantial impact on the fauna, although the low number of new species derived from surviving lineages,...

The Darwin Lyell extinction model

According to this model the past extinctions of single species and the phylogenetic clades where these species belong is a very slow process (Darwin 1859). In general, this follows the general lines that species as important biological units (Claridge et al. 1997) are subjected to a series of evolutionary events starting from origination and ending to extinction (Purvis et al. 2000). This scheme seems to have an impressive universality and has found support by many authors such as Gould et al....

The increased use of stable isotope stratigraphy

There are no doubts that the global importance of the Ireviken, Mulde, and Lau events has been confirmed and received increased attention because of the numerous carbon and oxygen stable isotope studies reported from around the globe. Anomalies in the S13C composition in calcite and organic carbon show that these events all are associated with profound positive carbon isotope excursions, reflecting perturbations in the global carbon cycle and thereby the global climate (Talent et al. 1993...

Umm Omieyid Formation

Fine-grain sands, trough cross-stratified sandstone and fissile shale indicate deposition in slightly agitated conditions reveled with coursing up sandstone beds with shell fragments of ammonites despite of their thickening walls. The ammonites fragmentation was affected by agitation at the shoreface where deposition took place the further regression with high agitated condition at this time is the favorable causes of above mentioned observations. Appearance of Hemiasterid echinoid suggested a...

The Late Silurian Lau Event

The Lau Event is associated with the most spectacular positive carbon isotope excursion of the entire Phanerozoic and its vast magnitude is difficult to explain by normal processes. The associated faunal crisis has for a long time been recognized as an important event in the late Ludfordian and is known to have affected pelagic as well as benthic faunas. Substantial ecosystem changes are known from carbonate platforms were the composition of reef-builders change during the event interval....

The prediction of certain insect extinctions

The prevailing opinion among scientists is that the extinctions are selective and affect only the most vulnerable species. For this reason with the appropriate design of reserves we can save the most endangered species by eliminating the factors that affect adversely these biological species (Lawton and May 1995 McKinney 1995 1997 Purvis et al. 2000). Because the current insect extinction is much more intense -between 103 and 104 times than previous events (Purvis et al. 2000)- we can detect...

The Quaternary megafauna extinctions 1321 What are megafauna

The term megafauna is one that is not easily defined. Marshall (1984) points out that four different definitions are provided by different authors in Martin and Klein's 1984 Quaternary Extinctions, one of the definitive works in the field. He goes on to criticize the use of the term, concluding that it is a hindrance to understanding the extinction process itself' (Marshall 1984 796). The use of the term is also examined by Wroe et al. (2004), who demonstrate that its imprecise nature can lead...

Trilobite extinction and larval form

Chatterton and Speyer (1989) drew attention to an unexpected pattern associated with the late Ordovician extinction. They studied trilobite extinction patterns and related survivability to the proposed lifestyle and larval forms of each family. What they discovered was that the greater the duration of an inferred planktonic larval phase, the greater the probability of extinction. Trilobites that were inferred to have planktonic larval stages and benthic adult stages were more likely to go...

U22

The design of reserves takes into account the phylogeny of the species expressed as a standardized species weight (W), which modifies the presence of each species in each of the three regions (R). T is the total of weights, P gives the percentage diversity scores for each of the three regions and U gives the percentage diversity scores on the basis of the complementary taxa to region R3 (Vane-Wright et al. 1991) (see text for explanations) This weight is put in the place of 1 (...

Vegetation

Vegetation in Southeast Asia is governed by two major factors water availability and vertical gradient (Corlett 2005). Southeast Asia has been described as the region of forests climates, which refers to the fact that, until human- generated deforestation within the last few thousand years, the climate of Southeast Asia was such that it supported little else but forest (Corlett 2005). Three major vegetation types for Southeast Asia have been described by Corlett (2005) lowland vegetation...

Sedimentary changes and sealevel

This event is related to pronounced facies shifts in Laurentia, Baltica and peri-Gondwana, independent of basin type contemporaneous facies anomalies are known from rapidly subsiding rift basins (Kaljo et al. 1995), from deep shale basins (Por bska et al. 2004) as well as from shallow intercontinental carbonate platforms (Calner and Jeppsson 2003) and off-platform slope and basin settings (Calner et al. 2006a Lenz et al. 2006). In shaly successions on peri-Gondwana as well as on Baltica, the...

Bivalvia

In the Cenomanian Turonian strata of north Wadi Qena area, Bivalvia occasionally oysters occur in accumulations, which generally represent shallow-marine environments. With the beginning of Turonian age, oysters become scarce or vanish, this may reelect the fact that, following the Cenomanian Turonian transgression, conditions became too deep for oysters to flourish, in addition the same criteria assign for the Turonian oysters of North Africa (Dhondt et al. 1999) and Brazil (Seeling and...

Cluster analysis

Cluster analysis based on the Euclidean distance measure of similarity (the weighted paired group method) applied to the thirty selected samples across the boundary resulted in two main groups (Fig. 2). Group A with samples below the K Pg boundary, which displayed high carbon S13C content for the whole rock samples. Group B with samples at and above the boundary with low carbon S13C content for the whole rock samples. The analysis revealed that the carbon S13C content (productivity) was the...

Geography of Southeast Asia

Southeast Asia, as discussed here, includes Southern China, Myanmar, Thailand, Laos, Cambodia, Vietnam, Malaysia, Borneo and Java. It is generally separated into two distinct provinces, those of Sunda and Indochina (Fig. 1), on the basis of a number of biogeographical differences (e.g. Tougard 2001 Louys et al. 2007). Southeast Asia can also be separated climatically (Chuan 2005) into continental (consisting of Southern China, Myanmar, Thailand, Laos, Cambodia and Vietnam) and insular...

Marine bivalves

The idea of a single mass extinction of marine bivalves at the end of the Triassic stems from Hallam (1981), who claimed a 92 extinction of bivalve species at the TJB. He based this estimate on combining all Norian (including Rhaetian) marine bivalve taxa into one number, thereby encompassing a stratigraphic interval with a minimum duration of 20 million years (Fig. 1). He then compared this to a single number of Hettangian marine bivalve diversity, thus providing a clear example of the...

The theory of Silurian oceanic events

There were no major flood basalt eruptions or extra-terrestrial catastrophes during the Silurian - dramatic processes that are often put forward as causes for mass extinction events. Two impact craters are known from Silurian strata of southern Baltica, representing the Ivar and Kaali bolide impacts (Puura et al. 2000). The Ivar crater formed in the Early Silurian and is situated south of the island of Oland (Sweden). The Kaali crater formed in the Late Silurian and is situated on the island of...

Ecological severity

McGhee et al. (2004) made the valuable point that not only should mass extinctions be evaluated in terms of biodiversity crises, but also in terms of their ecological severity. In their scheme of ecological severity, they evaluated the marine TJB extinction as category IIa and the continental TJB extinction as category I or IIa. Category I means that ecosystems before the extinction were replaced by new ecosystems post-extinction, whereas category IIa means that the extinctions caused permanent...

Radiolarians

Among major faunal groups, the Radiolaria are now considered by some as optimal for defining the TJB (Carter 1994 Ward et al. 2001 Longridge et al. 2007). However, understanding the nature of the timing and severity of radiolarian extinction at the TJB has been hampered by slow identification of suitable and correlatable sections on a global scale. Blome (1986), for example, found that Tethyan and North American assemblages differed significantly at the species level, preventing direct...

Principal coordinate analysis

The data matrix used in cluster analysis was treated by principal coordinate analysis. The results are summarized in Table 1. This table shows that the first three latent roots account for more than 50 of the trace, which seems suitable for interpreting the important causes led to mass extinction in the study area. Table 1. Summary of principal coordinate analysis Figure 3, plotting the first vs. second principal coordinates, separates the thirty studied samples according to their carbon S13C...

Discovery of the Silurian global events

Silurian faunal turnovers and extinctions have been known for a long time and the period yield a well documented record of bioevents (Jeppsson 1990 Barnes et al. 1995 Gradstein et al. 2004 Fig. 3). These events have historically been referred to by different names, depending on the group of taxa at hand, and this has from time to time led to some confusion. Along with improved biostratigraphy and stable isotope stratigraphy, however, it is now clear that the various published names sometimes...

Causes of the TJB extinctions

The end-Triassic drop in diversity was selective but notable for the rapid loss of specific marine taxa, such as ammonoids, conodonts, radiolarians and infaunal bivalves, suggesting physical processes that strongly affected ocean bioproductivity (Tanner et al. 2004). Moreover, the temporary loss of scleractinian corals and almost all calcareous nannoplankton has suggested to some a calcification crisis coincident with the above losses (Hautmann 2004 Schootbrugge et al. 2007). These biotic...

Conodonts

The Conodonta (a phylum or subphylum) is usually identified as one of the most significant groups to have suffered complete extinction at the end of the Triassic. This is misleading. Detailed reviews of conodont extinctions emphasize that conodonts suffered high rates of extinction and low rates of origination throughout the Triassic (e.g. Clark 1983, 1986, 1991 Sweet 1988 Kozur and Mock 1991 Aldridge and Smith 1993 De Renzi et al. 1996). During the Triassic, conodont diversity was highest...

Mass Extinction a general view

Geology Department, Faculty of Science, Minia University, Minia 61519, Egypt, aelewa link.net Mass extinction is considered as the most subject matter in paleontology that received several debated input. When looking to the past, we find five major mass extinctions, I believe, in the fossil record (e.g. Late Ordovician, Late Devonian, Late Permian, Late Triassic and Late Cretaceous). Some authors believe in six mass extinctions by adding Cambrian to the previous five events, some others speak...

The Raup extinction model and the kill curve

Raup (1991, 1996) suggested an extinction model that overcomes the problems of the Darwin-Lyell, namely the passive replacement of faunas after extinctions and the different times required for a taxon to disappear from the geological layers. Passive replacement is used in the sense that the replacing fauna took advantage of the lack of the replaced one and did not compete directly with it. A direct competition would mean an active replacement. The formulation of the extinction model involved...

Land plants

An extensive literature documents the lack of a major extinction turnover of the terrestrial macroflora and microflora at the TJB (e.g. Orbell 1973 Schuurman 1979 Pedersen and Lund 1980 Fisher and Dunay 1981 Brugman 1983 Niklas et al. 1983 Knoll 1984 Ash 1986 Traverse 1988 Edwards 1993 Cleal 1993a, b Kelber 1998 Hallam 2002 Tanner et al. 2004 Lucas and Tanner 2004, 2007b Galli et al. 2005 Ruckwied et al. 2006 Kuerschner et al. 2007). Thus, for example, Ash (1986) reviewed the global record of...

Climate change and megafauna

Climate change, and associated fluctuations in sea levels, has dramatically altered the region's vegetation, as discussed above. In particular, the existence of a savannah corridor running through the middle of Sundaland, a concept which seems foreign when we think of Southeast Asia, appears to have been the norm during the Pleistocene. Like other continents, Southeast Asia hosts a number of disharmonious assemblages, and the presence of this corridor provides a ready explanation for these...

Discussion and conclusions

The macrofaunal categories employed to infer paleoenvironmental conditions. Collectively the methods of establishment of the optimum conditions for the paleoecology are more precisely approached by analyzed the association grouply. We employ several lines of evidence from invertebrate fossils to propose a paleoenvironmental interpretation. The disappearance of many species and the general depletion of oyster diversity in late Cenomanian deposits are induced by the coeval sea-level rise and...

Tetrapods

What Wall Colour Warms Grey Paint

The idea of a substantial nonmarine tetrapod (amphibian and reptile) extinction at the TJB began with Colbert (1949, 1958), and has been more recently advocated by Olsen et al. (1987, 1990, 2002a, b), largely based on the tetrapod fossil record of the Newark Supergroup (eastern North America). Weems (1992), Benton (1994), Lucas (1994), Tanner et al. (2004) and Lucas and Tanner (2004, 2007b) rejected this conclusion, arguing against building a case for extinction on the very incomplete...

Habitat fragmentation destruction modification

In addition to the previous example, the work of Greuter (1972, 1979, 1995)-a systematic botanist-on island taxa indicated that island taxa, and insects predominate in these assemblages, exhibit some particularities. First, the earlier the habitation of the island by humans, as it happens in the Aegean and the Mediterranean in general, the lower the extinction rates unlike the islands in the Pacific where the human occupation varies inversely with extinction rates (Pimm et al. 1995). The first...

Hawashiya Formation

Hawashiya Formation is characterized by a decrease in faunal diversity and high reflux of course clastics, which indicate nearshore environment of high energy agitated conditions. Appearance of gypsiferous lamina indicates lagonal environment and arid conditions. Appearance of oyster bivalve again suggested stability in environment and homogeneous oxygenation percentage. They nevertheless could be met in the early circalittoral. Their accumulation seems rather localized in the early...

Lessons from island ecology

Perhaps the first attempt to explain the extinctions of species from islands was done by Ricklefs and Cox (1972 1978) who investigated the extinction of some bird species from the Lesser Antilles archipelago. The explanation involved the principle of 'taxon cycle', a term which parallels the life of a taxon with the life of an individual. The term was coined by Wilson (1961 see also Ricklefs and Birmingham 2002 for a more recent account of the concept) and it roughly describes the initial...

Southeast Asias megafauna

Unlike North America and Australia, many species of megafauna can still be found living in Southeast Asia. These include such charismatic species as the giant panda (Ailuropoda melanoleuca), the orangutan (Pongo pygmaeus), the Javan and Sumatran rhinoceroses (Rhinoceros sondaicus and Dicerorhinus sumatraensis), the Asian elephant (Elephas maximus) and the tiger (Panthera tigris). Southeast Asia's extinct megafauna is less well known to general audiences, but include several species of...

Early Silurian Ireviken Event

The Silurian global paleogeography was dominated by the vast Gondwanan continent, which covered much of the southern circumpolar areas. Laurentia, Baltica, and Avalonia assembled in the large Laurussian contintent at equatorial latitudes (modified from Cocks and Torsvik 2002). The figure shows locations where previous studies have presented firm evidence for anomalies either in stable isotopes, biodiversity, or facies during the Ireviken Event. Stars with white dot indicate that the...

Late Silurian Lau Event

The figure shows locations where previous studies have presented firm evidence for anomalies either in stable isotopes, biodiversity, or facies during the Lau Event. Stars with white dot indicate that the cited study does not include stable isotope data. AU - Austria (Sch nlaub 1986 Wenzel 1997) CR - Czech Republic (Lehnert et al. 2003, 2007b), EB - East Baltic Area (Kaljo et al. 2003), NE - Nevada (Saltzman 2001), NSW - New South Wales (Talent et al. 1993), OK - Oklahoma (Saltzman...

Geological History

The Southeast Asian continental block is largely composed of elements, which had broken off from the southern super-continent Gondwanaland (Gatinsky and Hutchinson 1987 Metcalf 1990, 1996). Much of the modern geographical aspects of Southeast Asia occurred as a result of the fusion between the Sinoburmalaya and Cathaysia plates, in an event known as the Late Triassic Indosinian Orogeny (Hutchinson 2005). More plate collisions followed, including the collision of the Burma plate with Shan...

Types of current insect extinctions

While it is accepted that current insect extinction are basically a human induced process various authors emphasize individual causative factors. These isolated factors are usually global warming (Thomas et al. 2004) elevated carbon dioxide (Penuelas and Estiarte, 1998), co-extinctions (Dunn 2005 Koh et al. 2004), habitat Zschokke et al. 2000 (Tscharntke and Kruess 1999 Steffan-Dewenter and Tscharntke 2002 Londre and Schnitzer 2006) and habitat loss (Seabloom et al. 2002 Pimm and Raven 2000) or...

Late Ordovician mass extinction

Geology Department, Faculty of Science, Minia University, Minia 61519, Egypt, aelewa link.net The Ordovician period was an era of extensive diversification and expansion of numerous marine clades. Although organisms also present in the Cambrian were numerous in the Ordovician, a variety of new types including cephalopods, corals (including rugose and tabulate forms), bryozoans, crinoids, graptolites, gastropods, and bivalves flourished. Ordovican communities typically displayed a higher...

The Middle Silurian Mulde Event

The Middle Silurian Mulde Event refers to a faunal overturn and crisis at the top of the Lower Homerian stage. A spectacular mass extinction among the graptolites characterizes the event. The mass mortality is locally expressed by extremely dense bedding plane accumulations of a few single survivor species, sometimes literally blackening the bedding planes (Lenz et al. 2006). Contemporaneous formation of organic-rich shale, alum shale, and not least the formation of the so-called 'boundary coal...

Conserving insect biodiversity in city parks and road verges

Among the human structures that fragment in a definite way the habitat of many species are the roads (Saarinen et al. 2005). Many animals attempting to cross this barrier are being killed by traffic. For the United States it is estimated that the daily rate of road-killed vertebrates is one million (Ries et al. 2001). No similar rates for invertebrates have been estimated but this source of mortality is of minor importance compared to other mortality sources. When Ries et al. (2001) followed...

References Global Environment Humanrole

Anshari G, Kershaw AP, van der Kaars S (2001) A Late Pleistocene and Holocene pollen and charcoal record from peat swamp forest, Lake Sentarum Wildlife Reserve, West Kalimantan, Indonesia. Palaeogeogr Palaeoclimat Palaeoecol 171 213-228 Batchelor BC (1979) Discontinuous rising Late Cainozoic eustatic sea-levels, with special reference to Sundaland, southeast Asia. Geologie en Mijnbouw 58 120 Batchelor DAF (1988) Dating of Malaysian fluvial tin placers. Journal of Southeast Asian Earth Sciences...

The Silurian marine scene

During the Silurian the continents were still largely unsettled which means that weathering processes, and the processes of erosion and transport of sediments from the continents to the shallow shelves must have differed substantially from post-Silurian times. The marine realm stood in sharp contrast to the silent land masses and yielded abundant and diverse life forms. The preceding Great Ordovician Biodiversification Event had resulted in a tremendous array of adaptive radiations among marine...

Reef builders

The scleractinian corals, important reef builders during the Triassic, suffered a marked decline at the end of the Triassic that was followed by a reef gap during part of the Early Jurassic (Hettangian-early Sinemurian), after which corals re-diversified to become the dominant reef builders (Stanley 1988). Stanley (2001, p. 26) viewed this as a rapid collapse of reefs at the TJB, concluded it was the result of a first-order mass extinction and noted that Jurassic recovery was slow. i< ji...

Temporal and spatial development and biodiversity

To be regarded a mass extinction an event should be (1) 'confined to a short interval of geological time, it should (2) affect a wide variety of clades occupying a wide spectrum of habitats and (3) it should eradicate a high proportion of species' (Brenchley and Harper 1998, p. 322 numbers added by the current author). These three prerequisites are only partly fulfilled by the Silurian global events, the minor amount of taxonomic loss during the Silurian global events being the main difference....

The Silurian events and carbonate platforms

Otto Tanks Morene

Todays carbonate platforms - such as the Bahamas platform or the Great Barrier Reef - are major marine ecosystems that respond to a wide variety of changes in the contemporaneous oceans. They have a life cycle and a carbonate production rate that depends on the interaction of climate, relative sea-level, and biotic factors such as diversification rate. For this reason, environmental changes in coastal marine waters are reflected in the type of carbonate production and thus in the sediment...

Insect extinctions from climate change

It is well known that the climate of the earth becomes warmer (Parmesan 1996 Schmitt 2003) and this is going to continue for the next 50-100 years (Parmesan et al. 1999). This situation triggered various associated processes such as the decline of plants, which are important hosts for herbivorous insects (Barber et al. 2000 Scott et al. 2002 Petrakis and Legakis 2005). In this sense global warming cannot be separated from other sources of extinction such as habitat loss and co-extinctions. The...

Human overhunting in Southeast Asia

Synchrony of colonisation and extinctions in Southeast Asia is particularly difficult to establish, and is exacerbated by questions of human evolution and poor chronology of sites (Louys et al. 2007). Unlike North America and Australia, the earliest colonisers in Southeast Asia were not modern humans but Homo erectus. Evidence as to whether Homo erectus in Asia subsisted predominantly on a scavenging or hunting diet is still equivocal, although current evidence is suggestive that the former...

Insect mass extinctions in the past

It is known that insects are very different from other organisms at least in the distinction of background and mass extinction. The difference lies in the fact that insects are always dependent on other organisms and usually are important parts of local ecological communities. Labandeira and Philips (1996) record the late Carboniferous (Middle-Late Pennsylvanian stage - Fig. 1) extinction and consider that this is the first major insect extinction. At the same time an extinction of extensive...