Middle Jurassic trace fossils from the Ridang Formation in Sajia County,South Tibet,and their palaeoenvironmental significance

An ichnofauna consisting of 18 ichnospecies (one of them new) in 14 ichnogenera are described for the first time from the Middle Jurassic Ridang Formation in Sajia County, South Tibet. The ichnofauna can be subdivided into two ichnoassemblages in ascending stratigraphic order: the Palaeophycus–Megagrapton ichnoassemblage in the lower and middle parts of the Ridang Formation, followed by the Cosmorhaphe–Nereites–Paleodictyon ichnoassemblage in the upper Ridang Formation. Overall, the trace fossils occur in a middle–distal turbidite fan sequence, as evidenced by both sedimentological analysis and the composition of the trace fossils. Several subenvironments of the middle–distal fan system have been recognized on the basis of the spatial distribution of the trace fossils. Typically, the channel-fill deposits in the middle part of the turbidite fan lack trace fossils, the interchannel and upper channel-fill (levee) subenvironments of the middle turbidite fan contain abundant facies-crossing trace fossils, in contrast to the distal part of the turbidite fan where deep-water trace fossils are dominant. The ichnofauna is similar to typical flysch ichnofaunas from Europe and North America in characteristics, and is interpreted to represent a typical deep-sea Nereites ichnofacies. The presence of these deep-sea trace fossils therefore would suggest that a continental slope environment existed in southern Tibet during the Middle Jurassic and the study area was located in a slope-abyssal plain setting.     

Middle Triassic horseshoe crab reproduction areas on intertidal flats of Europe with evidence of predation by archosaurs

A systematically excavated track site in a 243.5 Myr old Middle Triassic (Karlstadt Formation, Pelsonian, middle Anisian) intertidal carbonate mud‐flat palaeoenvironment at Bernburg (Saxony‐Anhalt, central Germany) has revealed extensive horseshoe crab trackways attributable to the Kouphichnium Nopsca, 1923 ichnogenus. The exposed track bed of a Germanic Basin‐wide spanned intertidal megatrack site is a mud‐cracked biolaminate surface on which detailed tracks have been preserved because of rapid drying and cementation as a result of high temperatures, followed by rapid covering with a protective layer of arenitic storm or tsunami sediments. The different trackway types and their orientations have allowed a tidal sequence to be reconstructed, with the initial appearance of swimming horseshoe crabs followed by half‐swimming/half‐hopping limulids under the shallowest water conditions. The Bernburg trackways, which have mapped lengths of up to 40 m, were all produced by adult animals and exhibit a variety of shapes and patterns that reflect a range of subaquatic locomotion behaviour more typical of mating than of feeding activities. The closest match to the proportions and dimensions of the horseshoe crab tracks at Bernburg is provided by the largest known Middle Triassic limulid Tachypleus gadeai, which is known from the north‐western Tethys in Spain. The horseshoe crab body fossils recognized in the German Mesozoic intertidal zones, instead, are from juveniles. The uniformly adult size indicated by the trackways therefore suggests that they may record the oldest intertidal reproductive zones of horseshoe crabs known from anywhere in the world, with the track‐makers having possibly migrated thousands of kilometres from shallow marine areas of the north‐western Tethys to reproduce in the intertidal palaeoenvironments of the Germanic Basin. Chirotherium trackways of large thecodont archosaurs also appeared on these flats where they appear to have fed on the limulids. With the tidal ebb, smaller reptiles such as Macrocnemus (Rhynchosauroides trackways) appeared on the dry intertidal flats, probably feeding on marine organisms and possibly also on horseshoe crab eggs. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103 , 76–105.     

A Valanginian crustacean microcoprolite ichnofauna from the shallow-marine hydrothermal vent site of Zengővárkony (Mecsek Mts., Hungary)

A rich and diverse crustacean microcoprolite ichnofauna is reported from the Valanginian of the Mecsek Mts., Hungary. Localities from the Bolondút and Dezső Rezső valleys near Zengővárkony (Eastern Mecsek Mts.) provided Favreina aff. dispentochetarius, Palaxius darjaensis, P. triochetarius, P. salataensis, P. tetraochetarius, and P. decaochetarius. They occur in limonitic and partly metasomatized limestones, limestone olistoliths, and ammonite body-chambers. The remarkable richness of this ichnofauna plus the previous records from the same environment (altogether 11 ichnospecies of four ichnogenera from a single stratigraphic level) make it the most diverse crustacean ichnofauna of the Mesozoic. The former ecosystem of the ichnofauna is considered a deeper shallow-marine (water depth <300 m) hydrothermal vent on which the producers of the microcoprolites lived. The related brachiopod fauna shows a remarkable size and is dominated by Lacunosella. This fauna is not similar to typical fossil deep-sea vent faunas; however, it offers a thorough understanding of other fossil shallow-marine hydrothermal vent faunas and the role of crustaceans in these ecosystems. This is the first record of crustacean coprolites from such a fossil site and documents that crustaceans were diverse and played an important role in shallow-marine, non photosynthesis-based ecosystems in the geological past.     

Trace fossils of the Jurassic,blue Lias,Lyme Regis,Southern England

The Lower Jurassic, Blue Lias Formation at Lyme Regis, Dorset, England is rhythmically bedded with symmetrical rhythms consisting of laminated black shale followed by dark then pale marls (sometimes cemented into pale limestones) and back to laminated black shale. Its trace fossil fauna includes nine ichno‐genera and represents a shallow shelf paleoenviron‐ment. The ichnofauna occurs in three assemblages named after consistently occurring ichnogenera. A Chondrites assemblage (diversity = 1 ichnogenus) and a Chondrites‐Arenicolites assemblage (diversity = 2–3 ichnogenera) are typical of dark marls but may penetrate tops of laminated black shales. A thalassi‐noides‐Chondrites‐Arenicolites assemblage (diversity up to 7 ichnogenera) is typical of pale marls or limestones. Blue Lias limestones are diagenetic: dark laminated limestones and pale bioturbated limestones are cemented equivalents of laminated black shales and pale marls, respectively. However, pale burrow fills in darker sediments and vice versa confirm the rhythms are primary. Rhythms represent redox cycles, fluctuating from anoxic laminated black shales lacking mac‐robenthos or infauna (bioturbation index = 0) to oxic, bioturbated, pale marls or limestones with large mac‐robenthos such as Gryphaea or Plagiostoma and diverse infauna (bioturbation index = 5).     

Insights from functional morphology and neoichnology for determining tracemakers: a case study of the reconstruction of an ancient glacial arthropod‐dominated fauna

Apportioning trace fossils to producers is significant for palaeoecological and palaeoenvironmental studies. A tracemaker is usually attributed through the comparison of the morphology of the trace to the body plans of modern and extinct animals. However, hypotheses of tracemaker identifications may be tested with the use of further methods. This contribution aims to evaluate the potential tracemakers of a trackway‐dominated ichnofauna preserved in the siltstone–claystone rhythmites of the Pennsylvanian Rio do Sul Formation in the southern Brazil. These deposits are typical of the deglaciation phase of the Late Palaeozoic Ice Age of Gondwana in the Paraná Basin. Thus, the parameters applied in this work are as follows: (1) functional analyses of the traces to infer the biomechanics of the locomotion of the producer; and (2) neoichnology, whereby modern traces whose producers are known are compared to those of the ichnofauna in question. The conclusions obtained with these methods strongly support millipedes as the producers of Diplichnites gouldi and Diplopodichnus biformis. The malacostracan crustacean‐related ichnogenera are Umfolozia sinuosa and Gluckstadtella elongata, produced by syncarids or peracarids, while isopods are suggested as the tracemakers of Glaciichnium isp. and Protovirgularia dichotoma. In terms of branchiopod crustaceans, Cruziana problematica is attributed to notostracans. Helminthoidichnites tenuis, Mermia carickensis and Treptichnus pollardi are considered traces produced by insect larvae. The palaeobiology of the tracemakers that produced the ichnofauna preserved in the rhythmites of the Rio do Sul Formation permits inferences that terrestrial (millipedes) and aquatic (crustaceans and insect larvae) animals colonized the sediments. This conclusion points to a dynamic depositional environment, with changing physical and chemical parameters conditioning the biota.     

Re-Examination of Some Large Early Mesozoic Tetrapod Footprints from the African Collection of Paul Ellenberger

The Late Triassic—Early Jurassic ichnofauna described mainly by Paul Ellenberger from southern Africa (Lesotho) is a valuable window on first phases of dinosaur diversification. Unfortunately, the present taxonomic status of several forms from that ichnofauna is unclear. The revision of this material has been frequently invoked and partially done without reaching many definitive results. Due to the enormous amount of data, a global revision seems at present impossible and must be accomplished in smaller steps. A small number of Ellenberger's ichnogenera including Tetrasauropus, Pseudotetrasauropus, Pentasauropus, Paratetrasauropus, Sauropodopus and Deuterosauropodopus, which different authors have ascribed to basal sauropodomorphs, are here revised in a consistent manner and their attribution to osteological clades is considered. Tetrasauropus and Pseudotetrasauropus are here validated as the only ichnotaxa related to sauropodomorphs. Pentasauropus is retained as valid, and a therapsid trackmaker is suggested. Paratetrasauropus and Sauropodopus are also validated and ascribed to non-dinosaurian trackmakers, and Deuterosauropodopus is synonymized with Sauropodopus.     

The Tetrapod Ichnogenus Protochirotherium Fichter and Kunz 2004, a Characteristic Early Triassic Morphotype of Central Pangea

Early Triassic chirotherian footprint assemblages from Poland, Germany, and Morocco are important for understanding archosaur evolution in the aftermath of the Permian-Triassic crisis. However, their ichnotaxonomy is confusing because various authors have interpreted their diversity differently. After an analysis and ichnotaxonomic re-assessment, the presence of the ichnogenera Brachychirotherium, Isochirotherium, and Chirotherium in these assemblages is not supported. Distant similarities with these ichnotaxa are functions of extra morphological variation and substrate-related factors. Instead, Early Triassic chirotherian footprints described under these names are assigned here to the ichnogenus Protochirotherium and to a more slender morphotype identified as Synaptichnium. In particular, Protochirotherium appears to be more widely distributed in central Pangea as a characteristic morphotype reflecting a distinct stage in archosaur evolution. Trackmakers were nonarchosaurian archosauriforms or, alternatively, stem-group crocodylians. Morphologically and temporally these footprints match the hypothetical ancestor of the Chirotherium barthii trackmaker. Chirotherium barthii appears by the beginning of the Middle Triassic. Because of its restricted stratigraphic range, and its wider distribution in central Pangea, Protochirotherium also has biostratigraphic significance for this region and can be considered as an indicator of Early Triassic-aged strata.     

Bioerosion in the Miocene Reefs of the northwest Red Sea,Egypt

Macroborings provide detailed information on the bioerosion, accretion and palaeoenvironment of both modern and fossil reefs. Dolomitized reefal carbonates in the Um Mahara Formation exhibit an outstanding example of spatially distributed, well‐preserved bioerosion structures in tropical to subtropical syn‐rift Miocene reefs. Ten ichnospecies belonging to five ichnogenera are identified; three belonging to the bivalve‐boring ichnogenus Gastrochaenolites, three attributed to the sponge‐boring ichnogenus Entobia, and four ichnospecies assigned to three worm‐boring ichnogenera Trypanites, Maeandropolydora and Caulostrepsis. The distribution of the reported borings is strongly linked to the palaeo‐reef zones. Two distinctive ichnological boring assemblages are recognized. The Gastrochaenolites‐dominated assemblage reflects shallower‐marine conditions, under water depths of a few metres, mostly in back‐reef to patch‐reef zones of a back‐reef lagoon. The Entobia‐dominated assemblage signifies relatively deeper marine conditions, mostly in reef core of the fringing Miocene reefs. These ichnological assemblages are attributed herein to the Entobia sub‐ichnofacies of the Trypanites ichnofacies. This ichnofacies indicates boring in hard carbonate substrates (such as corals, rhodoliths, carbonate cements and hardgrounds) during periods of non‐sedimentation or reduced sediment input.     

Early cretaceous bird-dominated and dinosaur footprint assemblages from the northwestern margin of the Junggar Basin, Xinjiang, China

Here we describe a number of mostly isolated bird and non-avian dinosaur footprints from the Huangyangquan track site in the Lower Cretaceous Lower Layer of the Tugulu Group near Huangyangquan Reservoir in the Wuerhe District, Karamay, Xinjiang Uyghur Autonomous Region, China. Bird footprints at the site pertain to Koreanaornis dodsoni n. ichnosp., Goseongornipes isp., Aquatilavipes isp., and Moguiornipes robusta n. ichnogen. n. ichnosp. Moguiornipes tracks may be the products of a bird with lobed feet. These shorebird-morph tracks are the first solid evidence of birds in the Tugulu Group, and greatly enrich the known faunal diversity of the Lower Layer of the Tugulu Group. The Huangyangquan avian ichnofauna is comparable to those of the Jindong Formation, Korea and the Dakota Formation, USA. Non-avian dinosaur footprints at the site pertain to cf. Jialingpus isp., Asianopodus isp., and Kayentapus isp. This is the first report of Jialingpus from Lower Cretaceous strata. The discoveries of Asianopodus isp. and Kayentapus isp. increase the known ranges of these two ichnogenera.     

Short-term colonization trace-fossil assemblages in a carbonate lacustrineKonservat-Lagerstätte (Las Hoyas fossil site, Lower Cretaceous, Cuenca, Central Spain)

Summary Rhythmically laminated fine-grained lacustrine carbonatcs of the Cretaceous La Huérguina Limestone Formation at Las Hoyas fossil site, central Spain, contain not only a spectacular body fossil fauna, but also vertebrate and invertebrate trace fossils. The study of the Las Hoyas invertebrate ichnofauna provides valuable taphonomic, paleoecological and paleoenvironmental information and represents one of the first attempts to study in detail a lacustrine trace-fossil assemblage in carbonate rocks. The Las Hoyas ichnofauna includesCruziana problematica, Helminthoidichnites tenuis, Lockeia isp.,Palaeophycus tubularis, andTreptichnus pollardi. This assemblage is characterized by low ichnodiversity and small burrow size, and it is dominated by surface trails and extremely shallow burrows produced mostly by detritus feeders. The Las Hoyas ichnofauna indicates low to moderately low energy, permanently submerged, shallow-lacustrine areas. The ichnofauna is suggestive of environmental stress, most likely oxygen-depleted conditions in interstitial waters. Occurrence of traces in event beds indicates opportunistic colonization by epifauna and very shallow infauna during brief periods of improved oxygenation related to the passage of density underflows and dilute turbidity currents. The Las Hoyas ichnofauna resembles other shallow lacustrine trace-fossil assemblages of the archetypalMermia ichnofacies and differs significantly from the archetypalScoyenia ichnofacies. It is therefore best regarded as a proximal, depauperate example of theMermia ichnofacies. The Las Hoyas assemblage is similar to the slightly older lacustrine Montsec ichnofauna, but it is remarkably different from marine ichnocoenoses of other Mesozoickonservat-lagerst?tten in lithographic limestones such as those of Cerin, Solnhofen and Nusplingen.     

Figures sédimentaireset traces d'origine biologique du Trias moyen de la bordure orientale du Massif Central signification sédimentologique et paléoécologique

The sandstones with foot-prints of reptiles and saltcasts from the Middle Triassic of the eastern border of the Massif Central (France) show a striking reptilian ichnofauna. The numerous sedimentary figures and trace fossils which are described here allow to deduce the following characteristics of the depositional environment: shallow water, lower flow regime, periodical increase of salinity. The reptiles used to pass through that environment where numerous stretches of water alternated with emerged, plant overgrown areas.     

Chirotheria and Other Ichnotaxa of the European Triassic

At the end of the Permian, numerous amphibians and therapsids vanished, creating many empty ecological niches, which were occupied by new creatures. This event brought new trends in animal locomotion thanks to modifications of the skeleton limbs. The newcomers were faster and more dangerous for other families. The prominent ichnogenera were Synaptichnium, Chirotherium, Brachychirotherium, Isochirotherium, and Sphingopus. Their trackmakers were Thecodonts, reptiles having the above-mentioned evolutive characteristics. Dinosaurs, which appeared at the end of the Triassic period, were likely their descendants, which raises the question of when and where the dinosaurs originated. The comparison of the trackways of the Middle and upper Triassic with those of the lower Jurassic leads to the conclusion that the two sets of tridactyl ichnites were similar and were made by the same group of trackmakers, the dinosaurs. We had many passionate discussions on this subject with Bill Sarjeant when studying the discoveries made in Europe the past 40 years.     

A new sauropodomorph ichnogenus from the Lower Jurassic of Sichuan,China fills a gap in the track record

A dinosaur tracksite in the Lower Jurassic Ziliujing Formation of Sichuan Province, China consists of a spectacular sub-vertical exposure, with multiple track-bearing levels and trackways showing parallel and bimodal orientations. Based on well-preserved material, the new ichnogenus and ichnospecies, Liujianpus shunan ichnogen. nov. ichnosp. nov. is erected to accommodate distinctive sauropodomorph trackways occurring in this assemblage. Liujianpus has a unique combination of features, some relating to the early Jurassic basal sauropodomorph (prosauropod in traditional usage) ichnogenus Otozoum, others to the sauropod ichnogenus Brontopodus. Despite such a mix of basal sauropodomorph- and sauropod-like features, the trackmaker of Liujianpus is likely a basal sauropodomorph. This identification is consistent with the occurrence of basal sauropodomorph skeletons from geographically and chronologically close localities. The other distinct morphotype from the tracksite is linked to a sauropod trackmaker. As such, the ichnofauna consisting of two distinct foot morphotypes reflects the diversity of sauropodomorph dinosaurs in the Early Jurassic of Asia.     

An Early Late Cretaceous Dinosaur Tracksite in Central Yukon Territory,Canada

Dinosaur tracks were first reported from the coal-bearing clastic sequences of the Ross River Block in 1999 by members of a University of Alaska Museum field party, and track sites were confirmed by a joint Alaska-Yukon team in 2000. This fault-bounded sedimentary block is 3 kilometers west of Ross River, in the Yukon Territory. The discovery was followed by two years of field mapping and collection. This research has resulted in the documentation of 251 individual tracks at two separate but stratigraphically related sites, as well as a short (four-footprint) trackway at one of the sites. Six ichnogenera were identified. Ornithomimipus, Amblydactylus, and Gypsichnites were recognized at one site. At a stratigraphically higher site, four ichnogenera were documented including Tetrapodosaurus, Irenesauripus, Amblydactylus, and Columbosauripus. This ichno-assemblage is compared with those of Aptian to Cenomanian age from Alberta, British Columbia, and Alaska.

The discovery of unequivocal dinosaur evidence in a small structural inlier in the Tintina Trench that was previously assumed to be Eocene in age resulted in a restudy of the palynology and biostratigraphy of this coal-bearing sequence and the recent assignment of a middle Albian to early Cenomanian age to the upper part of the dinosaur-bearing interval.     

A Revised Systematic Ichnotaxonomy and Review of the Vertebrate Footprint Ichnofamily Chirotheriidae from the British Triassic

Since 1838, many discoveries of the tetrapod footprint taxon Chirotherium and closely similar forms have been reported from the British Middle Triassic. These have been assigned to dozens of ichnotaxa, so that the identification and interpretation of members of the ichnofamily Chirotheriidae have become confused.

Part 1 of this article deals with ichnotaxonomy. Revision of all the available material shows that there are at least three valid ichnospecies of Chirotherium, one of Synaptichnium, and one of Isochirotherium. The presence of a fourth related ichnogenus, Brachychirotherium, cannot yet be confirmed in Britain. Emended diagnoses are proposed for all four ichnogenera; they may be readily distinguished by the shape of the hand (manus) and foot (pes) impression and especially by the phalangeal counts. The natural cast of a probable tail impression, associated with Chirotheriidae footprints from the British Triassic is figured for the first time, as is a rare detailed impression of skin and the tarsal region of an Isochirotherium lomasi pes cast.

Part 2 provides a critical history of the earliest discoveries of each of these ichnogenera in the British Triassic. It is subdivided into divisions, depending on the quality of data and existence of specimens, the localities in Britain which have yielded these ichnogenera; a detailed history and discussion is provided of the earliest discoveries made at each locality. The stratigraphic distribution and paleological significance of the ichnogenera/species are assessed.     

Late Jurassic footprints reveal walking kinematics of theropod dinosaurs

Avanzini, M., Piñuela, L. & García‐Ramos, J.C. 2011: Late Jurassic footprints reveal walking kinematics of theropod dinosaurs. Lethaia, Vol. 45, pp. 238–252. This study describes a set of theropod footprints collected from the Late Jurassic Lastres Formation (Asturias, N Spain). The footprints are natural casts (tracks and undertracks) grouped into three morphotypes, which are characterized by different size frequency, L/W relationship and divarication angles: ‘Grallatorid’ morphotype, ‘Kayentapus–Magnoavipes’ morphotype, ‘Hispanosauropus’ morphotype. The tracks were produced in firm, stiff and soft sediments. The infills of deep tracks, which are typically formed in soft mud, lack fine anatomical details, but they can reveal the walk kinematics of the trackmaker through the morphology of internal track fills and sinking traces. In all footprints, a horizontal outwardly directed translation movement and rotation are recognizable. The amount and geometry of digit penetration in the ground also show a pronounced difference. It can be inferred from the described sample that different theropoda‐related ichnogenera share common kinematics. □Asturias, dinosaur footprint, late jurassic, theropods, walking kinematics.     

Evolution of Devonian biodiversity of radiolarians with two porous spheres and one main spine

Features and major distinctions in the appearance and distribution of radiolarians with two porous spheres and one main spine in the Devonian basins are considered. Four solitary population waves and expansion scenario of radiolarians of this morphotype have been recognized in the Devonian. A new species, Radiobisphaera rozanovi sp. nov., from the Upper Emsian, Upper Eifelian, and Middle Frasnian of the southern Ural Mountains, from the Upper Eifelian of the Prague Basin (Barrandian), from the Middle-Upper Frasnian of the Rudnyi Altai, and from the Lower Famennian of the Timan-Pechora Basin and the Polar Ural Mountains is described.     

Anisian (middle triassic) buildups of the Northern Dolomites (Italy): The recovery of reef communities after the permian/triassic crisis

Summary After the end-Permian crisis and a global ‘reef gap’ in the early Triassic, reefs appeared again during the early Middle Triassic. Records of Anisian reefs are rare in the Tethys as well as in non-Tethyan regions. Most Anisian reefs are known from the western part of the Tethys but there are only very few studies focused on biota, facies types and the paleogeographical situation of these reefs. From the eastern part of the Tethys, Anisian reefs, reefal buildups or potential reef-building organisms have been reported from different regions of southern China. Most of the Anisian reefs known from western and central Europe as well as from southern China seem to be of middle and late Pelsonian age. The study area is situated in the northern Dolomites (South Tyrol, Italy) southeast of Bruneck (Brunico). It comprises the area between Olang (Valdaora) and Prags (Braies). The study is based on detailed investigations of the regional geology, stratigraphy and lithofacies (R. Zühlke, T. Bechst?dt) as well as on a comprehensive inventory of Anisian reef organisms (B. Senowbari-Daryan, E. Flügel). These data are used in the discussion of the controls on the recovery of reefs during the early Middle Triassic. Most late Anisian reef carbonates studied are represented by allochthonous talus reef blocks of cubicmeter size. Small biostromal autochthonous mounds are extremely rare (Piz da Peres). The reef mounds as well as most of the reef blocks occur within the middle to late Pelsonian Recoaro Formation. They were formed on the middle reaches of carbonate ramps in subtidal depths, slightly above the storm wave base with only moderate water energy. Most lithotypes observed in the reef blocks correspond to sponge and/or algal bafflestones. Low-growing sessile organisms (Olangocoelia (sponge, alga?), sphinctozoan sponges, bryozoans, soleno-poracean algae, corals) and encrusting epibionts (sponges, porostromate algae, cyanophycean crusts, foraminifera, worms, microproblematica) created low cm-sized biogenic structures (bioconstructions) which baffled and bound sediment. Organic framework was only of minor importance; it is restricted to theOlangocoelia lithotype. Framework porosity was small in these reef mounds. Submarine carbonate cements, therefore, are only of minor importance s compared with Permian or Ladinian reefs. The relatively high number of lithotypes encountered in the reef blocks indicates a high biofacies diversity. Regarding the relative frequency, the diverse biota consist in descending order ofOlangocoelia, sponges (sphinctozoans, inozoans, siliceous sponges), bryozoans, porostromate algae and worm tubes. The sphinctozoans are characterized by small, mostly incrusting forms. The numerical diversity (species richness) is low compared with late Permian or Ladinian and late Triassic sphinctozoan faunas occurring within reefs. Following the sponges, monospecific bryozoans (Reptonoditrypa cautica Sch?fer & Fois) are the most common organisms in the reef limestones. Porostromate algae were restricted to areas within the bioconstructions not inhabited by sponges. The low-diverse corals had no importance in the construction of an organic framework. Surprisingly, microbial crusts are rare or even lacking in the investigated Anisian bioconstructions. This is in contrast to late Permian and Ladinian as well as Carnian reefs which are characterized by the abundance of specific organic crusts. The same comes true for‘Tubiphytes’ which is a common constituent in Permian, Ladinian and Carnian reef carbonates but is very rare in the Anisian of the Olang Dolomites. Instead of‘Tubiphytes’ different kinds of worm tubes (spirorbid tubes, Mg-calcitic tubes and agglutinated tubes) were of importance as epifaunal elements. Macrobial encrustations consisting of characteristic successions of sponges, bryozoans, algae, worm tubes and microproblematica seem to be of greater quantitative importance than in Ladinian reefs. Destruction of organic skeletons (predominantly of bryozoans) by macroborers (cirripedia?) is a common feature. The Anisian reef organisms are distinctly different from late Permian and from most Ladinian reef-builders. No Permian Lazarus taxa have been found. New taxa: Sphinctozoan sponges—Celyphia? minima n.sp.,Thaumastocoelia dolomitica n. sp.,Deningeria tenuireticulata n. sp.,Deningeria crassireticulata n. sp.,Anisothalamia minima n.g. n.sp., Inozoan sponges-Meandrostia triassica n.sp. Microproblematica-Anisocellula fecunda n.g. n.sp., Porostromate alga-Brandneria dolomitica n.g. n.sp. Most of our data are in agreement with the model described byFois & Gaetani (1984) for the recovery of reef-building communities during the Ansian but the biotic diversity seems to be considerably higher than previously assumed. Anisian deposition and the formation of the reef mounds within the Pelsonian Recoaro Formation of the Dolomites were controlled by the combined effects of synsedimentary tectonics and eustatic changes in sea-level. During several time intervals, especially the early Anisian (northern and western Dolomites: tectonic uplift), the early Pelsonian (eastern Dolomites: drowning) and the late Illyrian (wide parts of the Dolomites: uplift and drowning), the sedimentation was predominantly controlled by regionally different tectonic subsidence rates. The amount of terrigenous clastic input associated with synsedimentary tectonics (tectonic uplift of hinterlands) had a major influence on carbonate deposition and reef development. The re-appearance of reef environments in the Olang Dolomites was controlled by a combination of regional and global factors (paleogeographic situation: development of carbonate ramps; decreasing subsidence of horst blocks; reduced terrigenous input; moderate rise in sea-level).     

First Occurrence of Tetrapod Footprints from Westphalian Strata of the Sidi Kassem Basin,Central Morocco

The Sidi Kassem Basin is the only limnic basin of Westphalian age in Morocco. It is built up of 1,250 m of alluvio-fluvial to lacustrine deposits that have so far yielded plant fossils and invertebrate remains only. Recent exploration for fossil tetrapod footprints in floodplain-deposits of the basin revealed a moderately diverse vertebrate ichnofauna composed of tracks assigned to cf. Batrachichnus Woodworth, 1900; cf. Hylopus Dawson, 1882; Dimetropus Romer and Price, 1940; and Notalacerta Butts, 1891. The tracks can be referred to temnospondyl, anamniote reptiliomorph, non-therapsid synapsid (pelycosaur), and captorhinomorph trackmakers. The described ichnoassemblage is important in at least three aspects: (1) It suggests an Early to mid-Pennsylvanian age for the footprint-bearing strata of the study area. (2) It is the oldest association of tetrapod footprints from Africa. (3) It is the first evidence of the relatively rare ichnogenera cf. Hylopus and Notalacerta outside of North America and Europe. Judged from the variety of tetrapod tracks and previously collected floral remains, the Sidi Kassem Basin must have represented a well-established continental ecosystem during Pennsylvanian time. Further exploration for trace and body fossils of Palaeozoic vertebrates in this basin may be important for the reconstruction of early tetrapod evolution.     

A diverse Upper Jurassic dinosaur ichnofauna from central‐west Portugal

Mateus, O. & Milàn, J. 2009: A diverse Upper Jurassic dinosaur ichnofauna from central‐west Portugal. Lethaia, Vol. 43, pp. 245–257. A newly discovered dinosaur track‐assemblage from the Upper Jurassic Lourinhã Formation (Lusitanian Basin, central‐west Portugal), comprises medium‐ to large‐sized sauropod tracks with well‐preserved impressions of soft tissue anatomy, stegosaur tracks and tracks from medium‐ to large‐sized theropods. The 400‐m‐thick Lourinhã Formation consists of mostly aluvial sediments, deposited during the early rifting of the Atlantic Ocean in the Kimmeridgian and Tithonian. The stratigraphic succession shows several shifts between flood‐plain mud and fluvial sands that favour preservation and fossilization of tracks. The studied track‐assemblage is found preserved as natural casts on the underside of a thin bivalve‐rich carbonate bed near the Tithonian–Kimmeridgian boundary. The diversity of the tracks from the new track assemblage is compared with similar faunas from the Upper Jurassic of Asturias, Spain and the Middle Jurassic Yorkshire Coast of England. The Portuguese record of Upper Jurassic dinosaur body fossils show close similarity to the track fauna from the Lourinhã Formation. □Dinosaur tracks, Lusitanian Basin, Portugal, skin impressions, Upper Jurassic.