A new species of Isoëtes (Isoëtaceae,Pteridophyta) for the Mediterranean

Abstract

Isoëtes iapygia from the Apulia region (southern Italy) is described as a new species and illustrated. It differs in several characters from the other Mediterranean Isoëtes species, but has some intermediate characteristics similar to terrestrial and amphibious Isoëtes. I. iapygia is similar to the amphibious species for the lack of phyllopodia, even if it has scales; it is similar to terrestrial species for the complete velum and tuberculate macrospores. A completely unique character is represented by the two air chambers. Its habitat is on limestone rocks, in temporary pools.     

A diagnosis of crocodile feeding traces on larger mammal bone, with fossil examples from the Plio-Pleistocene Olduvai Basin, Tanzania

Neotaphonomic studies have determined the patterns of bone damage created by larger mammalian carnivores when consuming mammalian carcasses. Typically, mammalian carnivores gnaw and break bones to various degrees in order to access marrow, grease, and brain tissue. In contrast, crocodiles attempt to swallow whole parts of mammal carcasses, inflicting in the process tooth marks and other feeding traces on some of the bones they are unable to ingest. Although crocodiles are major predators of larger mammals along the margins of protected tropical rivers and lakes, their feeding traces on bone have received little systematic attention in neotaphonomic research. We present diagnostic characteristics of Crocodylus niloticus damage to uningested mammal bones resulting from a series of controlled observations of captive crocodile feeding. The resulting bone assemblages are composed of primarily complete elements from articulating units, some of which bear an extremely high density of shallow to deep, transversely to obliquely oriented tooth scores over often large areas of the bone, along with shallow to deep pits and punctures. Some of the tooth marks (bisected pits and punctures, hook scores) have a distinctive morphology we have not observed to be produced by mammalian carnivores. The assemblages are also characterized by the retention of both low- and high-density bone portions, an absence of gross gnawing, and minimal fragmentation. Together, the damage characteristics associated with feeding by crocodiles are highly distinctive from those produced by mammalian carnivores. Modern surface bone assemblages along the Grumeti River in Tanzania's Serengeti National Park contain a mixture of specimens bearing damage characteristic of crocodiles and mammalian carnivores. Comparison of Plio-Pleistocene fossil bones from Olduvai Gorge, Tanzania, to bones damaged by captive and free-ranging Nile crocodiles reveals direct evidence of fossil crocodilian feeding from larger mammal bones associated with Oldowan stone artifacts.     

CIBOTIUM OREGONENSE: AN EOCENE TREE-FERN STEM AND PETIOLES WITH INTERNAL STRUCTURE

Cibotium oregonense sp. nov. is described from the Upper Eocene of Medford, Oregon. The fossil comprises petiole bases and stem periphery of a large fern preserved via permineralization. A stele devoid of sclerenchymatous sheathing and a petiole vascularized with a large number of leaf traces in a cyatheacean pattern characterize the fossil. A distinctive U-shaped interior series of leaf traces allows assignment to the genus Cibotium. This fossil provides evidence that the genus Cibotium was represented by an arborescent species with large leaves in the Early Tertiary of western North America.     

Crouching Theropods in Taxonomic Jungles: Ichnological and Ichnotaxonomic Investigations of Footprints with Metatarsal and Ischial Impressions

Tracks and traces of crouching theropods are rare, known from only three specimens from the Lower Jurassic of New England and the Lower to ?mid Jurassic of China. The New England specimens reveal manus, metatarsal and sub-crescentic ischial callosity impressions associated with Grallator-like tracks. The Chinese traces reveal metatarsal traces and a sub-triangular ischial callosity impression associated with Eubrontes-like tracks. All reveal symmetrical crouching postures. Theropod crouching traces should not be confused with ornithopod crouching traces, often assigned to Anomoepus. The ichnotaxonomy surrounding all these traces and associated footprints is very complex, and over split. Suggestions for simplification allow recognition that the North American and Chinese ichnofaunas have many similarities. The ichnotaxonomy is not as complex and confused as it may at first appear.     

First Report: Trace Fossil Assemblage Ptychoplasma (P. excelsum,P. vagans), Dendroidichnites (D. irregulare), Ctenopholeus (?C. kutcheri) and Bergaueria (B. hemispherica) in the Cretaceous Rocks of Bagh Formation,Mainland Gujarat,India

Abstract

This report documents the discovery of repichnia trace fossils Ptychoplasma (P. excelsum and P. vagans) and Dendroidichnites (D. irregulare); the fodichnia traces ?Ctenopholeus (?C. kutcheri) and cubichnia traces Bergaueria (B. hemishperica) from silty limestones of the Cretaceous Bagh Formation. These trace fossils have significant implications for the depositional facies and the paleo-environmental interpretations of the Bagh Formation, which have long been debated. Previously identified traces of Protovirgularia were also found in association with the newly discovered trace fossils, indicating the coexistence of both wedge and cleft-foot bivalves. The western area of the mainland Gujarat is known for its abundance and diversity of trace fossils. The trace fossil bearing Cretaceous rocks in the region occur as thin irregular detached patches and linear outcrops. Previous studies documenting trace fossil assemblages from the Bagh Formation characterised them as a combination of dwelling, feeding and locomotion forms, with the stratigraphic unit becoming less fossiliferous westward. Trace fossils in this formation have been studied and described by many workers in the surrounding areas; however, ichnofossils described in this study are new to the Bagh Formation in this area. These trace fossils were observed on recently exposed outcrops along road cuts associated with new road construction from Khasra to Mogra village around Kadipani in Mainland Gujarat.     

Modern Subsurface Bacteria in Pristine 2.7 Ga-Old Fossil Stromatolite Drillcore Samples from the Fortescue Group,Western Australia

Background

Several abiotic processes leading to the formation of life-like signatures or later contamination with actual biogenic traces can blur the interpretation of the earliest fossil record. In recent years, a large body of evidence showing the occurrence of diverse and active microbial communities in the terrestrial subsurface has accumulated. Considering the time elapsed since Archaean sedimentation, the contribution of subsurface microbial communities postdating the rock formation to the fossil biomarker pool and other biogenic remains in Archaean rocks may be far from negligible.

Methodology/Principal Findings

In order to evaluate the degree of potential contamination of Archean rocks by modern microorganisms, we looked for the presence of living indigenous bacteria in fresh diamond drillcores through 2,724 Myr-old stromatolites (Tumbiana Formation, Fortescue Group, Western Australia) using molecular methods based on the amplification of small subunit ribosomal RNA genes (SSU rDNAs). We analyzed drillcore samples from 4.3 m and 66.2 m depth, showing signs of meteoritic alteration, and also from deeper “fresh” samples showing no apparent evidence for late stage alteration (68 m, 78.8 m, and 99.3 m). We also analyzed control samples from drilling and sawing fluids and a series of laboratory controls to establish a list of potential contaminants introduced during sample manipulation and PCR experiments. We identified in this way the presence of indigenous bacteria belonging to Firmicutes, Actinobacteria, and Alpha-, Beta-, and Gammaproteobacteria in aseptically-sawed inner parts of drillcores down to at least 78.8 m depth.

Conclusions/Significance

The presence of modern bacterial communities in subsurface fossil stromatolite layers opens the possibility that a continuous microbial colonization had existed in the past and contributed to the accumulation of biogenic traces over geological timescales. This finding casts shadow on bulk analyses of early life remains and makes claims for morphological, chemical, isotopic, and biomarker traces syngenetic with the rock unreliable in the absence of detailed contextual analyses at microscale.     

Paleoecology of the marine endobenthos

Endobenthic animals, which reside within the sea bottom, include stationary suspension feeders, mobile deposit feeders and both stationary and mobile carnivores. Their activities, especially with regard to dwelling, feeding, walking/crawling and resting/nesting, are recorded as trace fossils.Abundance, diversity and density of some kinds of trace fossils allow interpretation of the population strategies of the trace-makers in terms of opportunistic (r-selected) and equilibrium (K-selected) strategies. Opportunistic ichnotaxa tend to be faciesbreaking traces, which are highly localized in low-diversity, high-density trace fossil associations in rocks representing environmental extremes (e.g., variable salinities, harsh temperatures, low oxygen levels or shifting substrates). Equilibrium ichnotaxa usually are restricted to particular sedimentary facies and are characteristic of high-diversity, low-dominance trace fossil associations in sediments reflecting stable, predictable environmental conditions.The most important environmental factors influencing the composition of trace fossil assemblages in marine settings are bathymetry, substrate, oxygen and hydrodynamic energy. The four factors are closely interrelated, because as water depth increases, there is a general decrease in sediment grain size and hydrodynamic energy of the depositional environment. As depth below the water—sediment interface increases, the firmness of the sediment (due to compaction and dewatering) increases and the oxygen content of interstitial waters drops drastically.Marine ichnofacies are largely substrate-controlled. Soupgrounds are water-saturated, incompetent substrates typified by highly compressed and usually unidentifiable burrows. Softgrounds commonly contain numerous distinctive burrows and are zoned bathymetrically by the Skolithos, Cruziana, Zoophycos and Nereites Ichnofacies. Firmgrounds are characterized by stiff, compacted sediments, in which traces of the Glossifungites Ichnofacies are excavated. Hardgrounds are cemented substrates, in which bioerosion traces of the Trypanites Ichnofacies are bored. Woodgrounds are woody materials that have been exposed to the sea and bored by bivalves, which produce characteristic traces of the Teredolites Ichnofacies. Tiering of endobenthic communities is common and is related to substrate preference of the burrowers and oxygen stratification of interstitial waters.     

Insect traces on early Permian plants of India

The study of fossil leaves from the Glossopteris flora of the Lower Permian Gondwana sequence of the Barakar Formation of the Raniganj Coalfield, India, has revealed the presence of different types of insect traces. The structures are compatible with a variety of insect activities on fossil leaves. Nibbled and cuspate margins, trench marks, obliterated surfaces, blotch marks, and holes of various shape constitute feeding traces, whereas egg pouches along the midrib and irregularly distributed oviposition marks are traces of egglaying. Although fossil records of both insects and their activities in the Glossopteris flora of India remain scarce, the different types of insect traces identified in the present study demonstrate the existence of a diverse insect fauna during the Permian Period of India.     

The ichnofamily Celliformidae for Celliforma and allied ichnogenera

This contribution undertakes a comprehensive revision, lacking until now, of all the ichnotaxa attributed to fossil bee cells, one of the most common traces in paleosols. These ichnotaxa are morphologically related to Celliforma and consequently grouped herein in the new ichnofamily Celliformidae. Two new ichnogenera are formulated, Cellical‐ichnns igen. nov., for several ichnospecies previously included in Celliforma, and a new ichnospecies, C. chubutensis isp. nov., belonging to this ichnofamily, and Brownichnus igen. nov., for the ichnospecies favosites, which is not morphologically related to Celliforma. The ichnogenera included in this ichnofamily involve traces in which Celliforma, the most simple trace of the group, is part of their structure. Paltniraichnus is akin to Celliforma with antechambers and discrete walls. Uruguay, Corim‐batichnus and Rosellichnus are clusters composed of adjacent rows of Celliforma, or Palmiraichnus‐like cells. Ellipsoideichnus and Cellicalichnus are different arrangements of Celliforma‐like cells attached to tunnels.

Celliformidae are based on the morphology of the traces, all of them comprising cells, groups of cells and cells attached to tunnels. As such, its component ichnotaxa are based exclusively on morphological ichnotaxobases, which, in turn, were evaluated and selected with respect to the nest architecture of the trace makers, the bees. This paper analyzes some procedures and clues (i.e. behavioral homologies) that may be used to select the proper taxobases to erect ichnotaxa when the identity of the trace makers is known, as in this study case.     

Positional Behavior of Delacour’s Langurs (Trachypithecus delacouri) in Northern Vietnam

Information on positional behavior can help elucidate relationships between a species’ morphology, behavior, and environment. Delacour’s langurs (Trachypithecus delacouri) are similar to other colobines in body mass and intermembral index, yet inhabit a limestone karst environment. From August 2007 to July 2008, we collected 372 h of positional behavior and substrate use data from 8 groups of Trachypithecus delacouri in Van Long Nature Reserve, Vietnam to address questions about how the distinct —and potentially dangerous— features of karst influence colobine positional behavior. Results show that Trachypithecus delacouri is predominantly quadrupedal (66%). However, they exhibit differences that set them apart from many other colobines. Nearly 80% of locomotor and postural behaviors were performed on rocks. Leaping was remarkably infrequent, representing only 6% of overall locomotion. They leapt 3 times more frequently on trees (13%) than on rocks (4%) and more frequently used trees as a landing substrate than rocks (38% vs. 23%), both significant differences. We argue that rock (and cliff) travel is altogether different from terrestrial and arboreal travel and propose using the term petrous to indicate the substrate and incorporate the implications of its precise sharpness and verticality that lead to the complexities and risk of locomotion on rock surfaces. Trachypithecus delacouri does not show specific adaptations for limestone karst. Instead they appear to be a behaviorally flexible species and, owing to the generalized locomotor capabilities that characterize cercopithecids, capable of locomoting through and living in the limestone rock environment to which they have relatively recently been restricted.     

The Upper Carboniferous Hamilton Fossil-Lagerstätte in Kansas: a valley-fill, tidally influenced deposit

A diverse assemblage of unusually well-preserved marine, euryhaline, freshwater, and terrestrial fossils (invertebrates, vertebrates, and plants) occurs within an Upper Carboniferous (Stephanian) Konservat Fossil-Lagerstätte near Hamilton, Kansas, USA. The Lagerstätte occurs within a paleovalley that was incised into the surrounding Carboniferous cyclothemic sequence during a time of low sea level, and was then filled-in during a subsequent transgression. The stratigraphically lowest and most voluminous facies within the valley is a cross-bedded, polymictic limestone conglomerate that contains caliche clasts and charcoal fragments as well as some normal-marine fossils apparently in situ. The origin of the conglomerate is enigmatic, but it was probably deposited by a migrating tidal channel. Overlying and interbedded with the conglomerate is an ostracode wackestone that contains plants (primarily seed ferns and ferns), eurypterids, shrimp, brachiopods, bivalves, and rare fish. The ostracode wackestone was deposited in a low-energy, marginal-marine environment. A thin sequence (<1 m thick) of interbedded laminated limestone and mudstone overlies the conglomerate in a small area. This facies contains a well-preserved mixed assemblage of terrestrial (conifers, insects, myriapods, reptile), freshwater (ostracodes), aquatic (amphibians, reptile), brackish or euryhaline (ostracodes, eurypterids, spirorbids, fish), and marine (brachiopods, echinoderms) fossils. Many of the vertebrates are articulated and show no evidence of preburial decay, scavenging, or predation. A few vertebrates exhibit signs of flotation. Most articulated vertebrate specimens exhibit soft-tissue preservation in the form of dark-brown to black early-diagenetic microbialite body outlines (‘skin preservation’) containing fossil bacteria. Rhythmic patterns of lamination thickness variation in the limestones and mudstones indicate that this facies was deposited in a tidal environment. High sedimentation rate and variable salinity (and therefore exclusion of bioturbators and invertebrate scavengers) are interpreted as key elements that led to the excellent preservation of the fossils in this ancient estuarine environment. □Lagerstätte, taphonomy, estuarine, tidal bedding, paleovalley, Carboniferous, Kansas.     

Taenidium and Associated Ichnofossils in Fluvial Deposits,Cretaceous Tuscaloosa Formation,Eastern Alabama,Southeastern U.S.A

Casts of the foraging tunnels of eastern American moles ( Scalopus aquaticus ) show impressions from the moles' mani along the lateral walls. The number of discernable impressions ranges from one to five, each showing two or three long, flat, blunt-ended claws. The size and shape of the impressions matches the claws on the paddle-like manus of S. aquaticus . The impressions are spaced at regular intervals of about two cm, and probably represent points at which the mole pushed off from the tunnel wall with alternating laterad digging strokes. Tunnel width generally exceeds height by about 15%, reflecting the laterally compressed body of the mole. These tunnel casts help show that clear, recognizable traces can be preserved in loose, humic soils, and demonstrate the type of traces left by a “lateral-thrust” digger with fully sprawled stance, such as S. aquaticus . Identification of traces on the tunnels of living moles may be applied to the fossil record, in which fossilized burrows with similar marks could be attributed to extinct burrowing moles or mole-like locomotion.     

A Suite of Dermestid Beetle Traces on Dinosaur Bone from the Upper Jurassic Morrison Formation,Wyoming, USA

Most studies of insect traces on fossil bone deal with one or two trace morphs found on isolated bone fragments, making it difficult to identify the trace-maker and its behavior. We report the discovery of a suite of insect traces on an articulated Camptosaurus dinosaur skeleton that permits the identification of the trace-maker and interpretations of its behavior. The traces include mandible marks, pits, and shallow bores on cortical bone, and deep, meandering furrows and tunnels (borings) on articular surfaces. The interiors of bones are intensely mined, and the cavities and borings are filled with fine bone fragments (insect frass). The distinctive mandible marks consist of opposing sets of parallel grooves, indicating the maker had two apical teeth set on symmetrical mandibles and that all of the traces were made by a single taxon. Comparison of the fossils with the mandible morphology and bone traces of extant insects indicates dermestid beetles made the traces. Based on extant dermestid behavior, soft tissues were likely absent and the bones were lipid-laden when the traces were made. Examination of more than 5,000 bones from the Morrison and Cedar Mountain formations shows insect traces on bone are common but overlooked and that many bones are substantially damaged by insect mining. The key to the recognition of these important yet subtle traces is a search model and an intense, oblique light source.     

Lunulichnus Tuberosus Ichnogen. and Ichnosp. Nov. from the Early Eocene Wasatch Formation,Fossil Butte National Monument,Wyoming: An Arthropod-Constructed Trace Fossil Associated with Alluvial Firmgrounds

A new trace fossil, Lunulichnus tuberosus, is described from fluvial deposits of the Wasatch Formation (early Eocene) at Fossil Butte National Monument, southwestern Wyoming, USA. L. tuberosus are straight, vertical to obliquely oriented, unlined cylindrical burrows with pronounced crescent-shaped wall sculptings. In situ examples of these trace fossils are most commonly preserved as sand-filled casts emanating from the erosional bases of fluvial channel sandstone bodies into underlying floodplain mudstone/siltstone beds. L. tuberosus is interpreted as the dwelling trace of a stream-dwelling decapod crustacean. Excellent preservation of fine detail, particularly their diagnostic crescent-shaped wall sculptings, support the hypothesis that L. tuberosus were excavated in firm substrata subjacent to fluvial erosional surfaces. As such, they are interpreted as constituents of alluvial Glossifungites trace fossil assemblages.     

New reconstruction of <Emphasis Type="Italic">Kimberella</Emphasis>, problematic Vendian metazoan

Six groups of fossil remains of Kimberella quadrata are described. They represent the imprints of the body in different types of preservation (including the group of specimens that are elongated more than twice in comparison with the common ones) and also the feeding traces and mucus secretions. The imprint is considered to be created only by the upper side of the body. The fossil material shows that Kimberella had hard sclerites, probably of aragonite, and several teeth in its mouth. Kimberella is suggested to have “the mantle” with sclerites, wider foot, which was spread over the outer surface of the mantle, and the strong transverse and longitudinal musculature.     

DEVELOPMENT AND SOCIAL FUNCTIONS OF SIGNATURE WHISTLES IN BOTTLENOSE DOLPHINS TURSIOPS TRUNCATUS

ABSTRACT

Bottlenose dolphins Tursiops truncatus produce individually distinctive signature whistles. Dolphins recognize the signature whistles of animals with which they share a social bond. Signature whistles develop within the first few months of life and are stable for a lifetime. Vocal learning appears to play a role in the development of signature whistles in bottlenose dolphins. The signature whistles of most female dolphins and about half of male dolphins differ from those of their mothers. Some dolphin calves born in captivity develop a signature whistle that matches either man-made whistles or those of an unrelated dolphin. Dolphins retain the ability as adults to imitate the whistles of animals with which they share strong individual-specific social relationships, bonds which may change throughout their lifetime. The exceptional imitative abilities of dolphin infants and the retention of this ability in adults may be related to the maintenance of changing individual specific social relationships. Individual recognition by the voice may differ in marine vs terrestrial mammals. Diving marine mammals may not be able to rely upon involuntary voice cues for individual recognition, but rather may require vocal learning to maintain a stable signature as their vocal tract changes shape with increasing pressure during a dive.     

Dental functional traits of mammals resolve productivity in terrestrial ecosystems past and present

We have recently shown that rainfall, one of the main climatic determinants of terrestrial net primary productivity (NPP), can be robustly estimated from mean molar tooth crown height (hypsodonty) of mammalian herbivores. Here, we show that another functional trait of herbivore molar surfaces, longitudinal loph count, can be similarly used to extract reasonable estimates of rainfall but also of temperature, the other main climatic determinant of terrestrial NPP. Together, molar height and the number of longitudinal lophs explain 73 per cent of the global variation in terrestrial NPP today and resolve the main terrestrial biomes in bivariate space. We explain the functional interpretation of the relationships between dental function and climate variables in terms of long- and short-term demands. We also show how the spatially and temporally dense fossil record of terrestrial mammals can be used to investigate the relationship between biodiversity and productivity under changing climates in geological time. The placement of the fossil chronofaunas in biome space suggests that they most probably represent multiple palaeobiomes, at least some of which do not correspond directly to any biomes of today's world.     

A new fossil record of Thyrsopteridaceae (Cyatheales) from the mid-Cretaceous amber of Myanmar

Paleopalynology evidence and megafossil records indicated that tree fern order Cyatheales, played an important role in Mesozoic terrestrial ecosystem. Few fossil records of the family Thyrsopteridaceae have been reported so far. In the present study, we describe a distinctive fertile pinnule segment of a fern plant preserved in a mid-Cretaceous amber from Myanmar. The well-preserved fertile pinnule is identified as a new species of the extant tree fern genus Thyrsopteris (Thyrsopteridaceae): Thyrsopteris cyathindusia n. sp. It represents the second fossil species of Thyrsopteridaceae found in the mid-Cretaceous amber from Myanmar. The new species shows distinctive characteristics of the sporophyll that are considered paleoecologically/paleobiogeographically significant for evolution of the Thyrsopteridaceae.     

A new genus and species of darner dragonfl y (Aeshnidae: Odonata) from the lower Eocene of Laguna del Hunco,Patagonia, Argentina

A new genus of Aeshnidae, Huncoaeshna n. gen., based on Huncoaeshna corrugata n. gen., n. sp., is erected from Laguna del Hunco (Ypresian) in Patagonia Argentina. The specimen presents a special kind of preservation with the middle part of the wing wrinkled. The presence of only two fossil specimens of Aeshnidae in South America is surely due to the lack of paleontomologists and collections of fossil insects in the subcontinent.     

Three New Ichnogenera of Biting and Gnawing Traces on Reptilian and Mammalian Bones: A Case Study from the Miocene of the Czech Republic

The Ahníkov (Miocene, Czech Republic) site represents a concentration of vertebrate skeletal remains in a swamp setting. Autochthonous bone deposits were strongly altered by sedimentary processes and early diagenesis. Biting and gnawing traces recognized on hard animal tissues (bones, teeth, antlers, turtle thoraces) represent seven recurring morphotypes. The following ichnotaxa are erected: Nihilichnus nihilicus n. igen. et n. isp., Nihilichnus mortalis n. isp., Machichnus regularis n. igen. et n. isp., Machichnus multilineatus n. isp., Machichnus bohemicus n. isp., and Brutalichnus brutalis n. igen. et n. isp. Each kind of bones or similar substrates bears a specific proportion of various bite traces but no observed morphotype is specific for a single substrate. Ethologically, traces of sharpening of teeth are principally different from predation traces. The beavers Steneofiber eseri and Steneofiber depereti, the carnivore Amphicyon sp. and the crocodiles are presumed as the tracemakers.