scholarly journals Dietary palaeoecology of an Early Cretaceous armoured dinosaur (Ornithischia; Nodosauridae) based on floral analysis of stomach contents

2020 ◽  
Vol 7 (6) ◽  
pp. 200305
Author(s):  
Caleb M. Brown ◽  
David R. Greenwood ◽  
Jessica E. Kalyniuk ◽  
Dennis R. Braman ◽  
Donald M. Henderson ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Cross Sections ◽  
Direct Evidence ◽  
Abdominal Cavity ◽  
Stomach Contents ◽  
Leaf Tissue ◽  
Conifer Forest ◽  
Large Herbivores ◽  
Clearwater Formation ◽  
Northern Alberta

The exceptionally well-preserved holotype of the armoured dinosaur Borealopelta markmitchelli (Ornithischia; Nodosauridae) from the Early Cretaceous (Clearwater Formation) of northern Alberta preserves a distinct mass within the abdominal cavity. Fourteen independent criteria (including: co-allochthony, anatomical position, gastroliths) support the interpretation of this mass as ingested stomach contents—a cololite. Palynomorphs in the cololite are a subset of the more diverse external sample. Analysis of the cololite documents well-preserved plant material dominated by leaf tissue (88%), including intact sporangia, leaf cross-sections and cuticle, but also including stems, wood and charcoal. The leaf fraction is dominated (85%) by leptosporangiate ferns (subclass Polypodiidae), with low cycad–cycadophyte (3%) and trace conifer foliage. These data represent the most well-supported and detailed direct evidence of diet in an herbivorous dinosaur. Details of the dietary palaeoecology of this nodosaur are revealed, including: selective feeding on ferns; preferential ingestion of leptosporangiate ferns to the exclusion of Osmundaceae and eusporangiate ferns such as Marattiaceae; and incidental consumption of cycad–cycadophyte and conifer leaves. The presence of significant (6%) charcoal may represent the dietary use of recently burned conifer forest undergoing fern succession, early evidence of a fire succession ecology, as is associated with many modern large herbivores.

scholarly journals Plankton food for benthic fish: de visu evidence of trophic interaction between rainbow wrasse (Coris julis) and pelagic tunicates (Pegea confoederata)

2017 ◽  
Vol 8 (2) ◽  
Author(s):  
Domenico D'Alelio ◽  
Gabriella Luongo ◽  
Iole Di Capua
Keyword(s):  
Trophic Interactions ◽  
Direct Evidence ◽  
Stomach Contents ◽  
Trophic Interaction ◽  
Benthic Fish ◽  
Marine Animals ◽  
Gulf Of Naples ◽  
Santa Croce ◽  
Rocky Outcrop ◽  
Recreational Scuba

Salps (pelagic tunicates) are rarely observed in nature and trophic interactions involving them mainly rely on the inspection of stomach contents of their potential predators. Moreover, salps have soft bodies that are hardly identified in potential consumers. We involved recreational SCUBA-divers and photographers in collecting de visu evidence of i) massive occurrence of salps and ii) trophic interactions involving salps as preys and benthic animals as consumers. Direct evidence of trophic interactions between salps and benthic fish was documented by photographic frames. We detected a long colony of the salp Pegea confaederata being transported by currents close to the substrate on top of Banco di Santa Croce, an underwater rocky outcrop in the Gulf of Naples (Italy). An individual of the rainbow wrasse Coris julis attacked the above-mentioned salp colony by selectively detaching individuals and biting their stomach. Our report of a trophic interaction between labrids and salps is the second in fifty years and the previous one was only indirect. In this study, citizen science allowed detecting both neglected marine animals like salps and trophic interactions involving them. Visual, direct evidence of predation on salps by benthic fish adds further knowledge about patterns of living-matter fluxes between plankton and benthos, opening new questions on the potential of global change in modifying the efficient circulation of organic matter in marine systems.

Direct evidence for the existence of multi-walled carbon nanotubes with hexagonal cross-sections

Carbon ◽  
2012 ◽  
Vol 50 (7) ◽  
pp. 2524-2529 ◽  
Author(s):  
Zhanbing He ◽  
Xiaoxing Ke ◽  
Sara Bals ◽  
Gustaaf Van Tendeloo
Keyword(s):  
Carbon Nanotubes ◽  
Cross Sections ◽  
Direct Evidence ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Paleohaemoproteus burmacis gen. n., sp. n. (Haemospororida: Plasmodiidae) from an Early Cretaceous biting midge (Diptera: Ceratopogonidae)

Parasitology ◽  
2005 ◽  
Vol 131 (1) ◽  
pp. 79-84 ◽  
Author(s):  
G. POINAR ◽  
S. R. TELFORD
Keyword(s):  
Early Cretaceous ◽  
Malaria Parasite ◽  
Developmental Stages ◽  
Abdominal Cavity ◽  
Malarial Parasite ◽  
Fossil Species ◽  
Extinct Species ◽  
Biting Midge ◽  
Extant Species ◽  
Wide Range

Paleohaemoproteus burmacis gen. n., sp. n. (Haemospororida: Plasmodiidae) is described from the abdominal cavity of a female biting midge (Diptera: Ceratopogonidae) preserved in 100 million year old amber from Myanmar (Burma). The description is based on the developmental stages of oocysts and sporozoites. The fossil species differs from extant species of Haemoproteus by its wide range of oocyst sizes, small sporozoites and occurrence in an extinct species of biting midge. Numerous sporozoites in the abdominal cavity suggest that the biting midge was an effective vector of this malarial parasite. Characters of the biting midge suggest that the host was a large, cold-blooded vertebrate. This is the earliest record of a malaria parasite and first indication that Early Cretaceous reptiles were infected with haemosporidial parasites.

scholarly journals Investigating Possible Gastroliths in a Referred Specimen of Bohaiornis guoi (Aves: Enantiornithes)

2021 ◽  
Vol 9 ◽  
Author(s):  
Shumin Liu ◽  
Zhiheng Li ◽  
Alida M. Bailleul ◽  
Min Wang ◽  
Jingmai O’Connor
Keyword(s):  
Digestive System ◽  
Multidisciplinary Approach ◽  
Direct Evidence ◽  
Soft Tissues ◽  
Indirect Evidence ◽  
Stomach Contents ◽  
Gastric Mill ◽  
Limited Evidence ◽  
X Ray ◽  
Two Samples

Gastroliths, where preserved, can provide indirect evidence regarding diet in extinct avian and non-avian dinosaurs. Masses of gastroliths consistent with the presence of a gastric mill are preserved in many Early Cretaceous Jehol birds mostly belonging to the Ornithuromorpha. Gastroliths are also present in basal birds Sapeornis and Jeholornis in which herbivory is supported by direct evidence these taxa consumed seeds in the form of crop or stomach contents. Although gastroliths have been correlated with herbivory in non-avian dinosaurs, the presence of gastroliths and bone together in Ambopteryx calls this association in to question. Despite being known from greater numbers of specimens than other avian lineages, no unequivocal direct or indirect evidence of diet has been recovered from Jehol deposits for the Enantiornithes. A referred specimen of Bohaiornis guoi IVPP V17963 was described as preserving a small number of gastroliths interpreted as rangle, gastroliths whose function is cleaning the stomach in extant raptorial birds. However, based on comparison with gastroliths in other Jehol birds, it has alternatively been suggested that the identified structures are not ingested stones at all but some unusual mineral precipitate. Considering the limited evidence regarding diet in Enantiornithes and the importance of accurately identifying the traces in Bohaiornis in order to understand the enantiornithine digestive system, we extracted two samples of these purported gastroliths and explored these traces using computerized laminography scanning, scanning electron microscopy, energy dispersive x-ray spectroscopy, ground sections, and body size to gastral mass regressions. Similar analyses were conducted on gastroliths extracted from undisputed gastral masses of two Jehol ornithuromorphs and the non-avian pennaraptoran Caudipteryx. The combined results contradict the hypothesis that these traces are gastroliths and supports the interpretation they are mineral precipitate, most likely authigenic quartz (chalcedony). Although authigenesis is commonly responsible for the preservation of soft tissues, it is unclear if these traces record part of the tissues of this Bohaiornis. This study highlights the importance of a multidisciplinary approach in understanding unusual traces in the fossil record and reveal a previously unidentified taphonomic phenomenon in fossils from Jehol deposits.

scholarly journals Reinterpretation of a previously described Jehol bird clarifies early trophic evolution in the Ornithuromorpha

2018 ◽  
Vol 285 (1871) ◽  
pp. 20172494 ◽  
Author(s):  
Xiaoting Zheng ◽  
Jingmai K. O'Connor ◽  
Xiaoli Wang ◽  
Yan Wang ◽  
Zhonghe Zhou
Keyword(s):  
New Species ◽  
Early Cretaceous ◽  
Tooth Loss ◽  
Direct Evidence ◽  
New Taxon ◽  
Gastric Mill ◽  
Ecological Inference ◽  
Close Inspection ◽  
Apparent Loss ◽  
A New Species

STM35-3 from the Yixian Formation is the only Early Cretaceous ornithuromorph preserving direct evidence of granivory. The crop contains numerous seeds and the preservation of gastroliths presumably within the ventriculus indicates this diet was paired with the presence of a gastric mill as in living granivorous birds. STM35-3 was originally referred to Hongshanornis longicresta , member of a diverse clade of small, basal ornithuromorphs with elongate hindlimbs known as the Hongshanornithidae. Hindlimb proportions suggest that hongshanornithids were wading birds, an ecological inference somewhat in conflict with direct evidence suggesting Hongshanornis fed on seeds. However, close inspection of STM35-3 reveals that the specimen represents a new species not closely related to hongshanornithids, distinguished by large forelimbs that exceed the length of the hindlimbs, robust and narrow coracoids, and a delicate edentulous rostrum. By contrast, all hongshanornithids have hindlimbs that far exceed the length of the forelimbs, coracoids with wide sternal margins, and small teeth throughout the upper and lower jaws. Reinterpretation of this new taxon, Eogranivora edentulata gen. et sp. nov, helps to clarify trophic driven patterns of tooth loss within the Ornithuromorpha. Apparent loss of the hallux may represent the first such occurrence in a Mesozoic bird and suggests a highly terrestrial lifestyle.

Architecture of the microtubule component of mitotic spindles from Dictyostelium discoideum

1985 ◽  
Vol 75 (1) ◽  
pp. 93-129
Author(s):  
J.R. McIntosh ◽  
U.P. Roos ◽  
B. Neighbors ◽  
K.L. McDonald
Keyword(s):  
Dictyostelium Discoideum ◽  
Cross Sections ◽  
Direct Evidence ◽  
Structural Data ◽  
Three Dimensions ◽  
Serial Sections ◽  
Mitotic Spindles ◽  
Central Spindle ◽  
Nearest Neighbours ◽  
Early Anaphase

Ten mitotic spindles from Dictyostelium discoideum have been studied by electron microscopy of serial sections. We have used computer graphics to track individual microtubules (MTs) in three dimensions and to compare seven spindles at different stages of anaphase and telophase. The central spindle of early anaphase is formed by the interdigitation of two sets of pole-associated MTs. The distribution of MT lengths at this stage is hetero-disperse. During anaphase total MT length decreases by a factor of about 2 as a result of two opposing changes in MT length: the longer MTs that interdigitate become even longer, while the short MTs, including those attached to kinetochores, become shorter still and decrease in number. The extent of MT interdigitation is less in longer spindles than in short ones. In metaphase and early anaphase, the MTs are not in an ordered arrangement as seen in spindle cross-sections, but as anaphase proceeds the MTs cluster into a square-packed, paracrystalline bundle in which most of the nearest neighbours come from opposite poles. This arrangement and the condensation-like increase in order suggest the existence of specific interactions between antiparallel MTs. A quantitative analysis of MT positions supports this interpretation, but direct evidence for convincing bridges between MTs is lacking. The pole-distal ends of the MTs that interdigitate show an irregular termination (C-shaped ends in transverse view), as is characteristic of MTs that are either adding or losing subunits. Since it is these interdigitating MTs that elongate, and since the shortening MTs show the customary blunt endings, we conclude that subunits add to the interdigitating MTs at their pole-distal ends. This inference, combined with other structural data, suggests that the interdigitating MTs of Dictyostelium are sliding over one another as they polymerize in anaphase. It also suggests a simple model for why the spindle becomes thinner as it elongates. We propose that MT interdigitation defines a region where MTs bind a factor that will associate only with antiparallel MTs. This factor biases the MT assembly equilibrium toward polymer. As the shorter MTs slide out of this region, they lose their polymerization advantage and depolymerize, releasing subunits to contribute to the further elongation of the already longer MTs. The properties of the Dictyostelium spindle are compared with those of both higher and lower eukaryotes.

scholarly journals Reanalysis of putative ovarian follicles suggests that Early Cretaceous birds were feeding not breeding

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Gerald Mayr ◽  
Thomas G. Kaye ◽  
Michael Pittman ◽  
Evan T. Saitta ◽  
Christian Pott
Keyword(s):  
Early Cretaceous ◽  
Fossil Record ◽  
Stomach Contents ◽  
Ovarian Follicles ◽  
Exact Nature ◽  
Carbonaceous Matter ◽  
Jehol Biota ◽  
Food Items ◽  
Micro Pattern ◽  
First Time

Abstract We address the identity of putative ovarian follicles in Early Cretaceous bird fossils from the Jehol Biota (China), whose identification has previously been challenged. For the first time, we present a link to the botanical fossil record, showing that the “follicles” of some enantiornithine fossils resemble plant propagules from the Jehol Biota, which belong to Carpolithes multiseminalis. The botanical affinities of this “form-taxon” are currently unresolved, but we note that C. multiseminalis propagules resemble propagules associated with cone-like organs described as Strobilites taxusoides, which in turn are possibly associated with sterile foliage allocated to Liaoningcladus. Laser-Stimulated Fluorescence imaging furthermore reveals different intensities of fluorescence of “follicles” associated with a skeleton of the confuciusornithid Eoconfuciusornis zhengi, with a non-fluorescent circular micro-pattern indicating carbonaceous (or originally carbonaceous) matter. This is inconsistent with the interpretation of these structures as ovarian follicles. We therefore reaffirm that the “follicles” represent ingested food items, and even though the exact nature of the Eoconfuciusornis stomach contents remains elusive, at least some enantiornithines ingested plant propagules.

McMurray Formation foraminifera within the lower Albian (Lower Cretaceous) Loon River shales of northern Alberta

2007 ◽  
Vol 44 (11) ◽  
pp. 1627-1651 ◽  
Author(s):  
C R Stelck ◽  
F H Trollope ◽  
A W Norris ◽  
S G Pemberton
Keyword(s):  
Lower Cretaceous ◽  
Isotopic Analysis ◽  
Radiometric Dating ◽  
Western Canada ◽  
Fort Mcmurray ◽  
Mcmurray Formation ◽  
Peace River ◽  
Clearwater Formation ◽  
Northeastern Alberta ◽  
Northern Alberta

Early Cretaceous paleogeography and biostratigraphy of western Canada are reviewed in light of a reassessment of foraminiferal and microfloral data from unpublished university theses on the early Albian Loon River shales of the lower Peace River area of northern Alberta (Norris 1951; Trollope 1951). The Loon River Formation, once considered to be an obsolete term, comprises numerous “zones” of foraminifera, radiolarian, and algal cysts, in ascending order Rectobolivina sp., lower Radiolarian zone, lower Leiosphaeridia zone, Haplophragmoides yukonensis, upper Radiolarian zone, upper Leiosphaeridia zone, Trochammina mcmurrayensis, Valvulineria loetterlei, Haplophragmoides topagorukensis, Marginulinopsis collinsi, and Haplophragmoides gigas minor. The upper part of the Loon River Formation, from the upper Radiolarian zone onwards, correlates with the McMurray, Wabiskaw, and Clearwater formations of the Fort McMurray area of northeastern Alberta. Molluscan data from various localities in western Canada indicates that the entire Loon River succession occurred within the early Albian. The presence of Inoceramus dowlingi and Cleoniceras sp. with the Marginulinopsis collinsi microfauna permits correlation of the type Clearwater Formation and type McMurray Formation with the Moosebar Formation of northeastern Bristish Columbia. An anomalous thick sequence of Leiosphaeridia (algal cysts) beds, bounded above and below by radiolarian-bearing strata, occurs in the mid part of the Loon River shales outcropping ~40 km along the lower Peace River. The Trochammina mcmurrayensis microfauna occurs 2–3 m below Inoceramus dowlingi and 30 m above Cleoniceras sp., and above the upper Leiosphaeridia zone. The radiolarian and Leiosphaeridia beds are considered to be the offshore neritic homotaxial equivalent of deltaic strata in the upper part of the McMurray Formation. The mid and lower Loon River shales are potential oil sources for the tar of the McMurray Formation, and this is supported by recent radiometric dating of the tar by Rhenium–Osmium isotopic analysis.

scholarly journals Exceptionally well-preserved Early Cretaceous leaves of Nilssoniopteris from central Mongolia

2018 ◽  
Vol 58 (2) ◽  
pp. 135-157 ◽  
Author(s):  
Fabiany Herrera ◽  
Gongle Shi ◽  
Gombosuren Tsolmon ◽  
Niiden Ichinnorov ◽  
Masamichi Takahashi ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Direct Evidence ◽  
Leaf Surface ◽  
Insect Herbivory ◽  
Bulk Sediment ◽  
Sediment Samples ◽  
Anatomical Features ◽  
Central Mongolia ◽  
Abaxial Leaf Surface ◽  
Use Efficiency

AbstractTwo new Early Cretaceous (Aptian-Albian) species of fossil bennettitalean leaves are described from central Mongolia and assigned to the genus Nilssoniopteris. Nilssoniopteris tomentosa F.Herrera, G.Shi, Tsolmon, Ichinnorov, Takahashi, P.R.Crane, et Herend. sp. nov., isolated from bulk sediment samples collected for mesofossils in the Tevshiingovi Formation at the Tevshiin Govi opencast coal mine, is distinctive in having a dense, well-developed indumentum composed of branched, flattened multicellular trichomes on the abaxial leaf surface. This species provides the first direct evidence of complex multicellular trichomes in Bennettitales and adds to the evidence of leaf anatomical features in the group that were probably advantageous in increasing water use efficiency and/or perhaps had other functions such as deterring insect herbivory. Comparison with other well-preserved leaves of Bennettitales, including Nilssoniopteris shiveeovoensis F.Herrera, G.Shi, Tsolmon, Ichinnorov, Takahashi, P.R.Crane, et Herend. sp. nov., collected as hand specimens from the Khukhteeg Formation at the Shivee Ovoo locality, suggests that the trichome bases seen commonly on the abaxial cuticle of bennettitalean leaves bore trichomes with very low fossilization potential. In some cases these trichomes may have been shed as the leaves matured, but in other cases they probably decayed during diagenesis or were destroyed during the standard processes by which fossil leaf cuticles are prepared.

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