نتایج جستجو برای: trace fossil

تعداد نتایج: 91986  

2013
GISELA GRUPE MATTHEW MIKE SCHWEISSING

The biological signal hidden in stable carbon, nitrogen, oxygen and strontium stable isotope ratios in archaeological and fossil skeletal finds give clues to a variety of palaeoecological parameters. In contrast to trace element analysis, these parameters can be assessed on the individual level, which is a major advantage for palaeoanthropology, where single finds prevail over multiple finds at...

Journal: :Science 2000
M W Martin D V Grazhdankin S A Bowring D A Evans M A Fedonkin J L Kirschvink

A uranium-lead zircon age for a volcanic ash interstratified with fossil-bearing, shallow marine siliciclastic rocks in the Zimnie Gory section of the White Sea region indicates that a diverse assemblage of body and trace fossils occurred before 555.3 +/- 0.3 million years ago. This age is a minimum for the oldest well-documented triploblastic bilaterian Kimberella. It also makes co-occurring t...

2014
Nizar Ibrahim David J. Varricchio Paul C. Sereno Jeff A. Wilson Didier B. Dutheil David M. Martill Lahssen Baidder Samir Zouhri

We describe an extensive ichnofossil assemblage from the likely Cenomanian-age 'lower' and 'upper' units of the 'Kem Kem beds' in southeastern Morocco. In the lower unit, trace fossils include narrow vertical burrows in cross-bedded sandstones and borings in dinosaur bone, with the latter identified as the insect ichnotaxon Cubiculum ornatus. In the upper unit, several horizons preserve abundan...

Journal: :Proceedings. Biological sciences 2011
N P Edwards H E Barden B E van Dongen P L Manning P L Larson U Bergmann W I Sellers R A Wogelius

Non-destructive Fourier Transform InfraRed (FTIR) mapping of Eocene aged fossil reptile skin shows that biological control on the distribution of endogenous organic components within fossilized soft tissue can be resolved. Mapped organic functional units within this approximately 50 Myr old specimen from the Green River Formation (USA) include amide and sulphur compounds. These compounds are mo...

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