Results 41 to 50 of about 24,683 (81)

An ubiquitous ~62 Myr periodic fluctuation superimposed on general trends in fossil biodiversity [PDF]

arXiv, 2010
A 62 Myr periodicity is superimposed on other longer-term trends in fossil biodiversity. This cycle can be discerned in marine data based on the Sepkoski compendium, the Paleobiology Database, and the Fossil Record 2. The signal also exists in changes in sea level/sediment, but is much weaker than in biodiversity itself.
arxiv  

A virtual world of paleontology [PDF]

, 2014
Computer-aided visualization and analysis of fossils has revolutionized the study of extinct organisms. Novel techniques allow fossils to be characterized in three dimensions and in unprecedented detail. This has enabled paleontologists to gain important
Cunningham, John A, Donoghue, Philip C J, Lautenschlager, Stephan, Rahman, Imran A, Rayfield, Emily J   +4 more
core   +1 more source

Species lifetime distribution for simple models of ecologies

, 2005
Interpretation of empirical results based on a taxa's lifetime distribution shows apparently conflicting results. Species' lifetime is reported to be exponentially distributed, whereas higher order taxa, such as families or genera, follow a broader ...
Flammini, A., Maritan, A., Marsili, M., Pigolotti, S.   +3 more
core   +2 more sources

Mechanics of Tunable Helices and Geometric Frustration in Biomimetic Seashells

, 2013
Helical structures are ubiquitous in nature and engineering, ranging from DNA molecules to plant tendrils, from sea snail shells to nanoribbons. While the helical shapes in natural and engineered systems often exhibit nearly uniform radius and pitch ...
Chen, Wenzhe, Chen, Zi, Dai, Pinqiang, Guo, Qiaohang, Li, Wei, Lin, Junjie, Ren, Kun, Taber, Larry A.   +7 more
core   +1 more source

Introduction to Analytical Paleobiology [PDF]

, 1991
Philip W. Signor, Norman L. Gilinsky
openalex   +1 more source

Evolution of Starfishes: Morphology, Molecules, Development and Paleobiology [PDF]

, 1998

openalex   +1 more source

Evolution of Starfishes: Morphology, Molecules, Development, and Paleobiology. Introduction to the Symposium1 [PDF]

, 2000
Daniel B. Blake, Daniel Janies, Rich Mooi   +2 more
openalex   +1 more source

Evolution of Starfishes: Morphology, Molecules, Development, and Paleobiology. Introduction to the Symposium [PDF]

, 2000
Daniel B. Blake, Daniel Janies, Rich Mooi   +2 more
openalex   +1 more source

The last common bilaterian ancestor [PDF]

, 2002
Many regulatory genes appear to be utilized in at least superficially similar ways in the development of particular body parts in Drosophila and in chordates.
Davidson, Eric H., Erwin, Douglas H.
core  

Atmospheric Consequences of Cosmic Ray Variability in the Extragalactic Shock Model II: Revised ionization levels and their consequences

, 2010
It has been suggested that galactic shock asymmetry induced by our galaxy's infall toward the Virgo Cluster may be a source of periodicity in cosmic ray exposure as the solar system oscillates perpendicular to the galactic plane.
Adrian L. Melott, Aguirre, Alpen, Atri, Bancroft, Binney, Björn, Blaustein, Boucher, Brian C. Thomas, Cornette, Davidson, Dimitra Atri, Djemil, Ejzak, Foukal, Gehrels, Gies, Graham W. Wilson, Harfoot, Hatch, Häder, Jagger, Juckett, Juckett, Kiesecker, Lieberman, Lockwood, Madronich, McCallum, Medvedev, Melott, Melott, Melott, Melott, Melott, Michael J. Murray, Mikhail V. Medvedev, Natarajan, Overholt, Pukkala, Rohde, Ruderman, Scherer, Shaffer, Solanki, Svensmark, Tevini, Thomas, Thomas, Thomas   +50 more
core   +1 more source