Extinction and re-evolution of similar adaptive types (ecomorphs) in Cenozoic North American ungulates and carnivores reflect van der Hammen's cycles

  title={Extinction and re-evolution of similar adaptive types (ecomorphs) in Cenozoic North American ungulates and carnivores reflect van der Hammen's cycles},
  author={T. J. Meehan and L. D. Martin},
  • T. Meehan, L. Martin
  • Published 7 February 2003
  • Environmental Science, Geography
  • Naturwissenschaften
Numerous patterns in periodicity (e.g., climate, extinction, and sedimentary cycles) and evolutionary change (e.g., chronofaunas and coordinated stasis) have been described based on aspects of the geologic record. Recently, convergent occurrences of faunal types or "repeating faunas" have received attention, but a highly specific, iterative pattern was first reported over 40 years ago. In the late 1950s, van der Hammen described climatic/floral cycles on the order of six million years based on… 

Extinction may not be forever

The phenomenon of ecomorph evolution and the hypothesis of iterative climatic cycles are reviewed and understanding of the underlying causes may lead to predictive theories of global biostratigraphy, evolutionary processes, and climatic change.

Functional ecological convergence between the thylacine and small prey-focused canids

This study finds little support for a wolf/dog-like functional ecology in the thylacine, with it instead being most similar to mid-sized canids such as African jackals and South American ‘foxes’ that mainly take prey less than half their size.

Identifying Aquatic Habits Of Herbivorous Mammals Through Stable Isotope Analysis

The results show that the mean δ18O value of fossil specimens is an effective tool for assessing the aquatic habits of extinct species, and is not significantly different from those of the associated fauna.

Evolving between land and water: key questions on the emergence and history of the Hippopotamidae (Hippopotamoidea, Cetancodonta, Cetartiodactyla)

The fossil record of the Hippopotamidae can shed light on three major issues in mammalian evolution, namely the sudden appearance of hippopotamines in the late Miocene, the subsequent rampant endemism in African basins, and the Pleistocene expansion of Hippopotamus.

Biological hierarchies and the nature of extinction

It is demonstrated how MALF fits into a hierarchical framework, showing that MALf can be a primary forcing mechanism at lower scales that still results in differential survivorship patterns at the species and clade level which vary depending upon the initial environmental forcing mechanism.

The Dire Consequences of Specializing on Large Herbivores

  • Branden T. Neufeld
  • Environmental Science
    USURJ: University of Saskatchewan Undergraduate Research Journal
  • 2018
Niche differentiation is a way in which similar species avoid competition. Some species do this by specializing in certain prey items. This review aims to determine why the dire wolf (Canis dirus)

Canine Evolution in Sabretoothed Carnivores: Natural Selection or Sexual Selection?

Scaling relationships indicate the probable importance of sexual selection in the evolution of the hypertrophied sabretooth anterior dentition.

Morphological convergence of the prey-killing arsenal of sabertooth predators

Results indicate that sabertooth morphs with longer, thinner canines show more robust limb proportions, and indicate a positive functional relationship between saber elongation and increased forelimb robustness, which suggests that saber carnivorans demonstrated niche partitioning of predation strategies according to canine shape and correspondingForelimb morphology.

Craniofacial morphology and feeding behavior in Canis dirus, the extinct Pleistocene dire wolf

The results indicated that the extinct dire wolf was similar to the living gray wolf in 11 of the 15 indices, and it is inferred that the dire wolf exhibited feeding behavior that approached that of the livinggray wolf, but may have differed in killing technique, where it held longer to its struggling prey.



Ten years in the library: new data confirm paleontological patterns.

  • J. Sepkoski
  • Geology, Environmental Science
  • 1993
A comparison is made between compilations of times of origination and extinction of fossil marine animal families published in 1982 and 1992; diversity curves compiled from the two data bases are very similar, with a goodness-of-fit of 99.


The term chronofauna 1 is proposed to differentiate faunal units in which time is an important factor from those in which it is not, and to gain information concerning both physical and biological aspects of environment adequate to provide a background for study of many phases of adaptive modifications of animals.


Pollen analysis has opened the possibility for the first time of also making detailed investigations on eventual climatic fluctuations of a minor order, and one can study now the changes of the flora and vegetation at relatively short time intervals if the sediments are favorable.

Fossil History of the Terrestrial Carnivora

Carnivores, because of their position on the ecological pyramid, are considerably rarer than their prey. They are also often intelligent and solitary animals, so that their chances of dying in a

Palynology of uppermost Jurassic and lowermost Cretaceous strata in the Eastern Netherlands

The present investigation is a systematical treatment of the sporomorphs from strata at the Jurassic-Cretaceous boundary in the eastern Netherlands Twente area, and an attempt to apply palynology to

Punctuated equilibria: an alternative to phyletic gradualism

Editorial introduction. Moving from populations to species. we recall that the process of speciation as seen through the hyperopic eyes of the paleontologist is an old and venerable theme. But the

The Paleocene and lower Eocene pollen flora of Guyana

A description is given of a Paleocene and Lower Eocene pollen flora of two bore-holes in Guana. Some new species are described and some remarks are made on their stratigraphical significance. Pollen

Tempo and mode in evolution.

  • W. FitchF. Ayala
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1994
In the introduction to his book, Simpson averred that an essential part of his study was an "attempted synthesis of paleontology and genetics," an effort that pervaded the whole book, but was particularly the subject of the first two chapters, which accounted for nearly half the book's pages.

Paläoklima, Stratigraphie und Evolution

ZusammenfassungDas ideale präquartäre Pollendiagramm gibt uns in gewissem Sinn ein zeiträumliches Bild der Vegetation. Die Vegetationsänderungen dieses Bildes werden hauptsächlich durch zwei Faktoren


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