Search the Article Database:

Search our library of articles, papers and other published materials. You can use keywords or boolean-style search:

Blood pressure adaptation in vertebrates: Comparative biology

With evolution from water to land, the osmotic regulation of body fluids and cardiovascular systems of vertebrates evolved to cope with dryness and gravity. While aquatic vertebrates can use buoyancy to compensate for the effects of gravity, terrestrial vertebrates cannot, and must circulate blood throughout their body – a necessity that likely led to the development of strong hearts and high blood pressure. These changes may be supported by anatomical evolution of the cardiovascular system and by functional evolution, with

View Details + Download

The evolutionary biomechanics of locomotor function in giant land animals

Giant land vertebrates have evolved more than 30 times, notably in dinosaurs and mammals. The evolutionary and biomechanical perspectives considered here unify data from extant and extinct species, assessing current theory regarding how the locomotor biomechanics of giants has evolved. In terrestrial tetrapods, isometric and allometric scaling patterns of bones are evident throughout evolutionary history, reflecting general trends and lineage-specific divergences as animals evolve giant size. Added to data on the scaling of other supportive tissues and neuromuscular control, these

View Details + Download

The ruminantia (mammalia, cetartiodactyla) from the oligocene to the early miocene of Western Europe: systematics, plaeoecology and palaeobiogeography

Nowadays, the ruminants are the most ecologically diverse hoofed mammals of the world. All the extent of families (including related species from the Burdigalian) and feeding habits can be deduced from the mandible shape. The Tragulidae possess a small coronoid process, a shortened diastema, and a weak incisura vasorum. The Eupecora have an elongated diastema (extremely extended within the Giraffidae), the coronoid process is elongated. The Cervidae are generally more slender than the Bovidae. A trend from the massive mandible

View Details + Download

The interrelationships of higher ruminant families with special emphasis on the members of the cervoidea

We analyze the interrelationships of the higher (Pecoran) ruminants, and suggest possible relationships between these families and the various genera of the polyphyletic assemblage “Gelocidae.” We also review the developmental processes of the cranial appendages of the living homed ruminant families, and conclude that giraffid ossicones, bovid horns, and cervid antlers cannot be considered to be homologous with each other. The characters that have been used in the past and in this paper to distinguish pecoran families are discussed and

View Details + Download

Comparisons of Schansitherium tafeli with Samotherium boissieri (Giraffidae, Mammalia) from the Late Miocene of Gansu Province, China

We are describing and figuring for the first time skulls of Schansitherium tafeli, which are abundant in the Gansu area of China from the Late Miocene. They were animals about the size of Samotherium with shorter necks that had two pairs of ossicones that merge at the base, which is unlike Samotherium. The anterior ossicones consist of anterior lineations, which may represent growth lines. They were likely mixed feeders similar to Samotherium. Schansitherium is tentatively placed in a very close

View Details + Download

Old world ruminant morphophysiology, life history, and fossil record: exploring key innovations of a diversification sequence

The omasum of pecoran ruminants (which is absent in tragulids) and shorter gestation periods in non-giraffid crown pecorans (as opposed to giraffids) could represent cases of key innovations that caused disparity in species diversity in extant ruminants. Literature suggests that the different ruminant groups inhabited similar niche spectra at different times, supporting the ‘increased fitness’ interpretation where a key innovation does not mainly open new niches, but allows more efficient use of existing ones. In this respect, we explored data

View Details + Download

Key innovations in ruminant evolution: A paleontological perspective

Key innovations are newly acquired structures that permit the performance of a new function and open new adaptive zones, and are, therefore, of paramount significance for understanding the history of the Ruminantia, particularly its diversification through the Miocene. Here we review and discuss what is known about these evolutionary novelties, with special emphasis on the appearance and evolution of cranial appendages and highcrowned (or hypsodont) teeth. Cranial appendages probably favored the diversification of pecorans by being structures strongly related to

View Details + Download

Dietary innovations spurred the diversification of ruminants during the Caenozoic

Global climate shifts and ecological flexibility are two major factors that may affect rates of speciation and extinction across clades. Here, we connect past climate to changes in diet and diversification dynamics of ruminant mammals. Using novel versions of Multi-State Speciation and Extinction models, we explore the most likely scenarios for evolutionary transitions among diets in this clade and ask whether ruminant lineages with different feeding styles (browsing, grazing and mixed feeding) underwent differential rates of diversification concomitant with global

View Details + Download

The Giraffe Biology, Ecology, Evolution and Behaviour (Book)

In one form or another, giraffes have been around for a very long time. And so has Homo sapiens. The interaction between giraffes and humans starts way back in prehistory, and rock art (paintings and engravings) is found all over Africa from Morocco, Algeria and Libya in the north, through Ethiopia, Somalia, Kenya and Tanzania in the east, to Botswana, Zimbabwe, Namibia and Mozambique in the south (Le Quellec 1993, 2004; Muzzolini 1995). Wherever, in fact, there has been savannah.

View Details + Download

Hypsodonty and tooth facet development in relation to diet and habitat in herbivorous ungulates: implications for understanding tooth wear

1. The evolution of high-crowned teeth or hypsodonty in herbivorous mammals is widely interpreted as a species specific adaptation to increasingly wear-inducing diets and environments at evolutionary time scales, with internal abrasives (such as phytoliths in grasses) and/or external abrasives (such as dust or grit) as putative causative factors. The mesowear score (MS) instead describes tooth wear experienced by individual animals during their lifetime. 2. Under the assumption that the abrasiveness that causes the MS in individuals is the same

View Details + Download
© All articles are copyrighted to the original authors/publishers unless otherwise stated. Any PDF files provided by the GRC are for personal use only and may not be reproduced. The files reflect the holdings of the GRC library and only contain pages relevant to giraffe study, and may not be complete. Users are obliged to follow all copyright restrictions.

Privacy Policy Cookie Policy