W. David Lambert

All Saints Episcopal School · Science

Unusual shovel-tusked gomphothere material from the late Clarendonian Black Butte Local Fauna (Juntura Formation, Oregon), including a lower tusk, partial upper tusk, and two mandibles including a second and a third molar, has been described and referred to Platybelodon. Platybelodon has the following diagnostic characteristics: molars strongly dou...

Of the North American gomphotheres, the status of Tetralophodon, primarily known from the Old World, is among the most controversial. This controversy stems from the incompleteness of the North American specimens. Along with elongation of the M/m3s and a tendency towards double trefoiling on the cheek teeth, Tetralophodon is diagnosed by complete t...

There is disagreement among ecologists as to whether ecosystem system behavior in general is the net result of all of the complex internal system interactions (bottom-driven) or if the behavior is driven by a limited number of key processes (top-driven). If ecosystems are primarily bottom-driven in nature, then it is unlikely that any two complex e...

There is disagreement among geologists as to whether ecosystem system behavior in general is the net result of all of the complex internal system interactions (bottom‐driven) or if the behavior is driven by a limited number of key processes (top‐driven). If ecosystems are primarily bottom‐driven in nature, then it is unlikely that any two complex e...

Though relatively common as fossils, isolated proboscidean ivory fragments are difficult to identify below the ordinal level because of their lack of diagnostic gross morphological features. To help rectify this situation, the microstructure of ivory from a wide variety of proboscideans was surveyed, including Zygolophodon, Mammut (family Mammutida...

Animal body sizes reflect the discontinuous architecture of the landscapes in which they live, and consequently their body-mass distributions are distinctly clumped rather than continuous. This architectural discontinuity is generated by ecological processes that discretely operate over micro-, meso-, and macroscales. Therefore, changes in these im...

The giant otter Enhydritherium terraenovae, a New World taxon thought to be related to both the Old World otter Enhydriodon and the extant sea otter Enhydra, was originally described on the basis of relatively limited material, mostly dental. However, an incomplete skeleton of E. terraenovae recovered from the early Hemphillian Moss Acres Racetrack...

The shovel-tusked gomphotheres are normally portrayed scooping up water plants with their shovellike mandibular tusks. This portrayal is based on speculation about the possible functions of the lower tusks and misinterpretation of mandibular-tusk wear patterns that goes back to the 1920s and 1930s. In addition, most literature concerning shovel-tus...

The diagnosis of the shovel-tusked gomphothere genus Amebelodon has been subject to dispute since it was first established by Barbour in 1927. This dispute stems from a failure to evaluate the phylogenetic nature of two characters found in some specimens referred to Amebelodon : four lophs(ids) on some intermediate cheek teeth (M2 and M1) and inter...

Typescript. Thesis (M.S.)--University of Florida, 1989. Vita. Includes bibliographical references (leaves 112-115).