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Articles 1 - 3 of 3
Full-Text Articles in Paleontology
Lilliput Effect Dynamics Across The Cretaceous-Paleogene Mass Extinction: Approaches, Prevalence, And Mechanisms, Matthew Brett Jarrett
Lilliput Effect Dynamics Across The Cretaceous-Paleogene Mass Extinction: Approaches, Prevalence, And Mechanisms, Matthew Brett Jarrett
USF Tampa Graduate Theses and Dissertations
An organism's body size entails both physiological and ecological costs. Furthermore, as a parameter in analyzing organisms, it represents a fundamental and essential morphometric character. Reductions in size following mass extinction is a commonly observed phenomenon in the fossil record. This study examines the evolutionary significance of this phenomenon termed the: 'Lilliput Effect' by proposing that it represents a rapid evolutionary response to altered selection pressures during a mass extinction. This primary hypothesis is evaluated against two additional hypotheses of size reduction: 1) stunted growth as a response to stressed ecosystems, and/or 2) mass extinctions are size selective.
These hypotheses …
Optimizing Methods For Extraction Of Organic Compounds From Molluscan Shells, Kaydee Jo West
Optimizing Methods For Extraction Of Organic Compounds From Molluscan Shells, Kaydee Jo West
USF Tampa Graduate Theses and Dissertations
Mollusk shells contain proteins within and between the crystals of calcium carbonate. These organic molecules play an important role in biomineralization and shell function, and their stable isotope ratios of carbon and nitrogen are also thought to record important ecological information about the animal's diet and nutrient sources. These proteins can be preserved for millions of years, offering potential insight into pre-anthropogenic ecological conditions. However, shell organics in older shells are typically recovered in reduced abundances due to leaching and remaining organics are often converted from insoluble proteins to soluble, free amino acids, making them difficult to detect and recover. …
Age Re-Assessment Of The Cave Bear Assemblage From Urşilor Cave, North-Western Romania, Marius V. Robu
Age Re-Assessment Of The Cave Bear Assemblage From Urşilor Cave, North-Western Romania, Marius V. Robu
International Journal of Speleology
The most common methods used for assessing the relative age of a cave bear bone assemblage are the P4/4 index (morphodynamic index of the cave bear fourth premolar), the K-index and the Index of Plumpness (both used for cave bear’s 2nd metatarsal). Preliminary work on this (Robu et al., 2011), for Urşilor Cave (NW Romania), has indicated one of the youngest European cave bear populations. As the number of extracted fossil bones from the palaeontological excavation increased recently, a re-assessment of the of the age of the cave bear assemblage is necessary. 206 cave bear fourth …