Funcional morphology on microfossils: and increasing subject of study

CALVO MARCILESE, L; PEREZ PANERA, J; CUSMINSKY , G. C.; BERNASCONI, E.; FERRERO, L; MARQUEZ, MELINA; RAMOS LORENA; COVIAGA, CORINA; PEREZ, PATRICIA

Mendoza

Congreso; 4th International Paleontological Congress; 2014

International Paleontological Asociation

The major purpose of this contribution is to discuss the functional morphology of diverse forms of calcareous microfossils. For decades one of the principal difficulties of comparative biology has been determining the function of a particular anatomical form. Shapes and forms are strongly correlated with life habit and function. So, the clue is to identify what is the adaptive advantage, if any, for selected variable morphological characters, and to use that information for paleobiological interpretations. Traditionally, micropaleontology and paleobiology have been in opposite sides, since microfossils are abundant in almost all types of sediments and are produced by species that evolve rapidly, their principal use has been in bioestratigraphy or connected to marine geology, with limited interest in paleobiological aspects. Many marine microorganisms are hard to be cultured in the laboratory, so the study of its biology is not easy. Despite this tradition, micropaleontologists have become increasingly interested in the paleobiology of their fossils. Nowadays, it is possible to find many studies related to the use of the substrate, diet, trophic webs and shell morphology in microfossils; for example, leg morphology in ostracoda and its relation to the type of sediment and way of locomotion; and carapace shape in ostracods related to reproduction patterns and environmental energy. Concerning another conspicuous group of microorganisms as foraminifera, the complex architecture of the shells is very useful to identify habits, habitats, a wide range of diets, and the recognition of analogous features permitting the search for the possible meaning of the functional element. Other calcareous microfossil groups yield not so evident morphology-function relation, but it seems difficult to assume that there is no adaptive advantage in the shape/ morphology of their hard parts. Coccoliths are a very good example of this case. The study of their functional morphology gave rise to a series of explanations and purposes that are conceptually reasonable, but have relatively low applicability and are extremely difficult to prove. Yet, it seems pointless that the highly variable, complex and energy-demanding coccosphaera has no function for the individual. A new perspective looking for new insights and possible pathways for micropaleontology, out of its applied framework has started. In Argentina first efforts culturing fresh water ostracods along with the study of modern analogs as useful tools for understanding the past has begun during the last decade and requires increased attention.