Carlos Jaramillo

Felipe de la Parra

Felipe de la Parra

Felipe de la Parra

Address

Instituto Colombiano del Petróleo
Kilómetro 7 vía Piedecuesta
Bucaramanga, Colombia.
felipedela@yahoo.com
delaparraf@si.edu

 

Research Interests

My interests are in the fields of Paleobiology and Paleoecology, with emphasis in Paleobotany. I am interested in biota diversity, its causes and how relates to ecological stability. I am also interested in how vegetation communities have responded to environmental crisis in the present and geological past. I would like to approach these questions using Paleobiological information by applying rigorous mathematical and statistical methods and by constructing theoretical models to understand the dynamics of the vegetal communities in the geological past. I think this information can help us to understand modern communities and their response to the present environmental crisis.

 

Current Research

The Cretaceous-Tertiary boundary in tropical latitudes: Understanding the response of tropical vegetation to a major environmental crisis: The Cretaceous-Tertiary (K-T) boundary is recognized as one of the major environmental crisis in earth's history and is associated with a significant extinction of the earth's biota.The palynological and megafloral record from mid latitudes show a dramatic and abrupt disappearance of most dominant taxa and nearly all of the late Cretaceous angiosperms following the K/T boundary. The basal Paleocene flora appears to be composed of taxa that were absent or extremely rare in the latest Cretaceous. Detailed K-T palynoflora records from other places in the world indicate that in the tropics and Southern Hemisphere, land plant response to the K-T boundary event was relatively minor. However these results lack adequate resolution and do not have statistical support.

 

The effect of the K-T boundary in tropical vegetation is not well known:

* How was tropical land vegetation affected by this extinction event?
* What taxa were more affected by the extinction?
* Was the temperate or the tropical vegetation more resilient to the crisis?
* Were extinction levels of tropical vegetation more intense than temperate communities?
* Did tropical vegetation recover faster than temperate floras?
Is there a relationship between Tertiary tropical angiosperm radiation and the KT boundary?

To answer these questions I have been studying a Cretaceous-Tertiary boundary section from Northern South America. This section is composed by 2200 feet's of shale and fine sandstone that accumulated in coastal plain and transitional environments during the middle Maastrichtian and early Paleocene.

 

Future Research Plans

What factors control the biogeographic distribution of tropical taxa across long periods of geological time? Several tropical taxa have peculiar distributions, being endemic to some regions today but distributed across the entire paleotropics in the geological past. By studying one of those cases we could understand what are the main factors controlling taxa distribution in the tropics and what role could play human disturbance in that distribution. I'm going to study the biogeography distribution of some species (i.e Crassoretitriletes vanraadshooveni) widely distributed in the tropics during the Miocene, and today restricted to a few locations.

What is the relationship between the diversity of a vegetal community and its stability? Based in theoretical and experimental models it has been proposed that the diversity of a community is directly proportional to its resistance to external disturbances. Others believe the opposite, highly diversified communities are unstable. The experiments and theoretical models that have reached this conclusion operate at ecological time scales, and/or in spatially restricted labs. However, at a geological scale and with greater magnitude disturbances (e.g. extraterrestrial impacts), what kind of relationship would exist between the diversity and stability of a community? To answer this question, I would use empirical data from at least three localities in different paleolatitudes, from tropical to temperate, to understand the community response to the environmental crisis of the K/T boundary across diverse diversity settings. Then I would compare the empirical data with theoretical models predicting the response of different degrees of diversity to environmental perturbations.

 

Selected Bibliography

Jaramillo, C., Muñoz, F., Cogollo, M., and De la Parra, F. 2005: Quantitative Biostratigraphy for the Paleogene of the Llanos Foothills, Colombia:Improving Palynological Resolution for Oil Exploration: In Powell, A.J and Riding, J. Riding (Eds), The Micropaleontological Society Special Publication, 145-159.

Jaramillo, C.A., Rueda, M., De la Parra, F., 2004: Quantitative Biostratigraphy for the Paleocene of the Llanos Foothills, Colombia: Improving Palynological Resolution for Oil Exploration: International Palynological Congress, España.

Jaramillo, C.A., Rueda, M., De La Parra, F., Rodríguez, G., 2005: Biostratigraphy Breaking Paradigms: The Absence of the Mirador Formation in the Eastern Llanos of Colombia: Geological Problem Solving with Microfossils, Rice University,Houston Texas.

De La Parra, F., Jaramillo C., 2005: The Cretaceous-Tertiary boundary in tropical latitudes: Understanding the response of tropical vegetation to a major environmental crisis. AASP 38th Annual meeting, St Louis. September 18-21, 2005