La investigación entra en varias categorías e incluye, el estudio de la fauna, microbiología, geoquímica, contaminación del agua, hidrología y geología.

Las cuevas inundadas son cápsulas de tiempo geológicas en donde restos fósiles y artefactos arqueológicos permanecen congelados en el tiempo y perfectamente preservados.

 

Las investigaciones arqueológicas y paleontológicas son muy comunes aquí.

 

 

PROJECT ANTILLOTHRIX,
FOSSILS OF HISPANIOLA'S FLOODED CAVES.

Alfred L. Rosenberger, PhD 

Professor. Department of Anthropology and Archaeology 

Brooklyn College, CUNY

 

Typically, the only large animals you’ll see today in the Dominican Republic countryside are domesticated, pet dogs, and the goats, cows and horses providing food and working on farms – all brought in by Europeans in the last few hundred years.  Step back in time a couple thousand years, and a walk through the more forested landscape that existed then, or along rivers, lagoons and beaches, and a very different picture comes to mind.  It’s an image that has been made real through discovering the fossils of extinct animals found in flooded caves.  There were 200 lb. giant ground sloths roaming about, monkeys moving through the treetops, a rodent called the twisted-toothed giant Hutia and others no longer living, a Cuban crocodile, and more.  They were all descendants of animals that managed to cross from the South American mainland or from other Caribbean islands, in some cases millions of years ago.  And they all became extinct over a brief period of time after people arrived in Hispaniola not much more than 5000 years ago.

 

The flooded caves of the Dominican Republic are a rich source of fossils, some more than a million years old.  Exactly how these caves accumulated their remains is a question that will require a lot of research to answer.  But one thing is clear.  The fossils tend to be exceptionally well preserved, although in some places they are so thickly crusted by dripstone, the same mineral material that forms stalagmites and stalactites, as to be almost unrecognizable.  For paleontologists, there is no place better to find fossils because the layered sediments that normally bury bones and begin the petrification process in other parts of the world are extremely rare in the DR.  Flooded cave paleontology is fast becoming one of the best potential sources for discovering how and when the native fauna of Hispaniola went extinct, whether it was the impact of humans occupying and using the land, or climate change, or perhaps a combination of factors.  It is a new way of discovering the past, and one of the scientific exploratory objectives of the DRSS.   

 

For several years, DRSS has partnered with the Museo del Hombre Dominicano and Brooklyn College to explore flooded caves in search of primates, mostly, and other vertebrate fossils.  Our aim is to assemble a collection of fossils that will help reconstruct the evolutionary history of mammals that occupied Hispaniola in the remote past, and tie that in to the fossil record coming from the rest of the Greater Antilles, from Puerto Rico, Jamaica and Cuba.  So far we have found examples of all of the groups of mammals that are known to be Dominican or Hispaniola natives, now and in the past.  We have found the remains of 25 mammal species.  At least 11 of the species are extinct, and 13 of them are unique to the Greater Antilles.  The monkeys are represented by Antillothrix bernensis, which was the first New World primate ever found in the Caribbean, although it took many years before anyone realized that since it was so unexpected.  Our studies of Antillothrix suggest it came to the Caribbean many millions of years ago, possibly before the primates that populate Amazonia evolved into an established ecological community, and one of the most successful mammal groups in South America.  

 

The most abundant species we find are bats, which is to be expected because they are a very prolific order of mammals and they also tend to roost in caves.  Second are the rodents.  A recent new fossil addition to the group is the first skull ever found of the largest Caribbean rodent, Quemisia gravis, the giant hutia mentioned above.  The giant ground sloths, several different genera, are commonly found as well.  They were the largest native mammals and they were abundant, so their chances of being discovered are relatively good.  The most surprising find has been one vertebra of a dolphin, the only marine mammal we have discovered so far.  How it became mixed up in a deposit of terrestrial mammals is still a mystery.  We have also found a few specimens of the rare solenodon, which is still alive on the island in small populations.  The burrowing solenodons may be the oldest mammal, geologically, to have inhabited the Caribbean.  Their roots may go back to the Age of Dinosaurs, but how and when they arrived is an unanswered question.  Aside from these mammals, we have also found remarkably complete specimens of exotic crocodiles, a complete turtle, snakes, and birds, including a large predatory raptor that also lived in the United States but is now everywhere extinct.    

 

The work continues.  There will be more.

 

 

 

 

INVESTIGACIONES DE MICROBIOLOGÍA Y GEOQUIMICA

Por Jenn Macalady.
 

Las cuevas sumergidas son ventanas dentro de un mundo oculto parcial o totalmente aislado de la atmósfera de oxigeno de la Tierra. En aguas con bajo nivel o con ausencia de oxígeno, los microorganismos nativos son más similares a la vida que habitó los océanos de la tierra billones de años antes que las formas de vida microbiales que se encuentran en los océanos en la actualidad. Esto hace que las cuevas sumergidas sean de interés para los científicos  que quieren entender cómo los ciclos bioquímicos trabajaban en la Tierra ancestral (y hasta en hipotéticos planetas extraterrestres pobres en oxigeno).

 

La química del agua de cada cueva sumergida refleja la geometría de sus pasajes (la plomería), la geología de la roca, las fuentes de agua y las cantidades de nutrientes que entran por percolación de suelos a través de las ventanas hacia la superficie. Las cuevas que están separadas por solo una milla sobre la tierra, podrían tener una diferencia significativa en la química y en los microorganismos. Esta variedad, más la posibilidad de descubrir algo nuevo acerca de la vida microbiana ancestral, hacen que las cuevas sumergidas sean lugares excitantes e importantes para estudiar la microbiología.

 

Esta figura muestra el árbol de la vida basado en secuencias de códigos de ADN para el gen marcador taxonómico llamado 16S rARN. La vida es organizada dentro de tres dominios (Eucarya, Archaea, y Bacteria). Los organismos en las  ramas cubiertas de azul pueden ser observadas a simple vista, e incluyen animales, plantas y hongos. El resto de las ramas representan diversos tipos de microorganismos.  La química y la microbiología de las aguas de las cuevas también dan importantes pistas acerca del movimiento del agua bajo la la superficie de la tierra. Entendiendo como el agua se mueve bajo la tierra puede ayudarnos a predecir el movimiento de nutrientes y contaminantes, una importante parte para salvaguardar los recursos de agua potable y hábitats naturales.