In today’s Academic Minute, Dr. Alex Hastings of Georgia Southern University reveals how work on the Panama Canal has helped paleontologist gain a better understanding of crocodile evolution.
Alex Hastings is a visiting instructor in the Department of Geology and Geography at Georgia Southern University in Statesboro, Georgia. His research is focused on questions regarding paleobiogeography, ecology, cladistics, and functional morphology, particularly of crocodilians. He holds a Ph.D. from the University of Florida.
Dr. Alex Hastings – Panama Canal and Crocodile Fossils
Fossil crocodilians have been largely a mystery from Central America with only a few fragmentary finds from a limited number of sites. The first fossil crocodilians reported go back to the initial excavations of the Panama Canal in 1912. Fossil crocs from this part of the world went largely unknown until funding from the National Science Foundation allowed for a large project to take full advantage of the newly exposed rock resulting from the widening of the canal.
These rocks have not seen the light of day in over 19 million years and now they are giving researchers the first glimpse at ancient life in this part of the world. In 2009, graduate student Aldo Rincon discovered the first fossil crocodilian skull from Central America as part of this project. Analysis of the skull revealed it as a new species, representing a primitive link between the alligators that evolved in North America and their descendants, the caimans of South America.
Another crocodilian skull was discovered in a slightly younger rock formation in 2011, confirming the presence of a second new species. Close relations between the Panamanian species and the South American caimans confirm they were dispersing across the short seaway from Panama to South America, which were not connected at the time. This discovery helps support recent findings that the seaway was much shorter than previously thought. Alligators and caimans do not have salt glands and cannot process saltwater and thus could only disperse across small distances of saltwater.
These discoveries in Panama allow us to see how animals have dispersed in the past, learn how successful they were, and learn more about what makes a species successful in a new area. Findings of this study become relevant as we deal with modern invasive species such as the non-native caimans and pythons of the Florida everglades.
Production support for the Academic Minute comes from Newman’s Own, giving all profits to charity and pursuing the common good for over 30 years, and from Mount Holyoke College.
