Kent State Research Highlights Biodiversity Hotspot in Fossil Coral Reef
Where do many decapod crustaceans such as lobsters, crabs and shrimp live today? One key habitat is coral reefs, even though reefs occupy only a small portion of today's oceans. A new report based on research conducted at Kent State University indicates that decapod biodiversity was also extremely high in fossilized coral reefs from the Cretaceous period (145 to 66 million years ago).
"As early as 100 million years ago, coral reefs in northern Spain were already inhabited by a massive number of decapods," said Adiël Klompmaker, Ph.D., a recent graduate from the Department of Geology at Kent State. "As many as 17 new species and eight new genera have been discovered since 2008. A total of 36 species are now known from the Koskobilo quarry, located within the Aldoirar patch reef."
In an article in the journal Cretaceous Research, a journal focusing on research on all aspects of the Cretaceous period, Klompmaker summarizes all decapods known from this limestone quarry - identifying 8 new species - and compares its diversity to that of other localities from the Cretaceous. It appears that the Koskobilo quarry is the most diverse locality for decapods from this period, in terms of number of species and genera.
"What is even more interesting to me is that three of the top four most diverse decapod faunas from the Cretaceous are found in rocks containing many corals," Klompmaker said. "This shows that reefs were a popular place to feed, mate and seek shelter for decapods. Thus, not much has changed from this perspective since the Cretaceous. Decapods still really like living in coral reefs, although today many different decapod families inhabit them."
The types of decapods found in the quarry are mainly true crabs, including the oldest known spider crabs, 10 species of squat lobsters and some hermit crabs. True lobsters were not found and are also not very abundant in today's reefs.
"Although shrimp are common in modern reefs, they have not been found in Koskobilo," Klompmaker explained. "This could seem like a riddle, but they simply may not have been preserved because their exoskeletons are generally weakly calcified."
Research on the decapods of the quarry is not finished.
"New studies show that most decapod species can be found in between a network of coral branches, as opposed to sites within the same quarry yielding fewer corals," Klompmaker said. "After five years of research, I never would have thought we could learn so much from a single locality far away in Spain. One wonders also what diversity would have been without reefs in this area."
Not many decapods are known from the time after living reefs disappeared in the study area.
Klompmaker, who is now a post-doctoral associate at the Florida Museum of Natural History (University of Florida), is gratified to have studied at Kent State.
"Kent State is home to some of the world's leading decapod researchers such as Drs. Rodney Feldmann and Carrie Schweitzer, which is why I chose to work on my doctorate there," Klompmaker said.
Last year, Klompmaker was part of the team that reported on a new hermit crab that was found at the same quarry named after Michael Jackson (Mesoparapylocheles michaeljacksoni). He also was involved in discovering the oldest known evidence of gregarious behavior of lobsters from the fossil record.
To read the report online, go to www.sciencedirect.com/science/article/pii/S0195667112001772.
For more information on Kent State's Department of Geology, visit www.kent.edu/geology.
# # #
Adiël Klompmaker, a recent graduate of Kent State University, is pictured in front of an active quarry (left) and the abandoned Koskobilo quarry (right) in the background. Photo provided by Adiël Klompmaker.
Caption: The limestones on southern wall of the Koskobilo quarry yielded 36 decapod species. Source: Adiël Klompmaker
Caption: The carapace of Mesoparapylocheles michaeljacksoni. The legs and tail part were not preserved. The scale bar is 1.0 mm. Source: Neues Jahrbuch für Geologie und Paläontologie
Caption: The carapace of one of the two oldest known spider crabs, Cretamaja granulata. The legs and tail part were not preserved. The scale bar is 1.0 mm. Source: Cretaceous Research
Caption: The carapace of the new crab Laeviprosopon crassum. The legs and tail part were not preserved. The scale bar is 1.0 mm. Source: Cretaceous Research