Sunday, August 29, 2010

Ellsemere Island Eocene Climate & Giant Reptiles

Ellesmere Island is adjacent to Greenalnd and covered with ice and permafrost today, but in the past it contained lush vegetation and some large reptiles. Jaelyn Eberle from the University of Colorado and colleagues have examined oxygen isotope ratios from Ellesmere fossil vertebrates that were 52 to 53 MY old and concluded that the warmest months on Ellesmere during the early Eocene averaged 66 to 68 degrees F (19-20 degrees C) and the coldest months averaged 32 to 38 degrees F (0-3.5 degrees F). Therefore it probably did not freeze, or freezing was not frequent.The island is known to have supported populations of giant tortoises and crocodilians as well as a variety of large mammals. Today there is concern that the Ellesmere fossil beds are threatened by coal mining. [Full Citation: Eberle et al. Seasonal variability in Arctic temperatures during early Eocene time. Earth and Planetary Science Letters, 2010; 296 (3-4): 481 DOI: 10.1016/j.epsl.2010.06.005]

No comments:

Post a Comment