Nearctic realm represented by the Madrean Region. Although North America and South America are presently joined by the Isthmus of Panama, these continents were separated for about 180 million years, and evolved very different plant and animal lineages. When the ancient supercontinent of Pangaea split into two about 180 million years ago, North America remained joined to Eurasia as part of the supercontinent of Laurasia, while South America was part of the supercontinent of Gondwana. North America later split from Eurasia. North America has been joined by land bridges to both Asia and South America since then, which allowed an exchange of
PANGAEA (data library) PANGAEA (data library) PANGAEA - Data Publisher for Earth & Environmental Science is a digital data library and a data publisher for earth system science. Data can be georeferenced in time (date/time or geological age) and space (latitude, longitude, depth/height). Scientific data are archived with related metainformation in a relational database (Sybase) through an editorial system. Data are in Open Access and are distributed through web services in standard formats on the Internet through various search engines and portals. Data set descriptions (metadata) are conform to the ISO 19115 standard and are served in various further formats (e.g. Directory Interchange