Fossilized spores suggest that higher plants (embryophytes) have lived on land for at least 475 million years. Early land plants reproduced sexually with flagellated, swimming sperm, like the green algae from which they evolved. An adaptation to terrestrialization was the development of upright meiosporangia for dispersal by spores to new habitats. This feature is lacking in the descendants of their nearest algal relatives, the Charophycean green algae. A later terrestrial adaptation took place with retention of the delicate, avascular sexual stage, the gametophyte, within the tissues of the vascular sporophyte. This occurred by spore germination within sporangia rather than spore release, as in non-seed plants. A current example of how this might have happened can be seen in the precocious spore germination in Selaginella, the spike-moss. The result for the ancestors of angiosperms was enclosing them in a case, the seed. The first seed bearing plants, like the ginkgo, and conifers (such as pines and firs), did not produce flowers. The pollen grains (males) of Ginkgo and cycads produce a pair of flagellated, mobile sperm cells that "swim" down the developing pollen tube to the female and her eggs.
Upright meisporangia allowed what to be dispersed to new habitats?
spores

Thuringia became a landgraviate in 1130 AD. After the extinction of the reigning Ludowingian line of counts and landgraves in 1247 and the War of the Thuringian Succession (12471264), the western half became independent under the name of "Hesse", never to become a part of Thuringia again. Most of the remaining Thuringia came under the rule of the Wettin dynasty of the nearby Margraviate of Meissen, the nucleus of the later Electorate and Kingdom of Saxony. With the division of the house of Wettin in 1485, Thuringia went to the senior Ernestine branch of the family, which subsequently subdivided the area into a number of smaller states, according to the Saxon tradition of dividing inheritance amongst male heirs. These were the "Saxon duchies", consisting, among others, of the states of Saxe-Weimar, Saxe-Eisenach, Saxe-Jena, Saxe-Meiningen, Saxe-Altenburg, Saxe-Coburg, and Saxe-Gotha; Thuringia became merely a geographical concept.
Who did the Saxon Duchies consist of?
the states of Saxe-Weimar, Saxe-Eisenach, Saxe-Jena, Saxe-Meiningen, Saxe-Altenburg, Saxe-Coburg, and Saxe-Gotha

In 1854 president Antonio Lopez de Santa Anna enlarged the area of the Federal District almost eightfold from the original 220 to 1,700 km2 (80 to 660 sq mi), annexing the rural and mountainous areas to secure the strategic mountain passes to the south and southwest to protect the city in event of a foreign invasion. (The MexicanAmerican War had just been fought.) The last changes to the limits of the Federal District were made between 1898 and 1902, reducing the area to the current 1,479 km2 (571 sq mi) by adjusting the southern border with the state of Morelos. By that time, the total number of municipalities within the Federal District was twenty-two.
What is the current area of Mexico City?
1,479 km2 (571 sq mi)