Evolutionary history of plants and radially symmetrical, is an integumented megasporangium surrounded by a cupule. The megasporangium bears an unopened distal extension protruding above the multilobed integument. It is suspected that the extension was involved in anemophilous pollination. "Runcaria" sheds new light on the sequence of character acquisition leading to the seed. "Runcaria" has all of the qualities of seed plants except for a solid seed coat and a system to guide the pollen to the ovule. The first spermatophytes (literally: "seed plants") – that is, the first plants to bear true seeds – are called pteridosperms: literally, "seed ferns", so called because their
Economics of nuclear power plants The 2003 study had estimated the cost as $0.067/kWh. According to Benjamin K. Sovacool, the marginal levelized cost for "a 1,000-MW facility built in 2009 would be 41.2 to 80.3 cents/kWh, presuming one actually takes into account construction, operation and fuel, reprocessing, waste storage, and decommissioning". A 2013 study indicates that the cost competitiveness of nuclear power is "questionable" and that public support will be required if new power stations are to be built within liberalized electricity markets. In 2014, the US Energy Information Administration estimated the levelized cost of electricity from new nuclear power plants going online in 2019