Of the six orders of Pulmonata, two â the Onchidiacea and Soleolifera â solely comprise slugs. A third family, the Sigmurethra, contains various clades of snails, semi-slugs (i.e. snails whose shells are too small for them to retract fully into) and slugs. The taxonomy of this group is in the process of being revised in light of DNA sequencing.
Q: How much of the worldâs oil reserves are located in OPEC countries? A: 80% of the world's oil reserves are located in just 13 countries which make up OPEC (the Organization of the Petroleum Exporting Countries). Algeria, Venezuela, Saudi Arabia, Iran, Iraq, Kuwait, Angola, Indonesia, Ecuador, Libya, Nigeria, Qatar, and the United Arab Emirates.
List of oil fields. USGS map of countries where oil is located. An oil refinery in Mina-Al-Ahmadi, Kuwait. This list of oil fields includes some major oil fields of the past and present. The list is incomplete; there are more than 65,000 oil and gas fields of all sizes in the world. However, 94% of known oil is concentrated in fewer than 1500 giant and major fields. Most of the world's largest oilfields are located in the Middle East, but there are also supergiant (>10 billion bbls) oilfields in Brazil, Mexico, Venezuela, Kazakhstan, and Russia.