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.
Some oil analysts believe that Ghawar passed its peak perhaps a decade ago, but Saudi Arabiaâs infamous lack of transparency keeps everyone guessing. Nevertheless, it remains the worldâs largest oil field, both in terms of reserves and production. It continues to produce 5 million barrels per day (bpd). 2. Burgan (Kuwait) Just behind Ghawar is another massive oil field located in the Middle East.