Rhode Island may be the smallest state in the U.S., but the Ocean State packs in a lot of attractions worth seeing, from its extravagant 20th-century mansions to secluded beaches to cultural sites.

The study site, Kurukop, is in South Africa’s Northern Cape province, in the Nama Karoo region, where the geological formation began to accumulate from about 300 million years ago, before the breakup ...