NEW YORK.- When Carlos Picon, the curator in charge of Greek and Roman art at the Metropolitan Museum, spotted an elaborately decorated Roman imperial urn at Sotheby’s sale of antiquities and Islamic art in New York this month, he knew the museum had to have it. "We only have four or five urns, and most of them are fairly standard," Mr. Picon said. "This is the most unusual one to come on the market in over a generation." Dating from the early first century A.D., the marble urn is festooned with intricately carved spoils of war: helmets, spears, horns, swords, even a roughly hewn tree trunk draped in a tunic and surmounted by a wreath of flowers. The urn was excavated in 1899 from a tomb near Anagni, 33 miles southeast of Rome. In early Roman imperial art, trophies and weapon friezes are more commonly found as decorations on monumental triumphal arches. Scholars believe that the designs could have been copied from a triumphal arch, now lost, and that the urn is an important historical document showing the types of arms used in battle by the armies Rome defeated. Unfortunately, he was not the only person to realize the rarity of the urn; four serious bidders fought to buy it. Sotheby’s had conservatively estimated the object would fetch $60,000 to $90,000. The Met ended up paying $262,500, making the urn the third highest priced work in the sale.