First-century burial grounds near Rome's main airport are yielding a rare look into how ancient longshoremen and other manual workers did backbreaking jobs, archaeologists said Monday.

The necropolis near the town of Ponte Galeria came to light last year when customs police noticed a clandestine dig by grave robbers seeking valuable ancient artifacts, Rome's archaeology office said.

Most of the 300 skeletons unearthed were male, and many of them showed signs of years of heavy work: joint and tendon inflammation, compressed vertebrae, hernias and spinal problems, archaeologists said. Sandy sediment helped preserve the remains well.

Judging by the condition of the skeletons, archaeologists concluded that the men likely carried loads on their backs at a nearby port during the early years of Imperial Rome, said Gabriella Gatto, a spokeswoman for the archaeology office.

Many ailments "seem to hark back to work as laborers, in transport and carrying of heavy loads, in an especially humid environment, circumstances that makes one think of the burial of individuals who worked in port areas of the city," the office said in a statement.

Finding a necropolis near ancient Rome is not rare, but most of them have been the burial grounds of the privileged classes. So the Ponte Galeria find is enlightening experts how the ancient lower class lived.

Also excavated was a skeleton of a man whose lower jaw was fused to his upper jaw.

Study indicated "how for all of his life this individual was fed, likely through the care of his family" with liquids or semisolids "introduced through a hole made through his teeth," the archaeology statement said.

The man lived into his 30s, a decent age at the time. Experts took that as evidence that the lower classes cared for the disabled.

Artifacts found in the necropolis were simple ones, including lanterns to guide the dead to their next life, Gatto said. One ceramic-and-glass lantern was decorated with a grape harvest scene.

The dig yielded a glimpse into a working-class community that was "humble and marked by strong ties and solidarity among its members," the statement said.

The necropolis was one of the most extensive ones to be excavated near Rome in recent years, archaeologists said.