Given the following context:

The scarce artifacts found in the city dating to the Bronze Age reveal that, culturally, Palmyra was most affiliated with western Syria. Classical Palmyra had a distinctive culture, based on a local Semitic tradition, and influenced by Greece and Rome. To appear better integrated into the Roman Empire, some Palmyrenes adopted Greco-Roman names, either alone or in addition to a second native name. The extent of Greek influence on Palmyra's culture is debated. Scholars interpreted the Palmyrenes' Greek practices differently; many see those characters as a superficial layer over a local essence. Palmyra's senate was an example; although Palmyrene texts written in Greek described it as a "boule" (a Greek institution), the senate was a gathering of non-elected tribal elders (a Near-Eastern assembly tradition). Others view Palmyra's culture as a fusion of local and Greco-Roman traditions.
The culture of Persia influenced Palmyrene military tactics, dress and court ceremonies. Palmyra had no large libraries or publishing facilities, and it lacked an intellectual movement characteristic of other Eastern cities such as Edessa or Antioch. Although Zenobia opened her court to academics, the only notable scholar documented was Cassius Longinus.Palmyra had a large agora. However, unlike the Greek Agoras (public gathering places shared with public buildings), Palmyra's agora resembled an Eastern caravanserai more than a hub of public life. The Palmyrenes buried their dead in elaborate family mausoleums, most with interior walls forming rows of burial chambers (loculi) in which the dead, laying at full length, were placed. A relief of the person interred formed part of the wall's decoration, acting as a headstone. Sarcophagi appeared in the late second century and were used in some of the tombs. Many burial monuments contained mummies embalmed in a method similar to that used in Ancient Egypt.

answer the following question:

What object began to appear in the late second century tombs of the people who inhabited the city most culturally affiliated with Western Syria? 

Sarcophagi