Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
From: The History of Rome, by Theodor Mommsen
Translated with the sanction of the author by William Purdie Dickson
The remains of the corps, including their leader wounded in the sword-arm, were driven to a slight eminence, where they only served for an easier mark to the enemy's archers. Mesopotamian Greeks, who were accurately acquainted with the country, adjured Crassus to ride off with them and make an attempt to escape; but he refused to separate his fate from that of the brave men whom his too-daring courage had led to death, and he caused himself to be stabbed by the hand of his shield-bearer. Following his example, most of the still surviving officers put themselves to death. Of the whole division, about 6000 strong, not more than 500 were taken prisoners; no one was able to escape.
Meanwhile the attack on the main army had slackened, and the Romans were but too glad to rest. When at length the absence of any tidings from the corps sent out startled them out of the deceitful calm, and they drew near to the scene of the battle for the purpose of learning its fate, the head of the son was displayed on a pole before his father's eyes; and the terrible onslaught began once more against the main army with the same fury and the same hopeless uniformity. They could neither break the ranks of the lancers nor reach the archers; night alone put an end to the slaughter. Had the Parthians bivouacked on the battle-field, hardly a man of the Roman army would have escaped. But not trained to fight otherwise than on horseback, and therefore afraid of a surprise, they were wont never to encamp close to the enemy; jeeringly they shouted to the Romans that they would give the general a night to bewail his son, and galloped off to return next morning and despatch the game that lay bleeding on the ground.
Do you see any typos or other mistakes? Please let us know and correct them
Reference address : https://www.ellopos.net/elpenor/rome/5-09-crassus-joint-rulers.asp?pg=11