In 422 BC Antonius was elected as consular tribune together with Lucius Manlius Capitolinus and Lucius Papirius Mugillanus. The year saw the beginning of the trial against the former consul Gaius Sempronius Atratinus, who had in 423 BC unsuccessfully fought against the Volscians. The trial was led by the plebeian tribunes and the prosecutor Lucius Hortentius. The trial would drag on and not reach a conclusion until 420 BC. The actions of the consular tribunes of this year was not recorded.^[3][4][5][6]

There exists some discussion about whether Antonius was a plebeian or a patrician, as the gens, the Antonia, is an plebeian gens in the late Republic. The two known Antonia of the early Republic, Quintus and his father Titus, are traditionally seen as patricians, as there were no plebeian consuls prior to 366 BC. Titus, the decemvir, is not listed by Dionysius as plebeian, but three of his colleagues are mentioned as plebeian. The classicist Broughton argues that Titus and another colleague from the gens Rabuleia, both should be considered plebeians, and that the second decemvirate consisted of equal proportions of patricians and plebeians. Secondly, even though Livy reaffirms that the first consular tribune of plebeian origin was elected in 400 BC there are indications of several plebeian names among the consular tribunes prior to this. This has led several classicists, such as Broughton, to consider Quintus and his father as plebeians and that no patrician branch of the Antonia ever existed.^[7][8][9]

• Manlia gens – Roman family