Divus Antoninus Pius AR antoninianus consecration issue

Struck at the midway point of the third century AD, the “Imperial Divi” series of silver antoniniani portrayed a selection of deified emperors from Rome’s past who were still being venerated as heroes and gods. Exactly who struck this series, however, remains mysterious, as the coins do not name the issuing emperor in the manner of earlier “restitution” issues.
In RIC IV Part II (1949), Harold Mattingly attributed the ‘Divus’ types to Trajan Decius (AD 249-251), specifically to the mint at Milan. Via a study of die-linkage, K.J.J. Elks has since refuted Mattingly’s mint attribution, placing the ‘Divi’ series in the last issue of Decius struck at Rome (see NumChron 1972, pp. 111-115 and pls. 14-15). The attribution to Decius has also been challenged by new theories placing the series with Philip I (AD 244-249) or Trebonianus Gallus (AD 251-253). On stylistic, metallurgical and hoard find grounds, however, Decius is still the most likely issuer.
Intriguingly, not all deified Caesars are honored: The series lacks Julius Caesar, Claudius, Lucius Verus, Pertinax and Caracalla, all of whom had been raised to Olympus by a vote of the Senate. To further confuse matters, the series does include one emperor who never seems to have been “officially” deified, Severus Alexander, although it is likely our surviving records are incomplete in this instance.