On the chest of the bull of the sculpture of Mithras killing the bull from the Mitreo delle Terme di Mitra is the inscription that mentions the name of the person who commanded it. It may have been M. Umbilius Criton, who is documented in the Mitreo della Planta Pedis. The statue seems to belong to the second century AD. The mithraeum may have been installed in the first half of the third century.
It may be significant that in the nearby Serapeum an inscription from 200 AD mentions a son of M. Umbilius Maximus, in 192 AD patronus of the corpus lenunculariorum tabulariorum auxiliariorum Ostiensium:
[IN]VICTO MITHRAE D(ONUM) D(EDIT) M(ARCUS) UMBILIUS CRITON
CUM PYLADEN VIL[ICO].
In the Severan period the family of the Umbilii is documented. A base for a statue was found [near the Serapeum] with the inscription:
M(arco) VMBILIO M(arci) F(ilio) ARN(ensi) / MAXIMINO / PRAETEXTATO C(larissimo) P(uero) PATRONO C(oloniae) / SACERDOTI GENI COL(oniae) / P(ublius) CALPVRNIVS / PRINCEPS EQVO PVBL(ico) / OMNIBVS HONORIBVS FVNCTVS / EDVCATOR
DEDICATA K(alendis) MARTI(i)S / SEVERO ET VICTORINO CO(n)S(ulibus)
The date is March 1st, 200 AD. The educator was probably a high official and teacher in the cult of Serapis. The title is not otherwise known.
Criton (ct. inscr. No. 231) probably was a libertus of M. Umbilius Maximinus (CIL XIV 177 and 251) who was a patronus of the corpus lenunculariorum tabulariorum auxiliariorum, ostiensium in 192 A.D. cf G. Barbieri, l'Albo senatorio di Settimio Severo a Carino (193-285) Roma 1952, 184f.
Other brothers from Ostia
This marble basin found in the Mithraeum of the Footprint bears an inscription of a certain Umbilius Criton, associated with a monumental tauroctonic sculpture also found in Ostia.
[In]victo Mithrae d(onum) d(edit) M(arcus) Umbilius Criton sum Pyladen vil[ico].
The dedicator of this marble basin could be the same person who offered the sculpture of Mithras slaying the bull in the Mitreo delle Terme di Mitra.
[In]victo Mithrae d(onum) d(edit) M(arcus) Umbilius Criton cum Pyladen vil[ico].
The person who commanded the sculpture may have been M. Umbilius Criton, documented in the Mitreo della Planta Pedis.
Κρίτων / Ἀθηναιος / έποίει.
Kriton / the Athenian / made [this statue].