1. Mesoproterozoic - Adjective
2. Mesoproterozoic - Proper noun
Mesoproterozoic (not comparable)
(geology) Of a geologic era within the Proterozoic eon; comprises the Calymmian, Ectasian and Stennian periods from about 1600 to 900 million years ago, when the Rodinia supercontinent was formed.
Mesoproterozoic
(geology) The Mesoproterozoic era.
The oldest rocks in Texas date from the Mesoproterozoic and are about 1,600 million years old. Source: Internet