The American black bear lived during the same period as short-faced bears (Arctodus simus and A. pristinus) and the Florida spectacled bear (Tremarctos floridanus). These Tremarctine bears evolved from bears that had emigrated from Asia to North America 7â8 ma.
A plenum space is a part of a building that can facilitate air circulation for heating and air conditioning systems, by providing pathways for either heated/conditioned or return airflows, usually at greater than atmospheric pressure.
Definition of PLENUM. 1. a: a space or all space every part of which is full of matter b: an air-filled space in a structure; especially: one that receives air from a blower for distribution (as in a ventilation system). 2.. a: a space or all space every part of which is full of matter b: an air-filled space in a structure; especially: one that receives air from a blower for distribution (as in a ventilation system).