An example of something that may have caused a mass extinction event in the Earth's past.³l​

Its 3^4 only becasuee i saidd

Kingdom archaebacteria is a group of single cell organisms adapted to living under extreme environmental conditions such as near volcanic activities, deep oceans among other places. they are anaerobic as well as aerobic prokaryotes. they have the following characteristics; they have no peptidoglycan in their cell walls. the cell wall is made up of glycoproteins and polysaccharides, the cell wall envelopes have high resistance to antibiotics and lytic agents due the difference in its composition. additionally they have very different lipid bi-layer making up the cell membranes, their rna polymerase and ribosomal proteins  are   similar to those of eukaryotes. these characteristic features distinguish these organisms from other kingdoms.