Figure 1. Maximum likelihood trees of coronaviruses based on A) 780-bp fragment of the RNA-dependent RNA polymerase gene and B) 1,797 bp of the helicase (HEL) domain of open reading frame 1b. Trees were inferred under the General Time Reversible (GTR + Γ₄ + I) model by using PAUP* version 4.0b (Sinauer Associates, Inc., Sunderland, MA, USA). Bootstrap support values >90% are indicated. Previously defined phylogenetic groups and a putative novel group (10) are delineated by the bars on the right. The numbering of these groups is as described in the eighth report of the International Committee on Taxonomy of Viruses with the alternative grouping proposed by Tang et al. (4) in brackets. Trinidadian bat coronavirus sequences are highlighted in red. GenBank accession numbers are noted in parentheses. Scale bars indicate number of nucleotide substitutions per site.