Table 2. The number of half-life estimates for each tissue type-taxon combination (hereafter referred to as ‘group’).

	Taxon
Tissue type	Invertebrates	Vertebrate ectotherms 1	Birds	Mammals	total
Muscle	11	88	16	29	144
Whole body	44	28	0	0	72
Organs	4*	37	43	50	134
Blood	1*	36	28	35	100
Plasma	0	17	9	10	36
total	60	206	96	124	486

Two groups (invertebrate organs and invertebrate blood; indicated by *) were excluded from group-level comparisons due to low sample size.

¹fishes, reptiles, and amphibians