Figure S2. Maximum likelihood trees using CO1 sequence data. from Upper limits to body size imposed by respiratory-structural trade-offs in Antarctic pycnogonids LaneSteven J. ShishidoCaitlin M. L. MoranAmy TobalskeBret W. ArangoClaudia P. Arthur WoodsH. 2017 Maximum likelihood trees using CO1 sequence data. A) Unconstrained topology, values along branches indicate bootstrap values (in percent). Only values above 50% are shown. Bar represents 0.125 substitutions per site. B) Constrained tree following topology of Arango and Wheeler (32). See text for details.