Placement of Guerrerostrongylus marginalis n. sp., relative to available heligmonellid nematodes. The phylogenetic tree (based on a fragment of the mitochondrial gene coding for the large ribosomal subunit RNA – rrnL-) represents the consensus used to calculate the posterior probability of the branches. Posterior probability is to the right of each node. Bootstrap support values are indicated to the left of the node, with values for Maximum Likelihood support over those obtained by parsimony.