def get_leaf_taxa_ids(phylogeny):
    """Given a phylogeny, return list of leaf taxa (taxa with no
    successors/descendants)

    Args:
        phylogeny (networkx.DiGraph): graph object that describes a phylogeny

    Returns:
        For all nodes in phylogeny, return ids of nodes with no successors
        (descendants).
    """
    extant_ids = [node for node in phylogeny.nodes
                  if len(list(phylogeny.successors(node))) == 0]
    return extant_ids