Modern cladistic work has not been conclusive. "Thecodontosaurus" was earlier put under the Prosauropoda. More recently was suggested that "Thecodontosaurus" and its relatives came before the prosauropod-sauropod split. "Thecodontosaurus" is sometimes placed in a very basal position among the sauropodomorph dinosaurs. New reconstructions show that its neck is proportionally shorter than those in more 'advanced' early sauropodomorphs.