The problem with cladistics, and all anatomically based phylogenics, is that they are often contradicted by DNA-DNA hybridrzatton studies. (Walking dinosaur costume)This suggests that even the best cladograms may be grossly in eruor. Then agarn, it is possible that the DNA-DNA studies are wrong or misleading. If the subjects are long extinct, like dinosaurs, there is no way to compare the two methods. (Realistic dinosaur costume)What we can say is that cladograms map character patterns, not necessarily true relationships. But there are many cases where we can show that the potential relationship, even an ancestordescendant one, has a high probability of being real. This is most true when a series of very similar species is found in a sequence of sediments lying directly one atop another, and the species show a consistent trend of change. However, such straight “lineages” are the exception. Mostly we are dealing with complex branching patterns or mainstreams of ancestory and descent. The main cladistic relationship is the sister clade or group. These are two clades which are neither ancestors nor descendants of each other, but which share a corrunon ancestor.
Along with figuring out the relationships of animals, one has to label them and their groups. Animatronic dinosaur Sad to say, dinosaur taxonomy has been near chaos, with every one doing pretty much their own thing. This laissez-faire attitude has led to a state where the single genus Megalosourus contains an array of very dissimilar forms, while extremely similar Torbosaurus botoar and TJnannoscurus rex are placed in different genera. Even worse, dinosaur taxonomy has been executed in isolation from the modern biological world. This violates a basic foundation of paleobiological sciences, the principle of uniformitarianism. Simply put, past systems are roughly similar to modern ones, and as far as possible should be categorved according to equivalent criteria. Only then can we compare fossil and living species in a truly meaningful way.