Dinosaur Classification Is a Mess

Are there a thousand species of dinosaurs – or far fewer?  John Horner, a dinosaur hunter himself, thinks the classification is a mess and wants to clean it up.  According to Science Magazine News Horner is worred that “with almost 1000 types of dinosaurs on record and a new species being named somewhere in the world every 2 weeks—too many supposedly new discoveries are actually duplicates of animals already on the books.”  Another paleontologist, Michael J. Benton, estimates that over half of the named dinosaurs are misclassified.
    Apparently human pride is to blame.  “Part of the problem, Horner says, is that scientists are sometimes too keen on finding and naming new dinosaurs.”  Naming a new dinosaur gets you noticed and published.  As a result, fossil hunters tend to focus on the differences instead of the similarities.  Additionally, “paleontologists are coming to realize that the bones of an adult dinosaur can be very different from those of a juvenile animal of the same species and can easily mislead scientists into thinking they are two different species.”
    Ignoring these pitfalls can lead to misinterpretations about dinosaur evolution.  “Early in their development, Horner explains, the skulls of young dinosaurs may resemble the relatively unspecialized skulls of primitive ancestral species.  To avoid confusion, paleontologists must know precisely where a specimen came from, how it appeared while still encased in rock, and which level it occupied in a geologic formation.”  Horner has proposed a “Unified Frame of Reference” (UFR) to fellow paleontologists to try to rein in these problems.

This is terrible.  What will they tell the children who memorized the names of some of these dinosaurs and love to show off their knowledge?  How can they tell them some of the creatures never existed?  It will break their hearts and shake their confidence in scientists.
    Classification is a problem not only for dinosaurs, but for all organisms.  Knowing where to draw the line between species is a human problem, because there are not joints in nature that will provide reliable division points.  The biological species concept (species are groups that produce fertile offspring), for instance, does not help with asexual microbes and fossils.
    Maybe there are only two kinds of dinosaurs: big ones and little ones (like potatoes).  Or maybe ones that walked on all fours and ones that walked on two hind legs.  Whatever scheme works for your purposes can be defended as scientific; even using as a criterion those that reproduce after their kind.