Literature

The Ceratopsidae is the name given to a Family of four-legged herbivores from the Upper Cretaceous of Western North America. They are classified in two subfamilies: the Ceratopsinae (which includes the well-known Triceratops) and the Centrosaurinae (which includes Styracosaurus). These are all horned dinosaurs, with a diverse range of protrusions from the frill, from above the eyes and above the nose. The Ceratopsinae are associated with long brow horns whereas in the Centrosaurinae they are short. A new dinosaur find reveals a centrosaurine with long brow horns. Based on the stratigraphical position and a cladistic analysis, the animal has been identified "as the basal member of the Centrosaurinae".
The oldest known horned dinosaur is called Zuniceratops and had large horns. Consequently, "the newly found creature [is] an intermediate between older forms with large horns and later small-horned relatives" suggests Jim Kirkland, State of Utah paleontologist, who co-identified Zuniceratops in 1998. "He predicted then that something like Ryan's find would turn up. "Lo and behold, evolutionary theory actually works," he said."
The extraordinary diversity of the dinosaurs in general is no less apparent in the Ceratopsidae, all of which are documented from a few states of the US and parts of Canada. Variation on a theme is prominent. Evolutionists generally start by trying to trace a linear pathway, with clearly defined intermediates, but more data transforms the picture to a bush, with no obvious tree-like structure. So, although we read a comment like "evolutionary theory actually works", it does not carry much weight. "It is very surprising that a Centrosaur would have long brow horns," said Don Brinkman of the Royal Tyrrell Museum in Drumheller. If the prediction was substantial, one would expect people to say that they were expecting this discovery.
It is worth adding that the real debate over evolutionary theory is not about the positions and sizes of horns. This is just variation affecting existing traits and not controversial at all. Of far greater interest is the origin of novel structures, especially those exhibiting complex specified information. It will be a great day when Darwinists realise that they cannot simply lump together the origin of novelty with observations of variation of existing traits. Then we might witness some really interesting discourse about what evolutionary theory actually is and which aspects actually work!

A new basal centrosaurine ceratopsid from the Oldman Formation, Southeastern Alberta
Michael J. Ryan
Journal of Paleontology, 81(2), March 2007, pp. 376-396

Abstract: A new centrosaurine ceratopsid, Albertaceratops nesmoi, is described from the lower Oldman Formation (Upper Cretaceous) of southern Alberta, and is based on a single, almost complete skull. Referred material is described from equivalent beds in the Judith River Formation of north-central Montana. A limited phylogenetic analysis of the Ceratopsidae places the new taxon as the basal member of the Centrosaurinae and indicates that robust, elongate postorbital horncores that form a synapomorphy of (Ceratopsidae + Zuniceratops) are also present in Centrosaurinae.

See also:

Cleveland Museum of Natural History Scientist Discovers New Horned Dinosaur Genus
Cleveland Museum of Natural History Press Release, February 24, 2007

Dinosaur had yard-long horns over eyebrows
CNN News, March 5 2007.